Structures of novel immunosuppressants, stevastelin A, B and B3(1) were determined by their spectroscopic and chemical studies. Three stevastelins were shown to be cyclic depsipeptides composed of a fatty acid and three amino acid moieties. The sequence of these moieties was determined to be as 3,5-dihydroxy-2,4-dimethylstearylvalylthreonyl (or O-sulfonylthreonyl in stevastelin A)-O-acetylserin...

Macrophomina phaseolina is a highly problematic fungus that causes diseases in hundreds of plant species. In order to search for an alternative chemical fungicides the control this devastating pathogen, leaf extract Tabernaemontana divaricata was assessed M. phaseolina. Five concentrations methanol viz. 1, 2, 3, 4 and 5% (w/v), were checked against All these significantly suppressed fungal grow...

We report the synthesis and total NMR characterization of 5-thia-1-azabicyclo-[4.2.0]oct-2-ene-2-carboxylic acid-3-[[[(4''-nitrophenoxy)carbonyl]oxy]-methyl]-8-oxo-7-[(2-thienyloxoacetyl)amino]-diphenylmethyl ester-5-dioxide (5), a new cephalosporin derivative. This compound can be used as the carrier of a wide range of drugs containing an amino group. The preparation of the intermediate produc...

in this work, we studied the effect of carboxylic acid on the rheological properties of a high-alumina cement mortar (ch45) produced by the algerian firm refractal.the investigated properties are setting time, water consumption, electrical conductivity, ph, density and the compressive strength. the results show a setting time of about 200 min for the acid free, 180 min with 0.1 % of carboxylic ...

Brevibacterium sp. strain DPO 1361 oxygenates dibenzofuran in the unusual angular position. The 3-(2-hydroxyphenyl)catechol thus generated is subject to meta ring cleavage in the proximal position, yielding 2-hydroxy-6-(2-hydroxyphenyl)-6-oxo-2,4-hexadienoic acid, which is hydrolyzed to 2-oxo-4-pentenoate and salicylate by 2-hydroxy-6-oxo-6-phenyl-2,4-hexadienoic acid hydrolase. The proximal mo...

Coordination compounds of 4-hydroxy-3-nitro-2H-chromen-2-one and their mixed ligand complexes with aminoethanoic acid and pyrrolidine-2-carboxylic acid were synthesized by the reaction of Cu(II) and Zn(II) salts in molar ratio 1 : 2 for the coumarin complexes and 1 : 1 : 1 for the mixed ligand complexes, in basic media. The compounds formed were characterized using infrared, Uv-vis spectrophoto...

1. The metabolism of 5-hydroxy[1'-(14)C]tryptamine creatinine sulphate in the nuclear fraction of rat-liver homogenate was studied. In the incubation mixture five metabolites were found. 2. Two metabolites were not radioactive; one of them was identified as 5-hydroxyindole-3-carboxylic acid and the second tentatively as 5-hydroxyindole-3-aldehyde. 3. 5-Hydroxyindol-3-ylacetic acid, 1'-N-acetyl-...

The main objective of this study was to identify compounds that contribute the bitter taste attributes American hazelnuts (C. americana) and derived hybrids. Sensory-guided Prep-LC fractionation analysis selected four as were further identified by MS NMR carpinontriol B, 2-(3-hydroxy-2-oxoindolin-3-yl)acetic acid 3-O-6′-galactopyranosyl-2″-(2″oxoindolin-3″yl) acetate, giffonin-2-O-[(α-d-glucopy...

1. The effect of pH, temperature, reactant concentration and reaction time has been investigated for the synthesis of benzylpenicillin, dl-alpha-hydroxybenzylpenicillin and d-alpha-aminobenzylpenicillin from 6-aminopenicillanic acid by the penicillin acylase of Escherichia coli. 2. Synthesis of penicillins from carboxylic acids proceeds most rapidly at pH5; with amides the optimum pH is higher ...