valtrate and didrovaltrate

The concise synthesis of 5,6-dihydrovaltrate (2), the bioisostere of valtrate (1) showing anti-HIV activity by inhibition for nuclear export of Rev, has been achieved from the commercially available iridoid genipin (3). Analysis of steric influence of the substituents linked to the three hydroxyl groups was conducted by the synthesized three analogs (2a-2c). Consequently, attenuation of steric hindrance around the epoxy portion was revealed to enhance inhibitory potency for Rev-export. In addition to this finding, 1-acetoxy analog 2b was disclosed as the promising Rev-export inhibitor superior to 1.

Topics: Anti-HIV Agents; Cell Nucleus; HeLa Cells; HIV Infections; HIV-1; Humans; Iridoid Glycosides; Iridoids; Protein Transport; rev Gene Products, Human Immunodeficiency Virus

Valeriana glechomifolia is a plant species endemic to southern Brazil that accumulates valepotriates, which are terpene derivatives, in all of its organs. Valepotriates are the presumed sedative generic components of the pharmaceutically used species of Valeriana. The influence of various concentrations of the auxins indole-3-acetic acid, indole-3-butyric acid and alpha-naphthaleneacetic acid on the growth of micropropagated V. glechomifolia was investigated under conditions of transient and continuous exposure. Changes in the development of roots and shoots as well as the production of the valepotriates acevaltrate, valtrate and didrovaltrate (analyzed by high-performance liquid chromatography) were evaluated. The best performance in valepotriate production, growth and survival under ex vitro conditions following plant acclimatization was achieved in the continuous presence of 5.71 microM IAA. When cultured in medium containing IAA plants produced stable levels of valepotriates throughout the entire cultivation period.

Topics: Acclimatization; Indoleacetic Acids; Indoles; Iridoids; Naphthaleneacetic Acids; Plant Roots; Plant Shoots; Valerian

Valtrate, DIA-valtrate, acevaltrate, 1-beta-acevaltrate and didrovaltrate have been quantitatively estimated by reversed-phase HPLC in the leaves, flowers, stems and roots of Valeriana glechomifolia Meyer, V. catharinensis Graebn., V. chamaedryfolia Cham. & Schltdl., V. eichleriana (C.A.Mull.) Graebn., V. polysthachya Smith, V. scandens L., V. eupatoria Sobral, V. salicariifolia Vahl and V. tajuvensis Sobral. All plants presented valepotriates being V. glechomifolia the richest one, followed by V. eupatoria, V. eichleriana and V. tajuvensis.

Topics: Brazil; Chromatography, High Pressure Liquid; Iridoids; Plant Extracts; Plant Leaves; Plant Roots; Plant Stems; Pyrans; Valerian

The effect of a mixture of valepotriates on the elevated plus-maze performance of diazepam withdrawn rats was evaluated. The rats were chronically (28 days) treated with diazepam (doses increased up to 5.0 mg/kg) and then treated with control solution for 3 days to induce a withdrawal syndrome. Chronically vehicle-treated rats were used as control. The abstinent animals treated with vehicle showed a significant decrease in the percentage of time spent in the open arms when compared with the control animals. Diazepam and valerian 12.0 mg/kg reversed this anxiogenic effect. Valerian 6.0 mg/kg did not show any difference in relation to the others group.

Topics: Analysis of Variance; Animals; Behavior, Animal; Diazepam; Injections, Intraperitoneal; Iridoids; Male; Physical Conditioning, Animal; Plant Extracts; Plants, Medicinal; Psychotropic Drugs; Pyrans; Rats; Rats, Wistar; Substance Withdrawal Syndrome; Valerian

The antagonistic activity of various thiol compounds versus the cytotoxic effects of valtrate and didrovaltrate has been evaluated on cultured hepatoma cells. Compounds with free SH groups like cysteine, mercaptoethanol, dithioerythritol, and glutathione were able to suppress the cytotoxicity of the valepotriates in a dose-dependent way, whereas compounds with blocked SH groups did not antagonize these toxic effects. The possible interactions between the valepotriates and thiol compounds are discussed.

Topics: Animals; Cytotoxins; Iridoids; Liver; Plant Extracts; Pyrans; Rats; Sulfhydryl Compounds; Tumor Cells, Cultured