title: Six new cassane diterpenes from the twigs and leaves of Tara (Caesalpinia spinosa Kuntze).
abstract: Six new cassane diterpenes, isoneocaesalpin H (1), caespinosin A (2), caespinosin B (3), a cassane diterpene with unique 6/6/7 carbon rings, and caespinosins C-E (4-6) were isolated from the twigs and leaves of Tara (Caesalpinia spinosa Kuntze). The absolute configuration of isoneocaesalpin H (1) was determined by single-crystal X-ray crystallographic analysis. Compound 3 represents a class of rare natural cassane diterpene bearing unique 6/6/7 carbon rings. Their structures were identified by 1D and 2D NMR spectral data. Cassane diterpenes were firstly reported from Tara. Compounds 1-5 were evaluated for their cytotoxicity on HL-60, SMMC-7721, A-549, MCF-7 and SW-480 human cancer cell lines, but they were inactive.
authors.affiliation: Faculty of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming 650050, China; State Key Laboratory of Phytochemistry, Plant Resources in West China, Kunming Institute of Botany, Kunming 650204, China.
authors.forename: Dongyang
authors.initials: D
authors.lastname: He
authors.affiliation: Faculty of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming 650050, China.
authors.forename: Yuanping
authors.initials: Y
authors.lastname: Li
authors.affiliation: Faculty of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming 650050, China.
authors.forename: Hongbo
authors.initials: H
authors.lastname: Tang
authors.affiliation: Faculty of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming 650050, China.
authors.forename: Ruijing
authors.initials: R
authors.lastname: Ma
authors.affiliation: Yunnan Institute of Materia Medica, Kunming, 650111, China.
authors.forename: Xiaonian
authors.initials: X
authors.lastname: Li
authors.affiliation: Faculty of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming 650050, China. Electronic address: lqwang@ynnu.edu.cn.
authors.forename: Liqin
authors.initials: L
authors.lastname: Wang
mesh_terms: D029911:Caesalpinia / Q000737:chemistry*; D045744:Cell Line, Tumor; D004224:Diterpenes / Q000737:chemistry* / Q000302:isolation & purification; D006801:Humans; D015394:Molecular Structure; D018515:Plant Leaves / Q000737:chemistry*
chemical_list: D004224:Diterpenes
keywords: Caesalpinia spinosa; Caespinosins A–E; Cassane diterpenoid; Leguminaceae; Tara