Synthesis and biological activity of silyl- and germylsubstituted trifluroacetylfurans.

A series of silyl, germyl and alkyl substituted trifluoroacetylfurans has been synthesized under Friedel-Crafts electrophilic acylation conditions. Biological investigations have demonstrated that germyl derivatives of trifluoroacetylfuran are more toxic than the silicon analogues. 5-Triethylgermyl-2- trifluoroacetylfuran was the most toxic compound (CD(nabla), 11.

Hypericum extract and hyperforin: memory-enhancing properties in rodents.

Effects of a Hypericum extract in therapeutic use and hyperforin sodium salt were evaluated in rat and mouse avoidance tests. In a conditioned avoidance response (CAR) test on the rat, oral daily administration of hyperforin (1.25 mg/kg/day) or of the extract (50 mg/kg/day) before the training sessions considerably improved learning ability from the second day onwards until the day 7.

The gamma(2)-MSH peptide mediates a central analgesic effect via a GABA-ergic mechanism that is independent from activation of melanocortin receptors.

Using the latency for tail-flick after thermal stimulation we have assessed the effects of alpha-, gamma(1)- and gamma(2)-MSH on nociceptive threshold in the mice. Intracisternal injections of gamma(2)-MSH induced a distinct analgesia, while gamma(1)-MSH in the same doses gave only a minor analgesia. Intracisternal alpha-MSH instead gave a short-term hyperalgesia.

"Atypical" neuromodulatory profile of glutapyrone, a representative of a novel 'class' of amino acid-containing dipeptide-mimicking 1,4-dihydropyridine (DHP) compounds: in vitro and in vivo studies.

Glutapyrone, a disodium salt of 2-(2,6-dimethyl-3,5-diethoxycarbonyl-1,4-dihydropyridine-4-carboxamido)- glutaric acid, is a representative of a novel 'class' of amino acid-containing 1,4-dihydropyridine (DHP) compounds developed at the Latvian Institute of Organic Synthesis, Riga, Latvia. Conceptually, the glutapyrone molecule can be regarded as a dipeptide-mimicking structure formed by the "free" amino acid (glutamate) moiety and "crypto" (built into the DHP cycle) amino acid ("GABA") elements. Both of these amino acids are joined by the peptide bond.

[The antiepileptic effects of the combined action of the new 1,4-dihydropyridine derivative glutapyrone with sodium valproate and phenobarbital].

Antiepileptic effects of a novel amino acid-containing 1,4-dihydropyridine glutapyrone and sodium valproate during combined therapy on generalized pentylenetetrazol- and focal 4-aminopyridine-induced epileptic activity in rat brain cortex were studied, as were combined effects of glutapyrone and phenobarbital on maximal electroshock in mice. The results of these investigations suggest that combined treatment by glutapyrone and sodium valproate or phenobarbital is reasonable and helps potentiate the effect of each drug, thus significantly reducing their doses, and minimize the risk of side effects of the drugs id used in higher doses in case of long treatment.