NAPHTHAQUINONE PIGMENTS FROM TORULA HERBARUM: STRUCTURE OF O-METHYLHERBARIN

Abstract

A third naphthaquinone pigment isolated from Torula herbarin is now identified as O-methylherbarin by IR, NMR and mass spectroscopic methods. The structure is confirmed by partial synthesis by methylation of herbarin using methyl iodide and silver oxide. The gas chromatographic-mass spectrometric characteristics of herbarin, dehydroherbarin and O-methylherbarin are described.