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Four thymol derivatives, 2,5-dimethoxythymol (1), 2-methoxythymol isobutyrate (2), 10-isobutyloxy-8,9-epoxythymolisobutyrate (3) and 10-(2-methylbutyloxy)-8,9-epoxythymolisobutyrate (4) were isolated from the aerial parts of Carpesium divaricatum. The structures were elucidated by high field 1D and 2D NMR techniques.
An outbreak of septicaemia with Pseudomonas aeruginosa amongst adult men with haematological malignancy involved eight patients on the same ward during a period of 5 weeks. The strains isolated from blood cultures from seven patients were indistinguishable by conventional typing methods. Thymol mouthwash which had been made up and distributed in communal jugs was found to be contaminated with the epidemic strain and was the likely source for this outbreak. A high rate of gastrointestinal colonization with the epidemic strain was found in the patients receiving the contaminated mouthwash. Only those patients with prolonged severe leucopenia developed septicaemia. Communal medications are an unnecessary hazard, particularly in oncology wards.
The biotransformations of aroma compounds of spices, such as thymol (1), carvacrol (2), and eugenol (3), were investigated using cultured plant cells of Eucalyptus perriniana. Besides a beta-glucoside product (4, 3%), a biotransformation product, i.e., 5-methyl-2-(1-methylethyl)phenyl 6-O-(beta-d-glucopyranosyl)-beta-d-glucopyranoside (5, beta-gentiobioside, 87%), was isolated from the suspension cells after the five-day incubation of 1. On administration of 2, a beta-glucoside (6, 5%) and a beta-gentiobioside, i.e., 2-methyl-5-(1-methylethyl)phenyl 6-O-(beta-d-glucopyranosyl)-beta-d-glucopyranoside (7, 56%), were produced. Furthermore, E. perriniana cells also converted 3 into the corresponding beta-glucoside (8, 7%) and beta-gentiobioside (9, 58%). The cultured cells of E. perriniana are able to convert these aroma compounds of spices into glycosides which are accumulated in the cells.
A gas chromatographic method to determine thymol, eucalyptol (cineole), menthol and camphor residues in honey and beeswax is proposed. To isolate the compounds, three methods involving liquid-liquid extraction with methylene chloride, distillation, or solid-phase extraction on octadecylsilica cartridges can be used. The GC separation is carried out on a 60 m x 0.53 mm Stabilwax DA capillary column, using a flame ionization detector. The method is applied to the analysis of natural honey and also honey and beeswax samples from beehives treated with the above compounds.
A high-performance liquid chromatographic method was developed as an alternative to automated enzymatic analysis of uric acid in human urine preserved with thymol and/or thimerosal. Uric acid (tR = 10 min) and creatinine (tR = 5 min) were separated and quantified during isocratic elution (0.025 M acetate buffer, pH 4.5) from a mu Bondapak C18 column. The uric-acid peak was identified chemically by incubating urine samples with uricase. The thymol/thimerosal peak appeared at 31 min during the washing step and did not interfere with the analysis. We validated the high-performance liquid chromatographic method for linearity, precision and accuracy, and the results were found to be excellent.
Major active compounds from essential oils are well-known to possess antimicrobial activity against both pathogen and spoilage microorganisms. The aim of this work was to determine the alteration of the membrane fatty acid profile as an adaptive mechanism of the cells in the presence of a sublethal concentration of antimicrobial compound in response to a stress condition. Methanolic solutions of thymol, carvacrol, limonene, cinnamaldehyde, and eugenol were added into growth media of Escherichia coli O157:H7, Salmonella enterica serovar typhimurium, Pseudomonas fluorescens, Brochothrix thermosphacta, and Staphylococcus aureus strains. Fatty acid extraction and gas chromatographic analysis were performed to assess changes in membrane fatty acid composition. Substantial changes were observed on the long chain unsaturated fatty acids when the E. coli and Salmonella strains grew in the presence of limonene and cinnamaldehyde and carvacrol and eugenol, respectively. All compounds influenced the fatty acid profile of B. thermosphacta, while Pseudomonas and S. aureus strains did not show substantial changes in their fatty acid compositions.
Sixteen new thymol derivatives have been isolated from Eupatorium fortunei and their structures determined based on spectroscopic data. They were classified into three groups (i-iii) depending on the oxidation levels: (i) one oxygen function at the 9-position, (ii) two oxygen functions at the 8- and 9-positions, and (iii) three oxygen functions at the 8-, 9-, and 10-positions. The hydroxyl groups are acylated with tigloyl, angeloyl, acetyl, isobutyryl, 3-methyl-2-butenoyl, or 2-methylbutyryl moieties. The compounds having chiral centers showed no specific rotation and exist as racemic mixtures.
In a prospective, randomised and blinded cohort study, the acceptance and effectiveness of a 3-monthly chlorhexidine-thymol varnish application was assessed in 8- to 10-yr-old children (n=29) with high caries incidence after brushing with a 1.23% fluoride gel. The children of the control group (n=25) brushed with a fluoride gel only. The standardised interview showed good acceptance of the varnish applications in spite of the bitter taste. Caries incidence in one year was 1.2 DMFS (SD 1.5, median 1; 95% confidence interval 0-1) for the test group and 2.1 DMFS (SD 2.3, median 2; 95% confidence interval 0-3) for the control group. Due to a slightly lower reduction in caries incidence (42.3%) than in other studies and a higher standard deviation than in unselected study groups, the power of the present study was not high enough to prove this difference in caries incidence to be statistically significant in the Mann-Whitney test (P=0.11). This was also found for the difference of 0.4 initial lesions. The distribution patterns of caries incidence for tooth groups (70% in the first permanent molar) and surfaces (58% on occlusal surfaces) did not differ between the test and the control group. The reductions of caries incidence which have been found in highly caries active children of the present study should be evaluated further with a larger study sample.
1. Pseudomonas putida when grown with thymol contained a meta-fission dioxygenase, which required ferrous ions and readily cleaved the benzene nucleus of catechols between adjacent carbon atoms bearing hydroxyl and isopropyl groups. 2. 3-Hydroxythymo-1,4-quinone was excreted towards the end of exponential growth and later was slowly metabolized. This compound was oxidized by partially purified extracts only when NADH was supplied; the substrate for the dioxygenase appeared to be 3-hydroxythymo-1,4-quinol, which was readily and non-enzymically oxidized to the quinone. 3. 2-Oxobutyrate (0.9 mole) was formed from 1 mole of 3-hydroxythymo-1,4-quinone with the consumption of 1 mole of oxygen; acetate, isobutyrate and 2-hydroxybutyrate (which arose from the enzymic reduction of 2-oxobutyrate) were also formed. 4. These products, which were produced only when the catechol substrate contained a third hydroxyl group, appeared to result from the enzymic hydrolysis of the ring-fission product.
The antimicrobial action of 21 pharmaceutical preparations has been compared in vitro by testing them against Staph. aureus (Oxford strain) in an identical environment. While a number of chemicals produced a degree of action, which can be considered adequate for clinical purposes, the combination thymol-camphor gave the best results.
High-performance liquid chromatography was employed to determine the contents of the eight marker components liquiritin, naringin, hesperidin, thymol, imperatorin, honokiol, isoimperatorin, and magnolol in the traditional Chinese medicinal preparation Huoxiang-zhengqi liquid. The separation was performed on a C(18) column by stepwise gradient elution with water-methanol-acetonitrile (0.01 min, 68:30:2; 20 min, 60:38:2; 50 min, 34:64:2; 65 min, 34:64:2; 75 min, 28:70:2; 85 min, 68:30:2) as the mobile phase at a flow rate of 1 ml/min, with UV detection at 283 nm. Eight regression equations showed good linear relationships between the peak area ratio of each marker to internal standard and amounts. The recoveries of the markers listed above were 97.4, 98.5, 97.4, 98.6, 97.8, 99.2, 97.0, and 97.5%, respectively. The repeatability and reproducibility (relative standard deviation) of the method were less than 2.2 and 3.0%, respectively.
The waterdistilled essential oil from dried aerial parts of one of the Algerian thymes, Thymus fontanesii Boiss. & Reut. grown in Setif province, Algeria, was analyzed by GC/MS. Fifteen components were characterized representing 99.4% of the total components detected. The major components of the oil were thymol (67.8%), gamma-terpinene (15.9%) and p-cymene (13.0%).
Inhibition of Clostridium perfringens spore germination and outgrowth by carvacrol, cinnamaldehyde, thymol, and oregano oil was evaluated during abusive chilling of cooked ground beef (75% lean) obtained from a local grocery store. Test substances were mixed into thawed ground beef at concentrations of 0.1, 0.5, 1.0, or 2.0% (wt/wt) along with a heat-activated three-strain C. perfringens spore cocktail to obtain final spore concentrations of ca. 2.8 log spores per g. Aliquots (5 g) of the ground beef mixtures were vacuum-packaged and then cooked in a water bath, the temperature of which was raised to 60 degrees C in 1 h. The products were cooled from 54.4 to 7.2 degrees C in 12, 15, 18, or 21 h, resulting in 3.18, 4.64, 4.76, and 5.04 log CFU/ g increases, respectively, in C. perfringens populations. Incorporation of test compounds (> or = 0.1%) into the beef completely inhibited C. perfringens spore germination and outgrowth (P < or = 0.05) during exponential cooling of the cooked beef in 12 h. Longer chilling times (15, 18, and 21 h) required greater concentrations to inhibit spore germination and outgrowth. Cinnamaldehyde was significantly (P < 0.05) more effective (< 1.0 log CFU/g growth) at a lower concentration (0.5%) at the most abusive chilling rate evaluated (21 h) than the other compounds. Incorporation of lower levels of these test compounds with other antimicrobials used in meat product formulations may reduce the potential risk of C. perfringens germination and outgrowth during abusive cooling regimes.
Current notions on the role of the thymol test (TT) in the diagnosis of viral hepatitis A are discussed. Changes in TT results over the course of the disease are presented, starting from the incubation period up to the second-third week; these values are compared to those of hepatitis A specific markers. The earliest TT shifts in hepatitis A are detectable already 15-18 days before the first clinical manifestations, when this parameter surpasses the upper threshold of the range of normal values. The incubation period TT values are 6.9-8.4 U S-H, those during the 3 weeks of the acute period are 9.1-9.7 U S-H. This test earlier reacts to liver inflammation than alanine aminotransferase (a hepatic enzyme) measurement, which fact recommends TT for active early detection of hepatitis A patients in epidemic foci in collective bodies. One more TT advantage over the detection of hepatitis A specific markers in epidemic foci is that it permits the diagnosis of hepatitis whatever its etiology.
The authors evaluated the enzymatic activity and thymol test of the blood serum in patients suffering of alcoholism. It was established that the spectra and degree of increase of the examined values in the blood serum differ in the first, second and third stages of the disease and, apparently, to a large extent are caused by functional or organic changes in the liver.
The effect of buffer type and pH, used in thymol test, was studied. Three methods for standardization of the test were compared via 5 kinds of reaking devices. The effect of bilirubinemia and environment on the results obtained was studied. The normal values of the test were determined under standard conditions in 688 healthy subjects, both sexes and all age groups. The clinical significance of the test was studied in 322 patients with liver diseases. It was established that best results were obtained with veronal or TRIS-mallein buffer, with pH 7,55, that the standardization was most stable via latex particles from the firm Dade, identical results were obtained when Zaphirol was used, provided the thes was read exactly by the 30th min, after the mixing of the reagents, and the work with barium sulphate was rather capricious and sometimes inaccurate. Specol ZV-EK5 or apectrophotometer SED2 are recommended for that purpose. Bilirubin inhibits the positivation of the test, whereas the temperature range from 4 to 37 degrees C has no effect. The normal values of the test at the age over 1 year, making use of veronal buffer with pH 7,55 fluctuates from 0 to 4,76 SHE and when TRIS-mallein buffer with the same pH was used - from 0 to 4,11 SHE. The test performed under standard conditions was concluded to be able to enhance considerably its clinical significance in case of liver diseases.
445 workers occupationally exposed to subtoxic diphenylformamide concentration were examined. No significant differences were found in results of thymol test, concentration of total protein, bilirubin, and activity of basic phosphatase in blood serum, compared with the control group. A higher activity of asparagine--and--alanine aminotransferas and gamma--glutamylotranspeptidase was found; it was, however, statistically insignificant.
This paper presents the results concerning the determination of the formation constants of the complexes between thymol blue, TB, and the metal ions Pb(II) or Cd(II). The experimental procedure was carried out in the presence of a nitrogen atmosphere at 25 degrees C. The spectrophotometry data obtained were processed through the software SQUAD to calculate the complexation constants of the metal-indicator and to establish an adequate base of the models which considered the structure of the indicator, and the actual metal species in the aqueous solutions. For the Pb(II)-TB-H2O system the logK value calculated for the PbTB complex was 5.591+/-0.057 while for the Cd(II)-TB-H2O system, the logK value of the CdTB complex was 5.099+/-0.008. Also, supporting theoretical chemistry results on the chemical hardness of TB molecule were performed to enable establishment of a relative prediction scale of the TB complexation constants ranking in the framework of the Principle of Hard and Soft Acids and Bases or HSAB Principle.