Gynosaponin TN-1 producing from the enzymatic conversion of gypenoside XLVI by naringinase and its cytotoxicity on hepatoma cell lines

Gypenoside XLVI (gyp XLVI) is one of the major dammarane-type triterpenoid saponins from Gynostamma pentaphallum with glucosyls at C-3 and C-20 positions, which may constrain its bioactivities. The enzymatic conversion of gyp XLVI by naringinase, and the cytotoxicity of enzymolysis product on SMMC7721 and Bel7402 hepatoma cells were investigated. The results showed that gynosaponin TN-1 (gyp TN-1) was produced from the enzymatic conversion of gyp XLVI by naringinase. The optimum enzymolysis conditions were pH 4.2, 47.3 °C, and 16 h, with a yield of 73.44 ± 6.52% for gyp TN-1. In addition, gyp TN-1 exhibited higher inhibitory activities on SMMC7721 and Bel7402 hepatoma cells than gyp XLVI. Results from methyl thiazolyl tetrazolium (MTT) assay and acridine orange (AO)/ethidium bromide (EB) double staining were highly consistent. These results demonstrated that enzymatic conversion could be a promising method for producing gyp TN-1 from the biotransformation of gyp XLVI and the preparation of gyp TN-1 might provide a reference for the acquisition of novel anticancer drugs.