title: Lagoden dimethylformamide hemisolvate dihydrate: absolute configuration, dipolar interactions and hydrogen-bonding interactions.
abstract: Lagoden (L.3H2O, where L is Na+.C20H33O6-; sodium 3beta,16,18-trihydroxy-8,13-epi-9,13-epoxylabdan-15-oate trihydrate) is widely used as an effective haemostatic agent. It has been crystallized from dimethylformamide (DMF) as sodium 3beta,16,18-trihydroxy-8,13-epi-9,13-epoxylabdan-15-oate dimethylformamide hemisolvate dihydrate, Na+.C20H33O6-.0.5C3H7NO.2H2O or L2.DMF.4H2O, and the asymmetric unit contains two of the latter formulation. The four symmetry-independent Na+ cations and lagoden anions, one DMF molecule and six of the eight symmetry-independent water molecules assemble into a one-dimensional polymeric structure via dipolar and hydrogen-bonding interactions. The lagoden anions coordinate to the Na+ cations via the carboxylate groups and the two primary hydroxy groups, whereas the secondary OH groups are solely involved in hydrogen bonding. Two of the four symmetry-independent lagoden anions act in a chelating mode, forming seven-membered chelate rings. The absolute structure, based on anomalous dispersion data collected at 130 K with Cu Kalpha radiation, confirms an inverted configuration at chiral centres C8 and C13 (labdane numbering) relative to the labdane skeleton.
authors.affiliation: Faculty of Chemistry, Adam Mickiewicz University, 60-780 Poznań, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Wicher
authors.forename: Maria
authors.initials: M
authors.lastname: Gdaniec
authors.forename: Davran N
authors.initials: DN
authors.lastname: Dalimov
authors.forename: Umardjon N
authors.initials: UN
authors.lastname: Zainutdinov
mesh_terms: D018360:Crystallography, X-Ray; D004126:Dimethylformamide / Q000737:chemistry*; D004224:Diterpenes / Q000737:chemistry*; D006860:Hydrogen Bonding; D007477:Ions / Q000737:chemistry; D008968:Molecular Conformation; D012997:Solvents / Q000737:chemistry; D014867:Water
chemical_list: D004224:Diterpenes; D007477:Ions; D012997:Solvents; C544638:sodium 3beta,16,18-trihydroxy-8,13-epi-9,13-epoxylabdan-15-oate trihydrate; D014867:Water; D004126:Dimethylformamide