J. Ethnopharmacol. 204, 26-35 (2017). HPTLC of quercitrin (1), isoquercitrin (2), quercitrin-3-O-β-D-xylopyranosyl-α-L-rhamnopyranoside (3) on silica gel with ethyl acetate – formic acid – acetic acid – water 100:11:11:26. Detection by spraying with NEU`s reagent (diphenylborinic acid 2-aminoethylester, natural product reagent), followed by drying at 110 °C for 2 min. Quantitative determination by absorbance measurement at 265 nm. LOD and LOQ were 31 ng/zone and 75 ng/zone for (2). Recovery was between 99.8 and 101.1 % for (2). Intermediate precision was <2 % (n=3).

Biochem. Biophys. Res. Commun. 487, 702-708 (2017). HPTLC of the reaction products of different 14C-labeled substrates of the mevalonate pathway (MVA, MVA-5-P, MVA-3-P, MVA-5-PP) and the recombinant Flavobacterium johnsoniae protein on silica gel with n-propanol – 28 % ammonia – water 6:3:1. The distribution of radioactivity on the TLC plate was detected using a suitable image analyzer.

J. Chromatogr. A 1473, 133-142 (2016). Development of a simple, accurate and precise method for the analysis of proton pump inhibitors and their co-formulated drugs, available as binary combination, by HPTLC on silica gel with toluene – iso-propranol – acetone – ammonia 50:23:25:2. Identification of 14 analytes (except for rabeprazole and lansoprazole which could not be separated) based on hRf and recorded peak spectra. Qantitative determination by densitometry at 290 nm. The linear response for the selected drugs was good with correlation coefficients ≥0.9993. The LOD and LOQ was between 7-160 ng/band and 21-478 ng/band, respectively, for all the analytes. Assessment of the method performance by analyzing different laboratory simulated mixtures and some marketed formulations of the selected drugs, and successful application of the method to investigate potential counterfeit of proton pump inhibitors through a series of simulated formulations with good accuracy and precision.

J. Sep. Sci. 41, 398-415 (2018). Review of analytical methods for the analysis of cannabinoids and their metabolites in cannabis, including the application of TLC and HPTLC. The review highlighted the use of automated multiple development (AMD) and optimum performance (or over-pressure) layer chromatography (OPLC) as considerable improvements to the use of classic TLC for cannabis analysis.

J. Planar Chromatogr. 30, 521-526 (2017). HPTLC of eupalitin-3-O-β-D-galactopyranoside in Boerhavia diffusa on silica gel with n-butanol – acetic acid ‒ water 8:1:1. Quantitative determination by absorbance measurement at 274 nm. The hRF value was 55. Linearity was between 0.05 and 2.5 μg/zone. LOD and LOQ were 1 and 4 ng/zone. The intermediate precision was <2 % (n=5). Average recovery was 98.3 %.

J. Chromatogr. A 1530, 192-196 (2017). HPTLC to measure the antioxidant and hypoglycemic effects in different extracts from Myrmecodia platytyrea, which can be a traditional medicine as alternative treatment for diabetes, because the substances produced by ants can reduce blood sugar levels. Measurement of the antioxidant activity in methanol, ethanol, dichloromethane (DCM) and ethyl acetate (EA) extracts with the HPTLC-2,2-diphenyl-1-picrylhydrazyl free radical (DPPH*) assay, and of the hypoglycemic effects with a newly developed α-amylase inhibitory activity assay. Detection of stigmasterol after derivatization with anisaldehyde reagent as purple colored zone under white light at hRF 66. The results showed the highest antioxidant activity in the ethanol extract rich in polyphenols and flavonoids. No antioxidant activity but significant α-amylase inhibitory activity was observed in the DCM extract. The highest α-amylase inhibitory activity was found in the EA and DCM extracts and was related to their stigmasterol content.

J. Planar Chromatogr. 31, 105-111 (2018). HPTLC of 13 quinobenzothiazine derivatives on RP-18 with acetone as organic modifier and aqueous TRIS buffer with pH 7.4 and ionic strength of 0.2 M. The contents of the organic modifier in the mobile phase ranged from 40 to 80% in 5 % increments. Lipophilicity parameters were determined for the analysis of structure–activity relationship (QSAR).

Biochem. Biophys. Res. Commun. 497, 1082-1088 (2018). TLC of lipids extracted from the different intraerytrocytic stages of P. falciparum labelled with nitrobenzoxadiazole-ceramide or nitrobenzoxadiazole-DHceramide as fluorescent precursors and treated or not with tamoxifen. TLC on silica gel with chloroform – methanol – water 40:10:1 for neutral and zwitterionic lipids and propanol – ammonia – water 15:1:1 for acidic lipids. The effect of tamoxifen on glycosphingolipid biosynthesis was evaluated by fluorescent precursor incorporation.