Planta Med. 84(16), 1174-1182 (2018). The fractionation and purification steps (column chromatography, including reverse-phase HPLC) of an ethanolic extract of Millettia pinnata (= Pongomia pinnata, Fabaceae) roots were monitored by TLC on silica gel with n-hexane – ethyl acetate mixtures 4:1 - 2:1. Detection at 254 and 336 nm, and by spraying with sulfuric vanillin reagent followed by heating. The process allowed the isolation of 2 flavanols (including pongaflavanol), 1 flavanol ether and 26 flavanones (including derrivanone, griffinones, isoderricines, isoglabrachromene, isolonchocarpin, liquiritigenin, maxima flavanone A, ovalichromene B, ovaliflavanones, pinostrobin, pongachin, pongamone C, ponganone III).

Planta Med. 84(12-13), 941-946 (2018). The activity-guided fractionation and purification steps (column chromatography and liquid-liquid partitions) of a hydromethanolic extract of Alchemilla vulgaris aerial parts (Rosaceae) were monitored by TLC on silica gel with ethyl acetate – acetic acid – formic acid – water 100:11:11:27. Detection at 254 and 336 nm, and by spraying with anisaldehyde reagent followed by heating. A flavonoid (quercetin-glucuronide) was isolated through this process.

Planta Medica 84(12-13), 902-912 (2018). A dichloromethane extract of Athrixia phyllicoides aerial parts (Asteraceae) was eluted on a silica gel column with different mixtures of ethyl acetate and hexane or methanol. This fractionation was monitored on TLC silica gel layers, using the combinations of the same solvents as mobile phases. Detection by derivatization with Natural Product Reagent and PEG, and visualization at UV 254 nm. This allowed the grouping of the fractions into 13 profiles and the isolation of three hydroxy-methoxyflavones and a coumarate.

Planta Medica 84(11), 813-819 (2018). Fluorinated analogues of epigallocatechin-gallate were purified after synthesis by extraction with ethyl acetate from the synthesis mixtures, followed by column chromatography or (for two pairs of isomers) by preparative TLC. This isolation (as well as monitoring of column elution for the other compounds) was performed by TLC on silica gel with mixtures of n-hexane and (less) ethyl acetate in several concentrations, allowing the separation of diastereoisomers (RF values and yields are given). No derivatisation, visualisation because of fluorescing agent in the layers. Structures were identified by NMR and HR-MS, but apart from the TLC.

J. Planar Chromatogr. 33, 439-448 (2020). HPTLC fingerprint of 182 samples of Sclerocarya birrea and traditional medicines on silica gel with ethyl acetate - formic acid - water 8:1:1. Detection by heating at 100 ºC for 3 min, following by cooling and derivatization with natural products reagent (1.0 g of 2-aminoethyl diphenylborinate in 100 mL of methanol) and subsequently with anisaldehyde reagent (170 mL of ice-cooled methanol with 20 mL of acetic acid, 10 mL of sulfuric acid, and 1 mL of anisaldehyde), and heating at 100 ºC for 3 min. Quantitative determination of quercetin-3-O-rhamnoside by absorbance measurement at 254 nm.

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 %.