- 著者
- Nobuyuki Okamura Hidetoshi Miyauchi Tominari Choshi Takashi Ishizu Akira Yagi
- 出版者
- The Pharmaceutical Society of Japan
- 雑誌
- Biological and Pharmaceutical Bulletin (ISSN:09186158)
- 巻号頁・発行日
- vol.26, no.5, pp.658-661, 2003 (Released:2003-05-01)
- 参考文献数
- 19
- 被引用文献数
- 7 9
A method for semi-micro high-performance liquid chromatography (HPLC) has been established for the simultaneous determination of 3α-hydroxyglycyrrhetic acid and 3-dehydroglycyrrhetic acid together with glycyrrhizin, glycyrrhetic acid and glycyrrhetic acid mono-glucuronide formed by incubation of glycyrrhizin with rat feces. The analysis was accomplished within 25 min with a TSKgel ODS-80TsQA (150×2.0 mm i.d.) column by linear gradient elution using a mobile phase containing aqueous phosphoric acid and acetonitrile at a flow rate of 0.2 ml·min−1, a thermostatic oven at 25 °C, and detection at 254 nm. The detection limits of these compounds were 0.2 pmol per injection (5 μl). The metabolites of glycyrrhizin, by anaerobic or aerobic incubation with rat fecal suspension over 48 h, were determined. Glycyrrhizin was almost completely converted to metabolite glycyrrhetic acid, and metabolites 3α-hydroxyglycyrrhetic acid and 3-dehydroglycyrrhetic acid in negligible amounts in anaerobic conditions. However, the metabolic time courses of 3-dehydroglycyrrhetic acid when incubated in aerobic conditions revealed that it apparently continued increasing during the whole incubation period.
1 0 0 0 OA Configurational Studies of Complexes of Various Tea Catechins and Caffeine in Crystal State
- 著者
- Hiroyuki Tsutsumi Yoshifumi Kinoshita Takashi Sato Takashi Ishizu
- 出版者
- The Pharmaceutical Society of Japan
- 雑誌
- Chemical and Pharmaceutical Bulletin (ISSN:00092363)
- 巻号頁・発行日
- vol.59, no.8, pp.1008-1015, 2011-08-01 (Released:2011-08-01)
- 参考文献数
- 28
- 被引用文献数
- 12 13 5
Crystals of the complexes of (+)-catechin (CA) of non-galloylated catechin and (−)-catechin-3-O-gallate (Cg) of galloylated catechin with caffeine were prepared, and their stereochemical structures and intermolecular interactions were determined by X-ray crystallographic analysis. CA formed a 1 : 1 complex with caffeine by intermolecular hydrogen bonds, whereas Cg formed a 1 : 2 complex with caffeine, which was formed by face-to-face and offset π–π interactions and intermolecular hydrogen bonds. A solution of two kinds of non-galloylated catechin, CA and (−)-epicatechin (EC), and caffeine (molar ratio 1 : 1 : 2) in water afforded a 1 : 1 : 2 complex, the crystal structure of which had two layers, one layer in which CA and caffeine formed alternate lines and an other layer in which EC and caffeine formed alternate lines. The 1 : 1 : 2 complex was formed by offset π–π and CH–π interactions and intermolecular hydrogen bonds.