J. Planar Chromatogr. 13, 457-462 (2000). TLC and HPTLC of extracts and standards (quinine, quinidine, cinchonine, cinchonidine) on silica gel with 7 different mobile phases. The quaternary mobile phase toluene - chloroform - diethyl ether - diethylamine 8:3:7:2 enabled the determination of alkaloids in a variety of preparations and extracts. Two different modes of densitometric evaluation (absorbance and fluorescence) were used. Results from quantitative analysis were statistically assessed by use of a calibration procedure, a calibration equation, the correlation coefficient, and the relative standard deviation.

Cultivated in Shanghai area.) (Chinese). J. Chinese Trad. & Herb. Drugs (Zhongcaoyao) 32 (4), 360-361 (2001). TLC on silica gel with petroleum ether (30-60°C) - ethyl acetate 49:1. Detection by spraying with 1% vanillin-sulfuric acid reagent. Identification by finger print technique.

Proc. Intern. Symp. on Planar Separations, Planar Chromatography 2001, pp. 201-209. TLC and HPTLC of plant extracts and catechin and epicatechin as standards on cellulose, silica gel, and cyano-, amino- and RP-18 modified silica gel with 8 different mobile phases. The best separation of catechin and epicatechin was achieved on the aminopropyl and octadecyl plates using acetone - acetic acid 93:7 and water - methanol - formic acid 84:15:1 or 69:30:1, respectively. Visualization by spraying with vanillin in sulfuric acid or by coupling with bis-diazotized sulfanilamide.

Inhibitory effect of naproxene and its 7-methoxy isomer on constitutive COX-1 and inducible COX-2. Planta med. 66, 471-473 (2000). Analytical and preparative TLC of naproxene (6-methoxy-a-methyl-2-naphthalene-acetic acid) on silica gel with n-hexane - acetone - dichloromethane 5:2: 3. Visualization under UV 254 nm.

Planta med. 66, 16-19 (2000). TLC of cycloartocarpin (artocarpin, artocarpesin, 4-prenyloxyresveratrol, artocarbene) on silica gel with ethyl acetate - hexane 1:1. Detection under UV.

J. Planar Chromatogr. 15, 442-448 (2002). HPTLC of phenolic acids (caffeic acid, protocatechuic acid, gallic acid) on silica gel with multiple development with dipropyl ether - heptane - formic acid 5:4:1. Densitometry at 254 nm.

J. Planar Chromatogr. 16, 15-18 (2003). HPTLC of 27 extracts of St John's wort on silica gel - prewashed with acetone with n-heptane - acetone - t-butyl methyl ether - formic acid 33:35:30:2. Three-dimensional chromatograms were obtained by use of a diode-array TLC scanner enabling measurements of HPTLC tracks simultaneously in the range of 200 - 600 nm. Spectroscopic HPTLC analysis combined with multivariate data analysis was shown to be suitable for characterization of the quality of herbal extracts according to both phytochemical and pharmacological criteria. New approach to the evaluation of HPTLC plates.

Proc. Intern. Symp. on Planar Separations Plan. Chrom. 25-39 (2003). TLC and HPTLC of selected flavan-3-ols [e.g. (+)-catechin, (-)-epicatechin, (+)-gallocatechin, (-)-epigallocatechin, (+)-catechin gallate, (-)-epicatechin gallate, epicatechin-(4b>8)-catechin, epicatechin-(4b>8)-epicatechin] on cellulose. The developing solutions consisted of aqueous solutions containing acetone, acetic acid, tetrahydrofuran, acetonitrile, ethyl acetate, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and 2-butanol as organic modifiers in various concentrations. TLC in twin-trough chambers (saturated and unsaturated) and in horizontal developing chambers, used in tank and sandwich configuration. Separations were performed at ambient temperature and humidity (20-24°C, 46-56%). Visualization after drying by immersion for 1 s into vanillin/phosphoric acid reagent. The final optimized HPTLC method with water - 1-propanol - acetic acid 80:20:1 provided a fast separation of the flavan-3-ols studied with satisfactory resolution. Ready-to-use cellulose plates must be prewashed with water. In most cases the development in horizontal chamber with sandwich configuration gave the best resolution.