In this paper, we discuss the synthesis and self-assembling behavior of new copolymers derived from fatty acid/amino acid components, namely dimers of linoleic acid (DLA) and tyrosine derived diphenols containing alkyl ester pendent chains, designated as "R" (DTR). Specific pendent chains were ethyl (E) and hexyl (H). These poly(aliphatic/aromatic-ester-amide)s were further reacted with poly(et...

Claus T. Fuchs and Gerhard Spiteller Institut für Organische Chemie I, Universität Bayreuth, Universitätsstr. 30, D-95440 Bayreuth, Germany Z. Naturforsch. 53c, 799-805 (1998); received February 20/April 16, 1998 Taphrina pruni, Plums, Catechins, Caffeoyl-D-quinic Acids, Photometric Determination Plums (Prunus domestica) affected by the fungus Taphrina pruni and healthy ones were harvested in i...

This paper reports experiments on the stereospecificity observed in the monophenolase and diphenolase activities of mushroom tyrosinase. Several enantiomorphs of monophenols and o-diphenols were assayed: L-tyrosine, D,L-tyrosine, D-tyrosine; L-alpha-methyltyrosine, D,L-alpha-methyltyrosine; L-dopa, D,L-dopa, D-dopa; L-alpha-methyldopa, D,L-alpha-methyldopa; L-isoprenaline, D,L-isoprenaline and ...

Sequencing of the genome of Ralstonia solanacearum revealed several genes that putatively code for polyphenol oxidases (PPOs). To study the actual expression of these genes, we looked for and detected all kinds of PPO activities, including laccase, cresolase, and catechol oxidase activities, in cellular extracts of this microorganism. The conditions for the PPO assays were optimized for the phe...

Phenol and its derivatives are hazardous, teratogenic mutagenic, have gained significant attention in recent years due to their high toxicity even at low concentrations. Phenolic compounds appear petroleum refinery wastewater from several sources, such as the neutralized spent caustic waste streams, tank water drain, desalter effluent production unit. Therefore, effective treatments of wastewat...

Polyphenol oxidases (PPOs) have a recognized role during pathogen and arthropod attack. As an immediate consequence of such wounding, cellular compartmentation is destroyed allowing the chloroplastic PPO enzyme to interact with vacuolar substrates catalyzing the oxidation of monophenols and/or o-diphenols to o-diquinones. This ultimately results in a reduction in the nutritional value of wounde...

Merremia emarginata plants were treated with different plant growth regulators (PGRs): naphthyl acetic acid (NAA), phenyl acetic acid (PAA) and gibberellic acid (GA 3). To determine the role of wall stiffening enzymes in internode elongation, IAA oxidase and peroxidase in the presence of different hydrogen donors like caffeic acid, chlorogenic acid and guaiacol were assayed. The levels of total...

Polyphenol oxidases (PPOs) are ubiquitous type-3 copper enzymes that catalyze the oxygen-dependent conversion of o-diphenols to the corresponding quinones. In most plants, PPOs are present as multiple isoenzymes that probably serve distinct functions, although the precise relationship between sequence, structure and function has not been addressed in detail. We therefore compared the characteri...

Extra-virgin olive oil is an integral ingredient of the Mediterranean diet, and it has been suggested that its high consumption has beneficial effects on human health. Its protective effect, in particular against the development of CVD, has been related not only to the high content of oleic acid, but also to the antioxidant and anti-inflammatory properties of polyphenols. In order to verify the...

BACKGROUND: Ensiling forages often leads to degradation of protein to non-protein nitrogen (NPN), which is poorly utilized by ruminants. Postharvest protein degradation is especially high in alfalfa (Medicago sativa L.). In contrast, red clover (Trifolium pratense L.) has up to 90% less protein loss during ensiling due to polyphenol oxidase (PPO) forming o-quinones from endogenous o-diphenols a...