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1
Wilke, Claudia. "Communication and cooperation in wild chimpanzees (Pan troglodytes schweinfurthii)." Thesis, University of York, 2016. http://etheses.whiterose.ac.uk/16373/.
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Comparisons between animal and human communication are invaluable for understanding the evolution of language and, as our closest living relatives, chimpanzees can provide particularly important insights into this. Here I examined unimodal (UM) and multimodal (MM) communication in wild chimpanzees, in an integrated manner. I found that although MM signals were produced infrequently, and at lower rates compared to captivity, the vast majority of adult and sub-adult individuals did freely combine vocal, gestural and facial signals to produce MM signals. A total of 48 free MM signal combinations were observed, incorporating a wide range of different signal types from different modalities. Focusing on one specific vocalgestural MM signal, I found that MM combinations and UM gestural signals were more successful in eliciting responses compared to UM vocal signals. To investigate signal function more systematically I focused on one common grooming gesture, the big loud scratch (BLS), and tested several competing functional hypotheses. I found little evidence to support the hypotheses that this signal operates as an attention-getter, or as a referential signal. In contrast, my data suggested that in this community of chimpanzees, the BLS facilitates the negotiation of roles within a grooming bout. Groomers used BLSs to request grooming during grooming bouts and the BLS seemed to show willingness to groom, both to initiate a grooming bout, and potentially during a bout when groomees intend to start grooming their partner. Finally, to explore the theoretical link between the evolution of communication and cooperation I tested whether, on an individual level, there was a positive relationship between communicativeness and cooperativeness in chimpanzees. In contrast to theoretical predictions, I found a significantly negative relationship between these two domains, indicating that more communicative chimpanzees were less cooperative. I explore several potential explanations for this highly unexpected finding.
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Wakibara, James. "Frugivory and seed dispersal by chimpanzees(Pan troglodytes schweinfurthii)at Mahale, Tanzania." 京都大学 (Kyoto University), 2003. http://hdl.handle.net/2433/149127.
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Townsend, Simon W. "Intra-sexual competition and vocal counter-strategies in wild female chimpanzees (Pan troglodytes schweinfurthii)." Thesis, St Andrews, 2009. http://hdl.handle.net/10023/774.
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Gruber, Thibaud. "A cognitive approach to the study of culture in wild chimpanzees (Pan troglodytes schweinfurthii)." Thesis, University of St Andrews, 2011. http://hdl.handle.net/10023/3101.
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The question of animal culture has been of interest for decades. Chimpanzees (Pan troglodytes) have played a key role in the debate of whether or not it is appropriate to use the term ‘culture' to describe animal behaviour and they continue to be one of the prime species for the study of the origins of human culture. Data suggesting that chimpanzees can be considered a cultural species continue to accumulate, but this has only enhanced the debate between proponents and opponents of animal culture. Opponents do not deny that behavioural diversity exists between different populations of the same species, but they maintain that such phenomena have little to do with human cultures and may be the result of genetic and environmental influences. In their view, human cultures are centred on socially shared sets of ideas, not behavioural traditions. In this thesis, my goal is to tackle this problem and to investigate whether a cognitive dimension can be found in some behavioural patterns of chimpanzees that have been put forward as examples of animal culture. To this end, I examine the different factors that could account for the development of tool use in animals (genetics, ecology, social). My first empirical contribution is a study of the tool use behaviour of the chimpanzees' closest relative, the bonobos, which are known to be limited tool-users in the wild. I show that captive bonobos are as flexible tool-users as chimpanzees, suggesting that genetic factors are unlikely to account for differences in tool use behaviour in the Pan clade. Second, through the use of field experiments, I show that wild chimpanzees from different Ugandan communities respond to the same apparatus and task in strikingly different ways. I interpret this finding as an outcome of differences in cultural knowledge, mainly because the affordances of their immediate environment do not determine their tool use behaviour. Finally, through a broad ecological and tool use survey of different chimpanzee communities in Uganda, I show that current ecological differences are poor predictors of tool use. I conclude that, if ecology plays a role in the development of tool use, then its influence is that of a selective force. Finally, when reviewing the outcome of this research I will argue that there is a profound cognitive dimension to tool use in wild chimpanzees, suggesting that behaviourally based definitions of animal culture may miss a key feature of the phenomenon, at least in chimpanzees. Chimpanzees are not only a cultural species, they also have a cultural mind.
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Laporte, Marion N. C. "Pant-grunts in wild chimpanzees (Pan troglodytes schweinfurthii) : the vocal development of a social signal." Thesis, University of St Andrews, 2011. http://hdl.handle.net/10023/1973.
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While the gestural communication of apes is widely recognised as intentional and flexible, their vocal communication still remains considered as mostly genetically determined and emotionally bound. Trying to limit the direct projections of linguistic concepts, that are far from holding a unified view on what constitute human language, this thesis presents a detailed description of the pant-grunt vocalisation usage and development in the chimpanzees (Pan troglodytes schweinfurthii) of the Budongo forest, Uganda. Pant-grunts are one of the most social vocalisations of the chimpanzee vocal repertoire and are always given from a subordinate individual to a dominant. The question of how such a signal is used and develops is critical for our understanding of chimpanzee social and vocal complexity in an ontogenetical and phylogenetical perpective. Results suggest that pant-grunt vocalisations can be used in a flexible way, both in their form and usage within a social group. More specifically, chimpanzees seemed to take into account the number and identity of surrounding individuals before producing these vocalisations. At the acoustic level, pant-grunts seem to be very variable vocalisations that corresponded to different social situations commonly encountered. Grunts are one of the first vocalisations produced by babies but they are not first produced in social contexts. Although some modifications of the social grunts form and usage could not entirely be attributed to maturation only, the role of the mother seemed to be restricted. Her direct influence was perhaps more visible in the rhythmic patterns of chorusing events. Taken together, this thesis suggests that chimpanzee vocalisations are more flexible in their usage, production and acquisition than previously thought and might therefore be more similar to gestural communication.
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Bates, Lucy. "Cognitive aspects of travel and food location by chimpanzees (Pan troglodytes schweinfurthii) of the Budongo Forest Reserve, Uganda." Thesis, University of St Andrews, 2005. http://hdl.handle.net/10023/2697.
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Finding food in tropical forests poses a potentially major problem for chimpanzees, whose ranging is thought primarily to be directed at locating suitable food resources: (1) chimpanzees are frugivorous, large bodied and live in large home ranges; (2) they lack specialised sensory or locomotor abilities, and terrestrial travel is known to be costly; but (3) fruits are randomly distributed in space and time. Evidence from studies of captive individuals suggests chimpanzees are capable of remembering the locations of out of sight resources and can compute least distance routes to these resources, but whether this ability translates to the natural foraging behaviour of wild chimpanzees has never been investigated. My observational study was designed to assess how the chimpanzees (Pan troglodytes schweinfurthii) of Budongo Forest, Uganda, locate these patchy resources. I mapped the routes of 14 focal individuals over a 12-month period. I considered how these foraging routes were structured by breaking the path into segments of travel between resources. Consecutive segments of travel between resources were found not to be independent, but assembled into "super-segments" that take in a number of resources along one trajectory. These super-segments are not necessarily directed towards feeding resources, however: travel is not always food directed. Comparisons of actual chimpanzee routes with randomly generated simulations suggest most individuals do not attempt to minimise their travel distances. There is evidence to suggest energetically stressed individuals can remember the locations of recently visited food resources and return to these patches in order to minimise travel distances when necessary, but overall, food is not difficult to find for this community of chimpanzees. I propose this is because males defend a territory with super-abundant food resources, meaning availability is not a limiting factor of foraging. Male chimpanzees can be characterised as convenience feeders, taking food whilst satisfying other, social needs.
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Odei-Addo, Frank. "Purification and characterization of serine proteinase inhibitors from two South African indigenous plants, Acacia karoo and Acacia schweinfurthii." Thesis, Nelson Mandela Metropolitan University, 2009. http://hdl.handle.net/10948/1291.
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Serine proteases are known to perform a wide range of functions essential to life; however there has to be some form of control mechanism in place. One of the many control mechanisms is their specific inhibition by protein proteinase inhibitors. Proteinase inhibitors in plants, present in their seeds, participate in defense mechanisms and their production is induced by herbivory or wounding. Plant proteinase inhibitors have been reported to inhibit a variety of serine proteinases, including enzymes of the blood coagulation cascade. In this study, various indigenous seed extracts were screened for potential serine proteinase inhibition. Acacia schweinfurthii was selected as a potential inhibitor that inhibited trypsin and factor X. The AS inhibitor was successfully purified to homogeneity by precipitating with 80 percent (v/v) acetone and the sequential chromatographic steps including ion-exchange chromatography, size exclusion chromatography, affinity purification on a trypsin-agarose column and RP-HPLC. Reducing SDS-PAGE conditions revealed an inhibitor of two polypeptide chains A and B of approximate molecular weights 16 and 10 kDa, respectively, and under non-reducing conditions, 25 kDa was observed. The inhibitor was shown to inhibit trypsin, chymotrypsin and factor X indicating the dynamic nature of the reactive site. An enzyme: inhibitor ratio of 1:1, and a Ki of 3.45nM was determined for the AS inhibitor on trypsin, and the inhibitor also weakly inhibit chymotrypsin. AS inhibitor and STI inhibited factor X with a Ki values of 13.7nM and 77.5μM respectively. Amino acid analysis revealed Mmin values of the A- and B- chain of 15,000 and 7,800, respectively. The effect of seed extracts on the activated partial thrombin time (APTT) and prothrombin time (PT) was tested. No prolongation of the PT was obtained. For the crude extracts of AK and AS, IC200 values of 4.6 and 189.62 μg/mL, were respectively obtained. For the purified fractions of STI, AS and AK, IC200 values of 51.5, 114.31 and 893.8 μg/ml were observed, respectively. Keywords: proteinase inhibitors, Acacia species, trypsin inhibitor, FX inhibitor.
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Nkouam, Gilles Bernard. "Conservation des fruits du karité (Vitellaria paradoxa Gaertn.) et de l'aiélé (Canarium schweinfurthii Engl.) : isothermes de sorption d'eau et extraction des matières grasses des fruits stockés." Thesis, Vandoeuvre-les-Nancy, INPL, 2007. http://www.theses.fr/2007INPL058N/document.
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La méthode microgravimétrique statique a permis d’observer que la pulpe de l’aiélé est plus hygroscopique que l’amande de karité à 25°C. A l’inverse, on fait l’observation contraire entre 35 et 55°C. Le modèle d’Oswin décrit le mieux les données de sorption des deux produits sur toute la gamme d’activité de l’eau. Les isothermes de l’amande de karité et de la pulpe de l’aiélé présentent le phénomène d’hystérésis entre 25 et 55°C. La conservation de ces oléagineux doit s’effectuer dans une atmosphère d’humidité relative comprise entre 40 et 60% afin d’obtenir des teneurs en eau recommandées. Un modèle adapté de prédiction des isothermes de sorption de ces oléagineux en deçà de 25°C et au delà de 55°C a été obtenu. L’extraction de la matière grasse au CO2 supercritique donne des rendements inférieurs à ceux obtenus de l’extraction à l’hexane. L’indice d’acide des matières grasses extraites au CO2 est supérieur à celui des lipides extraits à l’hexane. Ces indices, pour les lipides extraits des produits stockés à 18°C, sont les plus élevés. Quelque soient le mode de stockage et le solvant d’extraction, l’indice d’iode baisse avec le stockage. Le CO2 présente une sélectivité vis-à-vis de l’acide linolénique. Les lipides extraits au CO2 présentent les taux d’acides gras libres les plus élevés. Il ressort des résultats que le stockage -33°C est le meilleur. Toutefois, il ne doit pas dépasser 5 mois. L’extraction des lipides au CO2 supercritique doit utiliser les fruits frais ou stockés à -33°C. Les produits stockés à 18°C sont les plus durs et la dureté est corrélée négativement à la teneur en eau, mais positivement à l’indice d’acide des matières grasses extraitesThe static microgravimetric method permitted to observe that the Canarium pulp was more hygroscopic at 25°C than the sheanut kernels. On the other hand, sheanut kernel was more hygrocopic in the temperature range 35°C-55°C. The Oswin model best described the sorption data of the two products in the whole water activity range. Hysteresis was observed in the entire temperature range 25-55°C for sheanut kernel and Canarium pulp. It is suggested that these products should be stored in an environment with a relative humidity of 40-60%, in order to attain the recommended moisture content for storage. A model was adapted to predict the sorption isotherms of shea and Canarium below 25°C and above 55°C. The oil yields obtained with supercritical CO2 were lower than those obtained with hexane. The acid values of butter and oil extracted with carbon dioxide were greater than those of lipids extracted using hexane. The acid values of samples stored at 18°C were the largest. The iodine value of the oils decreased with an increase of the storage period, irrespective of the storage temperature and the solvent used for extraction. The extraction with CO2 did not extract linolenic acid. The proportion of free fatty acids increased when carbon dioxide was used for extraction. From the foregoing, it is suggested that storage at -33°C for up to 5 months presents the best means of preserving these products. Only fresh or fruits stored at -33°C should be used for the extraction of lipids using carbon dioxide. The products stored at 18°C were the most hard and the hardness was correlated negatively to the water content, but positively to the acid value of fatty material extracted
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Llorente, Caño Marina. "Estudio comparado de la conducta nidificadora de los chimpancés ("Pan troglodytes schweinfurthii") de la comunidad de Kanyawara (Parque Nacional de Kibale, Uganda)." Doctoral thesis, Universitat de Barcelona, 2004. http://hdl.handle.net/10803/2724.
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El objetivo principal es el estudio exhaustivo de la conducta nidificadota de los chimpancés de Kanyawara, teniendo en cuenta una amplia lista de variables (sexo, edad, variaciones estacionales, características del hábitat.) que podrían incidir sobre la mencionada conducta. Se completa el trabajo con la colaboración de mapas de macro-distribución de los sitios de nidificación en el área de estudio y micro-distribución de los nidos en las zonas de descanso, así como con el seguimiento de la dinámica de reutilización.Finalmente, los resultados conseguidos se quieren comparar con otros estudios, sobre este comportamiento en grandes simios salvajes, con el fin de establecer semejanzas y diferencias ecológicas, sociales y/o culturales.
La metodología utilizada es la usual en los trabajos etológicos de campo. El trabajo de campo va a suponer el seguimiento de la comunidad de chimpancés estudiada durante un año. El procedimiento empleado implicó el seguimiento diario (desde el amanecer hasta el crepúsculo) y el seguimiento de episodios nidificadores de los subgrupos de estudio, registrando sistemáticamente las conductas y variables relacionadas con la construcción de camas nocturnas y diurnas, además de la toma de medidas acerca de los nidos y de los sitios de anidaje conocidos, en ausencia de chimpancés, para su posterior análisis. Se presenta una amplia muestra, tanto por el número de nidos estudiados como por el número de episodios nidificadores nocturnos y diurnos observados.
Entre las aportaciones de esta investigación cabe destacar el extenso y rico conjunto de datos descriptivos sobre la construcción de nidos de los chimpancés de la comunidad de Kanyawara.
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Schoene, Claudia Ulrike Regina. "Assessment of the impact of a newly introduced free-ranging group of chimpanzees (Pan troglodytes schweinfurthii) on the vegetation of Ngamba Island, Lake Victoria, Uganda." Pretoria : [s.n.], 2003. http://upetd.up.ac.za/thesis/available/etd-05062005-151800.
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Nkouam, Gilles Bernard Dirand Michel Kapseu César Barth Danielle. "Conservation des fruits du karité (Vitellaria paradoxa Gaertn.) et de l'aiélé (Canarium schweinfurthii Engl.) isothermes de sorption d'eau et extraction des matières grasses des fruits stockés /." S. l. : S. l. : INPL ; Université de NGAOUNDERE, 2007. http://www.scd.inpl-nancy.fr/theses/2007_NKOUAM_G_B.pdf.
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Thèse de doctorat : Génie des procédés et des produits : INPL : 2007. Thèse de doctorat : Génie des procédés et des produits : Université de NGAOUNDERE : 2007.Titre provenant de l'écran-titre.
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Bédounguindzi, Walter Fiacre. "Caractérisation chimique et application à la préservation du bois des oléorésines d’Aucoumea klaineana (Okoumé), Canarium schweinfurthii (Aiélé), Dacryodes buettneri (Ozigo) et Dacryodes edulis (Safoutier) du Gabon." Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0070.
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Ce travail évalue l’apport des trois fractions (RB, RP et HE) d’Ak, Cs, Db et De du Gabon dans la préservation. Pour cela, une analyse chimique par GC/MS des trois fractions a d’abord été faite, ensuite l’étude de leurs activités antifongique et antitermite, enfin l’étude de leurs effets dans la protection des blocs de bois suite aux attaques des agents de dégradation. Les résultats des analyses chimiques montrent que les HE sont constitués des monoterpènes et de monoterpénoïdes, alors que les RB et RP sont composes d’un mélange de monoterpènes, de monoterpénoïdes et de triterpènes. Les tests biologiques de ces derniers vis-à-vis de PP, CP, CV et PS, montrent une faible activité antifongique, mais montrent une forte activité antitermite. Ces fractions améliorent la durabilité du bois contre les champignons a 20%, et une bonne résistance aux blocs de bois vis-à-vis des termites. Ces dernières associées au Tébuconazole, augmentent la résistance du bois face aux agents de dégradation du bois. Leurs caractères lessivables sont clairement mis en évidenceThis work evaluates the contribution of the three fractions (RR, PR and EO) of Ak, Cs, Db and De from Gabon to preservation. For that purpose, a chemical analysis by GC/MS of the three fractions was first made, then the study of their antifungal and antitermite activities, and finally the study of their effects in the protection of wood blocks following the attacks of the degradation agents. The results of the chemical analyses show that the HE are made up of monoterpenes and monoterpenoids, whereas the RB and RP are made up of a mixture of monoterpenes, monoterpenoids and triterpenes. Bioassays of the latter against PP, CP, CV and PS show low antifungal activity, but show high antitermite activity. These fractions improve the durability of the wood against fungi by 20%, and a good resistance of the wood blocks against termites. The latter, associated with Tebuconazole, increase the resistance of wood against wood degradation agents. Their leachable characteristics are clearly highlighted
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Krief, Sabrina. "Métabolites secondaires des plantes et comportement animal: surveillance sanitaire et observations de l'alimentation des chimpanzés (Pan troglodytes schweinfurthii) en Ouganda. Activités biologiques et étude chimique de plantes consommées." Phd thesis, Museum national d'histoire naturelle - MNHN PARIS, 2003. http://tel.archives-ouvertes.fr/tel-00006170.
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Afin de sélectionner des plantes ayant des propriétés pharmacologiques, un suivi éthologique et vétérinaire de chimpanzés (Pan troglodytes schweinfurthii), a été conduit, grâce à des méthodes non-invasives (parasitologie, analyses d'urine et observations vétérinaires) dans le Parc National de Kibale, en Ouganda. Des essais biologiques antiparasitaires, antibactériens, antifongiques, antiviraux et cytotoxiques ont été pratiqués in vitro sur 84 extraits bruts, provenant de 24 espèces de plantes. Parmi les nombreux extraits biologiquement actifs, deux binaphtoquinones, isolées de l'écorce de Diospyros abyssinica, et des acétogénines, telles l'annonacine et la gigantétrocine isolées des feuilles et écorces d'Uvariopsis congensis, possèdent une cytotoxicité significative. Deux nouveaux limonoïdes, à forte activité antipaludique, ont été isolés des feuilles de Trichilia rubescens. Ces résultats confirment que le régime alimentaire des chimpanzés peut agir de façon préventive et curative pour améliorer leur santé et pourrait être utilisé pour guider la recherche de nouvelles molécules potentiellement utilisables en médecine humaine.
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Kodet, John Gordon. "Studies on heteroaromatic schweinfurthin analogues." Diss., University of Iowa, 2010. https://ir.uiowa.edu/etd/2920.
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Natural products are a rich source of lead compounds for treatment of cancer as well as other diseases. Researchers at the National Cancer Institute, as part of their continuing effort to discover anticancer agents from natural sources, created the 60 human tumor cell-line anticancer screen to test natural products for their potential against various types of cancer. Through this screening process a family of natural products called schweinfurthins was discovered to possess potent and differential activity. Of potentially great significance, the pattern of activity that the schweinfurthins displayed in the screen does not correlate with any currently used anticancer drug, indicating that the schweinfurthins likely act via a previously unknown mechanism or on a novel target. Our group has synthesized many of the natural schweinfurthins as well as numerous analogues in an effort to probe the pharmacophore and gain understanding of the key features that are important for potency as well as differential activity. During the course of these studies, it was discovered that the right-half of the molecule is most amenable for modifications. One potential modification to the schweinfurthins is to replace the resorcinol substructure seen in the right-half of the natural product with a heteroaromatic moiety such as a benzofuran or indole system. This change may produce analogues that are potentially more active, that contain motifs that are seen in many therapeutic drugs, and that have improved chemical stability relative to the natural products. With this goal in mind benzofuran and indole containing schweinfurthin analogues were synthesized. Once these compounds were prepared, it was found that such modifications were welltolerated, and in the case of the indole analogues activity in the 60 cell-line screen was equivalent to the corresponding natural product. In an effort to improve that activity, prenyl and geranyl side chains were added to the indole system, at both the C-2 and C-3 positions, to better match the structure of the natural schweinfurthins. In addition, analogues methylated selectively on the indole nitrogen or phenol were synthesized to improve stability. The impact of those modifications on the activity was tested, and potent compounds were found. The left-half of the schweinfurthins is prepared via a Lewis acid mediated cascade of a geranyl epoxide. The protecting group that is typically employed on the terminating phenol, a methoxymethyl ether or MOM group, is cleaved during the reaction. In the past preparation of an analogue that lacked a substituent at the C-5 position, it was found that the MOM cation released during the cyclization would participate in an electrophilic aromatic substitution reaction at the neighbouring position which resulted in the formation of a benzyl methyl ether. In order to probe the scope of this reaction and its potential utility in the synthesis of natural products, several geranyl epoxides with various "protecting groups" on the phenol were prepared and subjected to the cyclization conditions. These investigations have established that stabilization of the liberated cation determines the likelihood and regioselectivity of a tandem electrophilic aromatic substitution reaction.
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Kuder, Craig Heath. "Schweinfurthins as novel anticancer agents." Diss., University of Iowa, 2009. https://ir.uiowa.edu/etd/840.
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Several members of the schweinfurthin family are potent and selective inhibitors of cancer cell growth in the NCI 60-cell cancer screen. The schweinfurthins display unique activity in this screen which suggests that these compounds have a previously unexploited target. This activity encourages development of the schweinfurthins as anti-cancer agents; however, the scarcity of the natural products has hindered biological evaluation. For this reason, a program was initiated to synthesize the natural products and analogues thereof. These efforts have made 5 natural product schweinfurthins and over 60 analogues available for biological evaluation.
Studies presented herein evaluate the biological activity, intracellular localization, and potential protein interactions of schweinfurthins analogues. To investigate the potent and differential effects of these compounds, a two-cell line screen was developed incorporating a sensitive cell (SF-295) and insensitive cell line (A549). The structure-function data obtained from this screen identified a schweinfurthin site amenable to modification. Based on this finding, fluorescent schweinfurthins were designed and synthesized. These compounds retain schweinfurthin-like potency and activity which is critical for their study. The intracellular localization of these schweinfurthins was investigated using fluorescence microscopy. These studies identified the lysosomes and peri-nuclear organelles as potential sites of schweinfurthin activity. Additionally, we describe the attachment of a fluorescent schweinfurthin to a solid support, which was utilized to identify protein-schweinfurthin interactions. This approach identified vimentin as a potential target of schweinfurthin activity.
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Topczewski, Joseph John. "Cascade cyclizations & the schweinfurthins." Diss., University of Iowa, 2011. https://ir.uiowa.edu/etd/2780.
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Cancer is a serious family of disease that continues to cripple and claim those afflicted. For the last several decades, America has invested in a national program to alleviate cancer and cancer related suffering, ultimately seeking a cure. As part of this goal, the National Cancer Institute (NCI) has spent significant effort scouring the globe with the hope of finding naturally occurring compounds that can successfully combat cancer. Presently, this effort has uncovered many natural products with chemotherapeutic potential and many of the lead agents used in the fight against cancer are either natural products themselves or are compounds inspired by a natural product.
This work describes one family of natural products uncovered by the NCI that is being explored for chemotherapeutic applications, namely the schweinfurthins. The schweinfurthins were isolated by the NCI; however the natural source, Macaranga schweinfurthii, did not provide these compounds in ample quantity to permit further study. The paucity of natural material indicated that a chemical synthesis of these compounds would be the most reliable method to provide meaningful amounts of schweinfurthins. The present work describes the chemical synthesis of four of the most potent schweinfurthins, describes the synthesis of numerous structural analogues, and details advances to the field of cascade cyclizations which makes their synthesis possible.
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Stockdale, David Paul. "The synthesis of isosteres of pawhuskin- and schweinfurthin-based stilbenes." Diss., University of Iowa, 2017. https://ir.uiowa.edu/etd/5999.
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The pawhuskins and schweinfurthins are two classes of stilbene natural product compounds that exhibit interesting biological activity, and because of this they have been studied extensively in our lab through synthetic means.
The pawhuskins are a class of small molecule non-nitrogenous opioid receptor modulators that differ significantly in structure from the classical opioid receptor ligands.
Some of the natural schweinfurnthins show strong and differential antiproliferative behavior towards a variety of human cancer cell lines.
Prior to this research, a significant structure-activity relationship study conducted in our lab has produced a large library of analogues of both classes of compounds. The most potent of theses analogues have served as lead compounds in this study where the stilbene motif present in both classes was substituted with either an amide or triazole linkage.
For the new pawhuskin analogues, three of the amide isomers and a triazole isomer synthesized showed antagonist activity for the opioid growth factor (OGF)/opioid growth factor receptor (OGFR) axis which is involved in cellular and organ growth control. This cellular signaling mechanism is targeted by “low-dose” naltrexone therapy which is being tested clinically for multiple sclerosis, Crohn’s disease, cancer, and wound healing disorders. The compounds described here are the first selective small molecule ligands for the OGF/OGFR system and will serve as important leads and probes for further study.
For the new schweinfurthins analogues, all compounds synthesized retained antiproliferative activity against similar cancer cell lines to that of the natural compounds. The new amide analogues were produced in pairs only differing in the orientation of the amide linkage replacement for the stilbene motif. Signifigantly greater activity was seen for one orientation of the amide over the other.
The synthetic efforts towards all of these analogues will be described herein along with their intriguing biological properties.
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Ulrich, Natalie Christine. "Cascade cyclizations in total synthesis: applications to the synthesis of cytotoxic natural products." Diss., University of Iowa, 2010. https://ir.uiowa.edu/etd/752.
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Plant-derived natural products continue to be a valuable source of useful therapies for cancer as well as other diseases. As part of a continuing mission to obtain anticancer agents from natural sources, researchers at the National Cancer Institute (NCI) established the 60 human tumor cell line anticancer screen. The schweinfurthins are one family of unique natural products discovered through this screening process. Most of these natural compounds exhibit potent and differential activity in the 60-cell screen. Importantly, the pattern of activity displayed by the schweinfurthins shows no correlation to any clinically used anticancer drug, indicating that this family of natural products probably acts via a novel mechanism or at a novel target. Our group has conducted extensive structure-activity relationship studies in an effort to illuminate the mechanism of action of the schweinfurthins. In this thesis, the preparation and biological activity of a number of new schweinfurthin F analogues possessing variations in the D-ring alkyl chain and stilbene moiety will be discussed. These studies have clarified the importance of the D-ring to the schweinfurthins' pharmacophore.
Based on the results obtained from the exploration of the structural requirements of these natural products, it was determi-ned that the right-half of the schweinfurthins would be an appropriate site for attachment of a molecular probe to be used in affinity experiments. The synthesis of these biotinylated probes will be examined in detail, and their use in pull-down assays will be summarized.
The preparation of key schweinfurthin intermediates has involved the extensive use of Lewis acid-mediated cationic cascade cyclizations terminated by MOM-protected phenols. Those successes have inspired investigations of additional applications of these cyclizations. In particular, a variant of these cyclizations using "MOM-protected" enol ethers as reasonable substitutes for β-keto ester terminating moieties has been studied. These interrelated studies involving the synthesis of schweinfurthin analogues and the exploration of cascade cyclizations will be discussed in detail.
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Roos, Dominika [Verfasser]. "Studien zur Synthese der Kernstruktur der Schweinfurthine / Dominika Roos." Tübingen : Universitätsbibliothek Tübingen, 2020. http://d-nb.info/1215568819/34.
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Zheng, Chaoqun. "Molecular mechanisms of the anti-cancer action of schweinfurthins." Diss., University of Iowa, 2015. https://ir.uiowa.edu/etd/1815.
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Schweinfurthins are a family of natural products with significant anti-cancer activities. They were originally identified in the National Cancer Institute (NCI) human 60 cancer cell line screening. The growth inhibition profile of schweinfurthins is distinct from other clinically used anti-cancer agents, indicating that they have a novel mechanism of action or have a previously unrecognized protein target. Previous studies showed that schweinfurthins affect multiple cellular processes in cancer cells. For example, schweinfurthins can alter cytoskeleton organization, induce ER stress and apoptosis, and inhibit the mevalonate pathway. The mevalonate pathway is responsible for the production of isoprenoids and cholesterol, which have been shown to play regulatory roles in the Hedgehog (Hh) signaling pathway. In this study, we found that the Hh signaling pathway in NIH-3T3 and SF-295 cells was inhibited by schweinfurthins. The supplementation of mevalonate and cholesterol partially restored Hh signaling, indicating that schweinfurthins inhibit Hh signaling partially by down-regulating the products from the mevalonate pathway. Interestingly, schweinfurthins in combination with cyclopamine, an inhibitor of the Hh singaling pathway, synergistically decreased cell viability.
In order to better understand the underlying mechanism of the anti-cancer action of schweinfurthins, we attempted to identify the protein target of schweifnurthins. Affinity chromatography was performed to pull down the protein target. We found that schweinfurhtins bound to the M2 isoform of pyruvate kinase (PKM2) and inhibit its pyruvate kinase activity. Knockdown of PKM2 by siRNA increased the sensitivity of SF-295 cells to schweinfurthins. The inhibition of PKM2 by schweinfurthins led to a reduction in the rate of glycolysis in cancer cells. Fructose 1,6-bisphosphate (FBP), an activator of PKM2, could alleviate schweinfurthin-mediated inhibition on PKM2 and glycolysis. Notably, FBP could also partially reverse the reduction of cell viability in the presence of schweinfurthins. Taken together, these studies revealed the mechanism by which schweinfurthins inhibit Hh signaling. In addition, we uncovered PKM2 as a schwienfurthin target and highlighted the importance of glycolysis suppression as a mechanism of the anti-cancer action of schweinfurthins.
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Schweinfurth, Nora [Verfasser]. "Minimale Resterkrankung beim Mantelzell-Lymphom nach allogener Stammzelltransplantation / Nora Schweinfurth." Greifswald : Universitätsbibliothek Greifswald, 2015. http://d-nb.info/1077186797/34.
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Sheehy, Ryan Michael. "Mechanisms of the anti-proliferative actions of the schweinfurthins in cancer cells." Diss., University of Iowa, 2015. https://ir.uiowa.edu/etd/1752.
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Schweinfurthins are intriguing natural product chemotherapeutics due to their potent yet selective activity and their unknown mechanism of growth inhibition in cancer. Much progress has been made in characterizing the intracellular effects of the schweinfurthins since they were first isolated from Macaranga schweinfurthii in 1986. Here, the L-type calcium channel and P- glycoprotein (Pgp) inhibitor verapamil has been found to enhance schweinfurthin- induced growth inhibition. Verapamil induces an increase in the intracellular concentration of a fluorescent schweinfurthin. However, the synergistic relationship between the schweinfurthins and verapamil is complex and not obvious in that verapamil fails to increase the intracellular concentration of a schweinfurthin analogue that is a known substrate of Pgp. Schweinfurthins are also found to induce alterations to cholesterol homeostasis by increasing the expression of the cholesterol efflux pump ABCA1 in an apparent liver X receptor- independent fashion. In addition, schweinfurthin treatment blunts epidermal growth factor downstream activation and phosphorylation of Akt. Lastly, a schweinfurthin-resistant cell line has been created and characterized for resistance to schweinfurthin-induced growth inhibition. The variety of intracellular effects characteristic of schweinfurthin treatment described here provide mechanistic framework for identifying the potential target and mechanism of growth inhibition for the schweinfurthins.
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Péresse, Tiphaine. "Vers la découverte du mécanisme d’action de stilbènes prénylés isolés de Macaranga spp." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS573.
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Des études phytochimiques dediverses espèces du genre Macaranga ontconduit à la découverte d’une familleintéressante de stilbènes prénylés nommésschweinfurthines (SWs). Le NCI (NationalCancer Institute) a évalué l’activité cytotoxiquede ces composés sur un panel de 60 lignéescellulaires cancéreuses : ces composésprésentent de très bonnes activités cytotoxiquessur certaines de ces lignées. De plus, leur profild’activité original suggère que ces composésagissent selon un nouveau mécanisme d’action,encore inconnu. Ainsi, ce projet de thèse a pourbut d’éclaircir ce mécanisme par identificationdes protéines cibles ainsi que des voies designalisations impliquées. Pour cela l’obtentiond’une grande quantité de SWs était nécessaire.Dans un premier temps, l'espèce vietnamienneMacaranga tanarius a été sélectionnée par uneapproche utilisant les réseaux moléculaires. Sonétude phytochimique a conduit à l’isolement denouveaux analogues et de SWs d’intérêt àl'échelle du gramme, permettant de réaliser dansun second temps des modifications chimiquesciblées. Une fonction alcyne a, par exemple, étéintroduite sur la SW G sans altérer son profild’activité. La présence de cette fonction aensuite permis le couplage de la SW avec unfluorophore et une biotine par chimie click incellulo. Des études de localisation intracellulaireet d’identification d’un partenaire protéique ontensuite été réalisées. En parallèle de ces travaux,l’interaction entre les SWs et la protéine OSBP(Oxysterol-binding protein), décrite commeétant une cible potentielle des SWs a égalementété investiguéePhytochemical studies fromMacaranga species led to the discovery of aninteresting family of prenylated stilbenesnamed schweinfurthins (SWs). The NCI(National Cancer Institute) evaluated thesemolecules on a panel of 60 human cancer cells:studying these molecules is of great interestbecause they display promisingantiproliferative activities for specific tumorderivedcell lines. Furthermore, theiruncommon activity profile suggests that itimplements a new mechanism of action. Ourproject aims to decipher this mechanism byfinding the targeted protein(s) and thesignalling pathway involved. For that purpose,a large amount of these natural stilbenes wasrequired. First, a vietnamese plant has beenselected using molecular networking approachto ensure the presence of these molecules.Then, a phytochemical study on a large scaleled to the isolation of the compounds of interest(several grams) and new analogues. An alkynemoiety has been introduced on one of thesemolecules by a selective chemical modificationwithout any loss of the specific cytotoxicprofile. This alkyne function allowed the incellulo click reaction between a fluorescentprobe or a biotin. Thus, studies of intracellularlocalization and protein identification havebeen achieved. Concurrently, interactionbetween SWs and Oxysterol-binding protein(OSBP), a previously described target of thesecompounds, has been studied
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Schweinfurth, Philipp [Verfasser], and Elmar W. [Gutachter] Gerharz. "Der Einfluss von bub1b und p53 auf den Zellzyklus sowie die Sensitivität gegenüber Docetaxel - Untersuchungen am Mausmodell und an murinen embryonalen Fibroblasten / Philipp Schweinfurth ; Gutachter: Elmar W. Gerharz." Würzburg : Universität Würzburg, 2019. http://d-nb.info/1189066130/34.
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"Ecological Role of Dry-Habitat Chimpanzees (Pan troglodytes schweinfurthii) at Issa, Ugalla, Tanzania." Doctoral diss., 2013. http://hdl.handle.net/2286/R.I.18012.
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abstract: Identifying the ecological role, or niche, that a species occupies within their larger community elucidates environmental adaptability and evolutionary success. This dissertation investigates the occupied niche of chimpanzees (Pan troglodytes schweinfurthii) living in an open, dry savanna-woodland environment by examining patterns of resource use and interspecific interactions. Data were collected October 2010--November 2011 at Issa, in the Ugalla region of western Tanzania, which is one of the driest, most open, and seasonal habitats inhabited by chimpanzees. Unlike most primatological studies which employ methods that include focal follows, this study focused instead on observing 'resource patches' for chimpanzees. Patch focals allow for the observation of all animals within a study area; capture resources that are not used by the study species; and are particularly well suited for unhabituated communities. In order to better understand relationships between environment and behavior, data collected at Issa are compared with published data from other chimpanzee populations. Issa chimpanzees were expected to have broader resource use than forest chimpanzees, as well as increased competition with other fauna, due to fewer available resources. However, in contrast to the assumption of food scarcity in dry habitats, dietary resources were available throughout the year. Like other populations, the diet of Issa chimpanzees consisted of mostly fruit, but unlike at other sites, the majority of plants consumed were woodland species. Additionally, although chimpanzees and other fauna shared spatial and dietary resources, there was only nominal overlap. These results point to extremely low levels of indirect competition between chimpanzees and other fauna. Despite extensive study of forest chimpanzees, little is known about their role within their faunal community in open, dry habitats, nor about how greater seasonality affects resource use. This project addresses both of these important issues and fosters novel approaches in anthropological studies, especially in reference to chimpanzee ecology and evolution. Understanding current chimpanzee behavioral relationships with their environments shapes hypotheses about their pasts, and also informs predictions about behaviors of similar taxa in paleo-environments. Lastly, examining the ecological role of chimpanzees within their larger communities will influence the formation of, as well as evaluate, conservation strategies.Dissertation/Thesis
Ph.D. Anthropology 2013
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Schoene, Claudia Ulrike Regina. "Assessment of the impact of a newly introduced free-ranging group of chimpanzees (Pan troglodytes schweinfurthii) on the vegetation of Ngamba Island, Lake Victoria in Uganda." Diss., 2004. http://hdl.handle.net/2263/24377.
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The purpose of the current research project was to undertake a thorough quantitative and qualitative survey of the vegetation on Ngamba Island. Based on the results of this survey suggestions are made for future management of the chimpanzees on the island. It was assumed that the introduction of chimpanzees onto an island that was previously not inhabited by this species would have an (to be defined) impact on the environment in general, and the vegetation cover, in particular. The woody vegetation was sampled and analysed using the varying quadrat plot method. This method gives the following results per (a) species, (b) stem growth form and (c) height class: 1. Canopy regime at different height levels; 2. Total projected canopy cover, and 3. Density. The results of the vegetation analysis showed that at this stage the forest structure on Ngamba Island still represents a healthy secondary rain forest cover. A major impact chimpanzees have on the woody vegetation cover of Ngamba Island is that they defoliate and destroy trees of all height classes. The number of mature trees that a parent tree produces per fruiting period might often be as little as < 1. Even though chimpanzees act as seed dispensers in their natural habitat the impressive number of seeds dispersed by each individual chimpanzee is therefore put into perspective by the very low final recruitment rate. Resulting from the above it is postulated that the impact of the Ngamba Island chimpanzees as seed dispersers for selected woody vegetation species is of low importance if not negligible. It is by far outweighed by the destruction caused to the secondary rain forest cover of the Island by this newly introduced species. Using different approaches and calculations to estimate the necessary home ranges for chimpanzees in a confined habitat the areas calculated range from 5-56 hectare per chimpanzee. Even though, there is an 11.2-fold difference between these estimates they indicate nevertheless, that Ngamba Island with an area of 42.40 ha of secondary rain forest cover and 16 adult and 17 juvenile chimpanzees is already highly overstocked. In summary the impact the newly introduced species of chimpanzees on Ngamba Island will have over time on the secondary rain forest cover of their forest refuge is that of continuing destruction. Using a rate of destruction of about 0.50 ha per chimpanzee per year the secondary rain forest cover of Ngamba Island will be completely destroyed in 53 years with a stocking density of 16 adult chimpanzees. Increasing stocking density – also through maturing of the juvenile chimpanzees currently present on the Island into a adulthood – will increase the rate of destruction of the woody vegetation cover of Ngamba Island proportionally.Dissertation (MSc(Wild Life Management))--University of Pretoria, 2006.
Animal and Wildlife Sciences
unrestricted
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Desruelle, Kelly. "Ontogénie du toilettage social chez les chimpanzés sauvages (Pan troglodytes schweinfurthii) à Ngogo en Ouganda : effets de l'âge et du sexe des petits et de la parité maternelle." Thesis, 2020. http://hdl.handle.net/1866/24141.
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Cette étude examine l'effet de l'âge, du sexe des immatures et de la parité maternelle sur le toilettage social des chimpanzés sauvages (Pan troglodytes schweinfurthii), une société à philopatrie mâle. De janvier à avril 2018, j'ai recueilli des données comportementales sur les immatures en utilisant des observations centrées sur le sujet d’une heure. J'ai mesuré les taux moyens de toilettage (épisodes/heure), les probabilités (présence/absence) et les durées (secondes par épisodes) ; et j'ai utilisé des équations d'estimation généralisées (EEG) pour déterminer les effets potentiels de l'âge, du sexe des immatures et de la parité maternelle sur chacune des variables de toilettage. J'ai inclus entre 17 et 23 progénitures, dont l'âge variait de la naissance à 7 ans. Lors des séances de toilettage avec leur mère et d'autres membres du groupe, les immatures plus âgés ont donné et reçu des séances de toilettage plus longues. Ces résultats soulignent que le toilettage des chimpanzés est un comportement social qui commence tôt dans la vie lors des interactions avec la mère, mais aussi avec d'autres membres; et qu'il devient plus important dans la vie des immatures à mesure qu'ils vieillissent. Le fait que l’immature soit un mâle ou une femelle n'a pas d'impact sur les dimensions du toilettage. Le toilettage peut être utilisé par les mâles ou femelles pour répondre aux différents besoins de leurs stratégies d'adaptation. Pour les femelles, cela inclut l'intégration dans un nouveau groupe social pendant la dispersion qui se produit à l'adolescence, et pour les mâles, cela inclut l'intégration dans la hiérarchie sociale, qui commence au début de l'âge adulte. Les mères primipares ont été toilettées par leur progéniture plus longtemps que les mères multipares. Les immatures issus de mères multipares ont reçu plus de toilettage (c'est-à-dire des taux plus élevés et une plus grande probabilité de présence de toilettage) par d'autres membres du groupe que les immatures issus de mères primipares. Contrairement aux primipares, les immatures de mères multipares bénéficient d'une plus grande expérience de toilettage de la part de divers congénères, car ces immatures ont accès à des frères et sœurs maternels élargis.This study examines the effect of age, sex of immatures, and maternal parity on social grooming in wild chimpanzees (Pan troglodytes schweinfurthii), a male philopatric society. From January to April 2018 I collected behavioral data of infants using one-hour focal animal sampling. I measured mean grooming rates (bouts/hour), probabilities (presence/absence), and durations (seconds per bout), and used Generalized Estimating Equations (GEE) to determine the potential effects of infant age, sex and maternal parity on each of the grooming variables. I included between 17 and 23 offspring, who ranged in age from birth to 7 years old. In grooming sessions with their mothers and others, older offspring gave and received longer grooming bouts. These results emphasize that grooming for chimpanzees is a social behavior that begins early in life during interactions mostly with mothers, but also with others, and that it becomes more prominent in infants’ lives as they age. Whether the infant was male, or female had no impact on grooming dimensions. Grooming may be used by both males and females to respond to the different needs of their adaptive strategies; for females this includes integrating into a new social group during dispersal, which happens in adolescence, and for males it includes integrating into the male social hierarchy, which begins in early adulthood. Primiparous mothers were groomed by their offspring longer than multiparous mothers. Infants from multiparous mothers received more grooming (i.e., higher rates and greater likelihood of grooming presence) by other group members than did infants from primiparous mothers. In contrast to primiparous females, infants of multiparous females benefit from having more grooming experiences from a variety of conspecifics, as these infants have access to extended maternal siblings.
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Schweinfurth, Yvonne Eva [Verfasser]. "Prozessierung und Reparatur von komplexen DNA-Schäden : mikroskopische Analyse und Quantifizierung des phosphorylierten Histons H2AX und des Tumorsuppressors p53 / von Yvonne Eva Schweinfurth." 2008. http://d-nb.info/993863906/34.
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