The acid protease (EC 2.4.23.6) that is produced extracellularly when Aspergillus oryzae is grown on liquid media has been isolated and characterized. The enzyme was purified by precipitation with tannic acid, chromatography on Duolite A-2, and gel filtration on Sephadex G-100. The last step yielded four active components, with varying molecular weights ranging from 42,000 to 60,000. Two of the...

Graphite oxide as a heterogeneous and recyclable solid acid catalyzed a simple and efficient method for the synthesis of β -amino alcohols by ring opening of epoxides with amines. This method is effective with various aromatic and aliphatic amines under solvent-free conditions. The corresponding β -amino alcohols are obtained in high yields (56%–95%) and short reaction times (15–30 min) with hi...

Silica-bonded N-propyldiethylenetriamine (7) is employed as a recyclable heterogeneous solid base catalyst for the synthesis of 2-amino-3,5-dicarbonitrile-6-thiopyridines through pseudo four-component condensation reaction between aromatic aldehydes, malononitrile, and 2-amino-thiophenol in refluxing ethanol. Silica-bonded N-propyldiethylenetriamine showed much the same efficiency when used in ...

An environmentally benign green protocol for the synthesis of 5-unsubstituted 3,4-dihydropyrimidin-2(1H)-ones using Amberlyst 15 DRY as a recyclable catalyst has been developed. The use of resinous, nontoxic, thermally stable, and inexpensive Amberlyst 15 DRY, as a recyclable heterogeneous catalyst, makes the process simple with negligible chemical waste. Among the various solid acid catalysts ...

abstract effect of different concentrations of salicylic acid on postharvest life of kiwifruit (actinidia deliciosa) cultivar hayward at 0 ±.5 °c and 90-95% rh was studied. fruits were treated with salicylic acid (0, 1 and 2 mmol/l-1) and stored at 0±.5°c for 16 weeks. fruit quality attributes assessment including firmness, total acidity, soluble solid content, ascorbic acid, antioxidant activi...

A suitable methodology of synthesis of coumarin derivatives by Pechmann reaction over heterogeneous solid acid catalysts in a free solvent media under microwave irradiation is described. Resorcinol, phenol and ethyl acetoacetate were selected as model reactants in the Pechmann condensation. The catalytic activity of several materials-Amberlyst-15, zeolite β and sulfonic acid functionalized hybr...

freshly prepared zno nanoparticles were used as an effective heterogeneous base catalyst for the synthesis of aryloximes. the conversion of arylaldehydes and arylketones into the corresponding oximes (up to quantitative yields) was achieved by simply mixing the liquid reactants and hydroxylamine hydrochloride with zno nanoparticles under solvent-free condition. the procedure was carried out und...

BACKGROUND Transesterification catalyzed by solid base catalyst is a brilliant technology for the noble process featuring the fast reaction under mild reacting condition in biodiesel production. Heterogeneous base catalysts are generally more reactive than solid acid catalysts which require extreme operating condition for high conversion and biodiesel yield. In the present study, synthesis of b...