China 
Africa 
Explore chapters and articles related to this topic
Laccase-Mediated Synthesis of Novel Antibiotics and Amino Acid Derivatives
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
The redox potentials of the ortho-dihydroxy aromatic acids listed in Table 8.4 range from 0.425 to 0.8 V and should have corresponding reactivities in laccase-mediated reactions (Mai et al., 2001). They should have comparable reactivities to the para-dihydroxy aromatic acids. Thus — as we already know from these para-substituted substrates — not only the redox potential and the reactivity influence the laccase-initiated amination, but in addition the structure of the substituents of the aromatic ring affect the extent of product formation. In the case of the methoxylated compounds listed in Table 8.4, probably, the amination cannot take place due to the missing quinoid intermediates which are formed from the para- and ortho-dihydroxylated substrates (Figs. 8.3 and 8.4) but not from methoxylated ones. Possible reaction steps during laccase-mediated reactions of ortho-dihydroxy aromatic acids 3,4-dihydroxybenzoic acid (64) (protocatechuic acid), 3,4-dihydroxyphenylacetic acid (65), 3-(3,4-dihydrox yphenyl)propionic acid (66) (dihydrocaffeic acid).
Physical Properties of Individual Groundwater Chemicals
Published in John H. Montgomery, Thomas Roy Crompton, Environmental Chemicals Desk Reference, 2017
John H. Montgomery, Thomas Roy Crompton
Biological. Protocatechuic acid (3,4-dihydroxybenzoic acid) is the central metabolite in the bacterial degradation of 4-methylphenol. Intermediate by-products include 4-hydroxybenzyl alcohol, 4-hydroxybenzaldehyde, and 4-hydroxybenzoic acid. In addition, 4-methylphenol may undergo hydroxylation to form 4-methylcatechol (Chapman, 1972). Chloroperoxidase, a fungal enzyme isolated from Caldariomyces fumago, reacted with 4-methylphenol, forming 4-methyl-2-chlorophenol (Wannstedt et al., 1990). Under methanogenic conditions, inocula from a municipal sewage treatment plant digester degraded 4-methylphenol to phenol prior to being mineralized to carbon dioxide and methane (Young and Rivera, 1985).
Organic Compounds in Raw and Finished Waters
Published in Samuel D. Faust, Osman M. Aly, Chemistry of Water Treatment, 2018
Many phenolic compounds may be derived from natural products. For example, seven hydroxy derivatives of benzene were found from degradative studies of the “color macromolecules.”96 These compounds were: catechol, resorcinol, vanillin, vanillic acid, syringic acid, protocatechuic acid, and 3,5-dihydroxybenzoic acid. In natural waters, there is the possibility that these compounds may arise from the microbially catalyzed degradation of color molecules. Many of these phenols have been recovered and identified in two rivers in Japan.97
Protocatechuic acid production from lignin-associated phenolics
Published in Preparative Biochemistry & Biotechnology, 2021
Phenolics such as p-hydroxycinnamic acids (ferulic and p-coumaric acid) are predominately associated with lignin via ester linkages wherein ferulic acid covalently links lignin moiety to hemicelluloses while p-coumaric acid helps in incorporation of the S-lignin monomers into lignin molecule.[10] Ferulic acid and p-coumaric acid form the prominent phenolics obtained from agri-residues such as corn bran, rice bran and wheat bran; wherefrom these can be biotransformed into protocatechuic acid.[11,12] China is a key player involved in industrial production of protocatechuic acid which includes Xi'an Season, Taizhou Zhongda Chemical, Aktin Chemical and Henan Lyle Wormwood.[13] Protocatechuic acid is found in several plants and has been proven to exhibit many pharmacological activities and is used as antioxidant, anticancer agent, antidiabetic, antiulcer agent, antifibrotic agent, anti-aging agent, antibacterial, anti-inflammatory, analgesic, antiviral, anti-atherosclerotic, hepato-protective agent, nephron-protectant and neurological agent.[14] It also in known to serves as precursor for the synthesis of polymers and plastics.[15] Protocatechuic acid is also naturally found in variety of spices, fruits, nuts and vegetables thereby forming an ingredient in food.[14,16] Protocatechuic acid is thus a commercially important platform chemical with potential applications in production of plastics, pharmaceuticals, food ingredients, and cosmetics.[11]