Kyoto Pharmaceutical University, 1 Shichono-cho, Misasagi, Yamashina-ku, Kyoto 607-8412, Japan.
Steroids. 2012 Oct;77(12):1198-204. doi: 10.1016/j.steroids.2012.07.006. Epub 2012 Jul 25.
Circular dichroism (CD) spectra of the 2,2'-binaphthyl ester derived from Δ(5)-sterols showed not bisignate CD but diagnostic CD bands at around 210 and 240 nm. These bands might be attributable to an interaction between an olefinic chromophore and a binaphthyl one. Various types of unsaturated sterols were thus derivatized followed by complete hydrogenation, to give saturated sterols. As a result, CD spectra of the binaphthyl derivatives of the saturated sterols showed bisignate curves centered at 240 nm (3S(β): positive chirality; 3R(α): negative one). This suggested a straightforward and practical method for discriminating the absolute stereogenic center at the C-3 positions of sterols based on an induced CD. This finding should contribute significantly to the analysis of metabolites of various types of sterols.
圆二色性（CD）光谱的 2,2'-联萘基酯衍生自 Δ(5)-甾醇显示不是双信号 CD 而是在 210 和 240nm 左右的诊断性 CD 带。这些带可能归因于烯烃发色团和联萘发色团之间的相互作用。因此，各种类型的不饱和甾醇被衍生化，然后完全氢化，得到饱和甾醇。结果，饱和甾醇的联萘衍生物的 CD 光谱显示出以 240nm 为中心的双信号曲线（3S(β)：正手性；3R(α)：负手性）。这表明了一种基于诱导 CD 区分甾醇 C-3 位绝对立体中心的简单实用的方法。这一发现应该对各种类型的甾醇代谢物的分析有重要贡献。
