Flavonoid sulfates from the Convolvulaceae

A novel flavonoid, quercetin 7-methyl ether-3,3'-disulfate (5), was obtaine d from the roots of Argyreia mollis, together with the known compounds quer cetin 7-methyl ether-3-sulfate (4) and kaempferol 7-methyl ether-3-sulfate (2). Two further new flavonoid sulfates, quercetin 3,7-dimethyl ether-4'-su lfate (6) and quercetin 3',4',7-trimethyl ether-3-sulfate (8), were isolate d from the aerial vegetative parts of Ipomoea regnellii, together with the known compound kaempferol 4',7-dimethyl ether-3-sulfate (3). This is the fi rst report on sulfated flavonoids in the Convolvulaceae family and, further more, the presence of flavonoids in A. capitata, A. mollis, I. reticulata a nd I. regnellii is reported for the first time. (C) 1998 Published by Elsev ier Science Ltd. All rights reserved.