Rhodiocyanosides A and B, new antiallergic cyanoglycosides from Chinese natural medicine "si lie hong jing tian", the underground part of Rhodiola quadrifida (Pall.) Fisch. et Mey.

Two new antiallergic cyanoglycosides named rhodiocyanosides A and B were isolated from the Chinese natural medicine "Si Lie Hong Jing Tian" (Shiretsukoukeiten in Japanese), the underground part of Rhodiola quadrifida (Pall.) Fisch. et Mey., together with two new glycosides, octyl alpha-L-arabinopyranosyl(1-6)-beta-D-glucopyranoside and gossypetin 7-O-beta-D-glucopyranosyl(1-3)-alpha-L-rhamnopyranoside. Their chemical structures were determined on the basis of chemical and physicochemical evidence. Rhodiocyanosides A and B exhibited inhibitory activity on the histamine release from rat peritoneal exudate cells sensitized with anti-DNP IgE. In addition, rhodiocyanoside A was found to inhibit the PCA reaction in rats.