近日,，中科院昆明植物研究所孫漢董研究員課題組與朱華結(jié)研究員課題組及其他合作者共同在著名雜志《歐洲化學(xué)》（Chemistry-A European Journal）（2008,，14：11584-11592）上發(fā)表了五味子科降三萜化學(xué)研究學(xué)術(shù)論文。該文報(bào)道了從紅花五味子(Schisandra rubriflora) 中分離得到一個(gè)新奇的具有生物活性的降三萜紅花五味子二內(nèi)酯C以及四個(gè)其他的降三萜化合物,，并通過波譜數(shù)據(jù)分析和利用GIAO理論方法在B3LYP/6-311++G(2d,p)//B3LYP/6-31G(d)水平上計(jì)算的13C NMR數(shù)據(jù)比較,，以及X－射線單晶衍射實(shí)驗(yàn)確定了化合物紅花五味子二內(nèi)酯C的結(jié)構(gòu)；利用DFT理論方法,，在B3LYP/6-311+G(d,p)的水平上,，通過過渡態(tài)能量計(jì)算，從計(jì)算的角度闡明了小花五味子二內(nèi)酯D和紅花五味子二內(nèi)酯C關(guān)鍵的生源步驟,；并根據(jù)該新的生源機(jī)制,，對其他可能形成的產(chǎn)物進(jìn)行了預(yù)測。
據(jù)悉,，孫漢董研究員課題組長期以來與中國醫(yī)學(xué)科學(xué)院鄭啟泰,、呂揚(yáng)教授等合作，利用X-衍射解決了許多五味子科植物中結(jié)構(gòu)復(fù)雜三萜類化合物的結(jié)構(gòu)鑒定,。近年來,，與朱華結(jié)研究員合作利用量子化學(xué)計(jì)算的手段，解決了五味子科植物中一些三萜類化合物特殊基團(tuán)構(gòu)象問題,，并已在Organic Letters以及Journal of Natural Products等發(fā)表了相關(guān)研究論文,。此次合作，通過利用過渡態(tài)能量計(jì)算對五味子科降三萜關(guān)鍵的生源步驟進(jìn)行了進(jìn)一步的闡述,，具有重要的學(xué)術(shù)意義,。（生物谷Bioon.com）
生物谷推薦原始出處：
Chemistry-A European Journal，Volume 14 Issue 36, Pages 11584 - 11592,，Wei-Lie Xiao,，Han-Dong Sun
Structure Elucidation and Theoretical Investigation of Key Steps in the Biogenetic Pathway of Schisanartane Nortriterpenoids by Using DFT Methods
Wei-Lie Xiao, Dr. 1, Chun Lei 1, Jie Ren 1, Tou-Gen Liao 1, Jian-Xin Pu 1, Charles U. Pittman Jr., Prof. 2, Yang Lu, Prof. 3, Yong-Tang Zheng, Prof. 4, Hua-Jie Zhu, Prof. 1 *, Han-Dong Sun 1 *
1State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Heilongtan, Kunming 650204, Yunnan (China)
2Department of Chemistry, Mississippi State University, Mississippi State, 39762, MS (USA)
3Institute of Materia Medica, Chinese Academy of Medical Sciences, Beijing 100050 (China)
4Key Laboratory of Animal Models and Human Disease Mechanisms and Laboratory of Molecular Immunopharmacology, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, Yunnan (China)
Rubrifloradilactone C (4), a novel bioactive nortriterpenoid, along with four other nortriterpenoids (1-3, 5) were isolated from Schisandra rubriflora. The structure of 4 was determined by extensive NMR spectral analysis, computational evidence by using the GIAO method at the B3LYP/6-311++G(2d,p)//B3LYP/6-31G(d) levels, and X-ray analysis. DFT at the B3LYP/6-311+G(d,p) level was selected to clarify the key mechanistic steps in the formation of 1 and 4 through transition-state (TS) investigations. The effect of enzymes on the TS barriers was considered by using the polarized continuum model. Other possible products based on the new mechanism were predicted.
