3 Biotech 13, 32 (2023). Samples were the products of transgalactosylation operated by β-galactosidase immobilized on modified carrageenan beads in a solution of lactose. Raffinose, a trisaccharide, was used as standard. TLC on silica gel with n-propanol – water 17:3. Detection of galacto-oligosaccharides by spraying naphthol reagent (50 mg α-naphtol in 95 mL ethanol and 5 mL sulfuric acid), followed by heating. The target zones from unsprayed layers were further extracted with methanol using a TLC-MS interface into a quadrupole MS (flow rate 0.2ml/min, positive and negative electrospray ionization (ESI), m/z range 10–1200). Galactose oligomers were found, from trimers to hexamers (heptamers were observed when the reaction time was beyond 3 hours).

J. AOAC Int. 106, 129-139 (2023). HPTLC fingerprint of Tinospora species on silica gel with chloroform - toluene - methanol - formic acid 35:20:10:1. Detection by spraying with vanillin sulfuric acid, followed by heating at 100 °C for 3 min. Further analysis by LC–ESI (electrospray ionization)-MS/MS.

J. AOAC Int. 106, 1598-1607 (2023). HPTLC bioautography of Rubia cordifolia on silica gel impregnated with kojic acid with toluene - ethyl acetate - formic acid 5:4:1. Antityrosinase activity by spraying with 2 mM L-tyrosine and incubated at room temperature for 10 min. The plate was the sprayed with tyrosinase solution (1 mL of mushroom tyrosinase enzyme (3333 units) in 10 mL PBS - sodium phosphate buffer solution, pH 6.8), followed by incubation at room temperature for 45 min. Clear white zones of tyrosinase enzyme inhibition allowed the detection of presence of active compounds. Further analysis by MS allowed the identification of purpurin with antityrosinase potential.

J. Liq. Chromatogr. Relat. Technol. doi:10.1080/10826076.2024.2301720 (2023). HPTLC of two series of b-tetralino-spiro-5-hydantoins on silica gel with acetonitrile in the range of 46-90 %, increment of 4 %. Detection under UV light at 254 nm. Quantitative–structure–retention relationship modeling and multiple linear regression were applied with the purpose to quantify different types of interactions that govern chromatographic retention.

J. Liq. Chromatogr. Relat. Technol. doi:10.1080/10826076.2023.2284707 (2023). HPTLC of iridoids, coumarins, pharmaceutical drugs, flavonoids, triterpenes, sesquiterpenes, steroids, phospholipids and cannabinoids on silica gel with three complementary developing solvents (CDS) of different strength and selectivity. Detection by spraying with Fast Blue Salt B, followed by heating at 100 °C for 3 min. Other detection by spraying with the mixture NP/PEG 1:1, followed by drying for 2 min. Machine learning was applied by evaluating three regressor algorithms for their ability to predict the RF values of 178 chemicals in the low polarity developing solvent. RF values were correlated with polarity related properties such as the octanol/water partition coefficient (SlogP) or the topological polar surface area (TPSA).

J. Liq. Chromatogr. Relat. Technol. doi:10.1080/10826076.2023.2284706 (2023). HPTLC of 19 lemon balm leaf samples on cyano phase with acetonitrile - water - acetic acid 20:30:1. Free radical scavenging activity was detected by dipping into a 0.02 % methanolic 1,1-diphenyl-2-picrylhydrazyl (DPPH) solution. Rosmarinic acid was identified by HPTLC–high-resolution mass spectrometry (HRMS). 

J. Liq. Chromatogr. Relat. Technol. DOI: 10.1080/10826076.2023.2284708 (2023). HPTLC of propolis and pollen samples on silica gel with the apolar mixture of toluene - ethyl acetate - methanol 6:3:1 or the mid-polar mixture of ethyl acetate - toluene - formic acid - water 12:4:3:2. Effect-directed profiling by spraying with a bioluminescent Aliivibrio fischeri bacteria suspension and by dipping into a Bacillus subtilis suspension. Acetylcholinesterase inhibition and a- or b-glucosidase inhibition assays were also performed. Selected zones were further analyzed by high-resolution mass spectrometry. 

J. Planar Chromatogr. 36, 237-249 (2023). HPTLC of the leaves of Ficus benghalensis on silica gel with toluene - ethyl acetate 93:7. Detection under UV light at 254 and 366 nm. Bioautography by pouring Bacillus subtilis culture over the plate, followed by incubation at 37 °C for 24 h. After incubation, 1 mL of 0.2 mg/mL p-iodonitrotetrazolium chloride was added to the bioautography plates and monitored at room temperature until a pink color developed. Zones of inhibition were selected and further analyzed by high-resolution liquid chromatography (HR-LC) and mass spectrometry (MS).