Patent ID: 7015339

Claim:
A method for isolating phenolic compounds comprising the steps of: (a) providing an aqueous plant extract at a first pH greater than 10, the aqueous plant extract comprising phenolic compounds, wherein the aqueous plant extract is obtained from a plant selected from the group consisting of soybean, chick pea, red clover, subterranean clover, ground pea, milk vetch, marama bean, sword bean, jack bean, seaside sword bean, carao bean, cluster bean, balu, hyacinth bean, grass pea, Indian vetch, garden pea, djenko bean, goa bean, yam bean, broad bean, earth pea, lentil, jumping bean, alfalfa, velvet bean, African locust bean, inga, Cyprus vetch, yebnut, tallow tree, Polynesian chestnut, kudzu root, oil bean tree, mesquite, tamarind, fenugreek, Indian licorice, ground nut, kinnow, gunpowder tea, buckwheat, clover, and preparations thereof; (b) washing the aqueous plant extract with an organic solvent wherein the organic solvent is selected from 1-butanol, 2-butanol, t-butanol, pentanol, hexanol, heptanol, octanol, ethyl acetate, tetrahydrofuran, hexane, heptane, octane, isohexane, diethylether, methyl ethyl ketone, diisopropylether, or a polar or non-polar organic solvent which is immiscible with water or mixtures thereof, to yield an aqueous phase and an organic phase; (c) adjusting the pH of the aqueous phase to a pH of less than 9 to yield a pH-adjusted aqueous phase; and (d) isolating flavonoid, anthocyanidin, flavone, flavonol, flavanone, isoflavone, glycosylated isoflavone, or proanthocyanidin compounds from the pH-adjusted aqueous phase.