García-Gutiérrez Hugo A, Cerda-García-Rojas Carlos M, Hernández-Hernández Juan D, Román-Marín Luisa U, Joseph-Nathan Pedro
Departamento de Química y Programa de Posgrado en Farmacología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Apartado 14-740, Mexico city 07000, Mexico.
Phytochemistry. 2008 Nov;69(16):2844-8. doi: 10.1016/j.phytochem.2008.09.013. Epub 2008 Oct 24.
Medium polarity fractions of the hexane extracts of the stems of Bursera suntui afforded six previously known (1-6) and four hitherto unknown verticillane derivatives: (1S,3Z,7S,8S,11S,12S)-(+)-7,8-epoxyverticill-3-en-12,20-diol (7), (1S,3Z,7S,8S,11S,12S)-(+)-7,8-epoxyverticill-3-en-12,20-diol 20-acetate (8), (1S,3Z,7S,11S,12S)-(+)-verticilla-3,8(19)-dien-7,12,20-triol (9), and (1S,3Z,7S,11S,12S)-(+)-verticilla-3,8(19)-dien-7,12,20-triol 20-acetate (10). Acetylation of 9 and 10 yielded (1S,3Z,7S,11S,12S)-(+)-verticilla-3,8(19)-dien-7,12,20-triol 7,20-diacetate (11), while hydrolysis of 8 gave 7. The structures and stereochemistry of 7-11 were established by spectroscopic analyses, particularly by 1D and 2D NMR spectra and HRESIMS. The conformational preferences of 7-11 were studied by molecular mechanics modelling employing the Monte Carlo protocol followed by B3LYP/DGDZVP DFT calculation, thus supporting the observed (1)H NMR NOESY cross peaks.
桑图伊裂榄茎部正己烷提取物的中等极性馏分得到了6个已知化合物（1 - 6）和4个新的环萜类衍生物：(1S,3Z,7S,8S,11S,12S)-(+)-7,8-环氧环萜-3-烯-12,20-二醇（7）、(1S,3Z,7S,8S,11S,12S)-(+)-7,8-环氧环萜-3-烯-12,20-二醇20-乙酸酯（8）、(1S,3Z,7S,11S,12S)-(+)-环萜-3,8(19)-二烯-7,12,20-三醇（9）和(1S,3Z,7S,11S,12S)-(+)-环萜-3,8(19)-二烯-7,12,20-三醇20-乙酸酯（10）。9和10的乙酰化反应得到了(1S,3Z,7S,11S,12S)-(+)-环萜-3,8(19)-二烯-7,12,20-三醇7,20-二乙酸酯（11），而8的水解反应得到了7。通过光谱分析，特别是一维和二维核磁共振谱以及高分辨电喷雾电离质谱，确定了7 - 11的结构和立体化学。采用蒙特卡罗方法的分子力学建模，随后进行B3LYP/DGDZVP密度泛函理论计算，研究了7 - 11的构象偏好，从而支持了观察到的氢核磁共振二维核欧沃豪斯效应谱交叉峰。
