Suárez-Ortiz G Alejandra, Cerda-García-Rojas Carlos M, Fragoso-Serrano Mabel, Pereda-Miranda Rogelio
Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Circuito Exterior Ciudad Universitaria , Mexico City 04510, Mexico.
Departamento de Química, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional , A. P. 14-740, Mexico City 07000, Mexico.
J Nat Prod. 2017 Jan 27;80(1):181-189. doi: 10.1021/acs.jnatprod.6b00953. Epub 2017 Jan 18.
Brevipolides K-O (1-5), five new cytotoxic 6-(6'-cinnamoyloxy-2',5'-epoxy-1'-hydroxyheptyl)-5,6-dihydro-2H-pyran-2-ones (IC values against six cancer cell lines, 1.7-10 μM), were purified by recycling HPLC from Hyptis brevipes. The structures, containing a distinctive tetrahydrofuran ring, were established by comprehensive quantum mechanical calculations and experimental spectroscopic analysis of their NMR and ECD data. Detailed analysis of the experimental NMR H-H vicinal coupling constants in comparison with the corresponding DFT-calculated values at the B3LYP/DGDZVP level confirmed the absolute configuration of 3 and revealed its conformational preferences, which were further strengthened by NOESY correlations. NMR anisotropy experiments by the application of Mosher's ester methodology and chemical correlations were also used to conclude that this novel brevipolide series (1-5) share the same absolute configuration corresponding to C-6(R), C-1'(S), C-2'(R), C-5'(S), and C-6'(S).
短柄内酯K - O（1 - 5），五种新型细胞毒性6 -（6'-肉桂酰氧基-2'，5'-环氧-1'-羟基庚基）-5，6 - 二氢-2H - 吡喃-2 - 酮（对六种癌细胞系的IC值为1.7 - 10 μM），通过循环高效液相色谱法从短柄香科科植物中纯化得到。其结构含有独特的四氢呋喃环，通过综合量子力学计算以及对其核磁共振（NMR）和电子圆二色（ECD）数据的实验光谱分析得以确定。将实验NMR的H - H邻位偶合常数与在B3LYP/DGDZVP水平下相应的密度泛函理论（DFT）计算值进行详细分析，证实了3的绝对构型并揭示了其构象偏好，这通过核Overhauser效应光谱（NOESY）相关进一步得到强化。应用莫舍尔酯方法的NMR各向异性实验和化学相关也用于得出结论，即这种新型短柄内酯系列（1 - 5）具有对应于C - 6（R）、C - 1'（S）、C - 2'（R）、C - 5'（S）和C - 6'（S）的相同绝对构型。
