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Zhu C, Wang H, Ma H, Yang Y, Li F. Tanning process promotes abiotic humification: separation and characterization of humic acid-like polymers complex. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:41437-41445. [PMID: 32683619 DOI: 10.1007/s11356-020-10111-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 07/10/2020] [Indexed: 06/11/2023]
Abstract
Humic-like substances are essential components of soluble organic matter in tannery wastewater. However, the tannery process can promote the abiotic humification in wastewater. Therefore, it is of great significance to clarify the pathway and degree of abiotic humification and the properties of the as-derived humic acid-like (HAL) complex polymers in the tannery process in order to control the refractory organic compounds. In the present study, considering the catechol-Maillard system and commercial humic acid (HA) as control, the polyphenol-Maillard humification in the tannery process was simulated under the catalysis of MnO2. Moreover, physicochemical and spectroscopic techniques were used to characterize the separated fractions of HAL further. As a result, it was found that the catechol-Maillard system with small molecule organic matter as precursor had higher humification degree. Furthermore, the ultraviolet-visible (UV-Vis), Fourier transform infrared (FTIR), and excitation-emission matrix (EEM) fluorescence spectrum of humic acid-like 0 (HAL0) derived from it was different from those of humic acid-like 1 and 2 (HAL1 and HAL2) of polyphenol-Maillard system, indicating the differences of polymer structure between them. In the polyphenol-Maillard system, tannin was the skeleton of polymerization or polycondensation reaction, and the high content of N and the H/C value of HAL2 indicated that in adding to amino acids, proteins promoted the humification, forming industry-specific HAL polymers with a high degree of aliphatic nature. Therefore, it can be concluded that controlling the raw materials in the tannery process (especially tannins), in order to reduce the occurrence of abiotic humification may be the key to improve the efficiency of wastewater treatment.
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Affiliation(s)
- Chao Zhu
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China
| | - Huiqin Wang
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China
| | - Hongrui Ma
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China.
| | - Yonglin Yang
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China
| | - Fan Li
- School of Science, Xi'an University of Architecture and Technology, Xi'an, 710055, China
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Ishak AA, Selamat J, Sulaiman R, Sukor R, Abdulmalek E, Jambari NN. Effect of Different Amino Acids and Heating Conditions on the Formation of 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and Its Kinetics Formation Using Chemical Model System. Molecules 2019; 24:E3828. [PMID: 31652883 PMCID: PMC6865075 DOI: 10.3390/molecules24213828] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 09/27/2019] [Accepted: 09/27/2019] [Indexed: 11/25/2022] Open
Abstract
The formation of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was investigated using a kinetic study approach as described by first-order, Arrhenius, and Eyring equations. Chemical model systems with different amino acid precursors (proline, phenylalanine, and glycine) were examined at different times (4, 8, 12, and 16 min) and temperatures (150, 180, 210, 240, and 270 °C). PhIP was detected using high-performance liquid chromatography equipped with fluorescence detector (HPLC-FLD). The good fit in first-order suggested that PhIP formation was influenced by the types of amino acids and PhIP concentration significantly increased with time and temperature (up to 240 °C). PhIP was detected in proline and phenylalanine model systems but not in the glycine model system. The phenylalanine model system demonstrated low activation energy (Ea) of 95.36 kJ/mol that resulted in a high rate of PhIP formation (great amount of PhIP formed). Based on the ∆S‡ values both proline and phenylalanine demonstrated bimolecular rate-limiting steps for PhIP formation. Altogether these kinetic results could provide valuable information in predicting the PhIP formation pathway.
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Affiliation(s)
- Ainaatul Asmaa Ishak
- Department of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia.
| | - Jinap Selamat
- Department of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia.
- Laboratory of Food Safety and Food Integrity, Institute of Tropical Agriculture and Food Security, University Putra Malaysia, Serdang 43400, Selangor, Malaysia.
| | - Rabiha Sulaiman
- Department of Food Technology, Faculty of Food Science and Technology, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia.
| | - Rashidah Sukor
- Department of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia.
- Laboratory of Food Safety and Food Integrity, Institute of Tropical Agriculture and Food Security, University Putra Malaysia, Serdang 43400, Selangor, Malaysia.
| | - Emilia Abdulmalek
- Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia.
| | - Nuzul Noorahya Jambari
- Department of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia.
- Laboratory of Food Safety and Food Integrity, Institute of Tropical Agriculture and Food Security, University Putra Malaysia, Serdang 43400, Selangor, Malaysia.
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Zhang Y, Yue D, Ma H. Darkening mechanism and kinetics of humification process in catechol-Maillard system. CHEMOSPHERE 2015; 130:40-45. [PMID: 25770693 DOI: 10.1016/j.chemosphere.2015.02.051] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 02/17/2015] [Accepted: 02/20/2015] [Indexed: 06/04/2023]
Abstract
Humic acids, products of humification process, are capable of interacting with contaminants and can be applied to environmental remediation. Browning mechanisms of humification is critical to understand and further control the process. This study aimed to investigate the mechanism of abiotic humification by tracking the fate of the precursors in systems containing glucose, glycine, and various CT concentrations, which were promoted by MnO2. Results show that the N-containing organic molecules significantly contributed in controlling the darkening effect. Increasing CT promoted the formation of Fulvic-like acids (FLAs) and Humic-like acids (HLAs). The entire reaction could be divided into two steps following pseudo-second-order kinetics equation and pseudo-zero-order kinetics equation. Moreover, increasing CT contributed to the increase of the degree of unsaturation in HLAs.
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Affiliation(s)
- Yingchao Zhang
- Key Laboratory for Solid Waste Management and Environment Safety (MOE), School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Dongbei Yue
- Key Laboratory for Solid Waste Management and Environment Safety (MOE), School of Environment, Tsinghua University, Beijing 100084, PR China; Collaborative Innovation Center for Regional Environmental Quality, Beijing 100084, PR China.
| | - Hong Ma
- Key Laboratory for Solid Waste Management and Environment Safety (MOE), School of Environment, Tsinghua University, Beijing 100084, PR China
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Explore the reaction mechanism of the Maillard reaction: a density functional theory study. J Mol Model 2015; 21:132. [PMID: 25934157 DOI: 10.1007/s00894-015-2674-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 04/01/2015] [Indexed: 01/07/2023]
Abstract
The mechanism of Maillard reaction has been investigated by means of density functional theory calculations in the gaseous phase and aqueous solution. The Maillard reaction is a cascade of consecutive and parallel reaction. In the present model system study, glucose and glycine were taken as the initial reactants. On the basis of previous experimental results, the mechanisms of Maillard reaction have been proposed, and the possibility for the formation of different compounds have been evaluated through calculating the relative energy changes for different steps of reaction under different pH conditions. Our calculations reveal that the TS3 in Amadori rearrangement reaction is the rate-determining step of Maillard reaction with the activation barriers of about 66.7 and 68.8 kcal mol(-1) in the gaseous phase and aqueous solution, respectively. The calculation results are in good agreement with previous studies and could provide insights into the reaction mechanism of Maillard reaction, since experimental evaluation of the role of intermediates in the Maillard reaction is quite complicated.
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Asayama S, Mori T, Nagaoka S, Kawakami H. Chemical modification of manganese porphyrins with biomolecules for new functional antioxidants. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2003; 14:1169-79. [PMID: 14768906 DOI: 10.1163/156856203322553419] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Superoxide dismutase (SOD), which catalyzes the reduction of O2*- to H2O2, is the key enzyme for the protection of oxidative stress. Here we have chemically modified manganese (Mn) porphyrins with biomolecules for new functional antioxidants. The Mn-porphyrins were conjugated with the following biochemical functional molecules: (1) catalase, to catalyze reduction of H2O2 to H2O. The resulting conjugate showed dual functions of SOD and catalase; (2) a carbohydrate, to facilitate receptor binding and, hence, active targeting. The resulting conjugate showed both SOD activity and carbohydrate recognition. These results suggest that the antioxidants promise the application to biomedical fields.
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Affiliation(s)
- S Asayama
- Department of Applied Chemistry, Tokyo Metropolitan University. Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
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