14 research outputs found

    Terpenoid biotransformations by Mucor species

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    Terpenoids are natural products of great interest due to their widespread use in agrochemicals, drugs, fragrances, flavouring and pigments. Biocatalysts are increasingly being used in the search for new derivatives with improved properties especially to obtain structurally novel leads for new drugs which are difficult to obtain using conventional organic chemical methods. This review, covering up to the end of 2012, reports on the application of Mucor species as catalysts in terpenoid biotransformation to obtain new drug targets, enhance pharmacological activity or decrease the unwanted effects of starting material

    Potencial alelopático de forrageiras tropicais: efeitos sobre invasoras de pastagens

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    Extratos aquosos de sementes, parte aérea e raízes de três gramíneas e três leguminosas forrageiras foram preparados a uma concentração de 10%, com o objetivo de avaliar os efeitos potencialmente alelopáticos sobre a germinação de sementes e o alongamento da radícula das invasoras de pastagens: desmódio, guanxuma e assa-peixe. A germinação foi monitorada em períodos de dez dias, com contagens diárias e eliminação das sementes germinadas. O alongamento da radícula era medido ao final de um período de dez dias de crescimento. Os efeitos do potencial osmótico foram isolados através de cálculos. As espécies doadoras evidenciaram potencialidades alelopáticas que variou de intensidade em função da especificidade entre espécies doadoras e receptoras. B. brizantha e calopogônio foram as espécies que promoveram as reduções mais intensas sobre a germinação das sementes e o alongamento da radícula das espécies receptoras. A parte aérea das espécies doadoras constituiu-se na principal fonte de substâncias potencialmente alelopáticas, solúveis em água. Independentemente da espécie doadora, desmódio e guanxuma foram as invasoras que se mostraram mais susceptíveis aos efeitos potencialmente alelopáticos, enquanto o assapeixe foi a mais tolerante.Aqueous extracts from seeds, aerial part and roots of grasses Brachiaria humidicola, Brachiaria decumbens and Brachiaria brizantha cv. Marandu and legumes forage Calopogonium mucunoides and Stylosant hes guianensi s cv. Mineirão were prepared in a concentration of 10% (w/v), to evaluate the allelopathic potential effects on seed germination and radicle elongation of the pasture weeds: Desmodium adscendens, Sida rhombifolia and Vernonia polyanthes. Seed germination was monitored in ten-day periods, with daily countand elimination of seed germination. At the end of the ten-day periods the radicle was measure d. The osmot ic potential effects were isolated by calculation. The donor species showed allelopathic potential that varied in function of donor and receiver species. Brachiaria brizantha and among grasses and Calopogonium mucunoides among legumes were the species that promoted the reduction more intensively on seed germination and radicle elongation of the receiver species. The aerial part of the donor species was the main source of water soluble allelopathic potential compounds. Independently of the donor species, D. adscendens and S. rhombifolia were the weeds with the greatest sensibility to allelopathic potencial effects from donor species, while V. polyanthes showed more tolerance
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