International J. Research in Ayurveda & Pharmacy 1(1), 131-134 (2010). Dried leaves of Calendula officinalis were extracted with petroleum ether, chloroform, methanol and water, the solvents were removed and the extracts were subjected to phytochemical analysis for amino acids, essential oils, triterpens, alkaloids, saponins, sterols, and fatty acids. TLC on silica gel with n-hexan – acetic acid – water 12:3:5, detection by spraying with ninhydrin solution, followed by heating at 105 °C revealed violet bands which indicated the presence of amino acids. For essential oils TLC on silica gel with dichloromethane – chloroform – ethyl acetate – n-propanol 94:90:4:5, followed by spraying with vanillin-sulfuric acid reagent and heating at 105 °C for 2 min. Pink brown coloured zones indicated the presence of essential oils. For triterpenoids TLC on silica gel with n-butanol – 2M ammonia 1:1 , detection by spraying with antimony trichloride solution. Purple coloured zones indicated the presence of triterpenoids. For alkaloids TLC on silica gel with chloroform – methanol 1:1, detection by alkaloids-reagent. For saponins TLC on silica gel with chloroform – methanol 12:1, detection by spraying with vanillin-sulfuric acid reagent. For sterols TLC on silica gel with chloroform – methanol 3:4, detection by anisaldehyde reagent. For fatty acids TLC on silica gel with n-hexane – ethyl acetate 19:1, detection by KMnO4 reagent.

Planta Med. 74, 1397-1402 (2008). Analytical and preparative TLC of three steroidal saponins (25R)-spirost-5-ene-3ß, 17alpha-diol (pennogenin), 3-O-{O-alpha-L-rhamnopyranosyl-(1-2)-O-[O-ß-xylopyranosyl-(1-5)-alpha-L-arabinofuranosyl-(1-4)]-ß-D-glucopyranoside} on silica gel with dichloromethane - methanol - water 80:19:1 or 70:29:1. Detection by spraying with phosphomolybdic acid. Additional detection by antifungal bioassays.

J. Planar Chromatogr. 24, 316-319 (2011). HPTLC of Palmarosa oil extracts in toluene and geraniol on silica gel with toluene - ethyl acetate 37:3 in a twin-trough chamber saturated for 30 min at 25 +/- 2 °C. Detection by spraying with 3 % vanillin in ethanol - sulfuric acid 49:1 followed by heating at 100 °C for 5 min. Quantitative determination by densitometry in absorption mode at 400 nm. The instrumental precision and the repeatability (n = 6), was 0.3 and 3.2 %, respectively. LOD and LOQ was 1.4 and 2.8 µg/mL, respectively. The intra-day recovery was 99.8 % and the inter-day recovery 99.4 %. The hRf value for geraniol was 36.

J. Planar Chromatogr. 24, 253-256 (2011). HPTLC of yohimbine on silica gel, prewashed with methanol, with toluene - ethyl acetate - diethyl amine 7:2:1 in a twin trough chamber saturated with mobile phase for 10 min at 25 +/- 2 °C. Quantitative determination by densitometry in absorbance mode at 285 nm. Linearity was between 400 and 1200 ng/band. The hRf value was 39. The repeatability as system precision and method precision (n = 6) was 0.9 and 0.8 % CV. The limit of detection and quantification was 80 ng and 260 ng. The instrument precision (n = 6), intra-day and inter-day precision (n = 3, %RSD) were 0.2, 0.1, and 0.1 %, respectively.

J. Planar Chromatogr. 24, 125-129 (2011). HPTLC of plant extracts and oxyresveratrol on silica gel, prewashed with methanol, with hexane - ethyl acetate - chloroform - methanol 15:10:17:8 in a twin-trough chamber lined with filter paper and saturated for 20 min. Quantitative determination by densitometry at 327 nm. LOD and LOQ were 50 and 200 ng/band, respectively. The hRf value of oxyresveratrol was 31. Intra-day and inter-day variation (%RSD) were consistently below 5.0 %. Within-day precisions for the replicate analysis (n = 3) were in the range of 1.1-4.1 %. Day-to-day replicates (n = 9) were between 2.1-2.8 %.

Food Chemistry 132, 549-553 (2012).. New HPTLC-based method to examine quantitatively the free radical scavenging activity of plant extracts. After chromatographic separation of polar compounds, and immersion of HPTLC plates in methanolic DPPH radical reagent, bleaching was observed and recorded using a photo camera and data analysis was carried out using an image processing software. The method is simple, fast and efficient for free-radical scavenging activity analysis of phytochemicals and crude plant extracts.

J. Planar Chromatogr. 24, 470-474 (2011). TLC of methanolic seed extracts with harmine, harmaline, and galanthamine as standards on silica gel with ethyl acetate - methanol - ammonia 20:3:1. Detection by inspection under UV 366 nm and by spraying with Dragendorff’s and vanillin-sulfuric acid reagent as well as by bioautography assay. For the bioautographic assay, AChE was dissolved in 150 mL of 0.05 M TRIS/hydrochloric acid buffer at pH 7.8. 150 mg bovine serum albumin was added for stabilization.The plates were dipped in the enzyme stock solution and incubated in a humid chamber at 37 °C for 20 min. For detection of the enzyme, solutions of 1-naphthyl acetate in ethanol and of Fast Blue B salt in water were prepared and mixed immediately before spraying the plate. The limits of AChE inhibitive activity were 10 ng/zone for all.

J. of Chinese Med. 26 (160), 1088-1090 (2011). Dangshi tablets are a herbal TCM preparation for cleaning heat, diuresis, and dissolving stones, and are prescribed to cure urinary tract infections and acute nephritis. For quality control, TLC of the extracts of the medicine on silica gel 1) for Poria cocos, with petroleum ether (30-60 ºC) – acetone – ethyl acetate 85:15:1, detection at UV 366 nm; 2) for Licorice, with chloroform – methanol – water 40:10:1, detection by spraying with 10 % sulfuric acid in ethanol and heating at 105 ° until the zones are visible, evaluation in daylight.