J. Sep. Sci. 45, 1616-1635 (2022). HPTLC of gallic acid (1), protocatechuic acid (2), vanillic acid (3), cinnamic acid (4), piperine (5), guggulsterone-E (6), and guggulsterone-Z (7) in Mahayograj Guggul on silica gel with toluene - ethyl acetate - formic acid 10:9:2 for (1) to (3) and toluene - acetone 9:1 for (4) to (7). Quantitative determination by absorbance measurement at 250 nm for (6) and (7), 280 nm for (1), (2), (3) and (4) and 343 nm for (5). The hRF values for (1) to (7) were 30, 41, 47, 15, 33, 41 and 45, respectively. Linearity was between 100 and 1000 µg/mL for (1), 5 and 60 µg/mL for (2), 10 and 80 µg/mL for (3), (4) and (7), 20 and 100 µg/mL for (5) and 40 and 120 µg/mL for (6). Inter-day and intra-day precisions were below 4 % (n=18). The LOD and LOQ were 4 and 14 µg/g for (1), 7 and 21 µg/g for (2), 24 and 72 µg/g for (3), 0.8 and 2.4 µg/g for (4), 12 and 35 µg/g for (5), 2 and 6 µg/g for (6) and 4 and 14 µg/g for (7), respectively. Recovery was between 86.6 and 102.0 % for (1) to (7).

Phytochem. Anal. 33, 564-576 (2022). HPTLC of flavonoids (1), anthocyanin (2) and antioxidant structures in sweet cherry (Prunus avium) on silica gel with ethyl acetate - dichloromethane - formic acid - acetic acid - water 100:25:10:10:11 for (1) and ethyl acetate - formic acid - acetic acid - water 100:11:11:26 for (2). Detection by spraying with natural product reagent/polyethylene glycol 400 (NP/PEG) solution or 0.1 % methanolic DPPH solution. Qualitative analysis under UV light at 366 nm. 

Chinese Medicine 7, 12 (2012). TLC of a Soxhlet hydro-ethanolic extract of Trichosanthes lobata leaves (Cucurbitaceae) on silica gel with n-hexane – ethyl acetate 7:3. Derivatization with anisaldehyde – sulfuric acid reagent. The presence of flavonoids, saponins, and tannins was found.

Chinese Medicine 7, 12 (2012). TLC of a Soxhlet hydro-ethanolic extract of Trichosanthes lobata leaves (Cucurbitaceae) on silica gel with n-hexane – ethyl acetate 7:3. Derivatization with anisaldehyde – sulfuric acid reagent. The presence of flavonoids, saponins, and tannins was found.

Food Control. 136, 108840 (2022). HPTLC of flavonoids, coumarins, sesquiterpene lactones and phenolic acids in German Chamomile (Matricaria recutita L.) on silica gel with ethyl acetate - methanol - water - acetic acid 200:25:20:1 and ethyl acetate - toluene 2:1. Detection of flavonoids and phenolic acids by spraying with Natural product reagent. Detection of sesquiterpene lactones by spraying with anisaldehyde sulfuric acid reagent. Qualitative analysis under UV light at 366 nm. Principal component analysis (PCA) was used for reducing data dimensionality and representing samples across principal components.

Food Chem. 133992 (2023). HPTLC of kiwi peel extracts on silica gel with ethyl acetate - formic acid - acetic acid - water 100:11:11:26. Detection of phenolics and tanning agents by heating the plate at 100 °C for 2 min, followed by dipping into fast blue B (140 mg fast blue salt B in a mixture of 140 mL methanol, 10 mL water, and 50 mL dichloromethane). Detection of flavanols, phenols and further natural compounds by dipping into a NPA solution (1 g 2-aminoethyl diphenylborinate in 200 mL of ethyl acetate), followed by drying, detection under UV light at 366 nm, followed by dipping into the anisaldehyde reagent (0.5 mL anisaldehyde, 10 mL acetic acid, 85 mL methanol, and 10 mL sulphuric acid), followed by heating at 100 °C for 5 min. Antioxidants were detected by dipping into a DPPH solution (0.4 g 2,2-diphenyl-1-picrylhydrazyl in 200 mL of methanol), followed by incubation in dark for 30 min. 

Marine Drugs 17(3), 148 (2019). Samples were ethyl acetate extracts of seagrass Amphibolis antarctica (Cymodoceaceae), and of algae: Austrophyllis harveyana (Kallymeniaceae), Carpoglossum confluens, Cystophora harveyi, C. monilifera, C. pectinata and C. subfarcinata, Myriodesma integrifolium, Sargassum lacerifolium (Sargassaceae), Codium fragile subsp. tasmanicum (Codiaceae), Ecklonia radiata (Lessoniaceae), Hypnea valida, Rhodophyllis membaneacea (Cystocloniaceae), Hormosira banksii (Hormosiraceae), Perithalia caudata (Sporochnaceae), Phyllospora comoasa, Scytothalia dorycarpa (Seirococcaceae), Plocamium dilatatum (Plocamiaceae), and epiphytic brown algae. HPTLC on silica gel (pre-washed with methanol and heated 30 min at 100 °C) with n-hexane – ethyl acetate – acetic acid 15:9:1. Derivatization by immersion: A) into anisaldehyde – sulfuric acid reagent, followed by 10 min heating at 105 °C, for the detection of steroids and terpenes; B) into DPPH• (0.2 % in methanol), followed by 30 min incubation in the dark, for the detection of antioxydants; C) into Fast Blue B solution (0.1 % in 70 % ethanol) for detection of phenols (with alkylresorcinols detected as dark purple zones on colorless background). Effect-directed analyses were performed directly on the plates. D) α-Amylase inhibition assay by immersion into enzyme solution, incubation 30 min at 37 °C, immersion into substrate solution (starch 2 % in water), incubation 20 min at 37 °C and immersion into Gram’s iodine solution for detection (inhibition zones appear blue on white background). E) Acetylcholinesterase (AChE) inhibition assay (after neutralization by immersion into phosphate buffer) by immersion into enzyme solution, incubation 30 min at 37 °C, immersion into substrate solution (α-naphthyl acetate) and into dye reagent (Fast Blue Salt B). Densitometry through automated scanning, quantification expressed as equivalents to the respective standards used for calibration curves: A) β-sitosterol (LOQ 1.6 µg/band), B) gallic acid (LOQ 60 ng/band), D) acarbose (LOQ 173 µg/band), E) donepezil (LOQ 96 µg/mL). Alkylresorcinols were detected as antioxydant in C. harveyi and C. pectinata (hRF 88), and in C. subfarcinata (hRF 72, 81, 88). Enzymatic inhibitors in C. fragile were considered as a flavone (hRF 65) and a terpenoid (hRF 77), due to their absorption curves (densitometric scan in range 200-400 nm).

J. Liq. Chromatogr. Relat. Technol. 44, 760-765 (2021). HPTLC of chrysin in chrysin loaded phytosomes on silica gel with n-hexane - ethyl acetate - methanol - formic acid 40:40:5:1. Quantitative determination by absorbance measurement at 268 nm. The hRF value for chrysin was 78. Linearity was between 50 and 250 ng/zone. Inter-day and intra-day precisions were below 2 % (n=3). The LOQ was 77 ng/zone.