螺甾烷醇类 异螺甾烷醇类 (spirostanol) (isospirostanols CHOH OH 呋甾烷醇类 变形螺甾烷醇类 (furostanol (pseudo- spirostanol)O HO O CH2OH O OH HO OH O O HO O O HO 螺甾烷醇类 (spirostanols) 异螺甾烷醇类 (isospirostanols) 呋甾烷醇类 (furostanols) 变形螺甾烷醇类 (pseudo- spirostanols)