J. Ethnopharmacol. 193, 490-499 (2016). HPTLC of quercetin in the leaves of Ocimum basilicum on silica gel with toluene – ethyl acetate – formic acid 17:11:2. Quantitative determination by absorbance measurement at 254 nm.

Chinese J. of Drug Evaluation 32 (4), 193-194 (2015). Fortune Paulownia leaf, the dry leaf of Paulownia fortunei (Seem.) Hemsl, is a TCM raw material used for treatment of carbuncles, furuncles, trauma, hemorrhage, etc. For quality control, TLC of its extracts on silica gel previously impregnated with 1 % iodine in dichloromethane and developed with cyclohexane – ethyl acetate – glacial acetic acid 20:6:1, detection by spraying with 10 % sulfuric acid in ethanol and heating at 105 ºC until the zones are clearly visualized, viewing (A) in white light and (B) under UV 366 nm. Identification by fingerprint comparison with the standards oleanolic acid (hRf 67) and ursolic acid (hRf 60) and the reference raw material in parallel.

Planta Medica 83(01/02), 135-142 (2017). Preparative TLC on silica gel for the purification of recrystallized farnesiferol B (hRF 50; with petroleum ether – ethyl acetate 8:1) and sinkianol B (hRF 40; with chloroform – methanol 15:1) isolated through column chromatography from petroleum ether – dichloromethane fractions of the chloroform extract of Ferula sinkiangensis gum resin.

J. Planar Chromatogr. 30, 211-215 (2017). HPTLC of benzyl isothiocyanate in the root of Salvadora persica on silica gel with n-hexane ‒ ethyl acetate 9:1. Quantitative determination by absorbance measurement at 191 nm. The hRF value for benzyl isothiocyanate was 61. Linearity was between 100 and 600 ng/zone. The intermediate precision was below 2 % (n=3). Recovery ranged from 97.6 to 99.5 %.

J. Planar Chromatogr. 30, 392-400 (2017). HPTLC of 13 Achillea species on silica gel with toluene – ethyl acetate – formic acid 50:49:1. Detection by spraying with anisaldehyde reagent, followed by heating at 126 °C for 10 min. TLC chromatograms were photographed and processed with ImageJ program. Also TLC on cyano phase with 2-propanol – n-heptane 1:1 and ethanol – water 3:2 for dichloromethane extracts and methanol – water 2:3 for methanolic extracts. Detection by spraying with 1 % solution of diphenylborinic acid 2-aminoethylester in methanol, followed by drying and spraying with 5 % solution of polyethylene glycol in methanol. Detection under UV 366 nm. Principal component analysis, similarity and distance measures were used to confirm the similarity between the studied samples.

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.

Planta Med. 83(07), 661-671 (2017). Structural modifications of 9α- and 9β-hydroxyparthenolide (isolated from Anvillea radiata aerial parts) were performed either by Heck’s reaction (a palladium(II) acetate treatment in presence of triethylamine and iodoaryl in dimethylformamide), or by acylation (here, addition of aroyl chlorides and/or acetic anhydride in dichloromethane and pyridine). TLC for reaction monitoring of the 21 derivatives on silica gel with petroleum ether – ethyl acetate in various proportions (3:2; 1:4; 1:1). Detection under UV or under white light after spraying with 5 % phosphomolybdic acid in ethanol, followed by heating.

CBS 120, 5-7 (2018). HPTLC of extracts of broad-leaved dock (Rumex obtusifolius) on silica gel with toluene – ethyl acetate – formic acid 1:8:1 over 75 mm. Detection by 3-step derivatization using automated spraying: 1) natural product reagent (NP), 2) NP in combination with polyethylene glycol solution (PEG), 3) vanillin-sulfuric acid reagent followed by heating at 100 °C for 3 min. To derivatize areas of the same plate with different reagents, the areas, which were to be evaluated underivatized by TLC-MS, were covered with a suitable segment of a used HPTLC plate, the layer turned upwards. Evaluation under UV 254 and 366 nm, white light, and by densitometry in absorbance measurement at 280 nm. Direct elution of target zones into a triple quadrupole mass spectrometer with electrospray ionization and recording in the negative ionization mode allowed a quick and easy screening of constituents. Overall, many flavan-3-ols, procyanidins, anthraquinones and naphthyl glycosides were detected in Rumex obtusifolius. The stilbenes frequently found in other Polygonaceae (Rheum spec.) were present only in small quantities.