Valepotriate Hydrines Isolated from an Anticonvulsant Fraction of Valeriana pavonii Poepp. & Endl

Abstract

The present study deals with the isolation and identification of three valepotriate hydrines that are first reported in Valeriana pavonii Poepp. & Endl. (Valerianaceae), which were obtained from a dichloromethane fraction showing anticonvulsant activity in vivo. The isolation and purification of dichloromethane fraction was carried out by chromatographic techniques. The compounds were identified by comparison of their 1H and 13C NMR spectra with previously published data in scientific literature. Maximal electroshock seizure was used as in vivo pharmacological test, additionally in vitro GABA-A/BDZ-binding site studies were performed. Three valepotriate hydrines: valtrate acetoxyhydrine (1), valtrate isovaleroyloxyhydrine (2) and valtrate chlorohydrine (3), were isolated from a dichloromethane fraction that offered 90% protection against crisis-like tonic-clonic seizures in an in vivo pharmacological maximal electroshock seizure (MES) test in mice (35 mg/kg, p.o.). According to an in vitro GABA-A/BDZ binding site test, the mechanism of action for these compounds does not involve binding to the GABA-A receptor. These compounds are reported in this species for the first time. The valepotriate hydrines isolated from V. pavonii could be active metabolites of this species with anticonvulsant properties, however further in vivo an in vitro studies are required. Their molecular mechanisms of action are unrelated to the benzodiazepine binding site of the GABA-A receptor.