O-acylated flavonoid glycosides from the needles ofPicea obovata II. 3′- and 6′-isomers of p-coumaroylastragalin

Two monoacylated glycosides have been isolated from the needles ofPicea obovata — the previously unknown 3-p-coumaroylastragalin (I) and 6-p-coumaroylastragalin (II). It has been established that under the conditions of mild saponification and acid hydrolysis isomerization of (I) into (II) and the splitting out of the acy1 residue takes place. The position of the acy1 substituent has been shown by PMR spectroscopy using the INDOR method. The physicochemical characteristics of the acylated glycosides and of their heptaacetates are given.All-Union Scientific-Research Institute of Medicinal Plants, Moscow. Irkutsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, Moscow. I. M. Sechenov First Moscow Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 186–190, March–April, 1980.