Xi an Pincredit Bio-tech Co., Ltd sell "Quercetin Powder"

Extracted from Sophora japonica buds, this quercetin is available as both the dihydrate (95% purity) and anhydrous (95%/98% USP) forms - a greenish-yellow, bitter-tasting powder that is only slightly water-soluble but dissolves readily in alkaline solvents. The dihydrate form retains 8-12% moisture versus under 4% for the anhydrous form, from which the crystalline water has been removed. Known for antiviral, antibacterial, antioxidant, antiallergic and antithrombotic activity, quercetin may help ease coughing, lower blood pressure and lipids, and strengthen capillary resistance; it is commonly incorporated into dietary supplements, beverages and food products, with free samples available on request.