Sarcodonins and sarcoviolins, bioactive polyhydroxy-p-terphenyl pyrazinediol dioxide conjugates from fruiting bodies of the basidiomycete Sarcodon leucopus

Six new polyhydroxy-p-terphenyl pyrazinediol dioxide conjugates (4-9) related to sarcodonin (3) have been isolated from the EtOAc extract of the fruiting bodies of the basidiomycete Sarcodon leucopus and we established their structures by spectral analysis and chemical conversions. Three of them, named sarcodonins alpha (4), beta (5), and gamma (6), afforded the same peracetate 12 upon acetylation. Compounds 7, 8, and 9 gave peracetate 13 and were characterized as the N-oxide epimers of 3-5, respectively, and are named, accordingly, episarcodonin, episarcodonin alpha, and episarcodonin beta. From the EtOH extract, we obtained a mixture of two violet pigments. Chemical and spectroscopic data allowed their structures to be established as the p-terphenyl ortho-quinones related to the sarcodonins, namely sarcoviolin alpha (10) and episarcoviolin alpha (11). Compounds 3, 4, 6, and 7 and the mixture of 10 and 11 were found to be active in assays against tumor cell cultures. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004).