Search results for "thymol"
showing 10 items of 36 documents
Chemical Composition of Thymus leucotrichus var. creticus Essential Oil and Its Protective Effects on Both Damage and Oxidative Stress in Leptodictyu…
2022
The chemical profile of the essential oil (EO) of the aerial parts of Thymus leucotrichus var. creticus (Lamiaceae), a taxon not previously studied, was investigated by GC–MS analysis, using a DB–Wax polar column. Oxygenated monoterpenes and monoterpene hydrocarbons dominate the EO, with thymol (46.97%) and p-cymene (28.64%) as the main constituent of these two classes, respectively. The ability of the EO of T. leucotrichus to reduce Cd toxicity was studied in aquatic moss Leptodictyum riparium. To study EO-induced tolerance to Cd toxicity, apex growth, number of dead cells, DNA damage and antioxidant response in gametophytes were examined. The exogenous application of the EO yields a resum…
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…
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…
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…
Understanding the potential benefits of thyme and its derived products for food industry and consumer health: From extraction of value-added compound…
2018
Natural bioactive compounds isolated from several aromatic plants have been studied for centuries due to their unique characteristics that carry great importance in food, and pharmaceutical, and cosmetic industries. For instance, several beneficial activities have been attributed to some specific compounds found in Thymus such as anti-inflammatory, antioxidant, antimicrobial, and antiseptic properties. Moreover, these compounds are classified as Generally Recognized as Safe (GRAS) which means they can be used as an ingrident of may food producs. Conventional extraction processes of these compounds and their derived forms from thyme leaves are well established. Hoewever, they present some im…
V2O5 nanowires with an intrinsic iodination activity leading to the formation of self-assembled melanin-like biopolymers
2011
V2O5 nanowires act as biomimetic catalysts resembling vanadium haloperoxidases (V-HPO). The nanowires display iodinating activity as confirmed by a colorimetric assay using thymol blue (TB), UV/Vis spectrophotometry and mass spectrometry (FD-MS). In the presence of dopamine these nanowires catalyze the fast and efficient synthesis of melanin-like biopolymers under mild conditions (aqueous solution, neutral pH and room temperature). The resulting melanin-like biopolymer obtained by the V2O5 nanowire catalysts was characterized by scanning electron microscopy (SEM), X-ray diffraction, UV-Vis, FT-IR and electric conductivity resembling the natural biopolymer both in its chemical and morphologi…
Chemical Composition and Antimicrobial Activity of the Essential Oils from Three Chemotypes of Origanum vulgare L. ssp. hirtum (Link) Ietswaart Growi…
2009
Essential oils obtained from inflorescences of three Origanum vulgare L.ssp. hirtum (Link) Ietswaart samples, growing wild in different locations in Campania (Southern Italy), were analysed. Three chemotypes were found: the first, with a prevalence of carvacrol/thymol; the second, characterized by the prevalence of thymol/alpha-terpineol; the third, featuring a prevalence of linalyl acetate and linalool. This chemical study attempts to provide a contribution in shedding light on the relationship between chemical composition and biotypes and/or chemotypes in Origanum vulgare ssp. hirtum. The essential oils were also evaluated for their antibacterial activity against 10 selected microorganism…
Antimicrobial and antioxidant properties of the essential oil of Salvia lanigera from Cyprus
2010
The essential oil of aerial parts of Salvia lanigera Poir. (Lamiaceae) growing wild in Cyprus was obtained by hydrodistillation and was analysed by GC and GC-MS. A total of 67 compounds, representing 93.6% of the oil, were identified, and the major components were showed to be thymol (12.1%), hexadecanoic acid (6.0%), carvacrol and α-thujone (5.7%). The essential oil was assayed for its antioxidant and antimicrobial activities. Antimicrobial activity of the oil, evaluated using the broth dilution method, resulted higher against Gram-positive bacteria than the other referenced strains tested. Antioxidant activity of the oil was evaluated by using DPPH and FRAP methods together with three ant…
Antimicrobial activity and enterococcus faecalis biofilm formation on chlorhexidine varnishes.
2011
Objective: To evaluate, in vitro, the antimicrobial activity and biofilm formation of three chlorhexidine varnishes in four Enterococcus faecalis strains: E. faecalis ATCC 29212, E. faecalis EF-D1 (from failed endodontic treatment), E. faecalis 072 (cheese) and E. faecalis U-1765 (nosocomial infection), and one Enterococcus durans strain (failed endodontic treatment). Study Design: The direct contact test was used to study the antimicrobial activity. Bacterial suspensions were exposed for one hour to EC40, Cervitec (CE) and Cervitec Plus (CEP) varnishes. “Eradication” was defined as 100% bacterial kill. The formation of enterococci biofilms was tested on the surface of the varnishes after 2…
Quantifying both ammonium and proline in wines and beer by using a PDMS composite for sensoring.
2019
Abstract Two of the reagents involved in the Berthelot's reaction, thymol and nitroprusside, were embedded in a PDMS composite in order to apply this assay to determine ammonium and proline, in wine and beers. Safety, portability, rapidity, cost-effectiveness and simplicity of the assay were improved. For the proline determination, a modified Berthelot's reaction, which included a ring cleavage of proline, was optimized. The accuracy of the assay was tested. The limits of detection for ammonium was 0.12 µg mL−1 and for proline was in the range from 0.7 to 4.1 µg mL−1, depending on the kind of wine (white, red, or sweet), for beer the LOD was 6 µg mL−1. The precision achieved was slower than…