The invention relates to a group of high-activity
glycosyl transferases responsible for
sugar chain extension and an application of the
glycosyl transferases. Specifically, the invention provides
glycosyl transferase and a derivative polypeptide thereof, which can efficiently catalyze the reaction of extending
sugar chains on the first glycosyl at the C-20 site and the first glycosyl at the C-6 site of a tetracyclic
triterpenoid substrate. The
ginsenoside products such asginsenoside Rb1, the
ginsenoside Rb3, the
ginsenoside DMGG, the ginsenoside DMGX, the
gynostemma pentaphyllum
saponin LXXV, the
gynostemma pentaphyllum
saponin XVII, the
gynostemma pentaphyllum
saponin XIII,
gynostemma pentaphyllum saponin IX, notoginsenoside U and the notoginsenoside R1, notoginsenoside R2, notoginsenoside R3, 3-O-beta-(D-xylopyranosyl)-beta-(D-glucopyranosyl)-CK, 20-O-glucosyl
ginsenoside Rf, Rd-C20-O-Rha, ginsenoside Rg2, and
ginsenoside Re and the like can be obtained. The glycosyl
transferase disclosed by the invention can also be applied to construction of artificially synthesized ginsenoside and a plurality of new ginsenosides and derivatives thereof.