Chinese  J. Guide for Trad. Chinese Med. & Pharm. 29 (1), 39-44 (2023). Resina Draconis (RD) is a rare Chinese medicinal plant, containing flavonoids and other medicinally active ingredients. It has hemostatic,  anti-inflammatory and analgesic effects and promotes blood circulation and cardiovascular protection. For quality control, TLC of the extracts from 18 batches of RD samples obtained from different regions in Yunnan province, on silica gel with petroleum ether (60-90 °C) – chloroform – ethyl acetate – methanol 15:8:2:1, detection by spraying with 10 % phosphomolybdate solution in ethanol, followed by heating at 105 °C until the zones are visible in daylight. 16 common components were characterized and 5 of them were confirmed and quantified: resveratrol, 7,4'-dihydroxyflavone, loureirin A, loureirin B and pterostilbene. Cluster and principal component analysis for chemometrics were applied, and considering the total content of the main components, a comprehensive scoring method was applied to evaluate the quality of RD samples from different regions and to provide an experimental basis for the establishment of quality control methods of RD medicinal materials and RD containing Chinese patent medicines.

Chinese J. Nat. Prod. Res. Devel. 35, 131-138 (2023). Ilicis Cornutae Folium is the leaf of Ilex cornuta Lindl. ex paxt., a TCM herb containing medicinally active ingredients, such as triterpenes and its saponins, flavones, polyphenols, and sterols. It is used as the main effective component of some TCM prescriptions with effects of lowering blood lipids, anti-myocardial ischemia, antioxidant, immunosuppression, and antifertility. TLC-bioautography-MS, as a drug screening technology integrating separation, identification and activity determination, is used in this study for quick characterization of lipase inhibiting active ingredients from the leaves, so as to provide a scientific basis for preparation of lipid-lowering prescriptions. TLC of the samples extracted from Ilicis Cornutae Folium,  the samples were applied as three parallel bands onto each of two silica gel plates,  and developed individually with chloroform – ethyl acetate – methanol – water 10:30:10:3 and ethyl acetate – methanol – water 6:2:1. Each chromatogram was divided into three pieces, 1)  is sprayed with 10 % sulfuric acid in ethanol, heated at 105°C and evaluated under day light; 2) is used for TLC-bioautography screening of zones with lipase inhibition activity; 3) is used for structure characterization of the target zones (Rf values determined in test 2) by in-situ TLC-EFISI-MSn method. 15 triterpenoids were identified, including 9 ursoguane triterpenoids, one oleanane triterpenoid, and 5 18,19-split ring triterpenoids. The method is proved to be able to quickly characterize and screen the active components with lipase inhibition contained in Ilicis Cornutae Folium, thus to provide a base for realizing its routine quality control in laboratory.

J. Chinese Trad. Patent Med. 44 (2), 667-671 (2022). Qingpi (Citri Reticulatae Pericarpium Viride) and Zhike (Fructus Aurantii)  are common TCM herbs with similar chemical compositions and the effects of improving the liver and biliary function. Their similaryity brings some difficulties to the qualitative identification and specification between the two in the quality control lab. Based on the methods provided in the Chinese Pharmacopoeia a method was developed for identifying the two drugs in full prescription and single-taste preparations (total 27 prescription preparations, including pills, granules, tablets, capsules, oral liquid, powder and paste) by TLC on polyamide stationary phase with dichloromethane – acetone – methanol at 20-25 °C to a distance of 10 cm. Detection by spraying with 3 % AlCl3 in ethanol solution and evaluation in UV light at 365 nm. Identification by comparing the fingerprints obtained through single procedure in the same condition for test samples of traditional Chinese full prescriptions and medical materials, the peel of dry young or immature fruits of Citrus reticulata Blanco. or its cultivated variety, Citrus aurantium L., and the standards of representative active ingredients, hesperidin, naringin, neohesperidin. In order to optimize the above method, all factors involved, e. g., sample preparation, stationary phase, mobile phase, developing distance, chamber temperature, and specificity, stability, etc. were investigated. The results obtained show that the method is simple, with obvious qualitative characteristics, good specificity, good repeatability and high reliability, which is well suitable for the title purpose.

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(11), e0294775 (2023). Sample was an Azadirachta indica seed extract (Meliaceae). TLC on silica gel with different mobile phases: (1) diethyl ether – methanol 49:1; (2) diethyl ether – acetone 2:1; (3) isopropanol – n-hexane 11:9; (4) dichloromethane – methanol – acetic acid 95:5:1. After 30 min hot air drying,detection under UV light. The hRF values of azadirachtin A (a limonoid) were 75, 42, 44, 55, respectively. Mobile phase (1) was therefore chosen as solvent for purification of azadirachtin A and for its quantification by Fourier transform infrared spectroscopy (FTIR).

J. AOAC Int. 106, 846-853 (2023). HPTLC of mebendazole (1) in the presence of its degraded product (2) on silica gel with ethanol - ethyl acetate - formic acid 60:160:1. Quantitative determination by absorbance measurement at 254 nm. The hRF values for mebendazole and its degraded product were 80 and 30, respectively. Linearity was in the range of 0.2-3 μg/zone. Intermediate precisions were below 2 % (n=3). LOD and LOQ were 0.58 and 1.85 μg/zone for (1) and 0.31 and 0.96 μg/zone for (2), respectively. Recovery was 100.2 % for (1) and 99.7 % for (2). 

J. AOAC Int. 106, 1654-1665 (2023). HPTLC of thiocolchicoside (1) and lornoxicam (2) on silica gel with n-heptane - acetone - ethanol 3:1:1. Quantitative determination by absorbance measurement at 370 nm. The hRF values for (1) and (2) were 25 and 60, respectively. Linearity was in the range of 20-100 ng/zone for (1) and (2). Intermediate precisions were below 2 % (n=3). LOD and LOQ were 0.3 and 1.0 μg/zone, respectively. Recovery was between 98 and 102 %. The developed method’s greenness was evaluated using the AGREE (Analytical Procedure Greenness) tool.

J. AOAC Int. 106, 1471-1477 (2023). HPTLC of evogliptin on silica gel with acetonitrile - water - formic acid 15:4:1. Quantitative determination by absorbance measurement at 270 nm. The hRF value for evogliptin was 62. Linearity was in the range of 1-5 μg/zone. Intermediate precisions were below 2 % (n=3). LOD and LOQ were 0.3 and 1.0 μg/zone, respectively. Average recovery was 101.1 %.