FLAVONOIDS FROM DISTEMONANTHUS-BENTHAMIANUS BAILLON - METHOXYLATED FLAVONES AND INTERRELATIONSHIPS OF BENTHAMIANIN, A "[2]BENZOPYRANO-[4,3-B][1]BENZOPYRAN

The yellow heartwood of the West African tree D. benthamianus Baillon contains 12 flavonols representing the 3,3'',4'',5,7-, 2'',3,4'',5'',5,7-, 3,3'',4'',5,6,7-, 2'',3,3'',5,6,7- and 2'',3'',3,4'',5,6,7-substitution patterns. A novel peltogynoid, benthamianin (3,4,8,10-tetrahydroxy-9-methoxy-7-oxo[2]benzopyrano[4,3-b][1]benzopyran) was isolated and its relationship with the 3-O-methyflavones and distemonanthin established chemically.