GERANYLATED AND PRENYLATED FLAVONOIDS FROM THE TWIGS OF DORSTENIA-MANNII

The twigs of Dorstenia mannii yielded three prenylated and one geranyl ated flavonoids: 3',4'-(2,2-dimethylchromano)-2' ,4-dihydroxychalcone, 6,7-bis-(2,2-dimethylchromano)-flavanone,7,8-(2,2- chromeno)-6-gerany l-3,5,3',4'-tetrahydroxyflavonol and hylallyl)-3,5,7,4'-tetrahydroxy-3 '-methoxyflavonol for which the names dorsmanin A-D, respectively, are proposed. Also identified were the known flavonoids: dimethylallyl)-5 ,7,4'-trihydroxy-3'-methoxyflavone and ,3-dimethylallyl)-5,7,3',4'-tet rahydroxyflavanone. (C) 1998 Elsevier Science Ltd. All rights reserved .