Biotransformation of ent‐kaur‐16‐en‐19‐oic acid using fungus Cunninghamella echinulata resulted in two novel hydroxylated metabolites together with five known compounds. Their structures were elucidated by means of extensive NMR and HR‐ESI‐MS data analysis. The eight compounds were measured for their cytotoxicity against the human breast carcinoma (MCF‐7) and human hepatoblastoma (HepG‐2) cell lines. Seven compounds showed no cytotoxicity to the two cell lines. One compound displayed moderate cytotoxicity against HepG‐2 and MCF‐7 with the IC50 values of 12.6 and 27.1 μM, respectively.

中文翻译：

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Cunninghamella echinulata 微生物转化 ent-Kaur-16-en-19-oic 酸的新衍生物

使用真菌 Cunninghamella echinulata 对 ent-kaur-16-en-19-oic 酸进行生物转化，产生了两种新型羟基化代谢物和五种已知化合物。通过广泛的 NMR 和 HR-ESI-MS 数据分析阐明了它们的结构。测量了八种化合物对人乳腺癌 (MCF-7) 和人肝母细胞瘤 (HepG-2) 细胞系的细胞毒性。七种化合物对两种细胞系没有细胞毒性。一种化合物对 HepG-2 和 MCF-7 显示出中等的细胞毒性，IC50 值分别为 12.6 和 27.1 μM。