Synthesis and adrenolytic activity of new propanolamines

The synthesis of (2R,S)-1-(6-methoxy-4-(methoxymethyl)-1H-indol-5-yloxy)-3-(2-(2-methoxyphenoxy)ethylamino)propan-2-ol and (2R,S)-1-(4-methoxy-6-(methoxymethyl)-1H-indol-5-yloxy)-3-(2-(2-methoxyphenoxy)ethylamino)propan-2-ol is described. The compounds were tested for electrographic, antiarrhythmic, hypotensive, and spasmolytic activity, as well as for alpha(1)-, alpha(2)- and beta(1)-adrenoceptor binding affinity.

Zinc-induced adaptive changes in NMDA/glutamatergic and serotonergic receptors

Preclinical data indicate the involvement of glutamatergic and serotonergic pathways in the antidepressant activity of zinc. The present study investigated alterations in N-methyl-D-aspartate (NMDA)/glutamatergic and serotonergic receptors (using radioligand binding) induced by chronic treatment (14-day) with zinc hydroaspartate (65 mg/kg). Moreover, the mRNA and protein levels of brain-derived neurotrophic factor (BDNF) were also assessed. Chronic zinc administration reduced the affinity of glycine to glycine/NMDA receptors in the rat frontal cortex and increased the density of 5-HT(1A) and 5-HT(2A) serotonin receptors in the hippocampus and frontal cortex, respectively. These receptor alterations may be in part due to increased BDNF mRNA and protein levels in the rat frontal cortex. These results indicate that chronic zinc treatment alters glutamatergic and serotonergic systems, which is a hallmark of clinically effective antidepressants.

The involvement of serotonergic system in the antidepressant effect of zinc in the forced swim test

Recent preclinical data indicated the antidepressant-like activity of zinc in different tests and models of depression. The present study investigates the involvement of the serotonergic system in zinc activity in the forced swim test (FST) in mice and rats. The combined treatment of sub-effective doses of zinc (hydroaspartate, 2.5 mg Zn/kg) and citalopram (15 mg/kg), fluoxetine (5 mg/kg) but not with reboxetine (2.5 mg/kg) significantly reduces the immobility time in the FST in mice. These treatments had no influence on the spontaneous locomotor activity. Moreover, while the antidepressant-like effect of zinc (5 mg/kg) in the FST was significantly blocked by pretreatment with inhibitor of serotonin synthesis, p-chlorophenylalanine (pCPA, 3x200 mg/kg), 5HT-2(A/C) receptor antagonist, ritanserin (4 mg/kg) or 5HT-1A receptor antagonist, WAY 1006335 (0.1 mg/kg), the zinc-induced reduction in the locomotor activity was not affected by these serotonin modulator agents. These results indicate the specific involvement of the serotonergic system in antidepressant but not the motion behavior of zinc in mice. Also, an increase in the swimming but not climbing parameter of the rat FST observed following zinc administration (2.5 and 5 mg Zn/kg) indicates the serotonin pathway participation. This present data indicates that the antidepressant-like activity of zinc observed in the FST involves interaction with the serotonergic system.

Synthesis, lipophilicity and antimicrobial activity of new derivatives of thiosemicarbazides and 1,2,4-triazoline-5-thione

In the reaction of hydrazide of 3,4-dimethoxyphenylacetic acid (1) with isothiocyanate the respective thiosemicarbazide derivatives (2) were obtained. Further cyclization with 2% NaOH led to the formation of 3-[(3,4-dimethoxyphenyl)methyl]-4-substituted-1,2,4-triazoline-5-thiones (3). The structures of all new products were confirmed by analytical and spectroscopic methods. All compounds were screened for their in vitro activity against some species of aerobic bacteria and fungi. The lipophilicity of the synthesized molecules was also studied.

Antidepressant-like effect of chromium chloride in the mouse forced swim test: involvement of glutamatergic and serotonergic receptors

Chromium (Cr) (III), an essential microelement of living organisms, was reported to exhibit potential antidepressant properties in preclinical and clinical studies. The aim of the present study was to examine the effect of CrCl(3) ip administration in the forced swim test (FST) in mice and the involvement of glutamatergic and serotonergic receptors in the antidepressant-like activity of chromium. CrCl(3) in a dose of 12 mg/kg, but not in doses of 6 or 32 mg/kg, reduced the immobility time in the FST. The locomotor activity was reduced by CrCl(3) in a dose of 32 mg/kg. Moreover, the reduction of the immobility time induced by the active dose (12 mg/kg) of CrCl(3) was completely abolished by NBQX (10 mg/kg; an antagonist of the AMPA receptor) pretreatment and partially inhibited by ritanserin (4 mg/kg; an antagonist of 5-HT(2A/C) receptor), WAY 1006335 (0.1 mg/kg; an antagonist of 5-HT(1A) receptor) and N-methyl-D-aspartate (75 mg/kg; agonist of NMDA receptor) administration. The present study demonstrates the antidepressant-like activity of chromium in the mouse FST and indicates the major role of the AMPA receptor and participation of NMDA glutamatergic and 5-HT(1) and 5-HT(2A/C) serotonin receptors in this activity.

Kinetic isotope effects on dehalogenations at an aromatic carbon

In order to interpret the observed isotopic fractionation it is necessaryto understand its relationship with the isotope effect(s) on steps that occur during the conversion of the initial reactant to the final product. We examine this relationship from the biochemical point of view and elaborate on the consequences of the assumptions that it is based on. We illustrate the discrepancies between theoretical and experimental interpretation of kinetic isotope effects on examples of dehalogenation reactions that occur at an aromatic carbon atom. The examples include 4-chlorobenzoyl-CoA dehalogenase-catalyzed conversion of 4-chlorobenzoyl-CoA to 4-hydroxybenzoyl-CoA, dehaloperoxidase-catalyzed conversion of 2,4,6-trichlorophenol to 2,6-dichloroquinone, and spontaneous hydrolysis of atrazine at pH 12. For this latter reaction we have measured the chlorine kinetic isotope effect and estimated its value theoretically at the DFT level of theory. Results of chlorine kinetic isotope effects suggest that the studied dechlorination reactions proceed in a single step with significant weakening of the carbon-chlorine bond in the transition state.

Lack of NMDA-AMPA interaction in antidepressant-like effect of CGP 37849, an antagonist of NMDA receptor, in the forced swim test

The NMDA receptor antagonist, CGP 37849-induced reduction in immobility time in the forced swim test in mice was not antagonized by pre-treatment with the AMPA receptor antagonist NBQX. This is the first demonstration of the antidepressant effect of the NMDA antagonist not being dependent on the AMPA transmission.

Novel 4-aryl-pyrido[1,2-c]pyrimidines with dual SSRI and 5-HT1A activity, part 1

A series of new derivatives of 4-aryl-pyrido[1,2-c]pyrimidine containing the 3-(4-piperidyl)-1H-indole residue or its 5-methoxy derivative were synthesized. They were characterized (i) in vitro by binding to 5-HT(1A) receptors and 5-HT transporter proteins in rat brain cortex membranes and (ii) in vivo in the mouse by induced hypothermia and forced swimming models for antagonist/agonist activity against the 5-HT(1A) autoreceptors and postsynaptic 5-HT(1A) receptors, respectively. Structure activity relationship evaluation indicated that the presence of the 3-(4-piperidyl)-1H-indole residue and ortho- or para-substituents with -F or -CH(3) groups in the aryl ring as well as an unsubstituted aryl in the 4-aryl-pyrido[1,2-c]pyrimidine moiety promoted low K(i) values for both receptors. In contrast, the presence of a 5-methoxy-3-(4-piperidyl)-1H-indole residue as well as -Cl or -OCH(3) substituents at the para position markedly reduced the receptor affinity.

Synthesis and some pharmacological properties of 3-(piperidin-4-yl)-4-substituted-D2-1,2,4-triazoline-5-thione derivatives

Synthesis of 3-(piperidin-4-yl)-4-substituted-D-2-1,2,4-triazoline-5-thione derivatives, AS-1-AS-4 is described. Results of a preliminary pharmacological screening of two compounds AS-1 and AS-3 are presented.