Aspectos quimicos da polinização de especies do genero Clusia e sintese da (+)-cis-nortailoriona e 7S-isotiociano-7, 8-Di-hidro-alfa-bisaboleno

AUTOR(ES)
DATA DE PUBLICAÇÃO

1997

RESUMO

This work has been divided in two main topics: a) Natural product isolation. In the first topic we have developed a non traditional phytochemical research concerning the identification of the constituents of floral oils and resins and their role in the Clusia polination phenomenon as well as their importance in the pollinating bee s life.We have focused on the floral resins and oils of Clusia belonging to the Chlamydoclusia subgroup, which are mainly composed by poliisoprenylated benzophenones while the staminal oil constituents are fatty acid derivatives. We report here the identification of 5 novel poliisoprenylated benzophenones and a known xanthone. Having accomplished the identification we became involved with their ecological aspects and biological activity. We have thus brought light into the chemistry behing this ecological system where the bees collect the resins to build theirs nests and also to protect them from certain microorganisms and in this process they poIlinate the Clusia flowers. One should mention that the type of reward (the floral resin) in not very usual. b) The second part focus organic synthesis from two different aspects. One envolves the determination of the absolute configuration of a new natural product, the (+) nortailoriona {( 1 S) - cis - 2 - [ 2 , 2 - dimethyl - 3 (3"- oxobutyl)-ciclopropyl ]ciclopent -2- en -1- ona}, previously detected in the essential oil of Artemisia annua. This was accomplished by GC and GC/MS using a chiral fused silica capilary column and racemic and homochiral synthetic standard of the compound. The racemic standard had been previously synthetized and we have obtained the homochiral standard from (+)-2-carene using the Pauson-Khand reaction in the key step of the synthetic pathways. Finally we have synthetized the natural 7S-isotiocianato-7,8-di-hidro-a-bisabolene as a consequence of a synthetic study on the chemio and regioselectivity of the HSCN addition to terpene double bonds.

ASSUNTO(S)

identificação produtos naturais isolamento

ACESSO AO ARTIGO

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