From leaves of Quercus suber L. in addition to ten known glycosides, two new acylated flavonoids have been isolated and identified as 3-O-kaempferol 2-O-(trans-p-coumaroyl)-beta-D-glucopyranoside (1) and 3-O-kaempferol 2,3-di-O-acetyl-4-O-(cis-p-coumaroyl)-6-O-(trans-p-coumaroyl)-beta-D-glucopyranoside (3). The structures of the previously described 3-O-kaempferol 2,4-di-O-(trans-p-coumaroyl)-beta-D-glucopyranoside2) and 3-O-kaempferol 3,6-di-O-acetyl-2,4-di-O-(trans-p-coumaroyl)-beta-D-glucopyranoside3) were revised to 3-O-kaempferol 2,6-di-O-(trans-p-coumaroyl)-beta-D-glucopyranoside (4) and 3-O-kaempferol 3,4-di-O-acetyl-2,6-di-O-(trans-p-coumaroyl)-beta-D-glucopyranoside (5).
Constituents of Cupuliferae. XIII. New and revised structures of acylated flavonoids from Quercus suber L
PIZZA, Cosimo;DE TOMMASI, Nunziatina
1991-01-01
Abstract
From leaves of Quercus suber L. in addition to ten known glycosides, two new acylated flavonoids have been isolated and identified as 3-O-kaempferol 2-O-(trans-p-coumaroyl)-beta-D-glucopyranoside (1) and 3-O-kaempferol 2,3-di-O-acetyl-4-O-(cis-p-coumaroyl)-6-O-(trans-p-coumaroyl)-beta-D-glucopyranoside (3). The structures of the previously described 3-O-kaempferol 2,4-di-O-(trans-p-coumaroyl)-beta-D-glucopyranoside2) and 3-O-kaempferol 3,6-di-O-acetyl-2,4-di-O-(trans-p-coumaroyl)-beta-D-glucopyranoside3) were revised to 3-O-kaempferol 2,6-di-O-(trans-p-coumaroyl)-beta-D-glucopyranoside (4) and 3-O-kaempferol 3,4-di-O-acetyl-2,6-di-O-(trans-p-coumaroyl)-beta-D-glucopyranoside (5).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
