目的 利用走马胎内生菌Sphingomonas yabuuchiae GTC 868^T（AB071955）和果胶酶Ultra AFP对走马胎三萜皂苷Ag3进行生物转化，制备具有抗肿瘤活性的三萜皂苷衍生物。方法 采用硅胶柱色谱分离技术对转化产物进行分离；采用波谱技术进行化合物结构鉴定；采用CCK法进行细胞毒活性测试。结果 制备得到5个三萜皂苷衍生物：3β-O-{α-L-吡喃鼠李糖基-（1→3）-[β-D-吡喃木糖基-（1→2）]-β-D-吡喃葡萄糖-（1→4）-α-L-吡喃阿拉伯糖基}-西克拉敏A（1）、3β-O-{β-D-吡喃葡萄糖基-（1→4）-[β-D-吡喃葡萄糖基-（1→2）]-α-L-吡喃阿拉伯糖基}-西克拉敏A（2）、3β-O-{β-D-吡喃葡萄糖基-（1→2）-α-L-吡喃阿拉伯糖基}-西克拉敏A（3）、3-O-α-L-吡喃阿拉伯糖基-西克拉敏A（4）和西克拉敏皂苷元A（5）。结论 化合物2~5为首次从走马胎三萜皂苷生物转化产物中分离得到，所得部分产物具有一定的抗肿瘤活性，其中化合物2对肝癌细胞的抑制活性强于底物和阳性药顺铂。

Objective To study the chemical constituents of transformed products by Sphingomonas yabuuchiae GTC 868^T (AB071955) and Pectinex Ultra AFP from the saponin of Ardisia gigantifolia. Methods Transformation products separated by the process of silica gel column, compounds were identified and elucidated by spectral and chemical methods. Their cytotoxicity activities were tested by Cell Counting Kit 8 colorimetric assay. Results Five triterpenoid saponins were obtained, including 3β-O-{α-L-rhamnopyranosyl-(1→3)-[β-D-xylopyranosyl-(1→2)]-β-D-glucopyranosyl-(1→4)-α-L-arabinopyranosyl}-cyclamiretin A (1), 3β-O-{β-D-glucopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→2)]-α-L-arabinopyranoside}-cyclamiretin A (2), 3β-O-{β-D-glucopyranosyl-(1→2)-α-L-arabinopyranoside}-cyclamiretin A (3), 3-O-α-L-arabinopyranosyl cyclamiretin A (4), and cyclamiretin A (5). Conclusion Compounds 2-5 are obtained by biotransformation for the first time. Some of the compounds showed certain antitumor activity, among them, compound 2 shows more cytotoxicity activity than Ag3 and positive control.

国家自然科学基金资助项目（31370006）