title: Complete assignments of 1H and 13C NMR spectral data for three polyhydroxylated 12-ursen-type triterpenoids from Dischidia esquirolii.
abstract: The complete assignments of all the (1)H and (13)C NMR signals of three polyhydroxylated 12-ursen-type triterpenes, 6beta,19alpha,22alpha-trihydroxyurs-12-en-3-oxo-28-oic acid (1), 3beta,6alpha,19alpha,23-tetrahydroxyurs-12-en-28- oic acid (2) and 3beta,6beta,19alpha,23-tetrahydroxyurs-12-en-28-oic acid (3), were carried out by means of homo- and hetero-nuclear two-dimensional NMR experiments. Compounds 1-3 were isolated from the aerial parts of Dischidia esquirolii. Of them, 1 and 2 were identified as new polyhydroxylated ursolic acid derivatives. Compound 2 is the C-6 hydroxyl epimer of 3, which was isolated first from Adina rubella, and its structure is revised in this paper.
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, P. R. China.
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Ma
authors.forename: Chongren
authors.initials: C
authors.lastname: Yang
authors.forename: Yingjun
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D002247:Carbon Isotopes / Q000737:chemistry; D004365:Drugs, Chinese Herbal / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D019684:Magnoliopsida / Q000378:metabolism*; D008968:Molecular Conformation; D035261:Plant Components, Aerial / Q000378:metabolism*; D011522:Protons; D014315:Triterpenes / Q000737:chemistry*
chemical_list: C453364:12-ursene; D002247:Carbon Isotopes; D004365:Drugs, Chinese Herbal; D011522:Protons; D014315:Triterpenes