Search results for "Thymol"
showing 10 items of 36 documents
Bioactivity of essential oils in phytopathogenic and post-harvest fungi control
2017
[EN] Commercial thyme and lavender essential oils were analysed by GC/MS. Sixty-six compounds accounting for 98.6¿99.6% of total essential oil were identified. Thymol (52.14 ± 0.21%), followed by pcymene (32.24 ± 0.16%), carvacrol (3.71 ± 0.01%) and ¿-terpinene (3.34 ± 0.02%), were the main compounds in thyme essential oil, while large amounts of oxygenated monoterpenes linalool acetate (37.07 ± 0.24%) and linalool (30.16 ± 0.06%) were found in lavender one. In vitro antifungal activity of the essential oils was evaluated at 200 and 300 ¿g/mL against 10 phytopathogenic and post-harvest fungi, which significantly affect agriculture. Micelial growth inhibition was calculated for each tested f…
Determination of titratable acidity and ascorbic acid in fruit juices in continuous-flow systems
1993
Two continuous-flow systems for the determination of titratable acidity and ascrobic acid in fruit juice samples are described. The assemblies permit on-line dialysis of analytes prior to the reaction step, thus improving selectivity and performing sample dilution. Flow systems are built with a channel carrying the donor phase (sample in both determinations) and another channel carrying an acceptor phase, both of them entering the dialyser. The outcoming stream transporting the dialysed sample fills the valve loop, permitting its injection into a carrier stream which continuously passes through the spectrophotometric detector. For the titratable acidity, acceptor phase and carrier are disti…
Comparison of combined application treatment with one-visit varnish treatments in an orthodontic population
2013
Objective: To evaluate the effect of chlorhexidine-thymol varnish alone, its combination with chlorhexidine-fluo - ride containing dentifrice and fluoride varnish on oral hygiene and caries prevention in orthodontic patients. Study design: Sixty patients, aged 12-18, with orthodontic fixed appliances were randomly assigned into three groups as follows: Group 1 (n=20): 1% chlorhexidine and 1% thymol varnish (Cervitec ® Plus); Group 2 (n=20): Cervitec ® Plus+ 0.2% chlorhexidine and 0.2% sodium fluoride (900 ppm fluoride) (Cervitec ® Gel)); and Group 3 (n=20): 0.1% fluoride varnish (Fluor Protector ® ). Mutans streptococci (MS), lactobacilli (LB) levels, buffering capacity (BC), visible plaque…
Quantification of phenolic acids by partial least squares Fourier-transform infrared (PLS-FTIR) in extracts of medicinal plants.
2020
Introduction Phenolic compounds are ubiquitous compounds found in all plants as their secondary metabolites. Phenols are becoming increasingly important particularly because of their beneficial effects on health. Objective To provide a faithful calibration model for the simultaneous determination and quantification of phenolic acids, as salicylic, vanillic, p-hydroxybenzoic acids, eugenol and thymol in different extracts of medicinal plants, a comparative study was made between two methods of infrared measurements based on attenuated total reflectance (ATR) and transmission. Methods Characteristic absorbance peak heights of mid-infrared spectra of individual phenolic acids were measured for…
Detection and correction of interferences in spectroscopy techniques
2001
By combining the apparent content curves method and the Youden method, we have developed a strategy for detecting constant and proportional errors in spectroscopy techniques. A method for elimination of spectral interferences (different of blank) is also proposed. To apply of this method there must be a matrix effect that varies with the amount of sample or a simulated matrix effect provided working under different experimental conditions that induce a variation of the analytical signal of the analyte. The proposed procedures have been applied to the determination of methyl orange in presence of phenol red, bromothymol blue and bromocresol purple.
Relevant essential oil components: a minireview on increasing applications and potential toxicity.
2021
[EN] Phenolic compounds carvacrol, thymol, eugenol, and vanillin are four of the most thoroughly investigated essential oil components given their relevant biological properties. These compounds are generally considered safe for consumption and have been used in a wide range of food and non-food applications. Significant biological properties, including antimicrobial, antioxidant, analgesic, anti-inflammatory, anti-mutagenic, or anti-carcinogenic activity, have been described for these components. They are versatile molecules with wide-ranging potential applications whose use may substantially increase in forthcoming years. However, some in vitro and in vivo studies, and several case report…
Chromatographic profiles and antimicrobial activity of the essential oils obtained from some species and cultivars of the Mentheae tribe (Lamiaceae)
2021
Abstract The present study was focused on the chemical composition and antimicrobial activity of the essential oils (EsO) obtained from five Lamiaceae representatives grown in the south of Ukraine. Among them are Salvia sclarea L., Monarda didyma (cultivar ‘Cambridge Scarlet’), Thymus pulegioides (cultivar ‘2/6-07’), Thymus vulgaris (cultivar ‘Jalos’), and Thymus serpyllum L. The component analysis of the EsO was carried out by gas chromatography method coupled with mass spectrometry (GC–MS). The antimicrobial properties of the EsO were determined using the agar diffusion test against widespread pathogenic bacterial strains (Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, St…
Chemical Composition and antimicrobial activity of the essential oils from two species of Thimus growing wild in southern Italy
2009
The volatile constituents of the aerial parts of two samples of Thymus longicaulis C. Presl, collected in Campania and in Sicily, and two samples of Thymus pulegioides L. from the same regions, were extracted by hydrodistillation and analyzed. Considering the four oils together, seventy-eight different compounds were identified: 57 for Thymus longicaulis from Sicily (91.1% of the total oil), 40 for Thymus longicaulis from Campania (91.5% of the oil), 39 for Thymus pulegioides from Sicily (92.5% of the oil) and 29 for Thymus pulegioides from Campania (90.1% of the oil). The composition of the oils is different, although the most abundant components are identical in T. pulegioides. The essent…
Chemical Composition of Herbal Macerates and Corresponding Commercial Essential Oils and Their Effect on Bacteria Escherichia coli
2017
This study addresses the chemical composition of some commercial essential oils (clove, juniper, oregano, and marjoram oils), as well as appropriate herbal extracts obtained in the process of cold maceration and their biological activity against selected Escherichia coli strains: E. coli ATTC 25922, E. coli ATTC 10536, and E. coli 127 isolated from poultry waste. On the basis of the gas chromatography-mass spectrometry (GCMS) analysis, it was found that the commercial essential oils revealed considerable differences in terms of the composition and diversity of terpenes, terpenoids and sesquiterpenes as compared with the extracts obtained from plant material. The commercial clove, oregano, a…
Essential oil characteristics of wild Sicilian oregano populations in relation to environmental conditions
2014
A study was carried out on the essential oil of Origanum vulgare ssp. hirtum (Link) Ietswaart taken from thirteen wild populations found in different parts of Sicily, Italy. The aim of the study was to evaluate the relationship that exists between essentials oil extracted from Sicilian wild populations of O. vulgare ssp. hirtum (Link) Ietswaart and various weather/climate and topographic factors in order to provide more information on aspects that influence the production potential of this species. The essential oils from the samples were extracted by hydrodistillation and analyzed by a combination of gas chromatography-flame ionization detector (GC-FID) and GC-mass spectrometry (GC-MS); se…