An innovative, simple, and sensitive spectrophotometric method was described for the determination of cimetidine in both its pureform pharmaceutical formulations. By oxidizing 2.4-dinitrophenylhydrazine (2.4-DNPH) mixing it with analkaline solution, a brightly colored chromogen maximum absorption wavelength 586 nm is created. After that,spectrophotometry used to quantify amount cimetidine. Othe...

We have recently reported’ the inhibition of xanthopterin oxidase and xanthine oxidase by synthetic pteroylglutamic acid (PGA). However, since an exceptionally pure sample2 of PGA, which was later examined, possessed less than one-sixth of the inhibitory power previously observed, it appears possible that the effect is due to traces of a contaminant. The observation by Lowry and Bessey3 that 2-...

Mitochondrial monoamine oxidase was inactivated with 2-[2-’4C]phenylcyclopropylamine, dialyzed, and treated with acidic 2,4-dinitrophenylhydrazine. Contrary to the report of Paech et al. (Paech, C., Salach, J. I., and Singer, T. P. (1980) J. Biol. Chern. 255, 2700-2704), the 2,4-dinitrophenylhydrazone obtained was not that of 2-phenylcyclopropanone, but rather of cinnamaldehyde. Futhermore, den...

Mitochondrial monoamine oxidase was inactivated with 2-[2-14C]phenylcyclopropylamine, dialyzed, and treated with acidic 2,4-dinitrophenylhydrazine. Contrary to the report of Paech et al. (Paech, C., Salach, J. I., and Singer, T. P. (1980) J. Biol. Chem. 255, 2700-2704), the 2,4-dinitrophenylhydrazone obtained was not that of 2-phenylcyclopropanone, but rather of cinnamaldehyde. Furthermore, den...

A relatively simple method for the quantitative determination of homogentisic acid in urine is presented. Homogentisic acid (2,5-dihydroxyphenylacetic acid) is oxidized by atmospheric oxygen in mild alkali to form 1,4-benzoquinone-2-acetic acid. The latter compound is then conjugated with 2,4-dinitrophenylhydrazine. The resulting hydrazone, in the presence of alcoholic sodium hydroxide, produce...

A sensitive and specific chemical method for the estimation of malic acid in biological materials has long been desired. The condensation of malic acid with orcinol in the presence of concentrated sulfuric acid to form the highly fluorescent homoumbelliferone (7-hydroxyd-methylcoumarin) was reported years ago (1). Although this reaction is relatively specific for malic acid, the quantitative pr...

A spectrophotometric method is proposed to determine isoniazid using oxidative coupling reaction. The depends on adding the oxidizing agent potassium periodate reagent solution 2,4-dinitrophenylhydrazine. Different optimum conditions are studied and explained based various experiments tests. wavelength (406) nm. Beer's law within concentration (0.2-40) µg/ml, with a molar absorptivity value of ...