BACKGROUND Tyrosinase is a bifunctional enzyme that catalyzes both the hydroxylation of monophenols to o-diphenols (monophenolase activity) and the subsequent oxidation of the diphenols to o-quinones (diphenolase activity). Due to the potential applications of tyrosinase in biotechnology, in particular in biocatalysis and for biosensors, it is desirable to develop a suitable low-cost process fo...

Enzymes catalyzing the oxidation of phenols occur widely in plant tissues and have been extensively studied (l-7), but the diversity of their properties and the complexities of the reactions catalyzed have made assays and their interpretations uncertain. In only a few instances have essentially pure enzyme preparations been studied (1, 6, S), and even in these cases the mechanism of oxidation i...

fractions obtained from partitioning of aerial methanolic extract of euphorbia aellenii with chloroform (e2), ethyl acetate (e3), n-butanol (e4) and water (e5) were investigated in vitro for their phytotoxicity, insecticidal, anti-leishmanial, cytotoxicity, antibacterial and antifungal activities. sample e2 appeared to have significant phytotoxic activity. in the insecticidal screening study on...

abstract: in a wide search program towards new and efficient antimicrobial agents, a series of 4-substituted-1,2,4-triazolidine-3,5-dione derivatives namely urazoles holding an alkyl moiety at position 4 have been synthesized and tested for their in vitro antibacterial and antifungal activities. the structures of these compounds have been investigated by spectral data. the synthesized compounds...

gen oxidoreductase, EC 1.14.18.1) is a copper-dependent protein widely distributed in nature. The enzyme catalyzes two different reactions: the hydroxylation of monophenols to o-diphenols (monophenolase activity) and the oxidation of odiphenols to o-quinones (diphenolase activity), both utilizing molecular oxygen. The enzymatic browning of fruits and vegetables is mostly related to the oxidatio...