Heliyon 6(8), e04654 (2020). HPTLC of ethanolic extracts of three algae (100µg/band) on silica gel, along with carotenoid standards (10µg/band), developed with toluene – acetone 7:3. Detection under white light. Carotenoids appeared orange or yellow, chlorophylls green, pheophytins dark khaki. Carotenoid patterns of the algae were very different depending on the family: red alga Eucheuma denticulatum (Solieriaceae) contained mainly zeaxanthin and lutein (hRF 44) and β-carotene (hRF 88), but also β-cryptoxanthin (hRF 69-71) and fucoxanthin (hRF 39); brown alga Sargassum polycystum (Sargassaceae) contained mainly fucoxanthin, and also cryptoxanthin; green alga Caulerpa lentillifera (Caulerpaceae) contained mainly zeaxanthin, but also astaxanthin (hRF 61) and canthaxanthin (hRF 77) in smaller amounts. Separately, HPLC-MS was used to confirm and quantify these compounds, which was necessary for carotenoids with similar hRF values: zeaxanthin and lutein (hRF 44), and β-carotene and lycopene (hRF 88).

J Pharm Bioallied Sci. 12(2), 139-145 (2020). An HPTLC method was validated for the fingerprint of flavonoids and other phenolic compounds (rutin, apigenin, luteolin, caffeic acid, chlorogenic acid, rosmarinic acid) in methanol macerates of dried aerial parts of five Lamiaceae (subfamily Nepetoideae: Dracocephalum moldavica, Lophanthus anisatus, Monarda fistulosa, Ocimum americanum, Satureja hortensis). HPTLC of extracts and standards on silica gel with chloroform – ethyl acetate – formic acid 5:4:1 or with ethyl acetate – formic acid – water 15:1:1. Detection under UV light before and after spraying with aluminium chloride 1 % in methanol. Rosmarinic acid was present and abundant in all extracts and was also quantified by densitometry at UV 366 nm without derivatization. The LOD was 29.2 µg/mL; the rosmarinic acid concentration range was between 12.6 mg/g (Lophanthus) and 24.8 mg/g (Dracocephalum).

J. Planar Chromatogr. 33, 547-565 (2020). HPTLC of seven species of the genus Justicia (J. adhatoda, J. beddomei, J. betonica, J. carnea, J. gendarussa, J. santapaui, J. wynaadensis) on silica gel with toluene - ethyl acetate 9:1 for n-hexane extracts and toluene - ethyl acetate 4:1 for chloroform extracts and toluene - ethyl acetate - methanol 7:3:1 for methanol extracts. Detection by spraying with anisaldehyde - sulfuric acid reagent, followed by heating at 105 °C for 5 min. Densitometric scanning at 254 nm, 366 nm and 550 nm.

J. Planar Chromatogr. 33, 669-677 (2020). HPTLC of tris(2-chloroethyl)amine (HN-3) on silica gel with benzene - methanol - triethylamine 425:75:1. Detection by spraying with derivatization reagent (2mg/mL of KMnO4 with 4 mL of H3PO4). The method allowed to study the influence of pH on the degradation of HN-3 and the triethanolamine rate of appearance.

J. of Chromatogr. Sci. 58 (8), 737-746 (2020). Presentation of a method for determination of the antimicrobial capability of the metabolite coriloxin, derived from mycoendophytic Xylaria sp. NBRTSB-20, and purified by column chromatography with its purity assessed by HPLC, UPLC-ESI-QTOF-MS, FT-IR and NMR. Determination of the antimicrobial capability by TLC–bioautography with the agar overlay technique. Evaluation under visible light. The LOD of coriloxin antimicrobial activity was 10 μg for Escherichia coli and 20 μg for Staphylococcus aureus and Fusarium oxysporum. Inter- and intra-day precision was below 6.6 %. The recovery was between 91.2 to 108.7 % with RSD values of 0.9-2.3 %.

J. of Chromatogr. Sci. 58 (6), 520 – 534 (2020). HPTLC of 10-hydroxy-2-decenoic acid (10-HDA) in royal jelly products marketed in Egypt, on silica gel with chloroform - acetic acid 10:1. Quantitative determination by densitometry at 210 nm. First and second derivative treatment of the data and comparison between three statistical regression methods: parametric, nonparametric and weighted regression (WR). Derivative treatment of the data improved the sensitivity of the chromatographic signals. The WR method was advantageous over the use of the other two models and resulted in an enhancement of the accuracy and precision of the 10-HDA analysis. Recovery was 99.9 % with WR and 99.6 and 98.6 % with the other statistical methods. Further, the royal jelly standard was subjected to forced degradation studies including the effect of hydrolysis, oxidation, photolysis and dry heat.

Quim. Nova. 43, 878-883 (2020). HPTLC of caryophyllene (1) and the diterpenic acids copalic (2), hydroxy-copalic (3), acetoxycopalic (4), agathic (5), and hardwickiic (6) in oilresin of Copaifera on silica gel with hexane - ethyl acetate 7:3. Detection by spraying with ethanol in 10 % sulfuric acid, followed by heating for 5 min. Qualitative analysis at 366 nm. The hRF values for (1) to (6) were 80, 50, 8, 28, 16 and 40, respectively.

Biochem. Biophys. Res. Commun. 534, 1069-1075 (2021). HPTLC of gangliosides in human and mouse siglecs on silica gel with chloroform - methanol - 0.2 % calcium chloride 60:25:4. Immunostaining by dipping into cyclohexane containing 0.1 % poly (isobutyl methacrylate) for 1 min, blocked by incubation in PBS containing 1 % BSA at room temperature for 1 h, incubated with premixture of Sig7EcFc WT or R124A and anti-hIgG + M + A-HRP in PBS containing 0.1 % BSA or S2-566 (anti-diSia antibody) in PBS containing 1 % BSA at room temperature for 2 h, and washed 5 times with PBS. Horseradish peroxidase activity was detected by chemiluminescence. Sig7EcFc corresponds to extracellular domain of Siglec-7 fused to the human IgG1 Fc region.