Antioxidant activities of the aqueous and ethanol extracts of pigeonpea [Cajanus
cajan (L.) Millsp.] leaves, as well as petroleum ether, ethyl acetate, n-butanol and water
fractions and the four main compounds separated from the ethanol extract, i.e.
cajaninstilbene acid (3-hydroxy-4-prenylmethoxystilbene-2-carboxylic acid), pinostrobin,
vitexin and orientin