Patent ID: 8137710

Claim:
A composition comprising a purified extract of the roots of Astragalus membranaceus , wherein the extract comprises: an arabinose:galactose ratio greater than 4.0:1 to 5.0:1; from about 5% to about 10% rhamnose; from about 15% to about 20% galactose; from about 10% to about 20% galacturonic acid; not more than 2% by weight protein, and, from about 10% to about 15% glucose; wherein, the extract is prepared using a first process that includes isolating a crude extract from Astragalus membranaceus and mildly treating the crude extract with an acid, the mildly treating including applying the acid to the crude extract at a concentration ranging from about 0.05M to about 0.5M, at a temperature ranging from about 15° C. to 25° C., and for a time ranging from about 1 hour to about 24 hours, wherein the temperature and time for applying the acid are selected to obtain the arabinose:galactose ratio, the galactose content, the glucose content, and a high yield; and, the extract is substantially higher in yield than an extract of the Astragalus membranaceus produced using a second process that includes applying the acid to the crude extract at a temperature and time selected to obtain an arabinose:galactose ratio of less than 3.5:1, 20%-35% galactose, and less than about 10% glucose.