Antimycobacterial natural products from higher plants

Two-hundred and thirty crude organic extracts from 118 plant species distributed among ten families of higher plants have been evaluated for antimycobacterial activity against Mycobacterium tuberculosis (H;Bioactive chromatographic fractions of Borrichia frutescens (Asteraceae) provided two new triterpenes and one known cycloartenol. In radiorespirometric bioassays against M. tuberculosis, the new (24R)-24,25-epoxycycloartan-3-one and the known (24R)-24,25-epoxycycloartan-3;In an attempt to study the structural dependence of antimycobacterial activity of the highly active guaianolide dehydrocostus lactone (MICs of 2 and 16 ;Antimycobacterial root extracts of Inula helenium and Rudbeckia subtomentosa were chemically investigated. Chromatographic fractions of active root extracts of I. helenium provided the known eudesmanolides alantolactone, isoalantolactone, and 11;Methanol extracts of fruits of Melia volkensii were chemically investigated and shown to contain two new triterpenes and the known triterpenoid kulonate. The structures of the new 12...