A simple, precise, rapid, selective, and cost-effective high-performance thin-layer chromatographic (HPTLC) method has been established for simultaneous estimation of curcumin, piperine, and thymol in an ayurvedic formulation. Chromatography was performed on silica gel 60 F
plates with toluene-ethyl acetate-methanol, 9 + 1 + 0.5 (
), as mobile phase. Plates were developed to a distance of 8 cm at room temperature, without chamber saturation. The plates were scanned and the compounds were quantified at their wavelengths of maximum absorption, 420, 333, and 277 nm for curcumin, piperine, and thymol, respectively. The respective
values of curcumin, piperine, and thymol were 0.23, 0.30, and 0.64. Response was a linear function of the amount applied to the plate in the ranges 50–250 ng, 10–60 ng, and 100–700 ng for curcumin, piperine, and thymol, respectively. LOD for curcumin, piperine, and thymol were 25, 5, and 50 ng, respectively. The mean results from assay of curcumin, piperine, and thymol in the ayurvedic formulation were found to be 0.85, 12.93, and 3.29 mg g
, respectively. The respective covariance for curcumin, piperine, and thymol was 0.78, 0.51, and 0.69%, respectively. Recovery was 100.41, 99.52, and 101.21% for curcumin, piperine and thymol, respectively. Rapid identification of curcumin, piperine, and thymol is also possible by spraying the plate with anisaldehyde in sulfuric acid reagent.
The separation and quantitative analysis of thymol in Satureja hortensis L. extracts is reported. The extracts were obtained by three different techniques: maceration, sonication, and microwave-assisted extraction. HPTLC separation was performed in a normal chromatographic chamber on silica gel 60 plates with toluene-ethyl acetate 93:7 (v/v) as mobile phase. Photodensitometric evaluation of the plates was performed by UV-visible absorbance at 513 nm, after spraying with anisaldehyde reagent. The quantity of thymol extracted depends on the composition of the extraction solvent and on the extraction technique. The best results were obtained by maceration with ethanol. The results obtained were compared and correlated with the method of extraction and confirm that this plant contains an important amount of thymol.
Authors:Erika-Beáta Kerekes, Anita Vidács, Julianna Jenei Török, Csilla Gömöri, Tamás Petkovits, Muthusamy Chandrasekaran, Shine Kadaikunnan, Naiyf S. Alharbi, Csaba Vágvölgyi, and Judit Krisch
The anti-listerial effect of marjoram, thyme essential oils (EOs) and thymol on Listeria monocytogenes inoculated chicken breast fillets was investigated. Before inoculation the fillets were pretreated by washing or not under running tap water. Inoculated samples were kept at 6 °C for 24 h to allow the growth of L. monocytogenes. After this, the fillets were put in marinating solutions containing salt (5%) and EOs or thymol in MIC/2 concentration established in vitro. Total germ count (TGC) and L. monocytogenes count was monitored on the meat surface and in the marinating solutions following 24 and 48 h storage at 6 °C. Thyme and thymol reduced significantly Listeria cell count (1–3 log CFU) in both samples. They also gave good flavour to the fried meat. The doses of EOs used were optimal for antimicrobial efficiency and had a pleasant flavour effect. Washing was not efficient in reducing total germ count.
Authors:Khabat Noori Hussein, Tímea Molnár, Richard Pinter, Adrienn Toth, Emna Ayari, Laszlo Friedrich, Istvan Dalmadi, and Gabriella Kiskó
monoterpenes can be classified based on their diverse functional groups: terpinene, pinene; alcohols, e.g. geraniol; aldehydes, e.g. citral; ketones, e.g. camphor or phenols, e.g. thymol and carvacrol ( Bakkali et al., 2008 ) ( Fig. 1 ). Some of these active
Authors:Ágnes M. Móricz, Dániel Krüzselyi, and Péter G. Ott
Overpressured layer chromatography (OPLC), ensuring pumpforced constant mobile phase flow and the possibility of overrun, offers the expanded exploitation of fine-particle adsorbent layers for a longer development distance. Using an infusion—transfusion OPLC method with a 26-cm long development, the separation of clove, rosemary, eucalyptus, tea tree, spearmint, thyme, and cinnamon bark essential oil components was achieved with good resolutions. In the combination of OPLC and Aliivibrio fischeri assay, the main essential oil components eugenol, borneol, (−)-R-carvone, thymol, and trans-cinnamaldehyde exhibited antibacterial effect. The OPLC—2,2-diphenyl-1-picrylhydrazyl (DPPH*) test showed two antioxidant components: eugenol and thymol.
Authors:Ágnes Móricz, Györgyi Horváth, Péter Molnár, Béla Kocsis, Andrea Böszörményi, Éva Lemberkovics, and Péter Ott
The composition of the essential oil of Thymus vulgaris L. has been determined by GC-FID and GC-MS. Because separation of thymol, carvacrol, and linalool, components of the essential oil, was more efficient by overpressured layer chromatography (OPLC) than by conventional thin-layer chromatography (TLC), the forced flow technique was used before biological detection. All three test compounds had antibacterial effect against the phytopathogenic bacterium Pseudomonas syringae pv. maculicola, in bioautography, although in essential oil thymol was present in sufficient quantity to produce an inhibiting zone in the adsorbent layer. In BioArena investigations, when reduced glutathione as a formaldehyde (HCHO) capturer was dissolved in the cell suspension before bioautographic exposure to the essential oil, the characteristic inhibiting activity of thymol and carvacrol against Bacillus subtilis soil bacteria was reduced, whereas the presence of the HCHO precursors NGmonomethyl-l-arginine or Nɛ-monomethyl-l-lysine enhanced their antibacterial effect. These results suggest that HCHO and its reaction products may be involved in the antibacterial activity of thymol and carvacrol.