Biosynthesis of tajixanthone and shamixanthone by Aspergillus variecolor: incorporation of oxygen-18 gas
Abstract
Mass spectral and 13C n.m.r. analyses of tajixanthone (1) and shamixanthone (2) formed during growth of Aspergillus variecolor under atmospheres containing [18O2] oxygen gas showed incorporation of four and three 18O labels per molecule of (1) and (2), respectively, and provided information about the mode of xanthone ring formation.