7-Aminoheptanoic acid derivatives as potential neuropharmacological agents. I

Characterization and identification of antimicrobial compounds from endophytic Fusarium incarnatum isolated from Cymbidium orchids

This study characterized and identified the antimicrobial compounds from an endophytic fungus (Fusarium incarnatum (C4)) isolated from the orchid, Cymbidium sp. Chromatographic techniques were employed to separate the bioactive compounds from the crude extracts of F. incarnatum (C4). Following bio-guided fractionation, two fractionated extracts (fractions 1 and 2) of F. incarnatum (C4) exhibited antibacterial and antifungal activities against Bacillus cereus (MIC: 0.156 mg/mL) and Ganoderma boninense (MIC: 0.3125 mg/mL), respectively. The active fractions were discovered to comprise of a variety of bioactive compounds with pharmacological importance (alkaloids, flavonoids, phenolic compounds, terpenoids, peptides and fatty acids). Liquid chromatography mass-spectrometry (LCMS) analysis detected the presence of antibacterial (kanzonol N, rifaximin, linoleic acid (d4), cannabisativine, docosanedioic acid, and stearamide) and antifungal components (3-methyl-quinolin-2-ol, prothiocarb, kanzonol N, peganine, 5Z-tridecene, and tetronasin) in fractions 1 and 2, respectively, which may have contributed to the antimicrobial effects. Findings from this study highlighted the important potential of fungal endophytes from medicinal hosts as producers of antimicrobials and antibiotics.

Influence of amineptine on changes of blood pressure evoked by norepinephrine and dopamine

The influence of amineptine, an antidepressant currently employed having mainly selective dopaminergic neurochemical activity, on the pressor responses evoked by norepinephrine (NE) and dopamine (DA) was studied in anesthetized whole rats. Amineptine at doses of 0.5, 1.5, and 5.0 mg/kg/30 min infused into the femoral vein of the rat caused a dose-related inhibition of the pressor responses of NE and DA. The hypertensive responses of NE and DA augmented by pretreatment with reserpine, a catecholamine depletor, were also clearly depressed following the infusion of amineptine with a rate of 1.5 mg/kg/30 min. Furthermore, the pressor responses of NE and DA potentiated by pretreatment with debrisoquin, a sympathetic neuron blocker, were markedly diminished after pretreatment with the infusion of amineptine at the above same rate (1.5 mg/kg/30 min). These experimental results demonstrate that amineptine causes an inhibitory effect on the pressor responses evoked by NE and DA. It is thought that the amineptine effect may be due to the blockade of the peripheral adrenergic alpha-receptors in addition to the previously described uptake inhibition of dopamine.

Gas chromatographic-mass spectrometric assessment of the pharmacokinetics of amineptine and its main metabolite in volunteers with liver impairment

A pharmacokinetic study of amineptine (Survector) and its C5 metabolite, resulting from a beta-oxidation of the heptanoic acid side-chain, was undertaken with ten human volunteers, who received a single 100-mg tablet of amineptine orally. They were affected with liver impairment in order to determine if this situation would alter greatly the pharmacokinetic parameters. The internal standard was the octanoic acid homologue. Analyses were carried out by gas chromatography (GC) and GC-mass spectrometry using TMS ester derivatives. Plasma samples were extracted using a C18 reversed-phase cartridge at pH 4.0. Mass fragmentographic measurements on the plasma samples were performed on the m/z ions (M + H)+ and (base peak)+ using ammonia chemical ionization. The global evaluation of precision was good and the coherence between the two modes of measurements, (base peak)+ and (M + H)+ ions, gave a regression factor r close to unity. For amineptine the total body clearance and mean residence time were accurate and precise with eight volunteers, but only four volunteers showed such coherent data for the slope of the elimination curve, beta, and half-life. However, the beta value, half-life and mean residence time of the C5 metabolite were accurate and precise with seven, eight and ten volunteers, respectively. It is concluded that the drug was still detoxified at normal levels.

Amineptine in the management of the depressive syndromes

The antidepressant activity of amineptine was evaluated in 34 patients in a double-blind study vs clomipramine. Clinical results, assessed using the Hamilton rating scale for depression, failed to show any significant difference in the activity of the two drugs. Amineptine was however much better tolerated than clomipramine. The antidepressant activity of amineptine was further investigated in an open multicenter study carried out in 351 depressed patients. The significant reductions in the scores of the Hamilton rating scale for depression and the final clinical evaluations (87% favorable results, 69% of which excellent or good) confirmed the therapeutic efficacy of amineptine. Tolerance was excellent also in elderly, at risk patients.

High-performance liquid chromatographic method for the determination of amineptine and its main metabolite in human plasma

An isocratic reversed-phase ion-pair liquid chromatographic method for the determination of amineptine and its main metabolite in plasma using an internal standard, is reported. The effects of stationary phase alkyl chain length and the concentration of alkyl sulfonate in the mobile phase were investigated. The drugs were extracted as ion pairs and the influence of various parameters on the extraction efficiency are discussed. Using a heptane-octanol-tetraheptylammonium bromide mixture (98:2:0.5, v/v/w) as extraction solvent, more than 60% of each drug was recovered with a very good selectivity. UV detection at 220 nm allowed drug determination down to 0.010 microgram/ml. Linear standard curves up to 1.00 microgram/ml were observed.