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Laks Ragupathy Bettina Pluhar Ulrich Ziener Harald Keller Rainer Dyllick-Brenzinger Katharina Landfester 《Journal of Molecular Catalysis .B, Enzymatic》2010,62(3-4):270-276
Lipase-catalyzed aminolysis of lactones under aqueous conditions usually leads to the hydrolysis of the ester bond with only a minor content of the corresponding amide. However, the aminolysis of pentadecanolide (PD) and hexadecanolide (HD), respectively, with oleylamine (OA) in aqueous miniemulsion under optimized conditions (temperature, concentration of enzyme, reaction time) yields >90% amide. Kinetic investigations performed with OA and PD reveal that the lipase catalyzes a novel reaction pathway, i.e., the hydrolysis of a lactone followed by the amidation requiring 30 min and 8 days reaction time, respectively. The demands of a high amount of lipase as well as the long reaction time are caused by the low reactivity of the carboxylic group and the formation of salt with the amine. Similar reactions were performed with PD and other amines such as dodecyl, decyl, octyl, benzyl and hexyl amine resulting the analogous amide compounds. 相似文献
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The phenology of principal fruits consumed by the endangered Great Pied Hornbill (Buceros bicornis) was monitored for two years in a wet forest habitat in southern India. Lipid–rich fruits, produced by several interior forest trees mainly of the family Lauraceae, were highly seasonal in their availability, and their production in the dry, hot season coincided with the breeding of the hornbill. Sugary fruits, produced mainly by several species of Ficus, were available year–round due to aseasonal fruiting patterns. Because Ficus fruited even at times of low fruit resource availability, and was heavily utilized by hornbills and other frugivores, it played a keystone role in the maintenance of the avian frugivore community. Overall fruit production was scarce between July and January during the southwest and northeast monsoon seasons. Vitex altissima produced berries abundantly during much of this time (September–December) and thus was another important fruit resource for avian frugivores. To safeguard the fruit resource base for the Great Pied Hornbill, we recommend: (1) The protection of Ficus and Vitex trees from overexploitation, and (2) the conservation of forest integrity to maintain compositions and densities of the lipid–rich fruit tree species utilized by the hornbill. 相似文献
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Subramanyam Ragupathy Newmaster G Steven Murugesan Maruthakkutti Balasubramaniam Velusamy Muneer M Ul-Huda 《Journal of ethnobiology and ethnomedicine》2008,4(1):1-14
Dusky grouper (garoupa, Epinephelus marginatus) is an important catch for several artisanal small-scale fisheries along the Brazilian coast. It is a sedentary, monandric, and late maturing protogynous species, which makes it vulnerable to overharvesting even though it is mainly caught through hook and line or spear fishing through free diving. Lack of information on the ecology and biology of this species in Brazil is astonishing. Much of the information found in the literature concerns Mediterranean dusky groupers. Studies compiling local knowledge (ethnoecology) about fish species complement biological data, and have been fundamental for effective fisheries management. In this study, our objectives are to obtain data about dusky grouper through fish catches and analysis of stomach contents and gonad maturation (macroscopic analyses), along with interviews from fishermen from six small-scales communities from the southern (Pântano do Sul, Florianópolis, Santa Catarina State) to the northern Brazilian coast (Porto Sauípe, Bahia State). We conclude that precautionary approaches and 'data-less' management approaches are needed in the coast of Brazil. Research on this species and on the potential of aquaculture for its cultivation, are urgent, due to the apparent vulnerability and decrease of dusky grouper along the coast of Brazil. 相似文献
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Jiangqin Zhao Shixing Tang James Storhoff Sudhakar Marla Y Paul Bao Xue Wang Eric Y Wong Viswanath Ragupathy Zhiping Ye Indira K Hewlett 《BMC biotechnology》2010,10(1):74