Wicher B, Gdaniec M, Dalimov DN, Zainutdinov UN
Lagoden dimethylformamide hemisolvate dihydrate: absolute configuration, dipolar interactions and hydrogen-bonding interactions. [Journal Article]
Acta Crystallogr C 2009 Oct; 65(Pt 10):m367-70.
Lagoden (L.3H(2)O, where L is Na(+).C(20)H(33)O(6)(-); 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(+).C(20)H(33)O(6)(-).0.5C(3)H(7)NO.2H(2)O or L(2).DMF.4H(2)O, 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.
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