COUMARINS OF HERACLEUM CANESCENS AND HERACLEUM PINNATUM

Abstract

Roots of Heracleum canescens have been found to be very rich in coumarins. A light petroleum ether extract of the roots gave coumarins in 9 per cent yield. This on Chromatographie separation led to the isolation of four coumarins which were identified as osthol, 8–geranoxypsoralen, imperatorin and heraclenin. The roots can be profitably exploited for the production of xanthotoxin, an important dermal photosensitizing agent. The petroleum ether extract of the roots of Heracleum pinnatum contains about 3 per cent coumarins which on repeated chromatography yielded five coumarins. These were identified as osthol, isobergapten, 8–geranoxypsoralen, imperatorin and heraclenin. The roots of H. pinnatum also are good source for xanthotoxin.