Journal articles: '1-penten-3-one'

1

O Dwyer, M. A., T. J. Carey, R. M. Healy, J. C. Wenger, B. Picquet-Varrault, and J. F. Doussin. "The Gas-phase Ozonolysis of 1-Penten-3-ol, (Z)-2-Penten-1-ol and 1-Penten-3-one: Kinetics, Products and Secondary Organic Aerosol Formation." Zeitschrift für Physikalische Chemie 224, no. 7-8 (2010): 1059–80. http://dx.doi.org/10.1524/zpch.2010.6141.

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Almirón, M. A., L. Camacho, E. Muñoz, J. L. Avila, and J. V. Sinisterra. "Electrochemical reduction of 4,4-dimethyl-1-phenyl-1-penten-3-one." Journal of Electroanalytical Chemistry and Interfacial Electrochemistry 241, no. 1-2 (1988): 297–308. http://dx.doi.org/10.1016/0022-0728(88)85133-7.

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Kurniadi, Toshinari H., Rachid Bel Rhlid, Marcel A. Juillerat, Martin Schüler, and Ralf G. Berger. "Enantiogenic synthesis of (R)-(−)-3-hydroxy-1-penten-4-one." Tetrahedron: Asymmetry 14, no. 3 (2003): 363–66. http://dx.doi.org/10.1016/s0957-4166(02)00800-5.

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4

Illmann, Niklas, Rodrigo Gastón Gibilisco, Iustinian Gabriel Bejan, Iulia Patroescu-Klotz та Peter Wiesen. "Atmospheric oxidation of α,β-unsaturated ketones: kinetics and mechanism of the OH radical reaction". Atmospheric Chemistry and Physics 21, № 17 (2021): 13667–86. http://dx.doi.org/10.5194/acp-21-13667-2021.

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Abstract. The OH-radical-initiated oxidation of 3-methyl-3-penten-2-one and 4-methyl-3-penten-2-one was investigated in two atmospheric simulation chambers at 298±3 K and 990±15 mbar using long-path FTIR spectroscopy. The rate coefficients of the reactions of 3-methyl-3-penten-2-one and 4-methyl-3-penten-2-one with OH radicals were determined to be (6.5±1.2)×10-11 and (8.1±1.3)×10-11 cm3molecule-1s-1, respectively. To enlarge the kinetics data pool the rate coefficients of the target species with Cl atoms were determined to be (2.8±0.4)×10-10 and (3.1±0.4)×10-10 cm3molecule-1s-1, respectively. The mechanistic investigation of the OH-initiated oxidation focuses on the RO2+NO reaction. The quantified products were acetoin, acetaldehyde, biacetyl, CO2 and peroxyacetyl nitrate (PAN) for the reaction of 3-methyl-3-penten-2-one with OH radicals and acetone, methyl glyoxal, 2-hydroxy-2-methylpropanal, CO2 and peroxyacetyl nitrate (PAN) for the reaction of 4-methyl-3-penten-2-one with OH, respectively. Based on the calculated product yields an upper limit of 0.15 was determined for the yield of RONO2 derived from the OH reaction of 4-methyl-3-penten-2-one. By contrast, no RONO2 formation was observed for the OH reaction of 3-methyl-3-penten-2-one. Additionally, a simple model is presented to correct product yields for secondary processes.

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Jiménez, Elena, Beatriz Lanza, María Antiñolo, and José Albaladejo. "Photooxidation of Leaf-Wound Oxygenated Compounds, 1-Penten-3-ol, (Z)-3-Hexen-1-ol, and 1-Penten-3-one, Initiated by OH Radicals and Sunlight." Environmental Science & Technology 43, no. 6 (2009): 1831–37. http://dx.doi.org/10.1021/es8027814.

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6

Patjens, Jan, and Paul Margaretha. "1-Amino- und 1-Alkylamino-4-hydroxy-4-methyl-1-penten-3-one aus 2,2-Dimethyl-3(2H)-furanon." Synthesis 1990, no. 06 (1990): 476–77. http://dx.doi.org/10.1055/s-1990-26909.

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7

Xie, Wan Cui, Xin Lian, Xi Hong Yang, Ya Dong Yang, and Dan Hui Mao. "Optimization of the SPME-GC-MS Techniques for Analyzing Headspace Volatiles in Shrimp Head of P. borealis." Advanced Materials Research 726-731 (August 2013): 416–19. http://dx.doi.org/10.4028/www.scientific.net/amr.726-731.416.

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To investigate the headspace volatiles in shrimp head P. borealis, optimized conditions were evaluated for solid-phase microextraction coupled to gas chromatography-mass spectrometry method. SPME fibers of 100-μm polydimetylsiloxane, 65-μm polydimetylsiloxane-divinylbenzene, 75-μm carboxen-polydimetylsiloxane, and 50/30-μm divinylbenzene-carboxen-polydimetylsiloxane (DVB/CAR/PDMS) were compared. The influence of several parameters such as type of fibers, volume of sample, extraction time, extraction temperature, and state of samples was systematically investigated. Suitable reproducibility and sensitivity were achieved by combining DVB/CAR/PDMS of 50/30-μm thickness as the liquid phase of SPME, 1.5 g of shrimp head lyophilized powder, 40 OC of isolation temperature and 40 min of isolation time. A total of 62 volatile compounds have been confirm, including hydrocarbons, ketones, alcohols, aldehydes, esters, nitrogen-containing compounds and sulfur-containing compounds. 3,5-octadien-2-one (E,Z), 3,5-octadien-2-one (E,E), 1-penten-3-one, 6-octen-2-one, ethyl acetate and alcohols such as 1-penten-3-ol, 2-penten-1-ol and 1-octen-3-ol were predicted as key compounds for SH flavor.

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8

Kamar, Afaf, Alexander Baldwin Young, and Raymond Evans March. "Experimentally determined proton affinities of 4-methyl-3-penten-2-one, 2-propyl ethanoate, and 4-hydroxy-4-methyl-2-pentanone in the gas phase." Canadian Journal of Chemistry 64, no. 12 (1986): 2368–70. http://dx.doi.org/10.1139/v86-391.

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Proton affinities have been determined for 4-methyl-3-penten-2-one, 2-propyl ethanoate, and 4-hydroxy-4-methyl-2-pentanone in the gas phase at 333 K. A quadrupole ion store (QUISTOR) was employed to study mass spectrometrically the equilibrium between a species of known proton affinity and one of the above compounds; equilibrium between protonated species was monitored over an ion storage duration of 100 ms. The values of the proton affinities were found to be 870.5 ± 0.8 kJ mol−1 for 4-methyl-3-penten-2-one (mesityl oxide); 842.7 ± 0.6 kJ mol−1 for 2-propyl ethanoate; and 831.6 ± 0.8 kJ mol−1 for 4-hydroxy-4-methyl-2-pentanone (diacetone alcohol).

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9

Håkansson, Mikael, Susan Jagner, and Martin Nilsson. "Synthesis and crystal structure of a polymeric complex between 1-penten-3-one and copper(1) chloride." Journal of Organometallic Chemistry 336, no. 1-2 (1987): 279–85. http://dx.doi.org/10.1016/0022-328x(87)87175-9.

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10

Wang, Jing, Li Zhou, Weigang Wang, and Maofa Ge. "Gas-phase reaction of two unsaturated ketones with atomic Cl and O3: kinetics and products." Physical Chemistry Chemical Physics 17, no. 18 (2015): 12000–12012. http://dx.doi.org/10.1039/c4cp05461j.

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The rate constants and products for the reactions of atomic Cl and O3 molecule with 3-methyl-3-buten-2-one (MBO332) and 3-methyl-3-penten-2-one (MPO332) were determined in a 100 L Teflon chamber at 293 ± 1 K and atmospheric pressure.

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11

Botvinnik, E. V., A. N. Blandov, and M. A. Kuznetsov. "ChemInform Abstract: Reaction of 1,5-Diphenyl-1,4-pentadien-3-one and 1,5-Diphenyl-1-penten-4-yn-3-one with Monosubstituted Hydrazines." ChemInform 32, no. 40 (2010): no. http://dx.doi.org/10.1002/chin.200140118.

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12

Maul, Fernando, Steven A. Sargent, Murat O. Balaban, Elizabeth A. Baldwin, Donald J. Huber, and Charles A. Sims. "Aroma Volatile Profiles from Ripe Tomatoes are Influenced by Physiological Maturity at Harvest: An Application for Electronic Nose Technology." Journal of the American Society for Horticultural Science 123, no. 6 (1998): 1094–101. http://dx.doi.org/10.21273/jashs.123.6.1094.

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The effect of physiological maturity at harvest on ripe tomato (Lycopersicon esculentum Mill.) volatile profiles was studied using ripening response time (in days) to 100 μL·L-1 exogenous ethylene treatment as a tool to separate immature-green from mature-green fruit. Electronic nose (EN) sensor array and gas chromatography (GC) analyses were used to document volatile profile changes in tomatoes that required a 1-, 3-, or 5-day ethylene treatment to reach the breaker stage. EN output analysis using multivariate discriminant and canonical analyses classified intact tomato and whole tomato homogenate samples that required 3 or 5 days of ethylene treatment as significantly different (P < 0.01) from those that required only 1 day. The GC aroma profiles from whole tomato homogenate showed that 1-day fruit had significantly higher levels (P < 0.05) of 1-penten-3-one, cis-3-hexenal, 6-methyl-5-hepten-2-one, 2-isobutylthiazole, and geranylacetone when compared to 5-day fruit. Analysis of excised tomato tissues showed that pericarp (including columnella) produced an average 219% greater concentration of the 16 aroma volatiles quantified by GC when compared to locular gel (442 and 203 μL·L-1, respectively). EN analysis concurred with GC by showing greater average Mahalanobis distance between pericarp tissue groupings when compared to locular gel groupings (78.25 and 12.33 units, respectively). Pericarp tissue from the 5-day ethylene treatment showed significantly lower levels of 1-penten-3-one, trans-2-heptenal, 6-methyl-5-hepten-2-one, 2-isobutylthiazole, geranylacetone, and β-ionone compared to the 1- and 3-day treatments, Similarly, locular gel from the 3- and 5-day ethylene treatments had significantly lower levels of 1-penten-3-one, 2-isobutylthiazole, and 1-nitro-2-phenylethane compared to 1-day samples. cis-3-Hexenol in locular gel was the only volatile compound that showed significantly higher levels with increasing ethylene treatment. EN analysis showed greater Mahalanobis distances between 1- and 3-day ethylene samples than between 3- and 5-day ethylene samples (32.09 and 12.90, 24.14 and 6.52, 116.31 and 65.04, and 15.74 and 13.28 units, for intact tomato, whole tomato, pericarp, and locular gel homogenate, respectively).

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13

Tecle, H., D. J. Lauffer, R. E. Davis, et al. "(±)-1-Azabicyclo[2.2.1]heptan-3-one, O-(3-methyl-5-aryl-2-penten-4-ynyl) oximes: Potent muscarinic agonists." Bioorganic & Medicinal Chemistry Letters 5, no. 6 (1995): 637–42. http://dx.doi.org/10.1016/0960-894x(95)00087-a.

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14

Moretti, Celso L., Elizabeth A. Baldwin, Steven A. Sargent, and Donald J. Huber. "Internal Bruising Alters Aroma Volatile Profiles in Tomato Fruit Tissues." HortScience 37, no. 2 (2002): 378–82. http://dx.doi.org/10.21273/hortsci.37.2.378.

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Tomato (Lycopersicon esculentum Mill.) fruit, cv. Solar Set, were harvested at the mature-green stage and treated with 50 μL·L-1 ethylene at 20 °C. Individual fruits at the breaker stage (<10% red color) were dropped onto a solid surface to induce internal bruising. Dropped and undropped fruit were stored at 20 °C until red-ripe, at which time pericarp, placental, and locule tissues were excised. Tissues from dropped tomatoes were examined for evidence of internal bruising and all tissues were analyzed for selected volatile profiles via headspace analysis. Individual volatile profiles of the three tissues in bruised fruit were significantly different from those of corresponding tissues in undropped, control fruit, notably: trans-2-hexenal from pericarp tissue; 1-penten-3-one, cis-3-hexenal, 6-methyl-5-hepten-2-one, cis-3-hexenol and 2-isobutylthiazole from locule tissue; and 1-penten-3-one and β-ionone from placental tissue. Alteration of volatile profiles was most pronounced in the locule tissue, which was more sensitive to internal bruising than the other tissues. Changes observed in the volatile profiles appear to be related to disruption of cellular structures.

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15

Buchbauer, Gerhard, Leopold Jirovetz, Michael Wasicky, and Alexej Nikiforov. "Headspace Constituents of Shellac." Zeitschrift für Naturforschung B 48, no. 2 (1993): 247–48. http://dx.doi.org/10.1515/znb-1993-0223.

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AbstractBy headspace analysis of the CO2-extract of shellac 4-methyl-3-penten-2-one (29.57%), 4-hydroxy-4-methyl-2-pentanone (16.66%) and 3-methyl-1-butanol (15.41%) could be identified as main constituents, as well as nearly forty hitherto unknown minor constituents (hydrocarbons, alcohols, aldehydes, ketones, acids and mainly C4-C8-esters). This investigation was carried out using GC-FID, GC-FTIR-MS and GC-Sniffing-Technique.

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16

DIMMOCK, J. R., P. KUMAR, M. CHEN, et al. "ChemInform Abstract: Synthesis and Cytotoxic Evaluation of Mesna Adducts of Some 1-Aryl-4,4- dimethyl-5-(1-piperidino)-1-penten-3-one Hydrochlorides." ChemInform 26, no. 44 (2010): no. http://dx.doi.org/10.1002/chin.199544147.

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17

Tokuno, K., M. Matsui, F. Miyoshi, Y. Asao, T. Ohashi, and K. Kihara. "Structures of the s-cis and s-trans conformers of (E)-5-methylthio-1,5-diphenyl-1-penten-3-one." Acta Crystallographica Section C Crystal Structure Communications 42, no. 1 (1986): 85–88. http://dx.doi.org/10.1107/s0108270186097226.

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18

Mall, Veronika, Ines Sellami, and Peter Schieberle. "New Degradation Pathways of the Key Aroma Compound 1-Penten-3-one during Storage of Not-from-Concentrate Orange Juice." Journal of Agricultural and Food Chemistry 66, no. 42 (2018): 11083–91. http://dx.doi.org/10.1021/acs.jafc.8b04334.

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19

Kuo, F., and P. L. Fuchs. "Use of 1-Penten-3-One-4- Phosphonate as a Kinetic Ethyl Vinyl Ketone Equivalent in the Robinson Annulation Reaction1." Synthetic Communications 16, no. 14 (1986): 1745–59. http://dx.doi.org/10.1080/00397918608057197.

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20

Kamar, Afaf, Alexander Baldwin Young, and Raymond Evans March. "A comparative ion chemistry study of acetone, diacetone alcohol, and mesityl oxide." Canadian Journal of Chemistry 64, no. 10 (1986): 1979–88. http://dx.doi.org/10.1139/v86-328.

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The evolution of ion species by unimolecular and bimolecular reactions, both concurrent and sequential, has been investigated for each of 2-propanone, d6-2-propanone, 4-hydroxy-4-methyl-2-pentanone, and 4-methyl-3-penten-2-one. Infrared multiphoton dissociation (IRMPD) has been used in order to differentiate between gaseous ionic isomers. It is concluded that the isomeric species, protonated 2-propanone dimer and protonated 4-hydroxy-4-methyl-2-pentanone, both of m/z 117, are of different structures. The ion species C6H11O+ of m/z 99, and its perdeuterated analogue, which is observed in all three systems, may exist in two forms, one of which is unique to 2-propanone while an alternative form appears to be common to 4-hydroxy-4-methyl-2-pentanone and 4-methyl-3-penten-2-one. The ion species of m/z 83 (C5H7O+) which is observed only in the latter two systems only could not be differentiated and may have a common structure. In the protonated dimers of 2-propanone and 4-hydroxy-4-methyl-2-pentanone, evidence obtained by IRMPD indicates that the activation energy for dedimerization (134 kJ mol−1) is less than that for the dehydration process.

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21

Devkota, Hari Prasad, Khem Raj Joshi, Takashi Watanabe, and Shoji Yahara. "Chemical Constituents from the Roots, Stems and Leaves of Diplomorpha sikokiana." Natural Product Communications 11, no. 4 (2016): 1934578X1601100. http://dx.doi.org/10.1177/1934578x1601100413.

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Four diarylpentanoids (1–4), two phenylpropanoids (5–6), three biflavonoids (7–9), two lignans (10–11) and a coumarin (12) were isolated from the roots of Diplomorpha sikokiana (Franchet & Savatier) Honda (Family: Thymelaeaceae). Similarly, two phenylpropanoids (5–6), five biflavonoids (7–9, 13, 14), three lignans (11, 15, 16), a flavonoid (17) and two coumarins (12, 18) were isolated from the stems, and five flavonoids (17, 19–22) from the leaves. Among them, 1,5-diphenyl-1-pentanone (1), 1,5-diphenyl-2-penten-1-one (2), 3( S)-hydroxy-1,5-diphenylpentane (3), stelleranol (8), (-)-syringaresinol (10), (-)-pinoresinol 4,4′-di- O-β-D-glucopyranoside (11), apiosylskimmin (12), syringaresinol 4- O-β-D-glucopyranoside (16), quercetin 3- O-α-L-rhamnopyranoside (19), kaempferol 3- O-α- L-rhamnopyranoside (20) and tiliroside (21) were isolated for the first time from D. sikokiana.

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22

Sexton, Daniel J., Jonathan R. Dimmock, and Bulent Mutus. "A spectrophotometric glutathione S-transferase assay displaying alpha-class selectivity utilizing l-p-chlorophenyl-4,4-dimethyl-5-diethylamino-l-penten-3-one hydrobromide." Biochemistry and Cell Biology 71, no. 1-2 (1993): 98–101. http://dx.doi.org/10.1139/o93-016.

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The conjugation of 1-p-chlorophenyl-4,4-dimethyl-5-diethylamino-1-penten-3-one hydrobromide (CDDP), a Mannich base of an α,β-unsaturated ketone, to glutathione is catalyzed selectively by alpha-class glutathione S-transferase. The reaction of CDDP with glutathione can be monitored continuously by following the conjugation-dependent decrease in absorbance of CDDP at 307 nm. The Km and Vmax for CDDP with alpha-class glutathione S-transferase from horse liver were determined to be 226 μM and 14.6 μmol/(min∙mg), respectively. CDDP is the first example of an alpha-class glutathione S-transferase selective substrate that monitors the glutathione conjugation activity, rather than the glutathione peroxidase activity of the enzyme.Key words: glutathione S-transferase, substrate, immunoblot analysis.

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23

Gibilisco, Rodrigo Gastón, Ian Barnes, Iustinian Gabriel Bejan, and Peter Wiesen. "Atmospheric fate of two relevant unsaturated ketoethers: kinetics, products and mechanisms for the reaction of hydroxyl radicals with (E)-4-methoxy-3-buten-2-one and (1E)-1-methoxy-2-methyl-1-penten-3-one." Atmospheric Chemistry and Physics 20, no. 14 (2020): 8939–51. http://dx.doi.org/10.5194/acp-20-8939-2020.

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Abstract. The kinetics of the gas phase reactions of hydroxyl radicals with two unsaturated ketoethers (UKEs) at (298±3) K and 1 atm of synthetic air have been studied for the first time using the relative-rate technique in an environmental reaction chamber by in situ Fourier-transform infrared spectroscopy (FTIR). The rate coefficients obtained using propene and isobutene as reference compounds were (in units of 10−10 cm3 molecule−1 s−1) as follows: kTMBO (OH + (E)-4-methoxy-3-buten-2-one) = (1.41±0.11) and kMMPO (OH + (1E)-1-methoxy-2-methyl-1-penten-3-one) = (3.34±0.43). In addition, quantification of the main oxidation products in the presence of NOx has been performed, and degradation mechanisms for these reactions were developed. Methyl formate, methyl glyoxal, peroxyacetyl nitrate (PAN) and peroxypropionyl nitrate (PPN) were identified as main reaction products and quantified for both reactions. The results of the present study provide new insights regarding the contribution of these multifunctional volatile organic compounds (VOCs) in the generation of secondary organic aerosols (SOAs) and long-lived nitrogen containing compounds in the atmosphere. Atmospheric lifetimes and implications are discussed in light of the obtained results.

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24

Gu, Sai Qi, Na Wu, Xi Chang Wang, Jing Jing Zhang, and Si Ru Ji. "Analysis of Key Odor Compounds in Steamed Chinese Mitten Crab (Eriocheir sinensis)." Advanced Materials Research 941-944 (June 2014): 1026–35. http://dx.doi.org/10.4028/www.scientific.net/amr.941-944.1026.

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Key odor compounds in different edible parts (abdomen, claw, leg meat and gonad) of steamed female Chinese mitten crab (Eriocheir sinensis) were extracted by a new type of adsorbent (MonoTrap), identified by gas chromatography-mass spectrometry (GC-MS) and determined by gas chromatography-olfactometry (GC-O). Ninteen key odor compounds (odor intensity value≥3) were obtained in Chinese mitten crab, among which trimethylamine (fishy), (Z)-4-heptenal (fishy) and 2-ethylpyridine (roasted potato) were found in all four edible parts of Eriocheir sinensis. In addition, 8 KOCs (2-ethylfuran, benzaldehyde, 1-octen-3-ol, 6-methyl-2-heptanone, 2-pentylfuran, (E,E)-3,5-octadien-2-one, nonanal and decanal) were also identified in the abdomen meat, 5 KOCs (toluene, 2,5-dimethylpyrazine, 1-octen-3-ol, (E,E)-3,5-octadien-2-one and 2-methylnaphthalene) in the claw meat, 3 KOCs (toluene, 2-nonanone and nonanal) in the leg meat, and 12 KOCs (1-penten-3-ol, toluene, hexanal, 1,3,5-octatriene, benzaldehyde, 1-octen-3-ol, 6-methyl-2-heptanone, 2-pentylfuran, (E,E)-3,5-octadien-2-one, nonanal, (E,Z)-2,6-nonadienal and decanal) in the gonad part.

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Thammarat, Poowadol, Chadin Kulsing, Kanet Wongravee, Natchanun Leepipatpiboon, and Thumnoon Nhujak. "Identification of Volatile Compounds and Selection of Discriminant Markers for Elephant Dung Coffee Using Static Headspace Gas Chromatography—Mass Spectrometry and Chemometrics." Molecules 23, no. 8 (2018): 1910. http://dx.doi.org/10.3390/molecules23081910.

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Elephant dung coffee (Black Ivory Coffee) is a unique Thai coffee produced from Arabica coffee cherries consumed by Asian elephants and collected from their feces. In this work, elephant dung coffee and controls were analyzed using static headspace gas chromatography hyphenated with mass spectrometry (SHS GC-MS), and chemometric approaches were applied for multivariate analysis and the selection of marker compounds that are characteristic of the coffee. Seventy-eight volatile compounds belonging to 13 chemical classes were tentatively identified, including six alcohols, five aldehydes, one carboxylic acid, three esters, 17 furans, one furanone, 13 ketones, two oxazoles, four phenolic compounds, 14 pyrazines, one pyridine, eight pyrroles and three sulfur-containing compounds. Moreover, four potential discriminant markers of elephant dung coffee, including 3-methyl-1-butanol, 2-methyl-1-butanol, 2-furfurylfuran and 3-penten-2-one were established. The proposed method may be useful for elephant dung coffee authentication and quality control.

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26

Malik, Hermen, and Douglas D. Archbold. "Manipulating Primocane Architecture in Thornless Blackberry with Uniconazole, GA3, and BA." HortScience 27, no. 2 (1992): 116–18. http://dx.doi.org/10.21273/hortsci.27.2.116.

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The potential for plant growth regulator (PGR) manipulation of `Chester Thornless' blackberry (fibus spp.) primocane growth was evaluated. PGR treatments included combinations of soil-applied uniconazole at 1, 5, 25, and 125 mg/plant and GA, foliar-applied one or two times at 100 ppm 3 and 4 weeks after a 25-mg/plant uniconazole application. Also, GA and BA were applied at 100 ppm alone or in combination one, two, or three times. Increasing rates of uniconazole reduced primocane length, leaflet count, and leaf, cane, and root dry weights. GA, applications reduced primocane length and increased branch elongation but failed to reverse the effects of uniconazole at 25 mg/plant, except those on branch length, leaflet count, and primocane dry weight. Only applications of BA + GA, increased both branch production and elongation and dry weights of some component tissues, while BA alone generally had no effects. Chemical names used: (E)-1-(p-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol (uniconazole); N-(phenylmethyl)-1H-purin-6-amine (benzyladenine, BA); gibberellic acid (GA).

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27

Schmid, Günter, and Wolfgang Meyer-Zaika. "Azaborolyl-Komplexe, 27 / Azaborolyl Complexes, 27." Zeitschrift für Naturforschung B 47, no. 5 (1992): 635–39. http://dx.doi.org/10.1515/znb-1992-0505.

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Alkenyl substituted 1H-1,2-azaborolyl (Ab) complexes are promising candidates for stereoselective reactions, due to the chirality of the AbM moiety and the intramolecular coordination of the alkenyl group to the metal atom. The synthesis of [1-tert-butyl-2-methy1-3-(4-penten- l -y1)-η5-1H-1,2-azaborolyl]-bis(triphenylphosphine)rhodium (3) is achieved by the reaction of AbLi (2) [from AbH (1)] with (Ph3P)3RhCl. In benzene solution one PPh3 ligand of 3 is substituted by the C=C group of the pentenyl substituent. Simultaneously the η5-coordination of the Ab ring changes to an allylic η3-coordination forming 4. Steric reasons seem to be responsible for this intramolecular rearrangement. The shorter 2-propen-1-yl substituent is unable to act in the same way and therefore only forms the stable complex [1-tert-butyl-2-methyl-3-(2-propen- l -yl)-η5-1H-1,2-azaborolyl]-bis(triphenylphosphine)rhodium (7). Mass spectrometry, 1H, 11B and 31P NMR data were used to characterize the novel complexes.

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28

Khiari, D., I. H. Suffet, and S. E. Barrett. "The determination of compounds causing fishy/swampy odors in drinking water supplies." Water Science and Technology 31, no. 11 (1995): 105–12. http://dx.doi.org/10.2166/wst.1995.0413.

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Two chemical isolation methods, closed-loop stripping analysis (CLSA) and simultaneous distillation/extraction (SDE) in combination with gas chromatography/mass spectroscopy (GC/MS) and two sensory methods, flavor profile analysis (FPA) and sensory GC analysis, were used to determine the compounds responsible for the fishy/swampy odors in potable water. Samples were collected during four different fishy/swampy odor episodes and analyzed. It was determined that the compounds should be extracted by the SDE method. The SDE method extracts more polar compounds than the CLSA method. The main compounds identified were two unsaturated aldehydes (trans,trans-2-4-heptadienal and trans,4-heptenal). A ketone (1-penten-3-one) was tentatively identified.

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29

Ke, Dangyang, and Michael Boersig. "Sensory and Chemical Analyses of Tomato Flavor." HortScience 31, no. 4 (1996): 599b—599. http://dx.doi.org/10.21273/hortsci.31.4.599b.

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Consumer acceptance of sensory quality was significantly correlated (P = 0.05) with overall eating quality of tomatoes (Lycopersicon esculentum Mill.) determined by a trained taste panel. The overall eating quality was partitioned into three flavor components (sweetness, sourness, and aroma) and internal texture. Relationships between the sensory flavor components and concentrations of several chemical compounds were analyzed in tomatoes of eleven varieties within a range of acceptable texture. Sweetness was significantly correlated with total sugar concentration and overall flavor at P = 0.01 and 0.001. High concentrations of two ketone volatiles (6-methyl-5-hepten-2-one and 1-penten-3-one) were significantly correlated with aroma and overall flavor at P = 0.05 to 0.001. This study indicates that positive tomato flavor may be characterized by high sweetness, moderate acidity, and high concentrations of certain ketone volatiles.

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30

Baldwin, Elizabeth A., Myrna O. Nisperos-Carriedo, and Manuel G. Moshonas. "QUANTITATIVE ANALYSIS OF FLAVOR VOLATILES AND OTHER PARAMETERS IN TWO TOMATO VARIETIES DURING RIPENING." HortScience 25, no. 9 (1990): 1090d—1090. http://dx.doi.org/10.21273/hortsci.25.9.1090d.

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Whole tomato fruit (Lycopersicon esculentum Mill.), cvs. Sunny and Solarset, were analyzed at 5 different ripening stages for ethylene and CO2 production. Homogenates from the same fruit were prepared for determination of color, flavor volatiles, sugars and organic acids. Of the flavor volatiles measured, only eugenol decreased during ripening in both varieties and 1-penten-3-one in `Sunny' tomatoes. Ethanol, and trans-2-trans-4-decadienal levels showed no change or fluctuated as the fruit matured while all other volatiles measured (cis-3-hexenol, 2-methyl-3-butanol, vinyl guiacol, acetaldehyde, cis-3-hexenal, trans-2-hexenal, hexanal, acetone, 6-methyl-5-hepten-2-one, geranylacetone and 2-isobutylthiazole) increased in concentration, peaking in the later stages of maturity. Synthesis of some volatile compounds occurred simultaneously with that of climacteric ethylene and color. `Solarset' fruit exhibited higher levels of sugars and all flavor components except ethanol, vinyl guiacol, hexanal and 2-methyl-3-butanol in the red stage. There were no differences between these varieties for acids

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31

Baldwin, E. A., J. W. Scott, and F. Maul. "Effect of Harvest Maturity and Ethylene Gassing on Tomato Flavor Volatile Concentrations." HortScience 33, no. 3 (1998): 490a—490. http://dx.doi.org/10.21273/hortsci.33.3.490a.

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Tomato fruit (Lycopersicon esculentum Mill.) cvs. Solar Set and Olympic were harvested at three maturity stages: green (stage 1, USDA color classification) gassed with 100 ppm ethylene, green not gassed, turning (stage 4), and red-ripe (stage 6). After ripening at 21 °C, the fruit were homogenized with CaCl2 and analyzed for important flavor volatile compounds. For `Solar Set', acetone, ethanol, 1-penten-3-one, hexanal, and trans-2-heptenal were significantly higher in red-harvested fruit, while 2+3-methylbutanol, and trans-2-hexenal were higher in green-harvested fruit. trans-2-Hexenal was at higher levels in green-harvested fruit not gassed compared to those that were gassed for `Solar Set'. `Olympic' fruit followed similar trends for harvest maturity and gassing, but there were fewer significant differences in volatile levels. Using a multivariate discriminant pattern recognition procedure, red fruit were separated from turning and green-harvested fruit, while green-gassed separated from non-gassed based on the aroma volatile profile within each cultivar.

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32

Mutus, Bulent, Jerome D. Wagner, Christopher J. Talpas, Jonathan R. Dimmock, Oludotun A. Phillips, and R. Stephen Reid. "1-p-Chlorophenyl-4,4-dimethyl-5-diethylamino-1-penten-3-one hydrobromide, a sulfhydryl-specific compound which reacts irreversibly with protein thiols but reversibly with small molecular weight thiols." Analytical Biochemistry 177, no. 2 (1989): 237–43. http://dx.doi.org/10.1016/0003-2697(89)90045-6.

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33

Cao, Simin, Yangyi Liu, Litao Zhao, et al. "Rapid, Wide-Range, and Low-Cost Determination of Formaldehyde Based on Porous Silica Gel Plate by Digital Image Colorimetry." Proceedings 42, no. 1 (2019): 13. http://dx.doi.org/10.3390/ecsa-6-06542.

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A porous silica gel plate impregnated with a colorimetric reagent, 4-amino-3-penten-2-one (Fluoral-P) has been fabricated for the first time to determinate formaldehyde. The reaction of formaldehyde and Fluoral-P produced a yellow product 3,5-diacetyl-1,4-dihydrolutidine (DDL), which was further photographed by a smartphone. A good linear relationship has been found between the intensity of blue component from the digital image and formaldehyde concentration in the range of 0–50 mg L−1 with low detection limit of 2.2 ± 0.1 mg L−1. A good precision in the range of 0.59–7.75%RSD and an accuracy with the relative error of +3.7% from control samples are also obtained. These results demonstrate that our developed low-cost sensor, together with digital image colorimetry, has potential for sensitively and quickly measuring formaldehyde.

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34

Duhaime, Randy M., та Alan C. Weedon. "Direct observation of dienols produced by photochemical enolisation of α,β-unsaturated ketones: rates and activation parameters for dienol reketonisation via a 1,5-hydrogen shift". Canadian Journal of Chemistry 65, № 8 (1987): 1867–72. http://dx.doi.org/10.1139/v87-313.

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The production of stable solutions of Z-dienols by ultraviolet light irradiation of α,β-unsaturated ketones at low temperatures (ca. −76 °C) in d4-methanol is reported. The rates of reketonisation of the dienols via a 1,5-sigmatropic hydrogen shift were determined at various temperatures between −43 °C and + 2 °C by monitoring the proton nmr spectra of the dienols. From the data the activation parameters for the reaction were calculated. For the dienol Z-2-hydroxy-4-methyl-2,4-pentadiene, 2, derived from photoenolisation of 4-methyl-3-penten-2-one, 1, the activation energy from the Arrhenius plot is 62 ± 4 kJ/mol, and the activation entropy and enthalpy from the Eyring plot are −87 ± 15 J/mol K and 60 ± 4 kJ/mol, respectively. For the dienol Z-4-tert-butyl-2-hydroxy-2,4-pentadiene, 4, obtained from photoenolisation of 4,5,5-trimethyl-3-hexen-2-one, 3, the activation energy, entropy, and enthalpy were found to be 47 ± 5 kJ/mol, −135 ± 19 J/mol K, and 45 ± 5 kJ/mol, respectively.

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35

Kaškonienė, Vilma, Paulius Kaškonas, Audrius Maruška, and Loreta Kubilienė. "Chemometric analysis of volatiles of propolis from different regions using static headspace GC-MS." Open Chemistry 12, no. 6 (2014): 736–46. http://dx.doi.org/10.2478/s11532-014-0521-7.

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AbstractSix samples of propolis were analyzed in the paper: a sample from Brazil, Estonia, China and three samples from different locations of Uruguay. Static headspace technique coupled with gas chromatography-mass spectrometry analysis has been applied for the determination of the characteristic volatile profile with the aim to differentiate the propolis from different regions. Monoterpenes (α- and β-pinenes) were predominant in all samples, except the sample from China. This sample separated itself by the alcohols 3-methyl-3-buten-1-ol and 3-methyl-2-buten-1-ol, (40.33% and 11.57%, respectively) and ester 4-penten-1-yl acetate (9.04%). α-Pinene and β-pinene composed 64.59–77.56% of volatiles in Brazilian and Uruguayan propolis, and 29.43% in Estonian propolis. Brazilian propolis was distinguished by a high amount of β-methyl crotonaldehyde (10.11%), one of Uruguayan samples 3- by limonene (15.58%), and the Estonian sample — by eucalyptol (25.95%). Statistical investigation of the samples was made applying principal component, hierarchical cluster and K-Means cluster analyses. Various data pre-processing techniques were proposed and used to study and obtain the important volatile compounds contributed to the differentiation of the propolis samples from different regions to separate clusters.

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36

Ramos, Arsenio, and Antonio Acedo Jr. "Morphological Effects of Paclobutrazol on the Regrowth of Rejuvenated Coffee (Coffea arabica L.) Trees." Science and Humanities Journal 10, no. 1 (2013): 36–53. http://dx.doi.org/10.47773/shj.1998.101.3.

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This study was conducted to determine the morphological response of the regrowth of rejuvenated coffee (Coffea arabica L.) to varying timing and levels of application of Paclobutrazol (PBZ) [2RS, 3RS)-1-4 (-chlorophenyl)-4,4-dimethyl-2-1, 2, 4-triazol-1-yl-penten-3-ol]. Plants applied with PBZ two months before cutting had delayed shoot emergence, were shorted and had bigger lateral brances but with comparable percent plant survival, vertical shoot stem characteristics, lateral branch morphology, leaf morphology and root volume and dry weight compared to those applied with PBZ one month before cutting. Regardless of timing of application, plants given 0.5 and 1.0 g a.i.PBZ/ m canopy span had shorter vertical shoots with shorter internodes, fewer and shorter lateral branches, smaller leaves, and bigger root volume but comarable plant survival, days to shoot emergence, vertical shoot stem diameter, number of nodes of lateral branches, number of leaves, LAI and root dry weight with the untreated plants.

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37

Raabe, Gerhard, Wolfgang Karl, Dieter Enders, and Jörg Fleischhauer. "Conformational Aspects of Substituents in Enamines. X-Ray Structure Analyses and Quantum Chemical Calculations." Zeitschrift für Naturforschung A 47, no. 7-8 (1992): 869–76. http://dx.doi.org/10.1515/zna-1992-7-812.

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Abstract X-ray structure determination of the enamine (Z)-4-(6'-t-butoxycarbonyl-2',2'-dimethyl-5'-phenyl- 3'-hexen-3'-yl)morpholine (1) reveals that certain bulky groups may enforce a relative orientation of the molecular subunits without conjugative interaction between the nitrogen lone pair and the olefinic double bond. According to the results of quantum chemical ab initio calculations the experimentally found arrangement would be the least favourable one in the absence of such substituents. A careful analysis of the molecular structure of 1 shows that this unusual arrangement is due to the presence of both, the a- and the ß-substituent. In (E)-4-(3'-t-butoxycarbonylmethyl-1'-phenyl-1'-penten-1'-yl)morpholine (2) rather the nitrogen lone pair than the phenyl n system is in conjugation with the olefinic double bound. The results of ab initio calculations on model compounds show that conjugation of the double bond with the nitrogen lone pair is by 2 - 6 kcal/mol more favourable than conjugative interaction between the phenyl group and the C = C bond. Closer examination of the molecular structure of 2, however, led to the conclusion that it is predominantly the ß-substituent which forces the phenyl ring in a position where conjugation with the enamine double bond is not possible

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38

Wang, Libin, Elizabeth A. Baldwin, Zhifang Yu, and Jinhe Bai. "The Impact of Kitchen and Food Service Preparation Practices on the Volatile Aroma Profile in Ripe Tomatoes: Effects of Refrigeration and Blanching." HortScience 50, no. 9 (2015): 1358–64. http://dx.doi.org/10.21273/hortsci.50.9.1358.

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Both refrigeration and blanching of red-stage tomatoes are common practices in Japan home kitchens and in food service operations. However, little is reported on the impact of such practices on aroma profiles in tomato fruits. In this study, ‘FL 47’ tomatoes at red stage were dipped in 50 °C hot water for 5 minutes or exposed to 5 °C for 4 days to simulate consumer handling of tomato in food service or home kitchens, respectively. Of the 42 volatile compounds detected, refrigeration generally suppressed production of aldehydes, alcohols, oxygen-containing heterocyclic compounds, and nitrogen- and oxygen-containing heterocyclic compounds, including the following abundant and/or important volatiles: pentanal, 3-methylbutanal, 2-methylbutanal, hexanal, cis-3-hexenal, trans-2-hexenal, 2-phenylacetaldehyde, pentanol, 3-methylbutanol, 2-phenylethanol, 1-penten-3-one, geranial, and geranylacetone. On the other hand, the production of aldehydes, alcohols, hydrocarbons, oxygen-containing heterocyclic compounds, and nitrogen- and oxygen-containing heterocyclic compounds was reduced by blanching, associated with low concentrations of 2-methylbutanal, pentanal, cis-3-hexenal, trans-2-hexenal, 2-phenylacetaldehyde, pentanol, 2-methylbutanol, and 2-phenylethanol. These results indicate that a short blanching or refrigeration of tomatoes substantially impacts tomato aroma quality.

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39

Alonso, A., R. García-Aliaga, S. García-Martínez, J. J. Ruiz, and A. A. Carbonell-Barrachina. "Characterization of Spanish Tomatoes using Aroma Composition and Discriminant Analysis." Food Science and Technology International 15, no. 1 (2009): 47–55. http://dx.doi.org/10.1177/1082013208102385.

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Nowadays, tomato breeders are trying to associate high fruit firmness, long shelf life, high disease resistance, and good flavor; however, breeding for sensory quality has been severely restricted up to date. In this study, a system specifically designed for the analysis of low amounts of material has been set up and tested to quantify the volatile aroma constituents of tomatoes. Ten volatile compounds with a major contribution to tomato aroma have been quantitatively determined in two traditional tomato types (Muchamiel and De la Pera) and one hybrid type (Odissea). Both traditional types presented higher intensities of tomato odor and aroma according to a trained panel and they were more accepted by a consumer panel than the hybrid tomatoes. The traditional tomatoes showed significantly higher contents of most of the volatiles studied. Significant differences among traditional and hybrid types were found and a mathematical model that successfully discriminated among tomato types was developed using only the concentrations of six volatile compounds: 3-methylbutanal, 1-penten-3-one, hexanal, trans-2-hexenal, 1-hexanol, and 2-isobutylthiazole. This mathematical model could help in using volatile determination as a possible tool in tomato breeding programs and in maintaining and improving traditional Spanish tomato cultivars.

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40

Baldwin, E. A., M. O. Nisperos-Carriedo, and M. G. Moshonas. "Quantitative Analysis of Flavor and Other Volatiles and for Certain Constituents of Two Tomato Cultivars during Ripening." Journal of the American Society for Horticultural Science 116, no. 2 (1991): 265–69. http://dx.doi.org/10.21273/jashs.116.2.265.

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Tomato (Lycopersicon esculentum Mill.) fruit, cvs. Sunny and Solar Set, were analyzed at five ripening stages for ethylene and CO2 production. Homogenates from the same fruit were prepared for determination of color, flavor volatiles, sugars, and organic acids. Changes in the levels of these compounds were compared to the pattern of climacteric ethylene production. Of the flavor volatiles measured, only eugenol decreased during ripening in both cultivars and 1-penten-3-one in `Sunny' tomatoes. Ethanol and trans-2-trans- 4-decadienal levels showed no change or fluctuated as the fruit ripened while all other volatiles measured (cis- 3-hexenol, acetaldehyde, cis- 3-hexenal, trans-2- hexenal, hexenal acetone, 6-methyl-5 -hepten-2-one, geranylacetone, and 2-isobutylthiazole) increased in concentration, peaking in the turning, pink, or red stage of maturity. Synthesis of some volatile compounds occurred simultaneously with that of climacteric ethylene, CO2 and lycopene production. `Solar Set' fruit exhibited higher levels than `Sunny' of all flavor components except ethanol and hexanal in the red stage. There were no differences in organic acid levels between the cultivars; however, `Solar Set' had higher levels of sugars. Changes in acid and sugar levels showed no temporal relationship to climacteric ethylene or CO2 production.

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41

Kim, Su-Jeong, Jun-Young Lee, Yun-Sang Choi, Jung-Min Sung, and Hae Won Jang. "Comparison of Different Types of SPME Arrow Sorbents to Analyze Volatile Compounds in Cirsium setidens Nakai." Foods 9, no. 6 (2020): 785. http://dx.doi.org/10.3390/foods9060785.

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Cirsium setidens Nakai is a perennial plant extensively used as food in Korea. Various reports have illustrated the presence of phytochemicals with antioxidant, anti-cancer, anti-tumor, and anti-inflammatory activities; however, little is known about the volatile compounds present in this plant. Here, a novel solid-phase microextraction (SPME) Arrow method was performed to extract and analyze volatile compounds from freeze-dried Cirsium setidens Nakai. Four types of SPME Arrows coated with films, such as carbon wide range/polydimethylsiloxane, divinylbenzene/polydimethylsiloxane, polydimethylsiloxane, and polyacrylate were evaluated to identify the most suitable Arrow. The carbon wide range/polydimethylsiloxane Arrow was found to exhibit high affinity for the volatile compounds present in Cirsium setidens Nakai. A total of 58 volatile compounds were identified. The major compounds were 2-Pentylfuran, 1-Methylcycloheptanol, 1-Penten-3-ol, 2,2,4,6,6-Pentamethylheptane, 2,3,6,7-Tetramethyloctane, 5-Ethyl-2,2,3-trimethylheptane, 3,5-Octadien-2-one, β-Cyclocitral, and trans-β-Ionone. The present study demonstrates that the SPME Arrow coated with the carbon wide range/polydimethylsiloxane film is suitable for the analytical profiling of volatile compounds present in Cirsium setidens Nakai.

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42

Liu, Hsing-Jang, Waiseng Martin Feng, Jeung Bea Kim, and Eric N. C. Browne. "Lewis acid catalyzed Diels–Alder reactions of two useful dienyl phosphate esters." Canadian Journal of Chemistry 72, no. 10 (1994): 2163–75. http://dx.doi.org/10.1139/v94-275.

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The Lewis acid catalyzed Diels–Alder reactions of dienyl phosphate esters 1 and 2 were examined. 2-Diethylphosphoryloxy-1,3-butadiene (1) was found to react with a variety of α,β-unsaturated carbonyl compounds under Lewis acid catalysis with excellent regioselectivity to give synthetically useful cyclohexene derivatives. The adducts were produced in accordance with the normal rules governing the Diels–Alder addition. In the presence of stannic chloride acyclic α,β-unsaturated ketones such as ethyl vinyl ketone and methyl vinyl ketone reacted rapidly with diene phosphate 1 to give exclusively the para-addition products 8 and 9 in excellent yields. When diene 1 was treated with the complex cyclic enone ester 14 in the presence of ferric chloride the single para-rule adduct 15 was obtained in good yield. The stannic chloride catalyzed Diels–Alder reactions of trans-2-diethylphosphoryloxy-1,3-pentadiene (2) were also studied. Diene phosphate 2 reacted efficiently with a number of acyclic α,β-unsaturated ketones such as methyl vinyl ketone, ethyl vinyl ketone, and trans-3-penten-2-one with complete regio- and stereoselectivity to give single cyclohexene derivatives 38, 39, and 40.

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43

Scott, J. W., and E. A. Baldwin. "Flavor Analysis of rin/+ and Other Tomato hybrids and Inbreds Using Sensory and Chemical Methods." HortScience 33, no. 3 (1998): 471e—472. http://dx.doi.org/10.21273/hortsci.33.3.471e.

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Consumer dissatisfaction with commercial tomato (Lycopersicon esculentum Mill.) eating quality is well-known. An array of tomato cultivars were tested for overall flavor by experienced or trained taste panels over several seasons. Fruit were also analyzed for aromatic volatiles, soluble solids (SS), and titratable acidity (TA). `Solar Set' was the most consistent cultivar for overall flavor, always ranking in the most preferred statistical group. Cultivars that were bred for increased firmness, either by crossing firm lines (ultrafirms) or that were heterozygous for the ripening inhibitor (rin) gene, tended to rank low in overall flavor and sweetness. Comparisons made included ultrafirm lines, rin/+ hybrids with one to three backcrosses to the high-flavored parent of `Solar Set' (Fla. 7060), Fla. 7060, and `Solar Set' with two rin backcrosses. Experienced panel ratings were highest for Fla 7060 followed by the rin/+ hybrids (in descending order of backcrosses to Fla. 7060), followed by the ultrafirm lines. SS and TA were highest in one ultrafirm (SS = 9.1, TA = 0.68) and lowest in one of the rin/+ hybrids (SS = 6.3, TA = 0.37) while the rest of the samples showed intermediate values. Analysis of flavor volatiles showed Fla. 7060 to be generally higher in most volatiles compared to the ultrafims and two of the rin/+ hybrids. Significant differences were found for methanol, ethanol, 1-penten-3-one, hexanal, trans-2-hexanal, trans-2-heptenal, cis-3-hexenol, 2+3-methylbutanol, 6-methyl-5-hepten-2-one, 2-isobutylthiazole, and geranylacetone.

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44

Kreiter, Cornelius G., та Wolfgang Conrad. "Gehinderte Ligandbewegungen in Übergangsmetallkomplexen, XLIV [1]: Photoreaktionen von Hexacarbonyl-μ-η5:5-fulvalen-dimolybdän mit Allen / Hindered Ligand Movements in Transition Metal Complexes, XLIV [1]: Photoreactions of Hexacarbonyl-μ-η5:5 -fulvalene-dimolybdenum with Allene". Zeitschrift für Naturforschung B 49, № 12 (1994): 1707–16. http://dx.doi.org/10.1515/znb-1994-1215.

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Hexacarbonyl-μ-η5:5-fulvalene-dimolybdenum (1) reacts photochemically with allene to η2-allene-pentacarbonyl-μ-η5:5-fulvalene-dimolybdenum (2), μ-η2:2-allene-tetracarbonyl- μ-η5:5-fulvalene-dimolybdenum (4), and dicarbonyl-μ-η5:5-fulvalene-μ-η1:2:3-2-methylene- 4-penten-1,4-diyl-dimolybdenum (5). Complex 2 rearranges readily at room temperature to pentacarbonyl-μ-η1:3-2-propen-1,2-diyl-μ-η5:5-fulvalene-dimolybdenum (3). Upon UV irradiation 4 yields with an excess of allene μ-η2:2-Allene-pentacarbonyl-μ-η5:5-fulvalene-dimolyb-denum (2) shows a hindered rotation of the allene ligand with an energy barrier of ⊿G#303 = 53.3 ± 2 kJ/mol. Hexacarbonyl-μ-η5:5-bis(cyclopentadiendiyl)methane-dimolybdenum (6) reacts with allene to μ-η2:2-ailene-tetracarbonyl-μ-η5:5-bis(cyclopentadiendiyl)methane- dimolybdenum (7) and octacarbonyl-bis{μ-η5:5:1-(cyclopentadiendiyl-cyclopentadientriyl)-methanejdihydrido-tetramolybdenum (8). For μ-η2:2-allene-tetracarbonyl-μ-η5:5-fulvalene-dimolybdenum (4) and 7 a hindered ligand movement was detected, by which the bridging allene ligand changes from one the side of the molecule to the other. The activation barriers of these pseudo rotations were determined for 4 with ⊿G#303 = 57.4 ± 2 kJ/mol and for 7 with ⊿G#293 = 63.4 ± 2 kJ/mol. Hexacarbonyl-μ-η5:5-fulvalene-ditungsten, hexacarbonyl-μ-η5-bis(cyclopentadiendiyl)ethane-dimolybdenum and hexacarbonyl-μ-η5:5-bis(cyclopen- tadiendiyl)propane-dimolybdenum form no stable photoproducts with allene.

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45

Canoles, Mauricio, Marisol Soto, and Randolph Beaudry. "Hydroperoxide Lyase Activity Necessary for Normal Aroma Volatile Biosynthesis of Tomato Fruit, Impacting Sensory Perception and Preference." HortScience 40, no. 4 (2005): 1130E—1131. http://dx.doi.org/10.21273/hortsci.40.4.1130e.

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The aldehydes cis-3-hexenal, hexanal, and trans-2-hexenal; the alcohols 1-hexanol, and cis-3-hexenol; and the ketone 1-penten-3-one are produced as a consequence of lipid degradation following tissue disruption and are among the most important volatile compounds in tomato (Lycopersicon esculentum Mill.) aroma. The biosynthesis of cis-3-hexenal and other volatiles noted involves the action of a sequence of enzymes including lipase, lipoxygenase (LOX), hydroperoxide lyase (HPL), isomerase, and alcohol dehydrogenase (ADH) on glycerolipids containing the fatty acids, linoleic acid (18:2) and linolenic acid (18:3), via the LOX pathway. In the current work, the formation and sensory perception of volatile compounds was studied in tomato plant lines where HPL activity was genetically altered. LeHPL co-suppression dramatically reduced the production of lipid-derived C6-volatiles in leaves, but in fruits, only unsaturated C6-volatile production was affected, suggesting LeHPL-independent formation of hexanal occurs in fruits, but not in leaves. Increased production of 5-carbon volatiles is proposed as an alternative way to metabolize 13-hydroperoxy linolenic acid in plants with reduced LeHPL activity. Changes in the volatile profile of leaves and fruits of tomato lines in which LeHPL activity is reduced markedly are readily detected by nontrained sensory panels. The studies demonstrate that a marked reduction in the activity of one of the most critical steps in the LOX pathway can markedly impact sensory perception. Efforts to improve total volatile formation may require the modification of LOX pathway at several steps simultaneously, including precursor formation, and LOX and HPL activities.

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46

He, Gong Xiu, Dang Quan Zhang, and Lin Lin Guo. "High-Grade Utilization of Recovering Wastewater from Cinnamomum Camphora Oil." Key Engineering Materials 480-481 (June 2011): 272–77. http://dx.doi.org/10.4028/www.scientific.net/kem.480-481.272.

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The production of noble Cinnamomum camphora oil from C. camphora leaves and twigs brings a mass of extracting wastewater which is pollutive to water environment. In order to better utilize and recover the productive wastewater from the Eucalyptus oil, we used GC/MS to analyze the possible top value-added components of benzene/ethanol extractives of leaves and twigs of C.camphora. The analytical result showed that only 15 compounds were identified from the benzene/ethanol extractive of C. camphora trigs, and 29 compounds from 30 peaks were identified from the benzene/ethanol extractive of C. camphora leaves. The analytical result showed that the main components of the benzene/ethanol extractive of C. camphora twigs by GC/MS are as: Bicyclo[2.2.1]heptan-2-one, 1,7,7-trimethyl-, (1R)- (36.85%), Linalyl propanoate (23.58%), Eucalyptol (10.07%), 1,3-Benzodioxole, 5-(2-propenyl)- (8.88%), 4,4-dimethylcholest-7-ene-3-ol (5.81%), Cyclopentanol (3.37%), 1,2,4-Cyclopentanetrione, 3-(2-pentenyl)- (2.52%), etc. The result by GC/MS analysis showed that the benzene/ethanol extractive of leaves of C. camphora are as: Eucalyptol (58.51%), 3-Cyclohexene-1-methanol, .alpha.,.alpha.4-trimethyl- (13.98% from two peaks), Sabinene (4.45%), 1-Mercapto-2-heptadecanone (2.69%), Phytol (2.29%), Camphene (1.94%), 1-Eicosanol (1.81%), Caryophyllene (1.63%), 1,3-Benzodioxole, 5,5'-(tetrahydro- 1H,3H-furo[3,4-c]furan-1,4-diyl)bis-, [1S-(1.alpha.,3a.alpha.,4.beta.,6a.alpha.)]- (1.50%), 1-Penten- 3-ol (1.01%), beta.-Pinene (0.86%), etc. There are many important constituents of rare natural medicine, cosmetic and spicery in the benzene/ethanol extractive of twigs and leaves of C. camphora.

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47

Baldwin, E. A., J. W. Scott, M. A. Einstein, et al. "Relationship between Sensory and Instrumental Analysis for Tomato Flavor." Journal of the American Society for Horticultural Science 123, no. 5 (1998): 906–15. http://dx.doi.org/10.21273/jashs.123.5.906.

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The major components of flavor in tomato (Lycopersicon esculentum Mill.) and other fruit are thought to be sugars, acids, and flavor volatiles. Tomato overall acceptability, tomato-like flavor, sweetness, and sourness for six to nine tomato cultivars were analyzed by experienced panels using a nine-point scale and by trained descriptive analysis panels using a 15-cm line scale for sweetness, sourness, three to five aroma and three to seven taste descriptors in three seasons. Relationships between sensory data and instrumental analyses, including flavor volatiles, soluble solids (SS), individual sugars converted to sucrose equivalents (SE), titratable acidity (TA), pH, SS/TA, and SE/TA, were established using correlation and multiple linear regression. For instrumental data, SS/TA, SE/TA, TA, and cis-3-hexenol correlated with overall acceptability (P = 0.05); SE, SE/TA (P≤0.03), geranylacetone, 2+3-methylbutanol and 6-methyl-5-hepten-2-one (P = 0.11) with tomato-like flavor; SE, pH, cis-3-hexenal, trans-2-hexenal, hexanal, cis-3-hexenol, geranylacetone, 2+3-methylbutanol, trans-2 heptenal, 6-methyl-5-hepten-2-one, and 1-nitro-2-phenylethane (P≤0.11) with sweetness; and SS, pH, acetaldehyde, aceton, 2-isobutylthiazole, geranlyacetone, β-ionone, ethanol, hexanal and cis-3-hexenal with sourness (P≤0.15) for experienced or trained panel data. Measurements for SS/TA correlated with overall taste (P=0.09) and SS with astringency, bitter aftertaste, and saltiness (P≤0.07) for trained panel data. In addition to the above mentioned flavor volatiles, methanol and 1-penten-3-one significantly affected sensory responses (P = 0.13) for certain aroma descriptors. Levels of aroma compounds affected perception of sweetness and sourness and measurements of SS showed a closer relationship to sourness, astringency, and bitterness than to sweetness.

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48

Wang, Yin-Tung, and Tsung-Yao Hsu. "Flowering and Growth of Phalaenopsis Orchids following Growth Retardant Applications." HortScience 29, no. 4 (1994): 285–88. http://dx.doi.org/10.21273/hortsci.29.4.285.

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Bare-root, mature, hybrid Phalaenopsis seedlings were dipped in one of three growth retardant solutions for 5 seconds or sprayed with a growth retardant 4 weeks following planting during inflorescence elongation. Dipping the entire plant in daminozide (2500, 5000, or 7500 mg·liter-1) before planting delayed flowering by 5-13 days, whereas foliar applications had no effect. Paclobutrazol (50, 100, 200, or 400 mg·liter-1) or uniconazole (25, 50, 100, or 200 mg·liter-1) dips did not affect the bloom date but effectively restricted inflorescence growth below the first flower (stalk). Increasing concentrations produced progressively less growth. Foliarly applied retardant treatments were less effective than dipping. Flower size, flower count, and stalk thickness were unaffected by treatments. Dipping in high concentrations of paclobutrazol (200 or 400 mg·liter-1) or uniconazole (100 or 200 mg·liter-1) caused plants to produce small, thick leaves. During the second bloom season, inflorescence emergence and bloom date were progressively delayed by increasing concentrations of paclobutrazol and uniconazole. Neither retardant affected flower count or size. Foliarly applied daminozide increased stalk length. In another experiment, foliar paclobutrazol treatment restricted stalk growth more effectively when sprayed before inflorescence emergence. Its effect progressively decreased when treatment was delayed. Paclobutrazol concentrations from 125 to 500 mg·liter-1 were equally effective in limiting stalk elongation when applied to the foliage. Chemical names used: butanedioic acid mono (2,2-dimethylhydrazide) (daminozide); (E)-1- (p -chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol(uniconazole); (2 RS, 3 RS) -1-(4-chlorophenyl)-4,4-dimethyl-2-(1 H- 1,2,4-triazol-1-yl) pentan-3-ol (paclobutrazol).

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49

Meucci, Annalisa, Anton Shiriaev, Irene Rosellini, Fernando Malorgio, and Beatrice Pezzarossa. "Se-Enrichment Pattern, Composition, and Aroma Profile of Ripe Tomatoes after Sodium Selenate Foliar Spraying Performed at Different Plant Developmental Stages." Plants 10, no. 6 (2021): 1050. http://dx.doi.org/10.3390/plants10061050.

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Foliar spray with selenium salts can be used to fortify tomatoes, but the results vary in relation to the Se concentration and the plant developmental stage. The effects of foliar spraying with sodium selenate at concentrations of 0, 1, and 1.5 mg Se L−1 at flowering and fruit immature green stage on Se accumulation and quality traits of tomatoes at ripening were investigated. Selenium accumulated up to 0.95 µg 100 g FW−1, with no significant difference between the two concentrations used in fruit of the first truss. The treatment performed at the flowering stage resulted in a higher selenium concentration compared to the immature green treatment in the fruit of the second truss. Cu, Zn, K, and Ca content was slightly modified by Se application, with no decrease in fruit quality. When applied at the immature green stage, Se reduced the incidence of blossom-end rot. A group of volatile organic compounds (2-phenylethyl alcohol, guaiacol, (E)-2-heptenal, 1-penten-3-one and (E)-2-pentenal), positively correlated with consumer liking and flavor intensity, increased following Se treatment. These findings indicate that foliar spraying, particularly if performed at flowering stage, is an efficient method to enrich tomatoes with Se, also resulting in positive changes in fruit aroma profile.

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50

Kil, Jin-Sang, Young Son, Yong-Kwan Cheong, et al. "Okanin, a chalcone found in the genus Bidens, and 3-penten-2-one inhibit inducible nitric oxide synthase expression via heme oxygenase-1 induction in RAW264.7 macrophages activated with lipopolysaccharide." Journal of Clinical Biochemistry and Nutrition 50, no. 1 (2011): 53–58. http://dx.doi.org/10.3164/jcbn.11-30.

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Journal articles on the topic '1-penten-3-one'

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