کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2028909 | 1070452 | 2008 | 5 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: A facile and efficient synthesis of some (6E)-hydroximino-4-en-3-one steroids, steroidal oximes from Cinachyrella spp. sponges A facile and efficient synthesis of some (6E)-hydroximino-4-en-3-one steroids, steroidal oximes from Cinachyrella spp. sponges](/preview/png/2028909.png)
Using β-sitosterol as a starting material, (6E)-hydroximino-24-ethylcholest-4-en-3-one (1), a natural steroidal oxime from Cinachyrella alloclada and C. apion, was synthesized in four steps with a high overall yield. First, β-sitosterol (5a) is transformed into the corresponding 24-ethylcholest-4-en-3,6-dione (6a) via oxidation with pyridinium chlorochromate (PCC). Selective reduction of 6a by NaBH4 in the presence of CoCl2 gives 24-ethylcholest- 4-en-3β-ol-6-one (7a). The reaction of 7a with hydroxylamine hydrochloride offers the oxime 8a and the oxidation of 8a by Jones reagent gives the target steroid 1. (6E)-Hydroximinocholest-4-en-3-one (2) and (6E)-hydroximino-24-ethylcholest-4,22-dien-3-one (4) were synthesized by a similar method. The cytotoxicity of the synthesized compounds against sk-Hep-1 (human liver carcinoma cell line), H-292 (human lung carcinoma cell line), PC-3 (human prostate carcinoma cell line) and Hey-1B (human ovarian carcinoma cell line) cells were investigated. The presence of a cholesterol-type side chain appears to be necessary for the biological activity.
Journal: Steroids - Volume 73, Issue 3, March 2008, Pages 252–256