a valuable composition of mentha piperita l. essential oil is menthol that is widely used fordifferent industries. the plants were treated with different concentrations of methyl jasmonate (meja) and after 24 h were evaluated for total soluble proteins, chlorophylls (a, b, and total), malondialdehyde, carbohydrates and antioxidant enzymes (superoxide dismutase and guaiacol peroxidase). variance...

Guaiacol peroxidases (GP) are haem-containing enzymes participating in many physiological processes in plants. The expression pattern of these enzymes is organ-specific and developmentally regulated. Methods: The presence of GP activity in extract samples, prepared from Crocus sativus L. corms that were either dormant or rooting for 3, 6 and 10 days, was investigated. Results: Kinetic studies r...

Carambola is a fruit grown in tropical and subtropical regions of the world. Natural antioxidants including vitamin C, carotenoids, certain phenolic substances are abundant carambola fruit. As support health by acting as nutraceutical functional food additives, they help preserve preventing oxidation processes. The various organic or inorganic substrates hydrogen peroxide peroxides terminal oxi...

The purpose of this study was to explore the effects of soil contamination by selected metals (cadmium, copper, nickel, lead or zinc) on the antioxidant response of Vicia faba plants. The levels of the antioxidants: glutathione, proline, non-protein thiols, as well as guaiacol peroxidase and catalase activities were measured in the upper parts of plants. Additionally, the potential bioavailabil...

Hydrogen peroxide (H(2)O(2)) scavenging systems of spruce (Picea abies) needles were investigated in both extracts obtained from the extracellular space and extracts of total needles. As assessed by the lack of activity of symplastic marker enzymes, the extracellular washing fluid was free from intracellular contaminations. In the extracellular washing fluid ascorbate, glutathione, cysteine, an...

The highly purified prostaglandin endoperoxide synthetase from bovine vesicular gland microsomes had two still unresolved enzyme activities; the oxygenative cyclization of 8,11,14-eicosatrienoic acid to produce prostaglandin G1 and the conversion of the 15-hydro-peroxide of prostaglandin G1 to a 15-hydroxyl group, producing prostaglandin H1. The latter enzymatic reaction required heme and was s...

Family studies on myeloperoxidase (MPO) deficiency have been carried out by quantitating the peroxidase activity of granulocyte preparations with three methods, namely guaiacol peroxidation, alanine decarboxylation, and spectroscopic analysis. The guaiacol assay failed to show a definite pattern of inheritance in two families with MPO-deficient subjects. Surprisingly, the granulocytes of three ...

Spleen cell suspensions from AKR and CD-1 mice contain peroxidase activity as determined by guaiacol oxidation. This activity is found predominately in the 20,000 x g pellet fraction of spleen cell homogenates. In the presence of H(2)O(2) and chloride ion at acidic pH, splenic peroxidase mediates the oxidation of d- or l-alanine to CO(2), NH(3), and acetaldehyde. The same reaction mixture witho...

Effect of low temperature stress treatment in five selected clones of Camellia sinensis (T-17, TV-19, TV-25, TV-29, TV-30) was found to be significant. Guaiacol Peroxidase (GPX) decreased with decreasing temperature. PPO decreased with decreasing temperature showing highest activities at 20°C in all clones. CAT activit ies decreased in T-17, TV29, and TV-30 with decrease in temperature with exc...