Diketopiperazines produced by endophytic fungi found in association with two Asteraceae species

Diketopiperazine (DKP) derivatives, named colletopiperazine, fusaperazine C and E as well as four known DKPs were isolated from cultures of Colletotrichum gloeosporioides, Penicillium crustosum, both endophytic fungi isolated from Viguiera robusta, and a Fusarium spp., an endophyte of Viguiera arenaria, respectively. Their structures were established on the basis of their spectroscopic data. Conformational analysis of two known DKPs showed that folded conformations were as energetically stable as the extended one. (C) 2010 Elsevier Ltd. All rights reserved.

Fundacao de Amparo Pesquisa do Estado de Sao Paulo (FAPESP)

""Conselho Nacional de Desenvolvimento Cientifico e Tecnologico"" (CNPq)

""Coordenacao de Aperfeicoamento de Pessoal Coordenacao de Pessoal de Nivel Superior"" (CAPES)

""Ministerio de Educacao e Ciencias da Espanha"" (DGU)