Constituents of enzymatically modified isoquercitrin and enzymatically modified rutin (extract).

Abstract

Enzymatically modified isoquercitrin and enzymatically modified rutin (extract) were analyzed to determine the structures and contents of their constituents. NMR analysis revealed that the 4-hydroxyl group of glucose was glucosylated in the manufacture of enzymatically modified isoquercitrin. LC/MS analysis established that enzymatically modified isoquercitrin consists of isoquercitrin and its α-glucosylated derivatives with 1-7 additional glucose moieties. Similarly, one sample of enzymatically modified rutin (extract) was shown to consist of rutin and its α-glucosylated derivatives. Rutin derivatives with up to 32 additional glucose moieties were detected. A different sample of enzymatically modified rutin (extract) consisted of rutin, its derivative with one additional glucose and isoquercitrin. It was suggested that two additional enzymes, as well as cyclodextrin glucanotransferase, play roles in the manufacture of this product. HPLC was employed to evaluate the contents of quercetin glycosides, which should determine solubility and antioxidative activity, in the three samples.