59th Indian Pharmaceutical Congress C-42, 234, (2007). HPTLC of E-guggulsterone (a steroidal ketone present in oily resin of Commiphora mukul) and five marketed ayurvedic tablet formulations, on silica gel with toluene - propane-1-ol - glacial acetic acid 8:1:1. Densitometry at 254 nm. The hRf of E-guggulsterone was 61. Several marketed formulations were evaluated for E-guggulsterone, the UV spectra of the standard and that of the formulations were comparable in respect of E-guggulsterone. The TLC pattern showed several other zones corresponding to unknown phytochemicals. The method was suitable for quantitative evaluation of formulation in respect of E-guggulsterone in presence of other phyto chemicals.

Journal of Natural Remedies 8(1), 61-67 (2008). During pharmacognostic studies on Sphaeranthus indicus (Asteraceae) the sesquiterpenoid 7-OH-eudesmanolide was isolated. HPTLC of the ethyl acetate soluble fraction of aqueous alcoholic Sphaeranthus indicus extracts, on silica gel with n-hexane - diethyl ether 3:7. The plant extract and the marker (7-OH-eudesmanolide) were chromatographed simultaneously. Quantitative determination by absorbance measurement at 213 nm.

J. Chromatogr. A 1112 (1-2), 156-164 (2006). HPTLC of glucosamine in a dietary supplement containing dried extracts of the main plants traditionally used for rheumatic disorders, on silica gel with a saturated mixture of 2-propanol - ethyl acetate - ammonia (8 %) 1:1:1. Detection by dipping into a modified anisaldehyde reagent and heating at 120 °C for 30 min in a drying oven. Quantitative determination by absorbance measurement at 415 nm. Validation of the method by applying the novel validation protocol proposed by a commission of the Société Française des Sciences et Techniques Pharmaceutiques. Relative standard deviations for repeatability and intermediate precision were between 4.9 and 8.6 %, accuracy was good, the two-sided 95 % beta-expectation tolerance interval was within the acceptance limits of 85 and 115 % on the whole analytical range (800 - 1200 ng of glucosamine).

J. Chromatogr. A 1216 (11), 2150-2155 (2009). Chaihu roots (Bupleuri radix), roots of Bupleurum chinense and Bupleurum scorzonerifolium are monographed in the Chinese Pharmacopoeia. Evaluation of the quality of 33 lots of authenticated Chaihu samples versus 31 lots of commercial samples by HPLC-ELSD and HPTLC analysis of the principal bioactive components (saikosaponins). Data acquired from HPLC fingerprints and HPTLC fluorescent images was analyzed by chemometrics for similarity and pattern recognition, including artificial neural networks, k-nearest neighbor (k-NN) and an expert’s panel. The k-NN classifier showed good performance with sufficient flexibility for processing HPTLC fingerprint images. These images were otherwise not easily dealt with by other algorithms due to the shift of hRf values and varying hue/saturation of the band colors between different TLC plates. The two chromatographic fingerprint methods are complementary measures for quality control. Chaihu roots from different species of the genus Bupleurum could readily be distinguished from each other. Commercial samples of Chaihu can easily be classified by investigating the content of major saikosaponins.

J. Planar Chromatogr. 22, 445-448 (2009). HPTLC of myristicin, safrole and extract of seeds on silica gel, prewashed with methanol, with toluene in an automatic developing chamber saturated for 20 min. Quantitative determination by absorbance measurement at 210 nm for myristicin and at 290 nm for safrole.

J. Planar Chromatogr. 22, 301-304 (2009). Analytical and preparative TLC of luteolin-7-rutinoside and luteolin-7-neohesperidoside on silica gel with ethyl acetate - formic acid - acetic acid - water 100:11:11:23, on cellulose with 30 % acetic acid, and on polyamide with chloroform - methanol - 2-butanone - acetyl acetone (= pentane-2,4-dione) 9:4:3:1. Detection by spraying with natural products reagent followed by treatment with PEG 4000, or by aniline phthalate.

Chinese J. Pharm. Anal. 28 (4), 608-610 (2008). TLC of hyperoside in the raw extract of Hypericum perforatum on silica gel with petroleum ether (60-90 °C) – ethyl acetate – methanol 1:4:2. Detection under daylight. Quantification by densitometry at 591 nm. Linearity was given between 0.1 and 14.4 µg/spot (r2 = 0.9892), recovery was between 96.4 and 100.1 %.

J. Planar Chromatogr. 23, 225-226 (2010). OPLC of oregano oil components (carvacrol, thymol, and linalool) on silica gel with dichloromethane. Detection under UV 254 nm, by spraying with vanillin-sulfuric acid reagent (0.1 g vanillin, 100 mL ethanol, and 2.2 mL 95-98 % sulfuric acid) and heating at 110 °C for 3 min, and in the BioArena system (the dried developed plates were dipped for 10 s into an aqueous cell suspension of the soil bacteria Bacillus subtilis and incubated for 2 h at 100 % rel. humidity and 30 °C). Visualizion of antimicrobial compounds was performed by immersing the plates for 5 s in an aqueous solution of MTT reagent (80 mg MTT and 100 mg Triton X-100 in 100 mL water). The layers were further incubated and and documented.