Two new flavonoid glycosides from Iris tectorum

Abstract Phytochemical investigation of the ethanol extract of rhizomes of Iris tectorum resulted in the isolation and characterization of two new flavonoid glycosides, tectorigenin-7- O -β- d -fucopyranoside ( 1 ), 3,5,4′-trihydroxy-7,3′-dimethoxyflavanone-5- O -α- l -rhamnopyranoside ( 2 ), together with two known ones ( 3 , 4 ). The rhamnose substituent at C-5 displayed uncommon connection in naturally occurring flavonoid glycosides. Their structures were elucidated on the basis of extensive spectroscopic analysis. All of the isolates were evaluated for their in vitro inhibitory activity against aldose reductase.