Kazuko Mori

Automated measurement of catecholamines in urine, plasma and tissue homogenates by high-performance liquid chromatography with fluorometric detection

An automated catecholamine analyzer was assembled from a high-performance liquid chromatograph, an autosampler and an air segmented reactor equipped with a sensitive fluorometer. The trihydroxyindole technique was applied to the fluorometric reactor. Urine, plasma and brain homogenate were usually purified on an alumina column prior to high-performance liquid chromatography (HPLC). Centrifuged urine and a supernatant of brain homogenate can, however, be injected onto the HPLC column without further pre-treatment. The measurement of noradrenaline and adrenaline in plasma of a man at rest required 0.5--1 ml samples. Approximately 100 alumina eluates from urine can be treated per day when the analyzer is operated continuously.

Anti-tumor promoting activity of polyphenols from Cowania mexicana and Coleogyne ramosissima

Chemical investigation on polyphenol-rich fractions of Cowania mexicana and Coleogyne ramosissima (Rosaceae) which showed significant inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), has led to the characterization of 10 compounds including C-glucosidic ellagitannin monomers and dimers from the former plant, and 17 polyphenols including flavonoid glycosides from the latter. The effects of individual components and their analogues with related structures on the TPA-induced EBV-EA activation were then evaluated. Among the compounds isolated from C. mexicana, two C-glucosidic ellagitannins, alienanin B and stenophyllanin A and a nitrile glucoside (lithospermoside), and among the constituents from C. ramosissima, two flavonoid glycosides, isorhamnetin 3-0-beta-D-glucoside and narcissin were revealed to possess strong inhibitory effects on EVB-EA activation, the potencies of which were either comparable to or stronger than that of a green tea polyphenol, (-)-epigallocatechin gallate. These polyphenols except for nitrile glucoside, which was not tested owing to an insufficient amount, were also found to exhibit anti-tumor promoting activity in two-stage mouse skin carcinogenesis using 7,12-dimethylbenz[a]anthracene (DMBA) and TPA.

The distribution of geraniin and mallotusinic acid in the order Geraniales.

Abstract The distribution of geraniin and mallotusinic acid in Geraniaceae, Euphorbiaceae and other families in the Geraniales were investigated by HPLC. Geraniin composes the main part of the tannin in all of the investigated species of Geranium, but not in species of Pelargonium. The species of Geraniaceae lack mallotusinic acid. Geraniin was also detected in most of the species in the subfamily Euphorbioideae of Euphorbiaceae, although the amount was generally smaller than in Geranium, except for some woody species. Several species of Euphorbioideae contained mallotusinic acid. Characteristic of the subfamily Phyllanthoideae is the absence of mallotusinic acid and poor distribution of geraniin. Geraniin and mallotusinic acid were not detected in most of the species of other families in the Geraniales, except in Erythroxylum coca. Hyperin was found to be the main flavonol glycoside in most species of Geranium.

Constituents of Geranium thunbergii Sieb. et Zucc. VII. High-performance reversed-phase liquid chromatography of hydrolysable tannins and related polyphenols

Abstract Hydrolysable tannins in plants were analysed by reversed-phase high-performance liquid chromatography (HPLC) on a hydrocarbon polymer column. Geraniin, corilagin, mallotusinic acid, mallotinic acid, chebulinic acid and chebulagic acid were separated from each other, from polyphenols of lower molecular weight and also from flavonol glycosides. Variations in both the structure and amount of these ellagitannins and their hydrolysis products during extraction were also demonstrated by HPLC. Comparisons of the results of the quantitation of these tannins in plants with those obtained by relative astringency determination indicate that tannins in some plants can be represented by peaks in HPLC.

Fractionation of Pharmacologically Active Plant Polyphenols by Centrifugal Partition Chromatography

Abstract Centrifugal partition chromatography (CPC) has been applied to the preparative fractionation of pharmacologically active polyphenols contained in the crude extracts from three medicinal plants. 1) (-)-Epigallocatechin gallate, the main component of tea polyphenols, which inhibits tumor promotion, 2) oligomeric hydrolyzable tannins, having host-mediated anti-tumor activity and antiviral activity, contained in Woodfordia fruticosa flower, 3) polyphenolic components of licorice, having anti-HIV activity. The results obtained with cartridges of medium volume and of small volume were compared during the fractionation of tea polyphenols.

Distribution of manno-heptulose and sedoheptulose in plants

Abstract Upon investigation of the distribution of heptuloses in plants, most of the plants which were positive to the preliminary PC of the heptulose were found to contain manno -heptulose by the confirmative tests with descending PC and GLC of TMS derivatives after purification on the thick paper chromatogram. The amounts of manno -heptulose in many plants were comparable to those of sedoheptulose, and often higher than that of the latter.