title: Isolation and structure elucidation of kadlongilactones C-F from Kadsura longipedunculata by NMR spectroscopy and DFT computational methods.
abstract: Four new triterpenoids, kadlongilactones C-F (2-5), containing a consecutive hexacyclic [7,7,5,6,6,6] ring system, were isolated from the leaves and stems of Kadsura longipedunculata. In comparison with the NMR data of kadlongilactones A (1) and D (3), a significant phenomena was discovered that ring D of 3 inverted from a half-chair in 1 to a half-boat conformation when the HO-16 group changed from alpha- to beta-orientation. The structures of 2-5 were established on the basis of detailed spectroscopic analysis, and DFT computational methods were applied in the structural validation of compounds 3 and 5. Compounds 1-4 showed significant cytotoxicity against A549, HT-29, and K562 cell lines with IC50 values of 0.49-3.61 microM in vitro.
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, People's Republic of China.
authors.forename: Jian-Xin
authors.initials: JX
authors.lastname: Pu
authors.forename: Sheng-Xiong
authors.initials: SX
authors.lastname: Huang
authors.forename: Jie
authors.initials: J
authors.lastname: Ren
authors.forename: Wei-Lie
authors.initials: WL
authors.lastname: Xiao
authors.forename: Li-Mei
authors.initials: LM
authors.lastname: Li
authors.forename: Rong-Tao
authors.initials: RT
authors.lastname: Li
authors.forename: Liang-Bo
authors.initials: LB
authors.lastname: Li
authors.forename: Tou-Gen
authors.initials: TG
authors.lastname: Liao
authors.forename: Li-Guang
authors.initials: LG
authors.lastname: Lou
authors.forename: Hua-Jie
authors.initials: HJ
authors.lastname: Zhu
authors.forename: Han-Dong
authors.initials: HD
authors.lastname: Sun
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D020128:Inhibitory Concentration 50; D032135:Kadsura / Q000737:chemistry*; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D018515:Plant Leaves / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D004365:Drugs, Chinese Herbal; D014315:Triterpenes