Enthalpies of dilution at 298.15 K of aqueous solutions of the dipeptides glycyl-l-valine, glycyl-d-leucine, glycyl-l-asparagine, glycyl-l-threonine, glycyl-dl-threonine and glycyl-dl-serine have been determined using flow microcalorimetry. The results obtained were used to determine the enthalp...

Glycyl-L-Valine (GLV) crystals were grown using distilled water as the solvent at room temperature by solution growth technique. Powder X-ray diffraction confirms the crystalline quality of GLV crystal. The molecular structure of GLV crystal was identified by 13C NMR spectral studies. The nonlin...

A great lack of knowledge of Hammam Pharaon's microbial community; the most famous hot spring in Sinai, Egypt, derived this work. Three different hyperthermophilic bacterial were isolated from vents in the area, where the temperature was above 80 °C. Response Surface Methodology algorithm ...

The asymmetric synthesis of the methyl ester of the natural β-amino acid of Onchidin (2S,3S)-methyl-3-amino-2-methyl-7-octynoate and its enantiomer is described. The preparation of an enantiomerically pure β-hydroxy acid through an enantioselective aldol condensation reaction and an intramolec...

The superelectrophilic activation of N-aryl amides of 3-arylpropynoic acids by Bronsted superacids (CF3SO3H, HSO3F) or strong Lewis acids AlX3 (X=Cl, Br) results in the formation of 4-aryl quinolin-2(1H)-ones in quantitative yields. The vinyl triflates or vinyl chlorides may be formed as additio...

A convenient synthesis of the chronic renal disease agent, trifluoro-N-[4-(3-oxo-3,5-dihydro-4H-1,4,8b-triazaacenaphthylen-4-yl)butyl]methanesulfonamide (1a), for large scale has been developed via ethyl 5-(chloromethyl)imidazo[1,2-a]pyridine-3-carboxylate (3), which was given by the regioselect...

This paper describes the synthesis and the in vitro antimalarial profile of two new imidazo[1,2-a]pyridine derivatives 4·HCl and 13·HCl, structurally proposed as mefloquine (1) analogues, by exploring bioisosterism and molecular simplification tools. The synthetic route employed to access the ...

Based on our recent finding that α1 selective GABA-A receptor potentiator—zolpidem—(a hypnotic drug) exerts antipsychotic-like effects in rats, we developed a series of fluorinated imidazo[1,2-a]pyridine derivatives as potential novel antipsychotic agents. The selected compounds displayed hig...

A mechanistic interpretation of the kinetic profiles obtained for the stereoselective reduction of acetophenone promoted by Galactomyces candidus GZ1 under aerobic and anaerobic conditions was made. Based on experimental and bibliographical data, a mechanism which may involve the participation o...

Intramolecular acyl transfer of (R)-5-(α-methylbenzyl)amino-1,3-dioxan-2-one (2) by treatment with DBU in CD2Cl2, CDCl3, C6D6, CD3CN, CD3NO2, DMSO-d6, DMF, THF-d8, iPrOH, and tBuOH at room temperature afforded (4S,αR)-4-hydroxymethyl-3-α-methylbenzyl-2-oxazolidinone [(4S)-3] in moderate to qu...

1,3-Diaminopropane has been detected, together with spermidine, in cucumber seeds. Quantitative estimation of the two metabolites in cucumber seeds and germinating seedlings (up to 21 days old) showed that the concentrations of both metabolites increased, then decreased with age. A metabolic seq...

The molecular conformation of achatin-II neutral form (H-Gly-Phe-Ala-Asp-OH), an endogenous peptide from the Achatina fulica ganglia, was elucidated by X-ray crystal analysis. The molecule takes an extended β-pleated structure stabilized by 5 intermolecular hydrogen bonds with the antiparallely...

The discovery of dipeptide, H-Asp(Gly)-OH, having an inhibition activity of PHA-induced lymphocyte transformation is reported. The seven analogs of H-Asp(Gly)-OH are described in which H-β-aspartyl, H-D-β-aspartyl, and Z-β-aspartyl respectively. The H-Gly-OH residue of H-Asp(Gly)-OH is also s...

Exiguobacterium sp. PMA utilized 4-chloroindole as its sole source of carbon and energy. The effect of initial concentrations of substrate on the 4-chloroindole degradation was studied and observed that strain PMA was capable of degrading 4-chloroindole up to concentration of 0.5 mM. The degrada...

Among the various esters of 3-(4-methoxyphenyl)glycidic acid, 4-chloro-3-methylphenyl ester (±)-3 was found to exist as a conglomerate, and could be alternately resolved into (+)- and (−)-3 of >98% ee by a preferential crystallization procedure. Furthermore, a 1,5-benzothiazepine derivative, (+...

In the last two decades, trans-sialidase of Trypanosoma cruzi (TcTS) has been an important pharmacological target for developing new anti-Chagas agents. In a continuous effort to discover new potential TcTS inhibitors, 3-amino-3-arylpropionic acid derivatives (series A) and novel phthaloyl deriv...

Epoxidation of 3-methoxy-16-methylene-estra-1,3,5(10)-trien-17-one in the presence of alkaline hydrogen peroxide gives rise to (16R)- and (16S)-spiro[3-methoxy-17-oxoestra-1,3,5(10)-triene-16,2′-oxirane] in similar proprotions. Epoxidation of the corresponding 16-methylene 17μ-alcohol and 16-m...

A four-step reaction sequence including (1) hydroxyl group-assisted epoxidation, (2) Jones oxidation, (3) DIBAH-reduction, and (4) epoxide deoxygenation has been devised in order to effect epimerization of 4 to 1, the overall yield approaching 65%.

Steroidal olefins 1 and 3 undergo dimethylaluminum chloride-mediated Prins reactions with paraformaldehyde to furnish homoallylic alcohols 4 and 16 as major products. These ene reaction-type intermediates are converted into 6 and 17 by hydroxyl group-assisted catalytic hydrogenation, while Birch...

A facile synthesis of 6,7-benzo-3-methoxyestra-1,3,5(10),8,14-pentaen-17-one from anisole is reported.