Synthesis of some novel 5, 6-dihydro-6-[4'-substituted phenyl]-12<i>H</i>- indeno [2, 1-<i>c</i>]-1, 5-benzodiazepin-7-ones

1322-1324Synthesis of hitherto unknown 5, 6-dihydro-6-phenyl-12H-indeno[2, 1-c]-1, 5-benzodiazepin-7-ones 2 through Michael type addition of o-phenylenediamine to 2-benzylideneindane-1, 3-diones is reported

Photo-reorganization of some 3-alkoxy-2-(alkoxyphenyl)chromones

685-691A photo-reorganization of 3-alkoxy-2-(alkoxyphenyl)chromones to the isomeric angular tetracyclic compounds through the 1,4-biradical generated by the excited carbonyl group through the γ-hydrogen abstraction has been described. Substituent effect of the 3-alkoxy group and the effect of position of alkoxy group in the 2-phenyl ring are explained

Purification and characterization of cathepsin L-like proteinase from goat brain

315-323Cathepsin L-like proteinase was purified ~1708-fold with 40% activity yield to an apparent electrophoretic homogeneity from goat brain by homogenization, acid-autolysis at pH 4.2, 30-80% (NH4)2SO4 fractionation, Sephadex G-100 column chromatography and ion-exchange chromatography on CM-Sephadex C-50 at pH 5.0 and 5.6. The molecular weight of proteinase was found to be ~65,000 Da, by gel-filtration chromatography. The pH optima were 5.9 and 4.5 for the hydrolysis of Z-Phe-Arg-4mβNA (benzyloxycarbonyl-L-phenylalanine-L-arginine-4-methoxy-β-naphthylamide) and azocasein, respectively. Of the synthetic chromogenic substrates tested, Z-Phe-Arg-4mβNA was hydrolyzed maximally by the enzyme (Km value for hydrolysis was 0.06 mM), followed by Z-Val-Lys-Lys-Arg-4mβNA, Z-Phe-Val-Arg-4mβNA, Z-Arg-Arg-4mβNA and Z-Ala-Arg-Arg-4mβNA. The proteinase was activated maximally by glutathione in conjunction with EDTA, followed by cysteine, dithioerythritol, thioglycolic acid, dithiothreitol and β-mercaptoethanol. It was strongly inhibited by p-hydroxymercuribenzenesulphonic acid, iodoacetic acid, iodoacetamide and microbial peptide inhibitors, leupeptin and antipain. Leupeptin inhibited the enzyme competitively with Ki value 44x10-9 M. The enzyme was strongly inhibited by 4 M urea. Metal ions, Hg2+, Ca2+, Cu2+, Li2+, K+, Cd2+, Ni2+, Ba2+, Mn2+, Co2+ and Sn2+ also inhibited the activity of the enzyme. The enzyme was stable between pH 4.0-6.0 and up to 40ºC. The optimum temperature for the hydrolysis of Z-Phe-Arg-4mβNA was ~50-55ºC with an activation energy Ea of ~6.34 KCal mole-1

Synthesis of spiropyrans: H-abstractions in 3-cycloalkenyloxybenzopyrans

A photochemical route for the synthesis of some benzopyronospiropyrans from 2-furyl-3-cycloalkenyloxybenzopyrones involving H-abstraction is reported. How a methyl group on the furyl ring affects the product formation is also investigated