title: Structure of tinosporide, a diterpenoid furanolactone from Tinospora cordifolia Miers.
abstract: (1S,2S,3R,4R,5R,8S,10R,12S)-4-Hydroxy-2,3:15,16-diepoxycleroda-13( 16),14- dieno-17,12:18,1-biscarbolactone, C20H22O7, Mr = 374, m.p. = 509-511 K, orthorhombic, P2(1)2(1)2(1), a = 9.191 (2), b = 13.8230 (6), c = 26.956 (2) A, V = 3424.50 A3, Z = 8, Dx = 1.450, Dm (by flotation) = 1.446 g cm-3, lambda (Cu K alpha) = 1.5418 A, mu = 8.20 cm-1, F(000) = 1584, T = 295 K, R = 0.0464, wR = 0.0579 for 3437 observed reflections. The asymmetric unit contains two molecules. The structure resembles that of a similar compound [Swaminathan, Sinha, Bhatt & Sabata (1988). Acta Cryst. C44, 1421-1424] with atom H(15) replacing the tertiary hydroxyl group at C(8). Atoms H(4) and H(15) are alpha- and beta-oriented respectively at sites C(12) and C(8). The terpene ring A is locked into a boat conformation by the C(1)-C(4) lactone bridge. The hydroxyl at C(4) is involved in hydrogen bonding.
authors.affiliation: Physics Department, Indian Institute of Technology, Powai, Bombay.
authors.forename: K
authors.initials: K
authors.lastname: Swaminathan
authors.forename: U C
authors.initials: UC
authors.lastname: Sinha
authors.forename: R K
authors.initials: RK
authors.lastname: Bhatt
authors.forename: B K
authors.initials: BK
authors.lastname: Sabata
authors.forename: S S
authors.initials: SS
authors.lastname: Tavale
mesh_terms: D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003460:Crystallization; D003461:Crystallography; D004224:Diterpenes / Q000302:isolation & purification*; D007783:Lactones / Q000302:isolation & purification*; D015394:Molecular Structure; D010946:Plants, Medicinal / Q000032:analysis*
chemical_list: D004224:Diterpenes; D007783:Lactones; C062507:tinosporide