Anal. Bioanal. Chem. https://doi.org/10.1007/s00216-023-05101-y (2024). HPTLC of monogalactosyldiacylglycerol (1), sulfoquinovosyl diacylglycerol (2), and phosphatidylglycerol (3) in microalgae strains Nannochloropsis granulata, Phaeodactylum tricornutum, Porphyridium purpureum, and Tetraselmis tetrathele on silica gel with methyl acetate - isopropanol - chloroform - methanol - 0.25 % aqueous KCl solution (acidified with glacial acetic acid) 500:500:500:200:87, n-hexane - acetone - isopropanol 16:4:1 and finally with n-hexane - diethyl ether - glacial acetic acid 70:30:1. Detection by dipping into a modified copper sulfate reagent (20 g of CuSO4 × 7 H2O in 200 mL of methanol and acidified with 8 mL of 96 % sulfuric acid and 8 mL of 85 % orthophosphoric acid) for 6 s, followed by heating at 140 °C for 30 min. Quantitative determination by absorbance measurement at 720 nm. Linearity was in the range of 100-2100 ng/zone. Intermediate precisions were below 4 % (n=3). The LOD and LOQ were in the range of 18-29 ng/zone and 63-90 ng/zone, respectively. Recovery was in the range of 93.1-108.1 %.

PLoS Pathogens 19(9), e1011636 (2023). Samples were total lipid extracts from Mycobacterium tuberculosis (Mycobacteriaceae) either wild-type (1), or a mutant strain knock-out for the gene of succinyl-transferase (sucT) (2), or addback bacteria obtained through plasmide transformation of the wild-type sucT gene into the mutant (3). Development on TLC silica gel layers with chloroform – methanol – water 65:25:4. Derivatization by spraying with cupric sulphate (A) or with α-naphthol (B), followed by heating above 100°C. The following lipids were detected with both reagents (as brown spots on blue background with (A) or as purple spots on yellowish background for (B)) in all strains, without significant quantitative variations: cardiolipin, and acylated phosphatidyl–myo-inositol mannosides.

PLoS Neglected Tropical Diseases 17(09), e0011646 (2023). Samples were extracts rich in sphingolipids obtained from Trypanosoma cruzi epimastigotes, or from Leishmania major promastigotes (Trypanosomatidae), or from Chlorocebus sp. kidney Vero cells (Cercopithecidae), all cell lines incubated 2h before the extractions with ceramide N-hexanoyl-D-erythro-sphingosine coupled to fluorescent NBD-amine group (NBD = nitrobenzoxadiazolyle). Dried extracts were resuspended in chloroform – methanol (1:1) before application on TLC silica gel layers. Development with chloroform – methanol – potassium chloride 0.25 % aqueous solution 11:9:2. Visualization under automated laser scanner. Three sphingolipids were detected due to the NBD fluorescent group: sphingomyelin (hRF 42) was present in Vero cells only (negative control), whereas the targeted inositol-phosphorylceramide (IPC, hRF 70), was present in both L. major (positive control) and T. cruzi wild-type. It was absent in T. cruzi cell lines knock-out (KO) for the IPC-synthase (IPCS) gene, but present again in the add-back cell-lines (obtained with plasmide transfection of the IPCS gene into KO cells). An unknown lipid (hRF 78) was detected in all T. cruzi samples.

PLoS ONE 18(10), e0292514 (2023). Samples were 8 glycolipids, either sialylated or not; the two main examples were monosialotetrahexosylganglioside (GM1) and gangliotetraosylceramide (= asialo-GM1 = ASGM1). TLC on silica gel with chloroform – methanol – water – acetic acid 300:200:30:1, followed by air-drying. Visualization of glycolipids by spraying 5-methylresorcinol solution (0.2 % in 2 M sulfuric acid), followed by 5 min heating at 110°C. For immunostaining, underivatized chromatograms were immersed into a blocking gel (1% gelatin, 1% polyvinylpyrrolidone and 1mM EDTA in phosphate-buffered saline solution (PBS)), followed by immersion into a solution of monoclonal (50 ng/mL) or polyclonal (1:1,000) anti-ASGM1 antibodies purposedly produced in rabbits. After 1h reaction at room temperature, the layers were washed thrice with T-PBS (0.05 % Tween 20 in PBS) and horseradish-peroxidase-conjugated anti-rabbit IgG (1:40,000) was added. After washing thrice with T-PBS, the TLC sheets were incubated in substrate solution (tetramethylbenzidine). Blue spots indicated the glycolipids bound by the antibody. In this TLC assay, each of the five monoclonal antibodies (as well as the polyclonal serum) was specific to ASGM1 (unsialylated), whereas in ELISA (enzyme-linked immunosorbent assay) at the same concentrations three of them displayed partial cross-reactivity towards GM1, GM3 or GD1b, which are sialylated glycolipids. 

J. Planar Chromatogr. 36, 99-110 (2023). HPTLC of lecithin in dietary supplements on silica gel with chloroform - methanol - glacial acetic acid 15:30:2. Detection by spraying with 0.5 % ammonium molybdate solution in a mixture of ethanol and sulfuric acid 1:9, followed by heating at 100 °C for 5 min. Quantitative determination by absorbance measurement at 360 nm. The hRF value for lecithin was 23. Linearity was in the range of 0.23-3.21 mg/mL. Intermediate precisions were below 2 % (n=6). LOD and LOQ were 0.09 and 0.26 mg/mL, respectively. Recovery was between 97 and 99 %.

Food Chem. 88, 2902-2918 (2023). HPTLC of high free fatty acid, monoacylglycerols, diacylglycerols and triacylglycerol on silica gel with hexane – diethyl ether - acetic acid 50:50:1. 

Biochem. Biophys. Res. Commun. 667, 146-152 (2023). HPTLC of intracellular lipids in sebocytes treated with calcium for 24 h and incubated with medium containing 2 µCi of [1-¹⁴C] on silica gel with hexane - ethyl acetate 6:1. Detection by autoradiography. The method allowed the identification of squalene, trygliceride and cholesterol.     

Food Res. Int. 165, 112472 (2023). HPTLC of galactolipids (monogalactosyldiacylglycerol and digalactosyldiacylglycerol) in chloroplast-rich pellet from spinach leaves on silica gel with chloroform - methanol - water 19:4:5. Detection by dipping into a thymol solution (1 g of thymol in 190 mL of ethanol following with a slow addition of 10 ml of sulphuric acid), followed by heating at 110 °C for 10 min. Image visualization under white light and under UV light at 254 and 366 nm.