Novel Biotransformation Process of Podophyllotoxin to 4 -Sulfur-Substituted Podophyllum Derivates with Anti-Tumor Activity by Penicillium purpurogenum Y.J. Tang
作者:J.-K. Bai、W. Zhao、H.-M. Li、Y.-J. Tang
DOI:10.2174/092986712799034914
日期:2012.2.1
According to the structure-function relationship of podophyllotoxin (PTOX) and its analogue of 4- demethylepipodophyllotoxin (DMEP), the 4 β-substitution of sulfur-containing heterocyclic compounds with a carbon-sulfur bond at 4 position of PTOX or DMEP is an essential modification direction for improving the anti-tumor activity. So, four novel 4 β-sulfursubstituted podophyllum derivatives (i.e., 4β -(1,2,4-triazole-3-yl)sulfanyl-4-deoxy-podophyllotoxin (4-MT-PTOX), 4β-(1,3,4- thiadiazole-2-yl)sulfanyl-4-deoxy-podophyllotoxin (4-MTD-PTOX), 4β-(1,2,4-triazole-3-yl)sulfanyl-4-deoxy-4 -demethylepipodophyllotoxin (4-MT-DMEP), and 4β-(1,3,4-thiadiazole-2-yl)sulfanyl-4-deoxy-4-demethylepipodophyllotoxin (4-MTD-DMEP)) were designed and then successfully biosynthesized in this work. In the novel sulfur-substituted biotransformation processes, PTOX and DMEP was linked with sulfur-containing compounds (i.e., 3-mercapto-1,2,4-triazole (MT) and 2-mercapto-1,3,4-thiadiazole (MTD)) at 4 position of cycloparaffin to produce 4-MT-PTOX (1), 4-MTD-PTOX (2), 4-MT-DMEP (3), and 4-MTD-DMEP (4) by Penicillium purpurogenum Y.J. Tang, respectively, which was screened out from Diphylleia sinensis Li (Hubei, China). All the novel compounds exhibited promising in vitro bioactivity, especially 4-MT-PTOX (1). Compared with etoposide (i.e., a 50 % effective concentration [EC50] of 25.72, 167.97, and 1.15 M), the EC50 values of 4-MT-PTOX (1) against tumor cell line BGC-823, A549 and HepG2 (i.e., 0.28, 0.76, and 0.42 M) were significantly improved by 91, 221 and 2.73 times, respectively. Moreover, the EC50 value of 4-MT-PTOX (1) against the normal human cell line HK-2 (i.e., 182.4μM) was 19 times higher than that of etoposide (i.e., 9.17 μM). Based on the rational design, four novel 4 β-sulfur-substituted podophyllum derivatives with superior in vitro anti-tumor activity were obtained for the first time. The correctness of structure-function relationship and rational drug design was strictly demonstrated by the in vitro biological activity tests.
根据荚膜多酚(PTOX)及其类似物4-去甲基荚膜多酚(DMEP)的结构-功能关系,在PTOX或DMEP的4位上以碳硫键取代含硫杂环化合物的4β取代是提高其抗肿瘤活性的一个重要改造方向。因此,四种新型 4 β-硫代荚膜衍生物(即、4β-(1,2,4-三唑-3-基)硫酰基-4-脱氧鬼臼毒素(4-MT-PTOX)、4β-(1,3,4-噻二唑-2-基)硫酰基-4-脱氧鬼臼毒素(4-MTD-PTOX)、4β-(1,2、4-MTD-DMEP) 和 4β-(1,3,4-噻二唑-2-基)硫酰-4-脱氧-4-去甲基鬼臼毒素 (4-MTD-DMEP)) 的设计,并成功地进行了生物合成。在新的硫代生物转化过程中,PTOX 和 DMEP 与含硫化合物(即、在新的硫代生物转化过程中,PTOX 和 DMEP 与含硫化合物(即 3-巯基-1,2,4-三氮唑(MT)和 2-巯基-1,3,4-噻二唑(MTD))在环烷烃的 4 位连接,由 Penicillium purpurogenum Y. J. Tang 分别生成 4-MT-PTOX (1)、4-MTD-PTOX (2)、4-MT-DMEP (3) 和 4-MTD-DMEP (4)。J. Tang分别从中国湖北省李氏双孢蘑菇中筛选出来。所有新化合物都表现出良好的体外生物活性,尤其是 4-MT-PTOX (1)。与依托泊苷(50%有效浓度[EC50]分别为 25.72、167.97 和 1.15 M)相比,4-MT-PTOX(1)对肿瘤细胞株 BGC-823、A549 和 HepG2 的 EC50 值(0.28、0.76 和 0.42 M)分别显著提高了 91、221 和 2.73 倍。此外,4-MT-PTOX(1)对正常人细胞株 HK-2 的 EC50 值(即 182.4μM)是依托泊苷(即 9.17 μM)的 19 倍。在合理设计的基础上,首次获得了四种体外抗肿瘤活性更强的新型 4 β-硫代荚蒾衍生物。体外生物活性试验严格证明了结构-功能关系和合理药物设计的正确性。