Separation of valtrate and isovaltrate by means of preparative liquid chromatography

Abstract

In this study valtrate and isovaltrate, two isomeric valepotriates present in various Valeriana species, were separated on a preparative scale with a Waters preparative Liquid Chromatography/500 A system. A rapid separation was achieved with the solvent methylene chloride-n-propanol-acetone (99 + 0.5 + 0.5). Extensive use of the recycle mode of the instrument resulted in a considerable reduction of the amount of solvent used, without affecting the purity and the recovery (greater than 90%) of the separated components. With the method presented in this communication 1 gram of a mixture of valtrate and isovaltrate was separated in 20 minutes using 2.1 liters of solvent.

DFT and NMR parameterized conformation of valeranone

“…20,21 The values for the dihedral angles together with the corresponding coupling constants are listed in Table 2. The population-weighted average coupling constant for each H-C-C-H dihedral fragment, also included in Table 2, was calculated using the equation 3 …”

“…1 In fact, it is known that this substance causes suppression of rhythmic contractions and relaxed potassium stimulated contractures in guinea-pig ileum. 3 The structure of 1 was definitively established by Hikino et al 2 and further confirmed by total syntheses from ( )-carvomenthone 4 and (C)-carvomenthone. 5 Since then, there have been several other synthetic constructions of 1 conducted to secure its stereochemistry, which was once a focus of dispute.…”

Comparative Study of Differentiation Levels and Valepotriate Content of in Vitro Cultures and Regenerated and Wild Plants of Valeriana edulis ssp. procera

“…8 Phytochemical analysis has shown that this plant contains high concentrations of valepotriates, from which valtrate (1) is perhaps the most important active compound of this group. 9 A recent report demonstrated the hypnotic effect and safety of acute treatment of a standarized hydro alcoholic extract of V. edulis ssp. procera on patients suffering from insomnia.…”

Valerian (Valeriana officinalisL.)

“…The essential oil of valerian contains over 150 compounds including sesquiterpenes (valerenic acid, valeranone), 13 sesquiterpene derivatives (acetoxyvalerenic acid, 3 β ,4 β -epoxyvalerenic acid, hydroxyvalerenic acid, valerane, valerenal, cryptofauronol), 14,15 bicyclic iridoid esters (valepotriates), 16 decomposition products of valepotriates (baldrinal, homobaldrinal, valtroxal), monoterpenes (bornyl acetate and isovalerate), fl avonoids (6 -methylapigenin, hesperidin), 17 furanofuran lignans, alkaloids (valerianine, actinidine), and free amino acids ( γ -aminobutyric acid, arginine, glutamine, tyrosine). Figure 94.1 displays the chemical structures of the major types of compounds in valerian.…”