MR566A and MR566B, New Melanin Synthesis Inhibitors Produced by Trichoderma harzianum

II. Physico-chemical Properties and Structural Elucidation

Abstract

New melanin synthesis inhibitors (MR566A and B) and six related known isocyanocyclopentenes were isolated from the fermentation broth of Trichoderma harzianum, and their structures were elucidated by spectroscopic methods. The structures of novel isocyanides, MR566A (1) and B (2), were elucidated as 1-(3-chloro-1, 2-dihydroxy-4-isocyano-4-cyclopenten-1-yl)ethanol, 1-(1, 2, 3-trihydroxy-3-isocyano-4-cyclopenten-1-yl)ethanol, respectively. The structure of novel oxazole, MR93B (9), was elucidated as 4-[(1Z)-3-hydroxy-2-hydroxymethyl-1-propen-1-yl]oxazole.