We describe a rapid, reliable "high-performance" liquid-chromatographic method of simultaneously analyzing for 4-hydroxy-3-methoxymandelic acid (I) and 4-hydroxy-3-methoxyphenylacetic acid (II) in urine. Paired-ion chromatography and amperometric detection are used in the method. A 5-mL aliquot of urine is adjusted to pH 6.1 and subjected to anion-exchange chromatography (Dowex AG 1-X4, 1.8 X 0...

No cytokinin activity was found in methanolic mesocarp extracts after purification with petroleum ether and ethyl acetate. Cytokinin activity did appear, however, in aqueous fraction after acid hydrolysis or passage through Dowex 50 (H(+)) ion exchange columns. The level of this activity, the fruit growth rate, and the cell division rate were found to be positively correlated (with each other)....

The inhibitory activity of an angiotensin I-converting enzyme (ACE) detected in soy sauce was fractionated into two major fractions ef high molecular weight (Hw) and low molecular weight (Lw) by gel fi1tration chromatography on Bio-gel P-2 after treatifig with ethanol. The Hw fractien reduced the blood pressure in hypertensive rats after orally administering, while the Lw fraction did not. The ...

The increased urinary excretion of methylmalonic acid in vitamin B12 deficiency has attracted attention and several studies have suggested that it has clinical value as a test of vitamin B12 deficiency (Cox and White, 1962; Bashir, Hinterberger, and Jones, 1966). Chromatographic methods of estimation have been used but are either time consuming or only semiquantitative over a narrow range of me...

A total of 10 cyanogen bromide peptides were isolated from the S-beta-carboxymethyl iron protein of nitrogenase. Purification of these peptides was performed mainly by gel filtration on Sephadex G-50; by ascending paper chromatography using the solvent system of pyridine, isoamyl alcohol, 0.1 M ammonium hydroxide; and also, in some cases, with additional steps such as anion exchange column chro...

In order to obtain a highly concentrated, pure and super-hot [ƒÁ-32P]ATP, we improved the purification method of super-hot [ƒÁ-32P]ATP which was synthesized by the method of Johnson and Walseth (1979). The super-hot [ƒÁ-32P]ATP was synthesized in a relatively large volume (2 ml) of reaction mixture and purified using semi-micro scale anion exchange chromatography (Dowex 1•~2, 60-70ƒÊl column vo...

Glycerinated rabbit psoas fibers were tested for their ability to contract under the influence of creatine phosphate and creatine kinase in the absence of free nucleotide. Tension development by the fibers was observed upon addition of creatine phosphate to the medium containing creatine kinase purified to the first lyophilization stage. However, when the enzyme was washed free of nucleotides b...

Quinaldic acid, which was found to be a metabolite of kynurenic acid (l), was not conjugated by the rabbit (2), but was excreted by the rat both free and as the glycine conjugate (3). When quinaldic acid was administered orally or parenterally to the cat, the urine contained little, if any, quinaldic acid or quinaldylglycine, but about two-thirds of the compound was accounted for as quinaldylgl...

During a study of the effect of 2,4-dichlorophenoxyacetic acid on the soluble nucleotides in soybean seedlings (1)) a nonnucleotide compound accumulated in the treated seedlings. The same compound was found in high concentrations in immature soybean seeds that would not germinate (2). The compound inhibited seed germination and markedly affected respiration and phosphorylation of both intact so...