The kapurimycin A3-guanine adduct was formed by alkylation of the antitumour antibiotic with d(CGCG)2. The site of alkylation of the guanine was confirmed by comparative NMR studies with N-7-methyl-guanine in DMSO-d6.
Fibraurin, chasmanthin, and palmarin were isolated from the stems of FIBRAUREA CHLOROLEUCA, Fam. Menispermaceae. The structure of the minor constituent, palmarin, was determined by X-ray crystallographic analysis.