6 DIHYDROFURANOFLAVONOLS FROM THE LEAF SURFACE OF VELLOZIA

2''-Isopropenyldihydrofurano (4'',5'':6,7) quercetin or velloquercetin has been characterised on the leaf surface of Vellozia streptophylla. It is accompanied by velloquercetin 4'-monomethyl ether, isorhamnetin and rhamnetin. The 3,4'-dimethyl and 3,3',4'-trimethyl ethers of velloquercetin as well as the 3-monomethyl and 3,4'-dimethyl ethers of vellokaempferol, the analogous kaempferol derivative, have similarly been identified on the leaf surface of V. stipitata. Methods for distinguishing these novel furanoflavonols from other lipophilic flavanoids are discussed. None of these compounds occur to any extent within the leaf of V. streptophylla, but instead quercetin 3-methyl ether, quercetin 3,4'-dimethyl ether, orientin, orientin 7-glucoside, iso-orientin and its 7-apioside and 7-glucoside were identified in leaf extracts.