Tyrosinase is known to be a key enzyme in melanin biosynthesis, involved in determining the color of mammalian skin and hair. Various dermatological disorders, such as melasma, age spots and sites of actinic damage, arise from the accumulation of an excessive level of epidermal pigmentation. In addition, unfavorable enzymatic browning of plant-derived foods by tyrosinase causes a decrease in nutritional quality and economic loss of food products. The inadequacy of current conventional techniques to prevent tyrosinase action encourages us to seek new potent tyrosinase inhibitors. This article overviews the various inhibitors obtained from natural and synthetic sources with their industrial importance.

Ring-Opening Polymerization of Cyclic Monomers 3807 2. Polymerization of Diacid Derivatives and Glycols 3810 3. Polycondensation of Oxyacid Derivatives 3812 4. Polymer Modification 3813 C. Proteases 3813 D. Other Hydrolases 3814 VI. Conclusion 3814 VII. Acknowledgments 3814 VIII. References 3814

The sequential injection of hyaluronic acid-tyramine conjugates and enzymes forms biodegradable hydrogels in vivo by enzyme-induced oxidative coupling, offering high potential as a promising biomaterial for drug delivery and tissue engineering.

The present article comprehensively reviews the macromolecular synthesis using enzymes as catalysts. Among the six main classes of enzymes, the three classes, oxidoreductases, transferases, and hydrolases, have been employed as catalysts for the in vitro macromolecular synthesis and modification reactions. Appropriate design of reaction including monomer and enzyme catalyst produces macromolecules with precisely controlled structure, similarly as in vivo enzymatic reactions. The reaction controls the product structure with respect to substrate selectivity, chemo-selectivity, regio-selectivity, stereoselectivity, and choro-selectivity. Oxidoreductases catalyze various oxidation polymerizations of aromatic compounds as well as vinyl polymerizations. Transferases are effective catalysts for producing polysaccharide having a variety of structure and polyesters. Hydrolases catalyzing the bond-cleaving of macromolecules in vivo, catalyze the reverse reaction for bond forming in vitro to give various polysaccharides and functionalized polyesters. The enzymatic polymerizations allowed the first in vitro synthesis of natural polysaccharides having complicated structures like cellulose, amylose, xylan, chitin, hyaluronan, and chondroitin. These polymerizations are "green" with several respects; nontoxicity of enzyme, high catalyst efficiency, selective reactions under mild conditions using green solvents and renewable starting materials, and producing minimal byproducts. Thus, the enzymatic polymerization is desirable for the environment and contributes to "green polymer chemistry" for maintaining sustainable society.

Highly porous N-doped activated carbon monoliths (ACMs) are fabricated by carbonization and physical activation of mesoporous polyacrylonitrile (PAN) monoliths in the presence of CO(2). The monoliths exhibit exceptionally high CO(2) uptake; 5.14 mmol g(-1) at ambient pressure and temperature and 11.51 mmol g(-1) at ambient pressure and 273 K.