A colorimetic assay for lipoxygenase activity has been developed. The assay is based on the detection of the lipoxygenase reaction product, linoleic acid hydroperoxide, by the oxidative coupling of 3-methyl-2-benzothiazolinone (MBTH) with 3-(dimethylamino)benzoic acid (DMAB) in a hemoglobin-catalyzed reaction. This test reaction is rapid and sensitive, and it offers advantages over other method...

The title hydrazone compound, C(15)H(13)N(3)O(3), was prepared by the condensation of 4-nitro-benzaldehyde with 2-methyl-benzohydrazide in methanol. The dihedral angle between the two benzene rings is 14.8 (2)°. In the crystal, mol-ecules are linked through inter-molecular N-H⋯O hydrogen bonds, forming chains along the a axis.

The known derivatives from hydroquinone, α and β-arbutin, are used as depigmenting agents. In this work, we demonstrate that the oxy form of tyrosinase (oxytyrosinase) hydroxylates α and β-arbutin in ortho position of the phenolic hydroxyl group, giving rise to a complex formed by met-tyrosinase with the hydroxylated α or β-arbutin. This complex could evolve in two ways: by oxidizing the origin...

Bound sialic acids on rat spermatozoa were assayed by oxidation with 1 mMNaIO4 at 0\s=deg\C,liberating C-9 as formaldehyde which was further quantitated using 3\x=req-\ methyl-2-benzothiazolinone. The mean \m=+-\s.d. (n = 20) content of bound sialic acids of spermatozoa from the caput and cauda epididymidis was 50\m=.\9 \m=+-\8\m=.\0and 25\m=.\2 \m=+-\3\m=.\8 nmol/108 spermatozoa respectively. ...

Three simple, accurate and economical spectrophotometric methods in ultraviolet and visible region were developed for the determination of cefprozil in bulk and dosage forms have been described. The method A is based on the reduction of ferric ion into ferrous ion by the mentioned drug in the presence of 1,10-phenanthroline to form a highly stable orange red colored ferrion complex measured at ...