Marine Drugs 20(12), 757 (2022). Samples were ethyl acetate macerates and diethyl ether Soxhlet extracts from invasive Caulerpa cylindracea and non-invasive C. lentillifera (Caulerpaceae), as well as caulerpine (bisindole alkaloid) as standard isolated from one of the extracts. TLC on silica gel with petroleum ether – diethyl ether 1:1. Quantitative evaluation by densitometry at 330 nm, quantification of caulerpine (hRF 41, LOD 20 ng/zone, LOQ 68 ng/zone). The concentrations of caulerpine in C. cylindracea extracts (96-112 µg/g) were higher than in C. lentillifera (0-8 µg/g).

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. AOAC Int. 104, 1188-1195 (2021). HPTLC of syringic acid (1) and vanillic acid (2) in the roots of Ricinus communis and aerial parts of Euphorbia hirta on silica gel with toluene - ethyl acetate - formic acid 14:5:1. Quantitative determination by absorbance measurement at 366 nm. The hRF values for (1) and (2) were 50 and 60, respectively. Linearity was between 2 and 10 µg/zone for both (1) and (2). Inter-day and intra-day precisions were below 2 % (n=3). The LOD and LOQ were 1518 and 5066 ng/zone for (1) and 331 and 1104 ng/zone for (2), respectively. Mean recovery was 99.4 % for (1) and 98.7 % for (2). 

Marine Drugs 20(2), 106 (2022). TLC was used to monitor the fractionation of hydro-methanolic extracts of Rhodophytes: Gracilaria gracilis (Gracilariaceae) (A), Porphyra sp. (Bangiaceae) (B), Spongoclonium pastorale (Ceramiaceae / Wrangeliaceae) (C); and to assess the purity of two isolated mycosporine-like amino acids: porphyra-334 and shinorine.  TLC on silica gel with n-butanol - acetic acid - water 3:1:1. Derivatization by spraying ninhydrin reagent for the detection of peptides and amino-acids; or by spraying anisaldehyde - sulfuric acid for most phytochemicals; in both cases, followed by 5 min heating at 100 °C. Visualization under white light and at 366 nm. Porphyra-334 (hRF 28) was isolated pure from (B) and (C). Shinorine (hRF 25), isolated from (A) and (B), contained a coeluting sugar (hRF 48), which was absent after further purification on solid phase extraction, and, only when isolated from (B), a coeluting peptide or amino-acid (hRF 35), which was absent after further purification on cyclodextrane column chromatography.

J. Liq. Chromatogr. Relat. Technol. https://doi.org/10.1080/10826076.2022.2159977 (2021). HPTLC of Ophiopogonis Radix from different habitats on silica gel with toluene - methanol - glacial acetic acid 800:50:1. Detection under UV light at 254 nm. 

J. Liq. Chromatogr. Relat. Technol. 44, 820-828 (2021). HPTLC of Gentiana extracts from in vitro cultures on silica gel with acetate - methanol - water 4:1:1 in sandwich mode. Detection under UV light at 254 nm and fluorescence at 312 nm (emission above 370 nm). Principal component analysis (PCA), hierarchical cluster analysis and the novel proposal—nonnegative PCA was performed to identify common and distinct features.

J. Liq. Chromatogr. Relat. Technol. 44, 599-609 (2021). HPTLC of lupeol in Betula alnoides on silica gel with chloroform. Detection by spraying with anisaldehyde sulfuric acid reagent. Quantitative determination by absorbance measurement at 525 nm for lupeol. The hRF value for lupeol was 44. Linearity was between 0.8 and 2.4 µg/zone. Inter-day and intra-day precisions were below 5 % (n=3). The LOD and LOQ were 0.2 and 0.5 µg/zone. Recovery was between 100.5 and 106.8 %.

J Chromatogr A, 1647, 462153 (2021). Samples were extracts of Pittosporum angustifolium leaves (Pittosporaceae), either pure or fermented 1-4 weeks in NaCl solution, as well as acarbose, gallic acid, β-sitosterol, caffeic and chlorogenic acids, as standards. HPTLC on silica gel (prewashed with methanol and dried 15 min at 105 °C) with n-hexane – ethyl acetate – acetic acid 15:9:1. Derivatization by immersion (speed 5 cm/s, time 1 s): (A) into DPPH• 0.2 % solution, to detect radical scavengers; (B) into neutralized ferric chloride (3 % in ethanol), followed by 5 min heating at 110 °C, for detection of phenolic compounds; (C) into anisaldehyde – sulphuric acid reagent, followed by 10 min heating at 110 °C, to detect terpenes and steroids. Effect-directed analysis (EDA) for α-amylase inhibition assay (D) by immersion into enzyme solution, incubation 15 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). In all cases, visualization under white light. Quantification was performed on pictures using image processing software, and expressed as equivalents to the respective standards used for calibration curves: (A) and (B) gallic acid (LOQ 250 and 740 ng/band, respectively), (C) β-sitosterol (LOQ 1.5 µg/band), (D) acarbose (LOQ 8 µg/band). Zones of interest, scraped from untreated plates and washed with ethyl acetate, were submitted by ATR-FTIR analysis. An amylase inhibiting zone (hRF 85) present in all extracts was identified as fatty acid esters: ethyl palmitate in unfermented and methyl linoleate in fermented extracts. Moreover, fermented extracts contained antioxidant zones (hRF 15 – 20), identified as monomers and oligomers (including hydroxycinnamic, guaiacyl, syringyl derivatives) from decomposed lignin.