Resumen
A glycoside derivative of compound K (CK) was synthesized by using a glycosyltransferase, and its biological activity was tested against various cancer-cell lines. A regiospecific, ß-1,4-galactosyltransferase (LgtB) converted 100% of 0.5 mmol CK into a galactosylated product in 3 h. The structure of the synthesized derivative was revealed with high performance liquid chromatography, mass spectroscopy, as well as nuclear magnetic resonance analyses, and it was recognized as 20-O-ß-D-lactopyranosyl-20(S)-protopanaxadiol (CKGal). Out of the four cancer-cell lines tested (gastric carcinoma (AGS), skin melanoma (B16F10), cervical carcinoma (HeLa), and brain carcinoma (U87MG)), CKGal showed the best cytotoxic ability against B16F10 and AGS when compared to other ginsenosides like compound K (20-O-ß-D-glucopyranosyl-20(S)-protopanaxadiol), Rh2 (3-O-ß-D-glucopyranosyl-20(S)-protopanaxadiol), and F12 (3-O-ß-D-glucopyranosyl-12-O-ß-D-glucopyranosyl-20(S)-protopanaxadiol). Thus, the synthesized derivative (CKGal) is a pharmacologically active ginsenoside.