Antioxidant Potential of Flavonoid Glycosides From Manniophyton Fulvum Müll. (Euphorbiaceae): Identification and Molecular Modeling

Abstract

Chemical investigation of the leaves of Manniophyton fulvum led to the isolation of seven flavonoid glycosides: myricetin-3- O - β- Dd -rhamnoside ( 1 ), kaempferol-3- O - β- d -rhamnoside ( 2 ), quercetin-3- O - β- d -glucoside ( 3 ), quercetin-3- O - β- d -rhamnoside ( 4 ), quercetin-3- O - β- d -galactoside ( 5 ), rutin ( 6) and quercetin ( 7 ). The structures of the com- pounds were established by spectroscopic analyses as well as by comparison with pub- lished data. Some of the compounds showed strong antioxidant activity which validates the traditional use of the plant. An attempted correlation between the computed HOMO- LUMO energies and the measured antioxidant activities was established. We have also es- timated the cardiotoxicity of the compounds by calculating the predicted logarithm of the human Ether-‘a-go-go Related Gene (loghERG) using the QikProp program. These purified flavonoids are new potential lead compounds for the development of antioxidant drugs