Three mechanisms of oxygen reduction by chloroplast lamellae in the presence of autoxidizable electron acceptors can be differentiated by product analyis in the presence or absence of either dibromothymoquinone (DBMIB) or superoxide dismutase (SOD) : 1) H20 2 is the product of two-electron oxygen reduction by 2,3-dimethyl-5,6-methylenedioxy-pbenzoquinone, involving only photosystem II. This rea...

The total phenols in virgin olive oil are highly dependent on cultivar, but also ripening stage and other agronomic factors. focus of most studies factors has been irrigation, while fertilization received less attention. Most the works find that nitrogen over-fertilization leads to a decrease phenol contents (VOO) extra (EVOO), under rain-fed or irrigation management. Ortho-diphenols with high ...

Many forages experience significant proteolytic losses when preserved by ensiling. Such losses in alfalfa (Medicago sativa L.) are especially high, with degradation of 44 to 87% of the forage protein to nonprotein N (NPN). In contrast, red clover (Trifolium pratense L.) has up to 90% less proteolysis during ensiling. Here we demonstrate that the combination of polyphenol oxidase (PPO) and o-dip...

The problematic increase in multidrug-resistant bacteria translates into the urgent need to discover novel and effective antimicrobial substances. Herein, mushrooms could be a promising alternative of natural source new antimicrobials. present work aimed compare phytochemical composition activity methanol aqueous crude extracts Lentinula edodes var. Koshin Donko. Disk diffusion method was used ...

Polyphenoloxidase (PPO; EC 1.14.18.1) extracted from Mentha arvensis leaves was isolated by (NH4)2SO4 precipitation and extensive dialysis. Its optimum pH and temperature varied with the substrate. The PPO showed activity with various diphenols. Km values were found 0.825, 0.928 and 7.41mM for caffeic acid, 4-methylcatechol and catechol, respectively. On heat-inactivation, half of the activity ...

Haemolymph associated phenol oxidase is a critical component of invertebrate immune reaction and cuticle sclerotization. Phenol oxidase catalyses the conversion of mono-phenols to diphenols and quinones which finally leads to melanin formation. We have cloned the c-DNA encoding phenol oxidase from the haemocytes of Spodoptera litura and expressed it in Escherichia coli. The encoding gene is 245...