tincture using thin-layer chromatography–direct bioautography and liquid chromatography–tandem mass spectrometry techniques. J. Planar Chromatogr. 30, 131-135 (2017). HPTLC direct bioautography of eriodictyol (1) and 4,4՛-dihydroxy-_x000D_
5,5՛-diisopropyl-2,2՛-dimethyl-3,6-bifenylodion (2) in Thymus vulgaris on silica gel with chloroform – diethyl ether – methanol 30:10:1. Detection by spraying with anisaldehyde sulfuric acid reagent, followed by heating at 100 °C for 5 min. Direct bioautography by dipping into cell suspensions of the following bacterial strains: Microccocus luteus, Bacillus subtilis, Staphylococcus aureus, methicillin-resistant Staphyloccocus aureus, Staphyloccocus epidermidis (Se), luminescence gene-tagged Pseudomonas syringae and naturally luminescent marine bacterium Aliivibrio fischeri. Bioactive components (1) and (2) were further identified by liquid chromatography‒tandem mass spectrometry.

J. Ethnopharmacol. 197, 165-172 (2017). HPTLC of arjunolic acid (1), arjunetin (2), berberin (3), piperine (4), resveratrol (5) and withaferin-A (6) in Ayurvedic formulation on silica gel with ethyl acetate – toluene – formic acid – acetic acid 6:3:5:1 for (1), n-butanol – glacial acetic acid – water 12:3:4 for (2), toluene – ethyl acetate – diethylether 6:3:1 for (3), chloroform – ethyl acetate – formic acid 25:10:1 for (4) and chloroform – methanol 19:1 for (5) and (6). Detection of (1-4) by spraying with anisaldehyde sulfuric acid reagent. Quantitative determination by absorbance measurement at 690 nm for (1) and (2), 366 nm for (3), 330 nm for (4), 307 nm for (5) and 225 nm for (5) and (6). The hRF values for (1-6) were 67, 31, 58, 24, 32 and 37, respectively.

J. Planar Chromatogr. 31, 48-56 (2018). HPTLC of _x000D_7 derivatives of 2-(2,4-dihydroxyphenyl)-1,3,4-thiadiazoles A) on silica gel with n-hexane ‒ toluene ‒ acetone 1:1:1 and B) on RP-18 with water – methanol or water – acetone. Changes of retention of chosen compounds were evaluated using perpendicular magnetic field with an inductivity of 0.44 T. Detection under UV 366 nm.

Phytochem. Anal. 29, 5-15 (2018). TLC fingerprint of Ipomoea aquatica on silica gel with methanol – water from 1:1 to 9:1 (1) or methanol with 0.05 % trifluoroacetic acid – water with 0.05 % trifluoroacetic acid 1:1 (2). Detection by spraying with anisaldehyde sulfuric acid reagent. Detection under UV 254 nm, 366 nm, and for (2), white light (yellow bands at hRF 19 and 25). The post chromatographic visualization possibilities indicate the potential of TLC in qualitative fingerprint analysis.

Trends. Anal. Chem. 96, 138-150 (2017). Review of quality control approaches, including sample preparation, separation and fraction, qualitative and quantitative analysis of polysaccharides in medicine dual-purposes Chinese herbs._x000D_

J. Planar Chromatogr. 30, 527-530 (2017). HPTLC of the essential oil of Chamomile anthodium on silica gel with isocratic elution and gradient elution. Isocratic elution with 0 %, 20 %, 40 %, 60 %, 80 %, and 100 % (v/v) heptane in toluene; 0 %, 2.5 %, 5 %, 10 %, 15 %, and 20 % ethyl acetate in toluene; and_x000D_ 2.5 %, 5 %, 10 %, 15 %, 20 %, and 30 % ethyl acetate in heptane. Gradient elution with single void volume of the mobile phase of pure heptane, followed by a 10 % solution of ethyl acetate in toluene. Detection by spraying with anisaldehyde reagent, followed by heating at 100–105 °C for 5–10 min. Qualitative determination under UV light at 366 nm. The obtained separation is better with gradient elution in comparison to isocratic elution.

J. Chromatogr. A 1490, 201-211 (2017). HPTLC for comparison of the phenolic profiles of polar extracts from Populus nigra L. (1), Populus alba L. (2) and Salix alba L. (3) buds. Five chemotypical patterns were distinguished after derivatization with Natural Products reagent and confirmed by principal component analysis. The HPTLC analysis was directly hyphenated to various microbiological and biochemical assays as well as spectrometric techniques, which directly linked to active molecules in the chromatograms. The results showed that polyvalent compounds were evident when all derivatization and activity assays were combined together. Detection of at least three antimicrobial compound zones using Aliivibrio fischeri and Bacillus subtilis bioassays and of one phyto-estrogen with the planar yeast estrogen screen in Populus buds. Detection of several inhibitors of acetyl- and butyrylcholinesterase and rabbit liver esterase in all samples. Bioactive compounds were assigned by HPTLC-MS, e.g. chrysin as selective cholinesterase inhibitor, and caffeic acid and galangin as antimicrobials in (1) and (2). The method is suitable to determine the botanical origin and quality of Populus bud extracts and propolis samples.

J. Planar Chromatogr. 31, 250-256 (2018). HPTLC of fifteen 17β-carboxamide glucocorticoid derivatives and prednisolone on RP-18 with acetonitrile – water (1:1, 3:2, 7:3, and 4:1), acetone – water (1:1, 3:2, 7:3, and 4:1, and 9:1), ethanol 96 % – water (1:1, 3:2, 7:3, and 4:1), methanol – water (3:2, 7:3, 4:1, and 9:1) and tetrahydrofuran – water (1:1, 3:2, 7:3, and 4:1). The system consisting of water and ethanol 96 % was selected as the most suitable for the prediction of octanol – water partition coefficients (log Po/w).