J. Planar Chromatogr. 33, 473-479 (2020). HPTLC of rutin (1), gallic acid (2) and quercetin (3) in the aerial parts of Euphorbia hirta and Euphorbia thymifolia on silica gel with toluene - ethyl acetate - methanol - formic acid 30:15:13:4. Quantitative determination by absorbance measurement at 254 nm. The hRF values for (1) to (3) were 2, 56 and 72, respectively. Linearity was between 40 and 480 ng/zone for (1) to (3). Intermediate precision was below 2 % (n=3). The LOD and LOQ were 15 and 45 ng/zone for (1), 45 and 139 ng/zone for (2) and 20 and 61 ng/zone for (3), respectively. Recovery ranged 98.3-100.2 % for (1), 98.5-99.6 % for (2) and 95.5-99.1 % for (3).

J. Planar Chromatogr. 33, 293-300 (2020). HPTLC of bavachin (1), bakuchiol (2), and psoralen (3) in the seeds of Psoralea corylifolia on silica gel with toluene - ether 1:1. Quantitative determination by absorbance measurement at 254 nm. The hRF values for (1) to (3) were 48, 87 and 75, respectively. Linearity was between 1000 and 11000 ng for (1) to (3). Intermediate precision was below 2 % (n=3). The LOD and LOQ were 275 and 832 ng for (1), 317 and 962 ng for (2) and 108 and 329 ng for (3), respectively. Average recovery was between 98.0 and 99.0 % for (1) to (3).

J. Planar Chromatogr. 33, 301-311 (2020). HPTLC of gallic acid in honey on silica gel with toluene - ethyl acetate - formic acid 6:5:1. Detection by derivatization with 2 mL of 0.4 % DPPH reagent. Quantitative determination under white light. The hRF value for gallic acid was 29. Linearity was between 40 and 140 ng/zone. Intermediate precision was below 4 % (n=3). The LOD and LOQ were 14 and 43 ng, respectively. Recovery was between 99.9 and 101.4 %.

J. Planar Chromatogr. 33, 313-319 (2020). HPTLC of berberine (1) and rutin (2) on silica gel with n-hexane - ethyl acetate - glacial acetic acid - methanol 100:11:11:25. Quantitative determination by absorbance measurement at 241 nm. Antioxidant activity was determined by dipping into a 0.05 % DPPH solution followed by qualitative analysis at 366 nm. The hRF values for (1) and (2) were 67 and 47, respectively. Linearity was between 0.2 and 1.4 µg/zone for (1) and 2 and 14 µg/zone for (2). Intermediate precision was below 1 % (n=6). The LOD and LOQ were 0.2 and 2 µg for both (1) and (2), respectively. Average recovery was 94.9 % for (1) and 96.3 % for (2).

Pharmacogn. Mag. 16, 227-234 (2020). HPTLC fingerprint of Evolvulus alsinoides on silica gel with toluene - ethyl acetate - formic acid 14:6:1. Qualitative determination under UV light at 254 nm. Detection of antioxidant molecules using 2,2‑Diphenyl‑1‑picrylhydrazyl (DPPH) assay.

J. Sep. Sci. 43, 1431-1439 (2020). HPTLC fingerprint of flavan-3-ols and proanthocyanidins in five different Rosa species (R. canina, R. glutinosa, R. rubiginosa, R. multiflora, and R. spinosissima) on silica gel with n-propanol - water - acetic acid 4:2:1. Detection by dipping into 4-dimethylaminocinnamaldehyde solution (60 mg  in 13 mL of concentrated hydrochloric acid, which was made up to 200 mL with ethanol). Qualitative determination under UV light at 366 nm. The blue zones visible on the derivatized plate were used for further analysis using a TLC-MS interface. The flavanol and proanthocyanidin profiles of Rosa species depend on the geographical origin rather than on the cultivar and genotype.

J. Liq. Chromatogr. Relat. Technol. 43, 361-366 (2020). HPTLC of the dried root and rhizome of Rhodiola rosea on silica gel with ethyl acetate - methanol - water 77:13:10. Detection by spraying with 1) a solution of p-anisaldehyde (0.5 mL in 85 mL methanol, 10 mL acetic acid and 5 mL sulfuric acid), followed by heating at 105 ºC for 5-7 min, 2) a solution of 2-isopropyl-5-methylphenol (0.5 g in 95 mL ethanol and 5 mL sulfuric acid), followed by heating at 120 ºC and 3) NP solution (1 g diphenylboryloxyethylamine in 100 mL methanol) and PEG solution (5 g PEG-4000 in 100 mL ethanol). Detection under UV 254 and 366 nm. Effect directed detection was performed using 1) DPPH* radical reagent assay: spraying with 0.2 % 2,2-diphenyl-1-picrylhydrazyl solution in methanol, 2) AChE assay: spraying with the enzyme solution (20 units of AChE and 150 mg BSA in 150 mL 0.05 M TRIS buffer, pH 7.8), follwed by incubation at 37 ºC for 20 min and spraying with 50 mg Fast Blue B salt diluted in 100 mL of water and 3) Bacillus subtilis bioassay: dipping into bacterial suspension for 8 s, followed by incubation at 37 ºC for 17 h and spraying with 0.2 % MTT aqueous solution. The bioautographic tests showed presence of both antioxidants (DPPH assay) and antibacterials (Bacillus subtilis assay) in the methanolic plant extract, however no acetylcholinesterase inhibitors were found. As marker compound, rosavin was detected.

Planta Medica 84(9/10), 710-715 (2018). The fractionation of an n-butanol extract of Cistanche phelypaea (Orobanchaceae) aerial parts through cyclodextran column chromatography with methanol was monitored on TLC silica gel with chloroform – methanol – water 70:30:3, detection by spraying with cerium sulfate reagent. In the 11 major fractions obtained, 4 new phenylethanoid glycosides were further identified, as well as brandioside (a phenylpropanoid glycoside), and heterosides of apigenin (flavonoid) and of pinoresinol (lignan).