Log in

Relevant bibliographies by topics / Purine derivatives / Journal articles

To see the other types of publications on this topic, follow the link: Purine derivatives.

Journal articles on the topic 'Purine derivatives'

Author: Grafiati

Published: 4 June 2021

Last updated: 26 July 2025

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Purine derivatives.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Verbic, J., X. B. Chen, N. A. MacLeod, and E. R. Ørskov. "Excretion of purine derivatives by ruminants. Effect of microbial nucleic acid infusion on purine derivative excretion by steers." Journal of Agricultural Science 114, no. 3 (1990): 243–48. http://dx.doi.org/10.1017/s0021859600072610.

Full text

Abstract:

SUMMARYTwo steers totally nourished by intragastric infusion of volatile fatty acids and casein were given an abomasal infusion of a microbial protein preparation (Pruteen) at eight rates with a purine input ranging from 0 to 170 mmol/day over 11 successive 5-day periods. The urinary excretion of purine derivatives relative to the purine input was measured. Negligible amounts of xanthine plus hypoxanthine were present in the urine. The relative contributions of allantoin and uric acid to the total excretion were not affected by the rate of purine infusion. Total purine derivative excretion (ur

APA, Harvard, Vancouver, ISO, and other styles

2

Giráldez, F. J., R. Peláez, E. Zorita, and C. Valdés. "Purine derivatives excretion in sheep urine in relation to metabolizable energy and rumen degradable protein intake." Proceedings of the British Society of Animal Production (1972) 1993 (March 1993): 186. http://dx.doi.org/10.1017/s0308229600025083.

Full text

Abstract:

Recently has been shown that allantoin or total purine derivatives excretion in urine are strongly related to the amount of purines reaching the small intestine (Chen et al., 1990; Balcells et al., 1992) and as consequence purine derivative output is propouse to be used as an index of microbial protein flow to small intestine.Because energy and rumen degradable protein supplies are the main factors affecting rumen microbial growth, the effect of changes in rumen degradable protein supplies at different levels of ME intake on urinary excretion of purine derivatives was studied in this work.

APA, Harvard, Vancouver, ISO, and other styles

3

Chen, X. B., F. D. DeB Hovell, E. R. Ørskov, and D. S. Brown. "Excretion of purine derivatives by ruminants: effect of exogenous nucleic acid supply on purine derivative excretion by sheep." British Journal of Nutrition 63, no. 1 (1990): 131–42. http://dx.doi.org/10.1079/bjn19900098.

Full text

Abstract:

The present study examined the relationship between the supply of exogenous nucleic acid (NA) purines and their recovery as the derivatives hypoxanthine, xanthine, uric acid and allantoin in urine. Six lambs, totally nourished by intragastric infusions of volatile fatty acids (VFA) and casein (i.e. no rumen fermentation), were given by abomasal infusion a microbial NA concentrate at six levels (from zero to 24·5 mmol purines/d). The true digestibility between the abomasum and terminal ileum of the NA purines was measured in a separate experiment using three lambs. The relative proportion of ur

APA, Harvard, Vancouver, ISO, and other styles

4

Surra, J., J. A. Guada, J. Balcells, and C. Castrillo. "Salivary losses of purine derivatives in sheep." Proceedings of the British Society of Animal Production (1972) 1993 (March 1993): 176. http://dx.doi.org/10.1017/s0308229600024983.

Full text

Abstract:

Developed models to estimate rumen microbial yield from the urinary excretion of purine derivatives fail to account for a complete absorbed purines (Chen et al., 1990a, Balcells et al., 1991). Ruminal degradation of purine derivatives recycled via saliva has been suggested as a possible explanation after detecting the presence of allantoin and uric acid in the sheep saliva (Chen et al. 1990b). However, it is not known to what extent these losses may be affected by dietary induced variations in saliva flow (Kay, 1966).This paper reports preliminary results of an experiment designed to study the

APA, Harvard, Vancouver, ISO, and other styles

5

Šála, Michal, Hubert Hřebabecký, Milena Masojídková, and Antonín Holý. "Synthesis of Novel Racemic Conformationally Locked Carbocyclic Nucleosides Derived from 7-Substituted Bicyclo[2.2.1]hept-5-ene-2,2-dimethanols." Collection of Czechoslovak Chemical Communications 71, no. 5 (2006): 635–49. http://dx.doi.org/10.1135/cccc20060635.

Full text

Abstract:

(1R*,4R*,7S*)-7-Aminobicyclo[2.2.1]hept-5-ene-2,2-dimethanol (15) was prepared in four easy steps from bicyclo[2.2.1]hept-5-ene-2,2-dimethanol (10). Reaction of amine 15 with ethyl N-((E)-3-ethoxymethacryloyl)carbamate afforded thymine derivatives 17a. The amine 15 was used to construct 6-chloro-9H-purine derivative 19a, 2-amino-6-chloro-9H-purine derivative 22a. Ammonolysis of 19a led to the adenine derivative 20a. Treatment of 22a with trifluoroacetic acid afforded guanine nucleoside 23a. (1R*,4R*,7S*)-7-[6-(Cyclopropylamino)-9H-purin-9-yl]bicyclo[2.2.1]hept-5-ene-2,2-dimethanol (21a) and (1

APA, Harvard, Vancouver, ISO, and other styles

6

Balcells, J., J. A. Guada, C. Castrillo, and J. Gasa. "Urinary excretion of allantoin and allantoin precursors by sheep after different rates of purine infusion into the duodenum." Journal of Agricultural Science 116, no. 2 (1991): 309–17. http://dx.doi.org/10.1017/s002185960007773x.

Full text

Abstract:

SUMMARYTwo experiments were carried out to determine endogenous losses and the response of urinary purine derivatives to increased duodenal inputs of purine bases. Four ewes each fitted with a re-entrant cannula at the proximal duodenum, and conventionally fed, were subjected to full replacement of duodenal digesta followed by the administration of a solution either free of purines (Expt 1) or enriched with increasing amounts of purines, to supply 0·48–21·27 mmol/animal per day (Expt 2). Basal daily urinary excretions of allantoin, uric acid, hypoxanthine and xanthine were 11·5 ± 0·94, 9·9 ± 0

APA, Harvard, Vancouver, ISO, and other styles

7

Muzychka, Oksana, Olexandr Kobzar, Oleg Shablykin, Volodymyr Brovarets, and Andriy Vovk. "5-Substituted N-(9H-purin-6-yl)-1,2-oxazole-3-carboxamides as xanthine oxidase inhibitors." Ukr. Bioorg. Acta 2020, Vol. 15, N1 15, no. 1 (2020): 20–25. http://dx.doi.org/10.15407/bioorganica2020.01.020.

Full text

Abstract:

Synthetic 6-substituted purine derivatives are known to exhibit diverse bioactivity. In this paper, a series of N-(9H-purin-6-yl)-1,2-oxazole-3-carboxamide derivatives were synthesized and evaluated in vitro against xanthine oxidase, an enzyme of purine catabolism. The introduction of aryl substituent at position 5 of the oxazole ring was found to increase the inhibition efficiency. Some of the inhibitors containing 5-substituted isoxazole and purine moieties were characterized by IC50 values in the nanomolar range. According to the kinetic data, the most active N-(9H-purin-6-yl)-5-(5,6,7,8-te

APA, Harvard, Vancouver, ISO, and other styles

8

Matsumura, Nobuko, and Koji Aoyama. "Glutathione-Mediated Neuroprotective Effect of Purine Derivatives." International Journal of Molecular Sciences 24, no. 17 (2023): 13067. http://dx.doi.org/10.3390/ijms241713067.

Full text

Abstract:

Numerous basic studies have reported on the neuroprotective properties of several purine derivatives such as caffeine and uric acid (UA). Epidemiological studies have also shown the inverse association of appropriate caffeine intake or serum urate levels with neurodegenerative diseases such as Alzheimer disease (AD) and Parkinson’s disease (PD). The well-established neuroprotective mechanisms of caffeine and UA involve adenosine A2A receptor antagonism and antioxidant activity, respectively. Our recent study found that another purine derivative, paraxanthine, has neuroprotective effects simila

APA, Harvard, Vancouver, ISO, and other styles

9

Krečmerová, Marcela, Milena Masojídková, and Antonín Holý. "Synthesis of N9- and N7-[2-Hydroxy-3-(phosphonomethoxy)propyl] Derivatives of N6-Substituted Adenines, 2,6-Diaminopurines and Related Compounds." Collection of Czechoslovak Chemical Communications 69, no. 10 (2004): 1889–913. http://dx.doi.org/10.1135/cccc20041889.

Full text

Abstract:

Base-catalyzed reactions of diethyl [(oxiranylmethoxy)methyl]phosphonate (2) with purine bases (adenine, 2,6-diaminopurine, 6-chloropurine and 2-amino-6-chloropurine) gave corresponding 9- or 7-[2-hydroxy-3-(phosphonomethoxy)propyl] purines. The adenine and 2,6-diaminopurine derivatives cyclize to cyclic phosphonates 4 and 6. The 9-[2-hydroxy-3-(phosphonomethoxy)propyl] derivatives of N6-substituted adenine and 2,6-diaminopurine (15-27) were prepared by the treatment of diethyl {[3-(6-chloropurin-9-yl)-2-hydroxypropoxy]methyl}phosphonate (11) or diethyl {[3-(2-amino-6-chloropurin-9-yl)-2-hydro

APA, Harvard, Vancouver, ISO, and other styles

10

Safranow, Krzysztof, and Zygmunt Machoy. "Methylated Purines in Urinary Stones." Clinical Chemistry 51, no. 8 (2005): 1493–98. http://dx.doi.org/10.1373/clinchem.2005.048033.

Full text

Abstract:

Abstract Background: The aim of the study was to measure the content of methylated purines that appear as admixtures in uric acid stones. Methods: We analyzed urinary calculi from 48 residents of Western Pomerania who underwent surgery at the urology ward in Szczecin. Stone samples were dissolved in 0.1 mol/L NaOH. Extracts were diluted in 50 mmol/L KH2PO4 and analyzed by reversed-phase HPLC with ultraviolet detection and use of a gradient of methanol concentration and pH. Results: Uric acid was the main component of 9 stones. All 9 showed admixtures of 9 other purine derivatives: endogenous p

APA, Harvard, Vancouver, ISO, and other styles

11

Šilhár, Peter, Radek Pohl, Ivan Votruba, and Michal Hocek. "Synthesis of 2-Substituted 6-(Hydroxymethyl)purine Bases and Nucleosides." Collection of Czechoslovak Chemical Communications 70, no. 10 (2005): 1669–95. http://dx.doi.org/10.1135/cccc20051669.

Full text

Abstract:

A facile and efficient methodology of the synthesis of 6-(hydroxymethyl)purine derivatives (bases and nucleosides) was developed based on Pd-catalyzed cross-coupling reactions of 6-halopurines or N-protected 2-amino-6-halopurines with (benzoyloxymethyl)zinc iodide followed by deprotection. Regioselective hydroxymethylations of 2,6-dihalopurines were also studied and used for the synthesis of 2-chloro-6-(hydroxymethyl)- or 2,6-bis(hydroxymethyl)purines. The 6-(hydroxymethyl)purine ribonucleoside 5f exerted high cytostatic effect and moderate inhibition of adenosine deaminase, while all the othe

APA, Harvard, Vancouver, ISO, and other styles

12

Fedotov, Victor V., Evgeny N. Ulomsky, Konstantin V. Savateev, et al. "A PASE Approach to the Synthesis of Benzimidazopurines as Polycondensed Purine Derivatives." Synthesis 52, no. 23 (2020): 3622–31. http://dx.doi.org/10.1055/s-0040-1707228.

Full text

Abstract:

A highly efficient PASE approach to a new class of polycyclic purine derivatives has been proposed. The strategy includes a consecutive reduction, auto-aromatization, and heterocyclization of the initial nitrobenzimidazopyrimidines obtained by a three-component condensation. It was shown that reduction of nitrobenzimidazopyrimidines by metals in acidic media was more efficient than heterogeneous hydrogenation. Novel derivatives of benz[4,5]imidazo[1,2-a]purines were obtained in good yields and the proposed structure was confirmed by X-ray crystal structure analysis. The obtained convergent b

APA, Harvard, Vancouver, ISO, and other styles

13

Hristov, A. N., T. A. McAllister, D. R. Ouellet, and G. A. Broderick. "Comparison of purines and nitrogen-15 as microbial flow markers in beef heifers fed barley- or corn-based diets." Canadian Journal of Animal Science 85, no. 2 (2005): 211–22. http://dx.doi.org/10.4141/a04-054.

Full text

Abstract:

The objective of this study was to estimate the contribution of microbial purine bases to duodenal purines and to purine derivatives [allantoin and uric acid (PD)] excreted in the urine. Additionally, microbial protein (MCP) flow estimated using duodenal flow of purine bases was compared to estimates using 15N as a microbial marker. Four beef heifers were fed two diets, barley silage/barley grain/soybean meal (diet B) or corn silage/corn grain/corn gluten meal (diet C), in a cross-over design study. (15NH4)2SO4 was infused in the rumen for 8 d to label ruminal microorganisms and their purine b

APA, Harvard, Vancouver, ISO, and other styles

14

Balcells, J., J. A. Guada, C. Castrillo, and J. I. Bonafonte. "Basal urinary excretion of purine derivatives in sheep." Proceedings of the British Society of Animal Production (1972) 1990 (March 1990): 109. http://dx.doi.org/10.1017/s0308229600018900.

Full text

Abstract:

In ruminants duodenal purines,mainly derived from microbial nucleic acids, are catabolised and excreted in the urine as xanthine, hypoxanthine, uric acid and allantoin. The use of purine derivatives as an index of net microbial syntesis in the rumen requires a better understanding of the contribution of endogenus losses to total urinary excretion.Similar levels of basal excretion of purine derivatives has been determined in ruminants maintained by intragastric nutrition (Giesecke et al. 1984, Fujihara et al. 1987) and preruminants fed on liquid diets (Linberg, 1989). However, lower excretion o

APA, Harvard, Vancouver, ISO, and other styles

15

Chen, X. B., E. R. Ørskov, and F. D. DeB Hovell. "Excretion of purine derivatives by ruminants: endogenous excretion, differences between cattle and sheep." British Journal of Nutrition 63, no. 1 (1990): 121–29. http://dx.doi.org/10.1079/bjn19900097.

Full text

Abstract:

The endogenous urinary excretion of the purine derivatives allantoin, uric acid and xanthine plus hypoxanthine were measured in twenty-nine lambs, ten cattle (six steers, one cow and three preruminant calves) and four pigs. The sheep and mature cattle were nourished by intragastric infusion and the calves were given a milk-substitute. The pigs were fed on a purine-free diet. The excretion of total purine derivatives was substantially greater by the cattle, being 514 (se 20.6) μmol/kg live weight (W)0·75 per d compared with 168 (se 5·0) μmol/kg W0·75 per d by the sheep and 166 (se 2·6) μmol/kg

APA, Harvard, Vancouver, ISO, and other styles

16

Okamura, Hidenori, Giang Hoang Trinh, Zhuoxin Dong, Wenjue Fan, and Fumi Nagatsugi. "Synthesis of 6-Alkynylated Purine-Containing DNA via On-Column Sonogashira Coupling and Investigation of Their Base-Pairing Properties." Molecules 28, no. 4 (2023): 1766. http://dx.doi.org/10.3390/molecules28041766.

Full text

Abstract:

Synthetic unnatural base pairs have been proven to be attractive tools for the development of DNA-based biotechnology. Our group has very recently reported on alkynylated purine–pyridazine pairs, which exhibit selective and stable base-pairing via hydrogen bond formation between pseudo-nucleobases in the major groove of duplex DNA. In this study, we attempted to develop an on-column synthesis methodology of oligodeoxynucleotides (ODNs) containing alkynylated purine derivatives to systematically explore the relationship between the structure and the corresponding base-pairing ability. Through S

APA, Harvard, Vancouver, ISO, and other styles

17

Bertrand, Jeanluc, Hana Dostálová, Vladimír Kryštof, et al. "Design, Synthesis, In Silico Studies and Inhibitory Activity towards Bcr-Abl, BTK and FLT3-ITD of New 2,6,9-Trisubstituted Purine Derivatives as Potential Agents for the Treatment of Leukaemia." Pharmaceutics 14, no. 6 (2022): 1294. http://dx.doi.org/10.3390/pharmaceutics14061294.

Full text

Abstract:

We report 31 new compounds designed, synthesized and evaluated on Bcr-Abl, BTK and FLT3-ITD as part of our program to develop 2,6,9-trisubstituted purine derivatives as inhibitors of oncogenic kinases. The design was inspired by the chemical structures of well-known kinase inhibitors and our previously developed purine derivatives. The synthesis of these purines was simple and used a microwave reactor for the final step. Kinase assays showed three inhibitors with high selectivity for each protein that were identified: 4f (IC50 = 70 nM for Bcr-Abl), 5j (IC50 = 0.41 μM for BTK) and 5b (IC50 = 0.

APA, Harvard, Vancouver, ISO, and other styles

18

N., Fernández-Sáez, Campos J.M., E. Camacho M., and Dora Carrión M. "NMR studies of new heterocycles tethered to purine moieties with anticancer activity." Magnetic Resonance in Chemsitry 57 (March 18, 2019): 331–34. https://doi.org/10.1002/mrc.4871.

Full text

Abstract:

This article details the unambiguous structural elucidation of several families of compounds with heterocyclic rings linked to purine residues by one- or two-methylene unit spacers, which have been evaluated as antitumour agents and shown to possess interesting antiproliferative properties, as well as the elucidation of the structures of their predecessor intermediates. The synthesised derivatives combine a six-membered heterocycle condensed with benzene (benzo-1,4-oxazines and tetrahydroquinolines) or a pyridine heterocycle condensed with a 1,4-oxazine (pyridoxazines) attached, in turn, to va

APA, Harvard, Vancouver, ISO, and other styles

19

Li, Luyong, Jie Hu, Yuqing Fu, et al. "Direct Regioselective C-H Cyanation of Purines." Molecules 28, no. 3 (2023): 914. http://dx.doi.org/10.3390/molecules28030914.

Full text

Abstract:

A direct regioselective C-H cyanation of purines was developed through a sequential triflic anhydride activation, nucleophilic cyanation with TMSCN, followed by a process of base-mediated elimination of triflous acid (CF3SO2H). In most cases, the direct C-H cyanation occurred on the electron-rich imidazole motif of purines, affording 8-cyanated purine derivatives in moderate to excellent yields. Various functional groups, including allyl, alkynyl, ketone, ester, nitro et al. were tolerated and acted as a C8 directing group. The electron-donating 6-diethylamino, as C2-directing group substituen

APA, Harvard, Vancouver, ISO, and other styles

20

Kim Thanh, Vo Thi, and E. R. Ørskov. "Causes of differences in urinary excretion of purine derivatives in buffaloes and cattle." Animal Science 82, no. 3 (2006): 355–58. http://dx.doi.org/10.1079/asc200637.

Full text

Abstract:

AbstractIn experiment 1, three male calves of Vietnamese cattle and three maleVietnamese swamp buffalo calves were weaned after receiving colostrum and reared by bottle feeding of milk. During the 1st month the animal did not have access to solid food. Urine was collected to determine differences in endogenous excretion of purine between the two types of animal. After that they were given access to equal amount of solid food for 2 months to stimulate rumen development, urine was again collected to determine the differences in purine excretion. In experiment 2, the same animals were given milk

APA, Harvard, Vancouver, ISO, and other styles

21

Funaba, M., K. Kagiyama, T. Iriki, and M. Abe. "Post-weaning excretion of purine derivatives by young calves." Canadian Journal of Animal Science 75, no. 1 (1995): 153–56. http://dx.doi.org/10.4141/cjas95-020.

Full text

Abstract:

Intestinal flow of MN was estimated from urinary purine derivative output in calves. Although estimated MN output (g d−1) increased with age, it was restricted to the period between weeks 6 and 11 after weaning when expressed as g d−1 kg−0.75. The estimated MN output to digestible organic matter ratio decreased with time after weaning, although the cubic contrast indicated to be highest on wks 1 and 11. Key words: Microbial nitrogen supply, purine derivatives, growing calves

APA, Harvard, Vancouver, ISO, and other styles

22

Šilhár, Peter, Radek Pohl, Ivan Votruba, Blanka Klepetářová, and Michal Hocek. "Synthesis of 6-Amino-, 6-Methyl- and 6-Aryl-2-(hydroxymethyl)purine Bases and Nucleosides." Collection of Czechoslovak Chemical Communications 71, no. 6 (2006): 788–803. http://dx.doi.org/10.1135/cccc20060788.

Full text

Abstract:

An efficient methodology of the synthesis of 6-substituted 2-(hydroxymethyl)purine derivatives (bases and nucleosides) was developed. Regioselective Pd-catalyzed cross-coupling reactions of 6-chloro-2-iodopurines with [(benzoyloxy)methyl]zinc iodide gave 2-[(benzoyloxy)-methyl]-6-chloropurines that were converted to 2-(hydroxymethyl)adenines by reactions with ammonia and to 6-methyl- or 6-aryl-2-(hydroxymethyl)purines by cross-coupling reactions with trimethylaluminium or arylboronic acids followed by deprotection. The title 6-substituted 2-(hydroxymethyl)purine bases and nucleosides did not e

APA, Harvard, Vancouver, ISO, and other styles

23

Sinha, Indranil, Lukas Heller, Jutta Kösters, and Jens Müller. "7-Methyl-6-furylpurine forms dinuclear metal complexes with N3,N9 coordination." Zeitschrift für Naturforschung B 73, no. 11 (2018): 813–17. http://dx.doi.org/10.1515/znb-2018-0110.

Full text

Abstract:

AbstractTwo dinuclear metal complexes bearing the purine derivative 7-methyl-6-furylpurine (1b) as a ligand are reported. In [Ag2(1b)2(DMSO)2](ClO4)2·DMSO and [Cu2(1b)2(NO3)2], two bridging purine derivatives coordinate the two metal ions via their N3 and N9 positions. In the silver(I) complex, the coordination environment of each metal ion is completed by a DMSO ligand, whereas an additional nitrato ligand coordinates to each copper(I) ion. The intramolecular Ag···Ag distance of 3.1069(5) Å is in agreement with the presence of a weak argentophilic interaction, whereas the Cu···Cu distance of

APA, Harvard, Vancouver, ISO, and other styles

24

Sousa, L. B., M. L. A. Pereira, H. G. O. Silva, et al. "Creatinine and purine derivatives excretion and microbial synthesis in lambs fed rain tree pod meal." Arquivo Brasileiro de Medicina Veterinária e Zootecnia 74, no. 1 (2022): 160–68. http://dx.doi.org/10.1590/1678-4162-12376.

Full text

Abstract:

ABSTRACT Evaluated the levels of rain tree (Samanea saman) pod meal (RTPM) (0, 10, 15, 20 and 25%) replacing maize in the dry matter of the diet on intake of DM, CP and ME, creatinine and total purine derivatives excretion in urine and microbial protein synthesis in lambs. Twenty-five uncastrated Bergamasca lambs were used, with an initial body weight of 24±5kg and an average age of 120 days. The experimental design was completely randomized, with five treatments and five replications. The trial lasted 84 days and the 24h and spot urine collections were performed in the last day of the experim

APA, Harvard, Vancouver, ISO, and other styles

25

Klečka, Martin, Tomáš Tobrman, and Dalimil Dvořák. "Cu(I)-Catalyzed Coupling of (9-Benzylpurin-6-yl)magnesium Chloride with Allyl Halides: An Approach to 6-Allylpurine Derivatives." Collection of Czechoslovak Chemical Communications 71, no. 8 (2006): 1221–28. http://dx.doi.org/10.1135/cccc20061221.

Full text

Abstract:

6-Allylpurine derivatives are formed by Cu(I)-catalyzed coupling of (9-benzyl-9H-purin-6-yl)- magnesium chloride with allyl halides. The reaction is accompanied by allylic rearrangement in some cases. Under acid conditions the double bond of the allyl group rearranges to the conjugation with purine ring.

APA, Harvard, Vancouver, ISO, and other styles

26

Szyk, Piotr, Beata Czarczynska-Goslinska, Dariusz T. Mlynarczyk, et al. "Polymer-Based Nanoparticles as Drug Delivery Systems for Purines of Established Importance in Medicine." Nanomaterials 13, no. 19 (2023): 2647. http://dx.doi.org/10.3390/nano13192647.

Full text

Abstract:

Many purine derivatives are active pharmaceutical ingredients of significant importance in the therapy of autoimmune diseases, cancers, and viral infections. In many cases, their medical use is limited due to unfavorable physicochemical and pharmacokinetic properties. These problems can be overcome by the preparation of the prodrugs of purines or by combining these compounds with nanoparticles. Herein, we aim to review the scientific progress and perspectives for polymer-based nanoparticles as drug delivery systems for purines. Polymeric nanoparticles turned out to have the potential to augmen

APA, Harvard, Vancouver, ISO, and other styles

27

Faichney, G. J., R. J. Welch, and G. H. Brown. "Prediction of the excretion of allantoin and total purine derivatives by sheep from the ‘creatinine coefficient’." Journal of Agricultural Science 125, no. 3 (1995): 425–28. http://dx.doi.org/10.1017/s0021859600084938.

Full text

Abstract:

SUMMARYThe urinary excretions of creatinine, allantoin and total purine derivatives by Merino ewes were compared with predictions based on the assumptions that creatinine excretion scaled to liveweight (the creatinine coefficient) was constant and was not affected by diet. The creatinine coefficient varied between individuals and was found to be affected by diet (P<0·01). As a result, there were systematic deviations (p<0·01) in the predictions of allantoin and total purine derivative excretion. If predictions of purine derivative excretion are to be made for individual animals in the ab

APA, Harvard, Vancouver, ISO, and other styles

28

CHEN, X. B., T. FUJIHARA, K. NAKAMURA, P. O. MAWUENYEGAH, M. F. FRANKLIN, and D. J. KYLE. "Response of urinary and plasma purine derivatives to various rates and infusion patterns of purines in sheep nourished by intragastric infusion." Journal of Agricultural Science 129, no. 3 (1997): 343–52. http://dx.doi.org/10.1017/s0021859697004589.

Full text

Abstract:

The effects of exogenous purine supply on plasma concentration and urinary excretion of purine derivatives (PD), which include allantoin, uric acid, xanthine and hypoxanthine, were studied. Five sheep, totally nourished by intragastric infusion of volatile fatty acids and casein, were given an abomasal infusion of a mixture of adenosine and guanosine at three levels (5·0, 10·0 and 20·0 mmol/day) each in four infusion patterns (as one, two, or four 3-h infusion periods per day or infused continuously, P1 to P4 respectively). Urine was collected hourly over 24 h, and plasma samples were collecte

APA, Harvard, Vancouver, ISO, and other styles

29

Areias, Filipe, Carla Correia, Ashly Rocha, et al. "2-Aryladenine Derivatives as a Potent Scaffold for Adenosine Receptor Antagonists: The 6-Morpholino Derivatives." Molecules 29, no. 11 (2024): 2543. http://dx.doi.org/10.3390/molecules29112543.

Full text

Abstract:

A set of 2-aryl-9-H or methyl-6-morpholinopurine derivatives were synthesized and assayed through radioligand binding tests at human A1, A2A, A2B, and A3 adenosine receptor subtypes. Eleven purines showed potent antagonism at A1, A3, dual A1/A2A, A1/A2B, or A1/A3 adenosine receptors. Additionally, three compounds showed high affinity without selectivity for any specific adenosine receptor. The structure-activity relationships were made for this group of new compounds. The 9-methylpurine derivatives were generally less potent but more selective, and the 9H-purine derivatives were more potent bu

APA, Harvard, Vancouver, ISO, and other styles

30

Holý, Antonín, Ivan Rosenberg, and Hana Dvořáková. "Synthesis of N-(2-phosphonylmethoxyethyl) derivatives of heterocyclic bases." Collection of Czechoslovak Chemical Communications 54, no. 8 (1989): 2190–210. http://dx.doi.org/10.1135/cccc19892190.

Full text

Abstract:

The preparation of N-(2-phosphonylmethoxyethyl) derivatives of purine and pyrimidine bases, IV, as analogs of the antiviral 9-(2-phosphonylmethoxyethyl)adenine (PMEA, I), is described. The synthesis consists in alkylation of alkali metal salts of heterocyclic bases or their N- or O-substituted derivatives with diethyl 2-p-toluenesulfonyloxyethoxymethylphosphonate (IIa), 2-chloroethoxymethylphosphonate (IIb) or 2-bromoethoxymethylphosphonate (IIc). The obtained N-(2-diethoxyphosphonylmethoxyethyl) derivatives of heterocyclic bases (III) were treated with bromotrimethylsilane to give phosphonic

APA, Harvard, Vancouver, ISO, and other styles

31

Fujihara, T., E. R. Ørskov, P. J. Reeds, and D. J. Kyle. "The effect of protein infusion on urinary excretion of purine derivatives in ruminants nourished by intragastric nutrition." Journal of Agricultural Science 109, no. 1 (1987): 7–12. http://dx.doi.org/10.1017/s0021859600080916.

Full text

Abstract:

SummaryTwo experiments were carried out to determine endogenous excretion of purine derivatives in steers and lambs, and to investigate the relationship between microbial nucleic acid input and urinary excretion of purine nitrogen.The endogenous excretion of allantoin after conversion of hypoxanthine, xanthine and uric acid to allantoin, was calculated to be 72 and 26 mg/kg W0·75 per day in steers and lambs, respectively, when the dietary protein contained no nucleic acid nitrogen.The excretion of purine derivatives increased linearly with increasing microbial nucleic acid input in lambs. The

APA, Harvard, Vancouver, ISO, and other styles

32

Chen, X., K. Bastow, B. Goz, L. Kucera, S. L. Morris-Natschke, and K. S. Ishaq. "Boronic Acid Derivatives Targeting HIV-1." Antiviral Chemistry and Chemotherapy 7, no. 2 (1996): 108–14. http://dx.doi.org/10.1177/095632029600700208.

Full text

Abstract:

A series of novel boronic acid derivatives containing either a pyrimidine or purine base was synthesized. The preparation involved the condensation of 4-bromobutyl boronic acid with the appropriate base. These acyclic nucleosides were designed as potential antiviral agents especially targeting the human immunodeficiency virus. Two analogues, 6-chloro-9-(4-dihydroxyborylbutyl)purine and 2,6-dichloro-9-(4-dihydroxyborylbutyl)purine, exhibited EC50 values of 7.7 μM and 0.99 μM, respectively, in an HIV-1 syncytial plaque reduction assay.

APA, Harvard, Vancouver, ISO, and other styles

33

Janeba, Zlatko, Antonín Holý, and Milena Masojídková. "Synthesis of Acyclic Nucleoside and Nucleotide Analogs Derived from 6-Amino-7H-purine-8(9H)-thione and 8-(Methylsulfanyl)adenine." Collection of Czechoslovak Chemical Communications 65, no. 11 (2000): 1698–712. http://dx.doi.org/10.1135/cccc20001698.

Full text

Abstract:

Reaction of 8-bromoadenine derivatives 1 with thiourea in ethanol or butanol was used for the synthesis of the corresponding N9-substituted 6-amino-7H-purine-8(9H)-thiones 2. 8-(Methylsulfanyl)adenine derivatives 3 were prepared by reaction of thiones 2 with iodomethane in 1 M sodium methoxide or in aqueous 1.5 M potassium hydroxide. Alkylation of 6-amino-7H-purine-8(9H)-thione (2a) proceeds preferentially on the sulfur atom. Under similar conditions, alkylation of 8-(methylsulfanyl)adenine (3a) with diverse alkylation agents afforded N9-substituted adenine derivatives 3 and 6, and N3-substitu

APA, Harvard, Vancouver, ISO, and other styles

34

Liu, Feng-Wu, Wenke Xu, Hui Yang та ін. "Facile Approaches to 2-Deoxy-d-glucose and 2-Deoxy-α-d-glucopyranonucleosides from d-Glucal". Synthesis 49, № 16 (2017): 3686–91. http://dx.doi.org/10.1055/s-0036-1589501.

Full text

Abstract:

Convenient and stereoselective methods for the preparation of 2-deoxy-d-glucose and purine 2-deoxy-α-d-glucopyranonucleosides were developed. Halogen-mediated O-glycosidation of d-glucal by bromine in MeOH followed by reductive removal of the halo group and hydrolysis of methoxy group by zinc in saturated aqueous sodium dihydrogen phosphate gave 2-deoxy-d-glucose. Treatment of 3,4,6-tri-O-acetyl-d-glucal with IBr and 2,6-dichloropurine based on haloetherification and subsequent reductive removal of iodine and deprotection allowed the isolation of purin-9-yl 2-deoxy-α-d-glucopyranonucleoside. P

APA, Harvard, Vancouver, ISO, and other styles

35

Zhang, Shi-Yi, Guo-Neng Fu, Li-Hua Du, et al. "Continuous flow biocatalysis: synthesis of purine nucleoside esters catalyzed by lipase TL IM from Thermomyces lanuginosus." RSC Advances 14, no. 16 (2024): 10953–61. http://dx.doi.org/10.1039/d4ra00097h.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Hřebabecký, Hubert, Milena Masojídková, Martin Dračínský, and Antonín Holý. "Synthesis of Novel Conformationally Locked Carbocyclic Nucleosides Derived from 3-(Hydroxymethyl)bicyclo[2.2.1]heptane-2,5-diol." Collection of Czechoslovak Chemical Communications 71, no. 6 (2006): 871–88. http://dx.doi.org/10.1135/cccc20060871.

Full text

Abstract:

(1R*,2R*,3R*,4R*,5R*,6S*)-3-Amino-5-(benzyloxy)-6-(hydroxymethyl)bicyclo[2.2.1]heptan-2-ol (18) was prepared in seven easy steps from benzyl (1R*,2S*,3S*,4S*)-3-(benzyloxy)bicyclo[2.2.1]hept-5-ene-2-carboxylate (10). Reaction of amine18with ethylN-((2E)-3-ethoxymethacryloyl)carbamate afforded 1-[(1R*,2R*,3R*,4R*,5S*,6R*)-6-(benzyloxy)-3-hydroxy-5- (hydroxymethyl)bicyclo[2.2.1]heptan-2-yl]-5-methylpyrimidine-2,4(1H,3H)-dione (21) and after deprotection by transfer hydrogenation, free thymine analogue22. The thymine derivative21was converted to 2,3'-anhydronucleoside26. Treatment of the benzyl d

APA, Harvard, Vancouver, ISO, and other styles

37

Astuti, D. A., and E. Wina. "Effect of tempe waste on excreation of purine derivatives and microbialâ€“N supply in lactating Etawah crossbred goats." Jurnal Ilmu Ternak dan Veteriner 7, no. 3 (2014): 162–66. https://doi.org/10.14334/jitv.v7i3.290.

Full text

Abstract:

The aim of this study was to evaluate excretion of purine derivatives and microbialâ€“N supply in lactating Etawah crossbred goats fed with fermented soybean waste. Sixteen first lactating goats were randomly allotted into four dietary treatment groups that received 50% king grass plus R1: 50% concentrate, R2: 25% concentrate and 25% fresh tempe waste, R3: 25% concentrate and 25% fermented tempe waste, and R4: 25% concentrate and 25% gelatinizing of liquid tempe waste. Fermented tempe waste was made by fermentation of tempe waste (seed content of soybean) using Aspergillus niger, while for the

APA, Harvard, Vancouver, ISO, and other styles

38

Herrera Gomez, F., F. D. Deb Hovell, and C. A. Sandoval Castro. "Urinary recovery of allantoin in normally fed steers." Proceedings of the British Society of Animal Science 1998 (1998): 80. http://dx.doi.org/10.1017/s1752756200597324.

Full text

Abstract:

Studies in the use of the purine derivatives technique in ruminants have been stimulated by the possible use of this technique as an estimator of the rumen microbial-N supplied to the host animal. The recovery factor influences the estimation of the total purines absorbed and therefore the microbial-N supply. The relationship between exogenous purine input and urinary excretion and recovery has been studied using cattle maintained with the intragastric infusion technique (Orskov et al., 1979). The urinary recovery of exogenous purines has been estimated to be 0.77-0.85 (Chen et al., 1990a, Ver

APA, Harvard, Vancouver, ISO, and other styles

39

Herrera Gomez, F., F. D. Deb Hovell, and C. A. Sandoval Castro. "Urinary recovery of allantoin in normally fed steers." Proceedings of the British Society of Animal Science 1998 (1998): 80. http://dx.doi.org/10.1017/s0308229600032931.

Full text

Abstract:

Studies in the use of the purine derivatives technique in ruminants have been stimulated by the possible use of this technique as an estimator of the rumen microbial-N supplied to the host animal. The recovery factor influences the estimation of the total purines absorbed and therefore the microbial-N supply. The relationship between exogenous purine input and urinary excretion and recovery has been studied using cattle maintained with the intragastric infusion technique (Orskov et al., 1979). The urinary recovery of exogenous purines has been estimated to be 0.77-0.85 (Chen et al., 1990a, Ver

APA, Harvard, Vancouver, ISO, and other styles

40

Gruzdev, D. A., V. V. Musiyak, G. L. Levit, V. P. Krasnov, and V. N. Charushin. "Purine derivatives with antituberculosis activity." Russian Chemical Reviews 87, no. 6 (2018): 604–18. http://dx.doi.org/10.1070/rcr4772.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Guada, J. A., J. Balcells, J. Gasa, and A. de Vega. "Response of urinary purine derivatives to urea supplementation of sodium hydroxide treated straw." Proceedings of the British Society of Animal Production (1972) 1990 (March 1990): 121. http://dx.doi.org/10.1017/s0308229600019012.

Full text

Abstract:

Since in ruminants urinary excretion of purine derivatives is related to duodenal absorption of purines (Fujihara et al.1987;Giesecke et al.1984), it may be a valuable index to identify nutritive constraints limiting rumen fermentation and microbial synthesis.In the present experiment, the response in the urinary excretion of purine derivatives to urea supplementation of a N deficient diet was studied to test the validity of the above assumption.Five Rasa Aragonesa ewes rumen cannulated and 38, 9±2, 52 Kg mean live weight, were offered “ad libitum” OHNa treated barley straw (50 g/Kg DM) ground

APA, Harvard, Vancouver, ISO, and other styles

42

Votruba, Ivan, Antonín Holý, Hana Dvořáková та ін. "Synthesis of 2-Deoxy-β-D-ribonucleosides and 2,3-Dideoxy-β-D-pentofuranosides on Immobilized Bacterial Cells". Collection of Czechoslovak Chemical Communications 59, № 10 (1994): 2303–30. http://dx.doi.org/10.1135/cccc19942303.

Full text

Abstract:

Alginate gel-entrapped cells of auxotrophic thymine-dependent strain of E. coli catalyze the transfer of 2-deoxy-D-ribofuranosyl moiety of 2'-deoxyuridine to purine and pyrimidine bases as well as their aza and deaza analogs. All experiments invariably gave β-anomers; in most cases, the reaction was regiospecific, affording N9-isomers in the purine and N1-isomers in the pyrimidine series. Also a 2,3-dideoxynucleoside can serve as donor of the glycosyl moiety. The acceptor activity of purine bases depends only little on substitution, the only condition being the presence of N7-nitrogen atom. On

APA, Harvard, Vancouver, ISO, and other styles

43

Qliveira, Luis, and Hanh Huynh. "Phototrophic Growth of Microalgae with Allantoic Acid or Hypoxanthine Serving as Nitrogen Source, Implications for Purine-N Utilization." Canadian Journal of Fisheries and Aquatic Sciences 47, no. 2 (1990): 351–56. http://dx.doi.org/10.1139/f90-036.

Full text

Abstract:

Eleven species of marine phytoplankters assigned to seven different taxonomic divisions were tested for their ability to grow on hypoxanthine and some of its derivatives (allantoin, allantoate, urea) to study the mechanism of purine-N utilization in microalgae. All species tested were able to utilize urea, but only six of these were capable of growth on hypoxanthine. Growth on allantoic acid was restricted to six species, while no growth occurred with allantoin. In some species growth occurred only after supplementation of the culture media with Ni2+ or it was enhanced by it. These results sug

APA, Harvard, Vancouver, ISO, and other styles

44

Kapadiya, Khushal, Kishor Kavadia, Jyoti Gohel, and Ranjan Khunt. "Regioselective synthesis of triazolo[3,4-e]purine derivatives and their anti-cancer activity against NCI-60 cell-lines." Folia Medica 63, no. 2 (2021): 213–20. http://dx.doi.org/10.3897/folmed.63.e52891.

Full text

Abstract:

Introduction: Due to the vast medicinal importance of purine nucleoside, a hybrid molecule of triazole with purine ring might&nbsp;explode a lead molecule in the pharma sector and based on the last decade&rsquo;s studies suggested that the nitrogen-rich molecules possess a wide range of medicinal importance. Aim: Due to the vast application of purine nucleoside itself in the field of cancer research, we synthesized triazolo[3,4-e]purines and screened them for their anti-cancer study against NCI-60 cell lines by the protocol used by NIH. Materials and methods: The targeted molecules, 4-

APA, Harvard, Vancouver, ISO, and other styles

45

Shibata, Hirofumi, Noriaki Ohnishi, Keiko Takeda, et al. "Germination of Bacillus cereus spores induced by purine ribosides and their analogs: effects of modification of base and sugar moieties of purine nucleosides on germination-inducing activity." Canadian Journal of Microbiology 32, no. 2 (1986): 186–89. http://dx.doi.org/10.1139/m86-038.

Full text

Abstract:

Purine riboside and some of its analogs were tested for their ability to induce germination of Bacillus cereus T spores. Hypoxanthine and adenine showed no germination-inducing activity either in the present or absence of D-ribose or its phosphorylated derivatives. Purine riboside and 18 analogs with modified purine base were all able to induce germination of the spores to various extents. In contrast to this, the requirement for the sugar moiety in the purine riboside appeared to be more stringent. Only those nucleosides that contained either D-ribose or deoxy-D-ribose, and certain species of

APA, Harvard, Vancouver, ISO, and other styles

46

Hřebabecký, Hubert, Milena Masojídková, and Antonín Holý. "Synthesis of Racemic 9-(6- and 2,6-Substituted 9H-Purin-9-yl)-5-oxatricyclo[4.2.1.03,7]nonane-3-methanols, Novel Conformationally Locked Carbocyclic Nucleosides." Collection of Czechoslovak Chemical Communications 70, no. 1 (2005): 103–23. http://dx.doi.org/10.1135/cccc20050103.

Full text

Abstract:

(1R*,3R*,6R*,7S*,9S*)- and (1R*,3R*,6R*,7S*,9R*)-9-Amino-5-oxatricyclo[4.2.1.03,7]nonane-3-methanols (16aand17a) were prepared from 2-(hydroxymethyl)bicyclo[2.2.1]hept-5-ene-2-methanol (10) in five easy steps. The amines16aand17awere used to construct 6-chloro-9H-purine20and21, 2-amino-6-chloro-9H-purine30and31, and 6-chloro-8-methyl-9H-purine analogues34and35. Ammonolysis of these compounds led to 6-amino-9H-purine22aand23a, 2,6-diamino-9H-purine32and33, and 6-amino-8-methyl-9H-purine derivatives of 5-oxatricyclo[4.2.1.03,7]nonane-3-methanol36and37. (1R*,3R*,6R*,7S*,9S*)- and (1R*,3R*,6R*,7S*

APA, Harvard, Vancouver, ISO, and other styles

47

Burcevs, Aleksejs, Māris Turks, and Irina Novosjolova. "Synthesis of Pyridinium Moiety Containing Triazolyl Purines." Molbank 2024, no. 3 (2024): M1855. http://dx.doi.org/10.3390/m1855.

Full text

Abstract:

Pyridinium salts of 2-piperidinyl-6-triazolylpurine derivatives were obtained by the introduction of pyridinium moieties into the propane-1,3-diol fragment at the N(9) position of purine to enhance the solubility of 2-amino-6-triazolylpurine derivatives in water. Target structures were obtained using the tosylation of hydroxyl groups of 2-(6-(4-(4-methoxyphenyl)-1H-1,2,3-triazol-1-yl)-2-(piperidin-1-yl)-9H-purin-9-yl)propane-1,3-diol, the subsequent introduction of pyridine, and ion exchange. The compounds were characterized using 1H- and 13C-NMR spectra, FTIR, UV–Vis, and HRMS data.

APA, Harvard, Vancouver, ISO, and other styles

48

Lin, Xiaoyu, and Morris J. Robins. "Nucleic Acid Related Compounds. 136. Synthesis of 2-Amino- and 2,6-Diaminopurine Derivatives via Inverse-Electron-Demand Diels-Alder Reactions." Collection of Czechoslovak Chemical Communications 71, no. 7 (2006): 1029–41. http://dx.doi.org/10.1135/cccc20061029.

Full text

Abstract:

Thermal inverse-electron-demand Diels-Alder reactions of 5-aminoimidazoles and 2,4,6-tris(ethoxycarbonyl)-1,3,5-triazine (2) with spontaneous retro-Diels-Alder loss of ethyl cyanoformate and elimination of ammonia give 2,6-bis(ethoxycarbonyl)purines. A report that selective alkaline hydrolysis followed by acid-catalyzed decarboxylation gave 6-(ethoxycarbonyl)purine products was not in harmony with known reactions in purine chemistry. Our reinvestigation has shown that the 6-(ethoxycarbonyl) group undergoes preferential base-promoted hydrolysis, as expected, but regioselectivity for attack of h

APA, Harvard, Vancouver, ISO, and other styles

49

Petrov, Viacheslav, Rebecca J. Dooley, Alexander A. Marchione, Elizabeth L. Diaz, Brittany S. Clem, and William Marshall. "Synthesis of purines and adenines containing the hexafluoroisopropyl group." Beilstein Journal of Organic Chemistry 16 (November 11, 2020): 2739–48. http://dx.doi.org/10.3762/bjoc.16.224.

Full text

Abstract:

Several new derivatives of adenine, purine, and theophylline containing the (CF3)2CH group connected to a nitrogen atom of the imidazole ring were prepared by the reaction of 2,2,4,4-tetrakis(trifluoromethyl)-1,3-dithietane (1) with the corresponding substrates, resulting in the selective alkylation of one of the nitrogen atoms of the imidazole ring. The reaction proceeds under mild conditions in a polar solvent, giving the alkylated products in 47–78% yield. While for purine and 4- and 5-azabenzimidazole, the reaction led to a mixture of two isomers, the reaction of adenine and the correspond

APA, Harvard, Vancouver, ISO, and other styles

50

Bibi, Nousheen, Zahida Parveen, Muhammad Sulaman Nawaz, and Mohammad Amjad Kamal. "In Silico Structure Modeling and Molecular Docking Analysis of Phosphoribosyl Pyrophosphate Amidotransferase (PPAT) with Antifolate Inhibitors." Current Cancer Drug Targets 19, no. 5 (2019): 408–16. http://dx.doi.org/10.2174/1568009619666181127115015.

Full text

Abstract:

Background: Cancer remains one of the most serious disease worldwide. Robust metabolism is the hallmark of cancer. PPAT (phosphoribosyl pyrophosphate amidotransferase) catalyzes the first committed step of de novo purine biosynthesis. Hence PPAT, the key regulatory spot in De novo purine nucleotide biosynthesis, is an attractive and credible drug target for leukemia and other cancer therapeutics. Objective: In the present study, detailed computational analysis has been performed for PPAT protein, the key enzyme in de novo purine biosynthesis which is inhibited by many folate derivatives, hence

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!