Structure elucidation and theoretical investigation of key steps in the biogenetic pathway of schisanartane nortriterpenoids by using DFT methods.
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.
Xiao
Wei-Lie
WL
State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Heilongtan, Kunming 650204, Yunnan, China.
Lei
Chun
C
Ren
Jie
J
Liao
Tou-Gen
TG
Pu
Jian-Xin
JX
Pittman
Charles U
CU
Lu
Yang
Y
Zheng
Yong-Tang
YT
Zhu
Hua-Jie
HJ
Sun
Han-Dong
HD
D045744:Cell Line, Tumor; D018360:Crystallography, X-Ray; D006801:Humans; D020128:Inhibitory Concentration 50; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D018515:Plant Leaves / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry; D032141:Schisandra / Q000737:chemistry* / Q000201:enzymology; D014315:Triterpenes / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology
D014315:Triterpenes; C534998:rubriflordilactone C; C512131:schisanartane