Novel epitetrathiodioxopiperazines, emethallicins B and C, as potent inhibitors of compound 48/80-induced histamine release, from Emericella heterothallica

Abstract

The structure elucidation of emethallicins B (1) and C (2), novel epitetrathiodioxopiperazines, possessing strong inhibitory activity of the histamine release from mast cells, isolated from the mycelial extract of Emericella heterothallica(mating type a), is reported, based on their ¹H and ¹³C n.m.r. spectra and a chemical correlation of emethallicin A (10) with apoaranotin (11); they are diesters of two C₆–C₂ acids having the same basic skeletons as apoaranotin (11) and aranotin (13), respectively.