J. Liq. Chromatogr. Relat. Technol. 43, 344-350 (2020). HPTLC of hydrodistilled Plectranthus amboinicus essential oil on silica gel with n-hexane - ethyl acetate - ethanol 95:3:2. Detection by dipping into anisaldehyde sulfuric acid reagent, followed by heating at 100 ºC for 5 min. HPTLC-bioprofiling was performed using the following assays by dipping the chromatogram into the respective solution, followed by drying, incubation and documentation at white light or measuring bioluminescence: DPPH* radical reagent assay (using a 0.2 mg/mL 2,2-diphenyl-1-picrylhydrazyl solution in methanol), AChE inhibitory assay, tyrosinase inhibitory assay, alpha- and beta-glucosidase inhibitory assays, alpha-amylase inhibitory assay, Gram-negative antimicrobial bioassay (chromatogram immersion into a A. fischeri suspension), and Gram-positive antimicrobial bioassay (chromatogram immersion into a B. subtilis bacterial suspension). Direct analysis in real time mass spectrometry allowed the detection of five bioactive compounds: caryophyllene oxide (hR_F 20), a-humulene (hR_F 26), carvacrol (hR_F 40), methyl carvacrol ether (hR_F 76) and caryophyllene (hR_F 84).

Planta Medica 84(9/10), 716-720 (2018). The fractionations of n-hexane and chloroform extracts of Guarea guidonia aerial parts (Meliaceae) through silica gel column chromatography was monitored on TLC silica gel with cerium sulfate / sulfuric acid as derivatization reagent. In the fractions obtained, 3 new tirucallane-type triterpenoids (guareolide, guareoic acids A and B) were further identified, as well as other terpenoids (flindissone, acetyldihydronomilin, picroquassin E, boscartol C, and acneorubins A, B, and X).

Planta Medica 84(9/10), 729-735 (2018). The chloroform fraction of a methanolic extract of Euphorbia taurinensis whole plant (Euphorbiaceae) was submitted to a multi-step fractionation through column chromatography. Monitoring by TLC on silica gel (mobile phases see below) followed by derivatization with concentrated sulfuric acid and heating at 105°C. The fractions obtained were purified by repeated cycles of preparative TLC alone or alternating with preparative HPLC, leading to the isolation of segetane, ingenane, and jatrophane diterpenes. Depending on the subfractions, preparative TLC silica gel and reverse-phase C18 layers were used, with cyclohexane – ethyl acetate – ethanol 25:15:1 for normal phase, and with mixtures of acetonitrile (or methanol) and water for RP.

Planta Medica 84(1), 59-64 (2018). A multi-step fractionation through silica gel column chromatography (CC) of a methanolic extract of Plectranthus africanus (whole plant, Lamiaceae) was monitored through TLC on silica gel with various solvent mixtures (n-hexane or dichloromethane with either acetone or methanol). Zones were detected under UV and further by spraying with sulfuric acid 20 % and heating at 100°C. For each fraction or TLC profile, the authors provide the CC gradient, the optimal proportions of the solvents used for the TLC mobile phase, as well as the RF values of the molecules isolated by this CC method: new abietane-type diterpenoids (plectranthroyleanones A, B, C), betulinic and oleanolic acids, heterosides of apigenin, rhamnetin and sitosterol.

J. Planar Chromatogr. 32, 359-364 (2019). HPTLC of Schizonepeta annua on silica gel with chloroform - toluene - acetic acid 600:100:3. Detection by spraying with 5 % vanillin - sulfuric acid reagent (mixture of 2.5 g vanillin, 45 mL ethanol, and 5 mL concentrated sulfuric acid), followed by heating at 105 °C for 5 min. Antibacterial assay was performed by dipping the plate into a cell suspension culture (Brain heart infusion broth and brain heart infusion agar in the ratio of 9:1), followed by incubation at 35 °C for 16 h and immersion into 0.2 % MTT solution for 3s, followed by incubation at 35 °C for 3h. Plates were scanned at 546 nm. The hRF values for thymol and carvacol were 88 and 78, respectively.

Planta Med. 83(16), 1289-1296 (2017). A cycloartene-diol, a dihydroxycicloartenone and an isopimaradiene-diol were isolated from subfractions of an ethanolic extract of Guarea macrophylla (Meliaceae) leaves through elution on preparative TLC silica gel layers with chloroform – acetone 19:1, or with n-hexane – ethyl acetate 9:1 or 1:1, respectively.

J. Planar Chromatogr. 32, 205-210 (2019). HPTLC fingerprint of essential oils from five sandalwood species, namely, Santalum album, Santalum spicatum, Santalum austrocaledonicum, Santalum paniculatum, Santalum lanceolatum on silica gel with toluene - ethyl acetate 17:3. Detection by spraying with p-anisaldehyde sulfuric acid reagent. Qualitative identification under UV light at 254 and 366 nm. The hRF value of α-bisabolol was 48. 

International Journal of ChemTech Research 1(4), 1129-1135 (2009) The marker compound was first isolated by column chromatography over silica gel by elution with toluene - ethyl acetate 17:3. TLC of ethanolic extracts of Syzgium cumini seed on silica gel with toluene - ethyl acetate 17:3. The hRf value of the marker compound was 50. Densitometric evaluation in fluorescence mode at 366 nm. The method was linear in the range of 1-5 µg/band. The extract of the powdered sample contained 7.4 % of the marker compound.