Koshy K T
J Chromatogr. 1976 Nov 3;126:641-50. doi: 10.1016/s0021-9673(01)84108-x.
Structure-electron capture sensitivity relationships were established for underivatized 17alpha-acetoxyprogesterones. While progesterone was very insensitive, 17alpha-acetoxyprogesterone had a response of 4.8 X 10(2) C/mole. Methyl groups in the A or B ring of 17alpha-acetoxyprogesterone had no effect. A keto group at C-6 was 25 times more sensitive (1.2 X 10(4) C/mole). A double bond at C-6,7 enhanced the sensitivity sevenfold (3.5 X 10(3) C/mole), but double bonds at C-1,2 or C-9,11 had only slight effect. Substitution at C-16 was important. A methyl group at C-16 had two and three times the sensitivity in the 3-keto delta4 and 3-keto delta4,6 series (1.1 X 10(3) and 1.1 X 10(4) C/mole), respectively. A methylene group at C-16, in contrast showed a six-and twofold greater sensitivity over the C-16 methyl in the two series (7 X 10(3) and 2.2 X 10(4) C/mole), respectively. The most sensitive compound was 6-dehydro-6methyl-16-methylene-17alpha-acetoxyprogesterone (melengestrol acetate). Its sensitivity was 2.2 X 10(4) C/MOL, Comparable to the most sensitive halo esters of steroid alcohols reported in the literature. Its electron capture coefficient was 3-7.6X 10(10) 1/mole. The coef-icient was independent of the detector temperature, indicating low activation energy for electron absorpiton.
建立了未衍生化的17α - 乙酰氧基孕酮的结构 - 电子捕获灵敏度关系。孕酮非常不敏感，而17α - 乙酰氧基孕酮的响应为4.8×10² C/摩尔。17α - 乙酰氧基孕酮的A环或B环中的甲基没有影响。C - 6位的酮基敏感度高25倍（1.2×10⁴ C/摩尔）。C - 6,7位的双键使敏感度提高了7倍（3.5×10³ C/摩尔），但C - 1,2或C - 9,11位的双键只有轻微影响。C - 16位的取代很重要。C - 16位的甲基在3 - 酮基δ⁴和3 - 酮基δ⁴,6系列中的敏感度分别是其2倍和3倍（分别为1.1×10³和1.1×10⁴ C/摩尔）。相比之下，C - 16位的亚甲基在这两个系列中的敏感度分别比C - 16位甲基高6倍和2倍（分别为7×10³和2.2×10⁴ C/摩尔）。最敏感的化合物是6 - 脱氢 - 6 - 甲基 - 16 - 亚甲基 - 17α - 乙酰氧基孕酮（醋酸美仑孕酮）。其敏感度为2.2×10⁴ C/摩尔，与文献中报道的最敏感的甾醇卤代酯相当。其电子捕获系数为3 - 7.6×10¹⁰ 1/摩尔。该系数与检测器温度无关，表明电子吸收的活化能较低。
