Inhibition of lens aldose reductase by biflavones from Ouratea spectabilis.

Two biflavonoids were isolated from the EtOH extract from leaves of Ouratea spectabilis. Their structures were established to be the novel 6,6"-bigenkwanin and 7,7"-dimethoxyagathisflavone on the basis of spectroscopic data. The inhibition of bovine lens aldose reductase exerted by these biflavones has been studied.