Frontiers in Marine Science 7, 266 (2020). Methanol extracts from marine sponge Haliclona cnidata (Chalinidae) submitted to different stresses (antibiotics and/or darkness) were separated on HPTLC silica gel with an automated 15-step gradient based on methanol, dichloromethane and n-hexane. Bioluminescence was recorded after immersing the HPTLC plates into Aliivibrio fischeri suspension. Antibacterial activity and quorum sensing enhancement were analysed on software, and Pearson’s similarity coefficient was applied to generate similarity matrices for cluster analysis (UPGMA, Unweighted Pair Group Method with Arithmetic Mean). Only slight differences were observed, especially in QS enhanced zones in stressed vs. control cultures.

J. Planar Chromatogr. 34, 455-466 (2021). HPTLC of mometasone furoate (1) and salicylic acid (2) on silica gel with chloroform - ethanol 9:1. Quantitative determination by absorbance measurement at 250 nm for (1) and 300 nm for (2). The hRF values for (1) and (2) were 13 and 93, respectively. Linearity was between 100 and 1600 ng/zone for (1) and 400 and 5000 ng/zone for (2). LOD and LOQ were 16 and 47 ng/zone for (1) and 7 and 20 ng/zone for (2), respectively. Intermediate precisions were below 2 %. Recovery was between 98 and 102 %.

J. Planar Chromatogr. 34, 403-410 (2021). HPTLC of Meyna spinosa on silica gel with ethyl acetate - water 10:1. Detection by spraying with anisaldehyde‒sulfuric acid reagent and visualized under UV light at 366 nm. Further analysis by high-performance liquid chromatography coupled with electrospray ionization‒quadrupole-time of flight‒mass spectrometry (LC‒ESI‒Q-TOF‒MS).

J. Planar Chromatogr. 34, 467-477 (2021). HPTLC of five antihypertensive drugs, atenolol (1), amlodipine (2), losartan (3), hydrochlorothiazide (4), and telmisartan (5) on silica gel with chloroform - toluene - methanol - acetone - formic acid 400:300:150:260:3. Quantitative determination by absorbance measurement at 254 nm. The hRF values for (1) to (5) were 7, 12, 45, 56 and 64, respectively. Linearity ranged from 1-25 μg/zone for (1), (3) and (5) and 1-20 μg/zone for (2) and (4). LOD and LOQ were 300 and 900 ng/zone for (1), 130 and 420 ng/zone for (2), 230 and 690 ng/zone for (3), 140 and 430 ng/zone for (4) and 190 and 560 ng/zone for (5). Intermediate precisions were below 1 % (n=9). Mean recovery was 99.3 % fo (1), 100.1 % for (2), 99.7 % for (3), 99.7 % for (4) and 100.3 % for (5).

J. Planar Chromatogr. 34, 337-343 (2021). HPTLC of montelukast (1) and bilastine (2) on silica gel with acetonitrile - ethyl acetate - ammonia 40:60:1. Quantitative determination by absorbance measurement at 282 nm. The hRF values for (1) and (2) were 53 and 27, respectively. Linearity was between 100 and 500 ng/zone for (1) and 200 and 1000 ng/zone for (2). LOD and LOQ were 13 and 40 ng/zone for (1) and 65 and 198 ng/zone for (2). Intermediate precisions were below 2 % (n=3). Recovery was between 98.0 and 99.7 % for (1) and 98.0 and 99.0 % for (2).

J. Pharm. Biomed. Anal. 189, 113488 (2020). Various extracts from red alga Plocamium dilatatum (Plocamiaceae), green alga Codium fragile tasmanicum (Codiaceae) and brown algae Carpoglossum confluens (1), Cystophora platylobium (2) and C. retorta (3) (Sargassaceae), Ecklonia radiata (Lessoniaceae), Hormosira banksia (Hormosiraceae), Phyllospora comosa (4) (Seirococcaceae) were separated on HPTLC silica gel with n-hexane – ethyl acetate – acetic acid 70:27:3. Detection A) for antioxidant activity by spraying with methanolic DPPH solution, followed by waiting for 30 min at room temperature; B) for steroids and terpenes with anisaldehyde - sulfuric acid solution, followed by heating for 10 min at 110°C; C) for carbohydrates and polyols with thymol - sulfuric acid, followed by heating for 15-20 min at 120°C. Image-based evaluation in white light and UV 366 nm. The most active bands were also characterized by ATR-FTIR (= attenuated total reflectance – Fourier-transformed infrared) spectroscopy.

J. Planar Chromatogr. 34, 361-366 (2021). HPTLC of 19 iridoids, including ten iridoid glycosides (catalpol, aucubin, ajugol, hastatoside, loganin, geniposide, harpagoside, verbenalin, agnuside, nuzhenide), six secoiridoid glycosides (harpagide, sweroside, swertiamarin, gentiopicroside, oleuropein, amarogentin) and three nonglycosylated iridoids (loganic acid, genipin, valtrate) in samples of Gentiana lutea, Verbena officinalis, Olea europaea and Harpagophytum procumbens on silica gel with nine different mobile phases. Detection by spraying with anisaldehyde reagent, vanillin reagent, sulfuric acid reagent, respectively, followed by heating at 100 °C for 3 min. After derivatizing the plate with Ehrlich’s reagent, the plate was heated at 100 °C for 5 min. Digital images were recorded under UV light at 254 nm and 366 nm. The data is part of a HPTLC database under development for different families of phytochemicals.

J. Planar Chromatogr. 34, 263-270 (2021). HPTLC of quetiapine fumarate (1) and its related genotoxic impurities 2-chloroaniline (2) and 2-aminodiphenylsulide (3) on silica gel with ethyl acetate - ethanol - n-heptane 5:1:4. Quantitative determination by absorbance measurement at 229 nm. The hRF values for (1) to (3) were 13, 57 and 76, respectively. Linearity was between 100 and 600 ng/zone for (1) and 10 and 60 ng/zone for (2) and (3). Intermediate precisions were below 2 %. The LOD and LOQ were 0.9 and 2.8 ng/zone for (1), 0.3 and 0.9 ng/zone for (2) and 0.2 and 0.5 ng/zone for (3), respectively. Recovery of the impurity in quetiapine fumarate ranged between 99 % and 101 %.