An efficient synthesis of several A,B-modified D-homo lactone androstane derivatives is reported. The synthetic scheme shows the transformation of 17-oxa-D-homoandrost-5-en-16-on-3β-yl acetate 1 into the 5α-hydroxy-17-oxa-D-homoandrostane-6,16-dion-3β-yl acetate (4). After the dehydration of 4, the newly synthesized 6-keto-androst-4-ene-3β-yl acetate derivative 5 was oximinated to give the 6-hydroximino derivative 6, which was converted to A,B-condensed isoxazole derivatives 7 and 8. Compound 4 was also converted (via 6(E)- and 6(Z)-hydroximino derivatives 9 and 10) to the B-seco-cyano derivative 11 under a Beckmann fragmentation, while compound 5 was transformed to the 4β,5β-epoxy derivative 12. Structures were confirmed by IR, 1H NMR, 13C NMR, and HRMS, and for 7 and 8 by X-ray crystallography. All compounds were tested in vitro on six malignant cell lines (MCF-7, MDA-MB-231, PC-3, HeLa, HT-29, K562) and one non-tumor MRC-5 cell line. Significant antiproliferative activity was observed for specific compounds against prostate (PC-3), cervical (HeLa) and colon (HT-29) cancer cells, while no compounds showed antiproliferative activity to non-cancerous control cells (MRC-5). Interestingly, 1–8 displayed selective antiproliferative activity against estrogen-independent (ER−, MDA-MB-231) breast cancer cells over estrogen-dependent (ER+, MCF-7) breast cancer cells.
本研究报道了几种 A、B 改性 D-高内酯雄烷衍
生物的高效合成方法。合成方案显示了 17-oxa-D-homoandrost-5-en-16-on-3β-yl acetate 1 转化为 5α-hydroxy-17-oxa-D-homoandrostane-6,16-dion-3β-yl acetate (4)的过程。4 脱
水后,新合成的 6-酮基
雄甾烷-4-烯-3β-基
乙酸酯衍
生物 5 被氧化,得到 6-羟基亚
氨基衍
生物 6,再将其转化为 A,B-缩合
异噁唑衍
生物 7 和 8。化合物 4 还(通过 6(E)- 和 6(Z)- 羟基亚
氨基衍
生物 9 和 10)在贝克曼碎片作用下转化为 B-共
氰衍
生物 11,而化合物 5 则转化为 4β,5β-环氧衍
生物 12。红外光谱、1H NMR、13C NMR 和 HRMS 对化合物的结构进行了确认,X 射线晶体学对 7 和 8 进行了确认。所有化合物都在六种恶性
细胞系(MCF-7、
MDA-MB-231、PC-3、HeLa、HT-29、K562)和一种非肿瘤 MRC-5
细胞系上进行了体外测试。观察发现,特定化合物对前列腺癌细胞(PC-3)、宫颈癌细胞(HeLa)和结肠癌细胞(HT-29)具有显著的抗增殖活性,而对非癌症对照细胞(MRC-5)则没有发现任何化合物具有抗增殖活性。有趣的是,与
雌激素依赖性(ER+,MCF-7)乳腺癌细胞相比,1-8 对
雌激素依赖性(ER-,
MDA-MB-231)乳腺癌细胞具有选择性抗增殖活性。