Catechols are found in nature taking part in a remarkably broad scope of biochemical processes and functions. Though not exclusively, such versatility may be traced back to several properties uniquely found together in the o -dihydroxyaryl chemical function; namely, its ability to establish reversible equilibria at moderate redox potentials and pHs and to irreversibly cross-link through complex...

There have been growing evidences for the critical roles of metal-coordination complexes in defining structural and mechanical properties of unmineralized biological materials, including hardness, toughness, and abrasion resistance. Their dynamic (e.g. pH-responsive, self-healable, reversible) properties inspire promising applications of synthetic materials following this concept. However, mech...

Quinone tanning is a well-characterized biochemical process found in invertebrates, which produce diverse materials from extremely hard tissues to soft water-resistant adhesives. Herein, we report new types of catecholamine PEG derivatives, PEG-NH-catechols that can utilize an expanded spectrum of catecholamine chemistry. The PEGs enable simultaneous participation of amine and catechol in quino...

Phenols and their derivatives commonly exist in the environment. These compounds are used as the components of dyes, polymers, drugs and other organic substances. The presence of phenols in the ecosystems is also related with production and degradation of numerous pesticides and the generation of industrial and municipal sewages. Some phenols are also formed during natural processes. These comp...

Many studies in vitro have implicated cytochrome oxidase and monoamine oxidase in the metabolism of epinephrine and other cateehol amines (2). However, no evidence for the participation of cytochrome oxidase in the metabolism of epinephrine in viva has been obtained. Furthermore, several investigations have indicated that monoamine oxidase plays only a minor role in the inactivation of epinephr...

As most intracellular signaling takes place via cascades of phosphorylation and dephosphorylation of tyrosines, protein tyrosine phosphatases have emerged as new and promising targets. Among them, protein tyrosine phosphatase 1B (PTP1B) negatively regulates insulin signaling by dephosphorylation of key tyrosine residues within the regulatory domain of the β-subunit of the insulin receptor, ther...

Many studies in vitro have implicated cytochrome oxidase and monoamine oxidase in the metabolism of epinephrine and other cateehol amines (2). However, no evidence for the participation of cytochrome oxidase in the metabolism of epinephrine in viva has been obtained. Furthermore, several investigations have indicated that monoamine oxidase plays only a minor role in the inactivation of epinephr...

We studied the modulating effects of caffeic acid and chlorogenic acid (two common coffee polyphenols) on the in vitro methylation of synthetic DNA substrates and also on the methylation status of the promoter region of a representative gene in two human cancer cells lines. Under conditions that were suitable for the in vitro enzymatic methylation of DNA and dietary catechols, we found that the...