1
|
Wen Y, Sun J, Jia H, Qi X, Mao X. Inactivation of polyphenol oxidase by low intensity DC field: Experiment and mechanism analysis via molecular dynamics simulation and molecular docking. Food Res Int 2024; 188:114325. [PMID: 38823824 DOI: 10.1016/j.foodres.2024.114325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 04/01/2024] [Accepted: 04/16/2024] [Indexed: 06/03/2024]
Abstract
In this study, inactivation of mushroom polyphenol oxidase (PPO) by low intensity direct current (DC) electric field and its molecular mechanism were investigated. In the experiments under 3 V/cm, 5 V/cm, 7 V/cm and 9 V/cm electric fields, PPOs were all completely inactivated after different exposure times. Under 1 V/cm, a residual activity of 11.88 % remained. The inactivation kinetics confirms to Weibull model. Under 1-7 V/cm, n value closes to a constant about 1.3. The structural analysis of PPO under 3 V/cm and 5 V/cm by fluorescence emission spectroscopy and molecular dynamics (MD) simulation showed that the tertiary structure was slightly changed with increased radius of gyration, higher potential energy and rate of C-alpha fluctuation. After exposure to the electric field, most of the hydrophobic tryptophan (TRP) residues turned to the hydrophilic surface, resulting the fluorescence red-shifted and quenched. Molecular docking indicated that the receptor binding domain of catechol in PPO was changed. PPO under electric field was MD simulated the first time, revealing the changing mechanism of the electric field itself on PPO, a binuclear copper enzyme, which has a metallic center. All these suggest that the low intensity DC electric field would be a promising option for enzymatic browning inhibition or even enzyme activity inactivation.
Collapse
Affiliation(s)
- Yanbing Wen
- State Key Laboratory of Marine Food Processing and Safety Control, College of Food Science and Engineering, Ocean University of China, Qingdao 266404, PR China; Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China; Qingdao Key Laboratory of Food Biotechnology, Qingdao 266404, PR China; Key Laboratory of Biological Processing of Aquatic Products, China National Light Industry, Qingdao 266404, PR China
| | - Jing Sun
- State Key Laboratory of Marine Food Processing and Safety Control, College of Food Science and Engineering, Ocean University of China, Qingdao 266404, PR China; Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China; Qingdao Key Laboratory of Food Biotechnology, Qingdao 266404, PR China; Key Laboratory of Biological Processing of Aquatic Products, China National Light Industry, Qingdao 266404, PR China
| | - Hongxin Jia
- State Key Laboratory of Marine Food Processing and Safety Control, College of Food Science and Engineering, Ocean University of China, Qingdao 266404, PR China; Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China; Qingdao Key Laboratory of Food Biotechnology, Qingdao 266404, PR China; Key Laboratory of Biological Processing of Aquatic Products, China National Light Industry, Qingdao 266404, PR China
| | - Xiangming Qi
- State Key Laboratory of Marine Food Processing and Safety Control, College of Food Science and Engineering, Ocean University of China, Qingdao 266404, PR China; Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China; Qingdao Key Laboratory of Food Biotechnology, Qingdao 266404, PR China; Key Laboratory of Biological Processing of Aquatic Products, China National Light Industry, Qingdao 266404, PR China.
| | - Xiangzhao Mao
- State Key Laboratory of Marine Food Processing and Safety Control, College of Food Science and Engineering, Ocean University of China, Qingdao 266404, PR China; Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China; Qingdao Key Laboratory of Food Biotechnology, Qingdao 266404, PR China; Key Laboratory of Biological Processing of Aquatic Products, China National Light Industry, Qingdao 266404, PR China
| |
Collapse
|
2
|
Jiang H, Zhou L, Wang Y, Liu G, Peng S, Yu W, Tian Y, Liu J, Liu W. Inhibition of cinnamic acid and its derivatives on polyphenol oxidase: Effect of inhibitor carboxyl group and system pH. Int J Biol Macromol 2024; 259:129285. [PMID: 38211907 DOI: 10.1016/j.ijbiomac.2024.129285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 01/04/2024] [Accepted: 01/04/2024] [Indexed: 01/13/2024]
Abstract
Phenolic acids are promising inhibitors of polyphenol oxidase (PPO), but the effects of carboxyl group and pH on their inhibition effects are still unclear. In this study, methyl cinnamate, cinnamic acid and 4-carboxycinnamic acid were investigated by their inhibitory effects with pH varied from 6.8 to 5.0. Results showed that 4-carboxycinnamic acid had the strongest inhibitory effect on PPO, followed by cinnamic acid and methyl cinnamate. Acidic pH enhanced the inhibitory effects of cinnamic acid and its derivatives on PPO, and the enhancement degree, IC50 and Ki declining degree were followed as 4-carboxycinnamic acid > cinnamic acid > methyl cinnamate. Methyl cinnamate exhibited competitive inhibition on PPO, while cinnamic acid and 4-carboxycinnamic acid exhibited mixed-type inhibition. Inhibitors induced slight changes in the secondary and tertiary structures of PPO, which were enhanced by acidic pH. Molecular docking results showed that 4-carboxycinnamic acid exhibited the strongest binding ability, and the main interaction forces were around carboxyl groups, and acidic pH enhanced the binding effect through more interactions and lower binding energy. This study could provide new insights into industrial application of cinnamic acid and its derivatives for the control of enzymatic browning of fruits and vegetables.
Collapse
Affiliation(s)
- Hongwei Jiang
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330047, China
| | - Lei Zhou
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330047, China.
| | - Yue Wang
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330047, China
| | - Guangxian Liu
- Institute of Agricultural Products Processing, Jiangxi Academy of Agricultural Sciences, Nanchang, Jiangxi 330200, China
| | - Shengfeng Peng
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330047, China
| | - Wenzhi Yu
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330047, China
| | - Yuqing Tian
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330047, China
| | - Junping Liu
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330047, China
| | - Wei Liu
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330047, China; National R&D Center for Freshwater Fish Processing, Jiangxi Normal University, Nanchang 330022, China
| |
Collapse
|
3
|
García Molina P, Antonio Teruel Puche J, Luis Muñoz Muñoz J, Neptuno Rodriguez Lopez J, García Canovas F, García Molina F. Considerations on the action of polyphenoloxidase on 4-hydroxy-cinnamic acid. Molecular docking simulation. Food Chem 2023; 429:136982. [PMID: 37499510 DOI: 10.1016/j.foodchem.2023.136982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 07/12/2023] [Accepted: 07/21/2023] [Indexed: 07/29/2023]
Affiliation(s)
- Pablo García Molina
- GENZ-Group of Research on Enzymology, Departament of Biochemistry and Molecular Biology-A, Regional Campus of International Excellence, "Campus Mare Nostrum", University of Murcia, Espinardo, Murcia, Spain
| | - Jose Antonio Teruel Puche
- Departament of Biochemestry and Molecular Biology-A, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, Espinardo, Murcia, Spain
| | - Jose Luis Muñoz Muñoz
- Microbial Enzymology Lab, Department of Applied Sciences, Ellison Building, A, University of Northumbria, Newcastle Upon Tyne, UK.
| | - Jose Neptuno Rodriguez Lopez
- Departament of Anatomía Patológica, Hospital General Universitario Reina, Sofía, Av. Intendente Jorge Palacios, 1, 30003 Murcia, Spain
| | - Francisco García Canovas
- GENZ-Group of Research on Enzymology, Departament of Biochemistry and Molecular Biology-A, Regional Campus of International Excellence, "Campus Mare Nostrum", University of Murcia, Espinardo, Murcia, Spain
| | - Francisco García Molina
- Departament of Biochemestry and Molecular Biology-A, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, Espinardo, Murcia, Spain.
| |
Collapse
|
4
|
Boldea LS, Aprodu I, Enachi E, Dumitrașcu L, Păcularu-Burada B, Chițescu C, Râpeanu G, Stănciuc N. Advanced interactional characterization of the inhibitory effect of anthocyanin extract from Hibiscus sabdariffa L. on apple polyphenol oxidase. J Food Sci 2023; 88:5026-5043. [PMID: 37872831 DOI: 10.1111/1750-3841.16808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 09/25/2023] [Accepted: 10/04/2023] [Indexed: 10/25/2023]
Abstract
In this study, a comprehensive approach to advance the inhibitory effect of Hibiscus sabdariffa extract on apple polyphenol oxidase (PPO) was performed. PPO was extracted, purified, and characterized for optimal activity, whereas response surface methodology generated a quadratic polynomial model to fit the experimental results for hibiscus extraction. The optimum conditions allowed to predict a maximum recovery of anthocyanins (256.11 mg delphinidin-3-O-glucoside/g), with a validated value of 272.87 mg delphinidin-3-O-glucoside/g dry weight (DW). The chromatographic methods highlighted the presence of gallic acid (36,812.90 µg/g DW extract), myricetin (141,933.84 µg/g DW extract), caffeic acid (101,394.07 µg/g DW extract), sinapic acid (1157.46 µg/g DW extract), kaempferol (2136.76 µg/g DW extract), and delphinidin 3-O-β-d-glucoside (226,367.08 µg/g DW extract). The inactivation of PPO followed a first-order kinetic model. A temperature-mediated flexible fit between PPO and anthocyanins was suggested, whereas the molecular docking tests indicated that PPO is a good receptor for cafestol, gallic acid, and catechin, involving hydrophobic and hydrogen bond interactions. PRACTICAL APPLICATION: It is well known that enzymatic browning is one of the most important challenges in the industrial minimal processing of selected fruit and vegetable products. Novel inhibitors for polyphenol oxidase are proposed in this study by using an anthocyanin-enriched extract from Hibiscus sabdariffa L. Based on our results, combining the chemical effect of phytochemicals from hibiscus extract with different functional groups with minimal heating could be an interesting approach for the development of a new strategy to inhibit apple polyphenol oxidase.
Collapse
Affiliation(s)
- Lavinia Stan Boldea
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galați, Romania
| | - Iuliana Aprodu
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galați, Romania
| | - Elena Enachi
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galați, Romania
- Faculty of Medicine and Pharmacy, Dunarea de Jos University of Galati, Galaţi, Romania
| | - Loredana Dumitrașcu
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galați, Romania
| | - Bogdan Păcularu-Burada
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galați, Romania
| | - Carmen Chițescu
- Faculty of Medicine and Pharmacy, Dunarea de Jos University of Galati, Galaţi, Romania
| | - Gabriela Râpeanu
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galați, Romania
| | - Nicoleta Stănciuc
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galați, Romania
| |
Collapse
|
5
|
Mittal A, Singh A, Zhang B, Zhao Q, Benjakul S. Inhibition Mechanism of Chitooligosaccharide-Polyphenol Conjugates toward Polyphenoloxidase from Shrimp Cephalothorax. Molecules 2023; 28:5560. [PMID: 37513432 PMCID: PMC10385636 DOI: 10.3390/molecules28145560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 07/17/2023] [Accepted: 07/19/2023] [Indexed: 07/30/2023] Open
Abstract
Crustaceans are perishable with a short shelf-life. They are prone to deterioration after capture, particularly during handling, processing, and storage due to melanosis caused by polyphenoloxidase (PPO). Therefore, inhibitory effects of chitooligosaccharide (CHOS) in comparison with CHOS-catechin (CHOS-CAT), CHOS-epigallocatechin gallate (CHOS-EGCG), and CHOS-gallic acid (CHOS-GAL) conjugates on Pacific white shrimp cephalothorax PPO were studied. IC50 of CHOS-CAT (0.32 mg/mL) toward PPO was less than those of all conjugates tested (p < 0.05). CHOS-CAT exhibited the mixed-type inhibition. Kic (0.58 mg/mL) and Kiu (0.02 mg/mL) of CHOS-CAT were lower than those of other conjugates (p < 0.05). CHOS-CAT showed static fluorescence-quenching, suggesting a change in micro-environment around the active site of PPO. Moreover, CHOS-CAT was linked with various amino acid residues, including Tyr208 or Tyr209 of proPPO via van der Waals, hydrophobic interaction, and hydrogen bonding as elucidated by the molecular docking of proPPO. Although CHOS-CAT had the highest PPO inhibitory activity, it showed a lower binding energy (-8.5 kcal/mol) than other samples, except for CHOS-EGCG (-10.2 kcal/mol). Therefore, CHOS-CAT could act as an anti-melanosis agent in shrimp and other crustaceans to prevent undesirable discoloration associated with quality losses.
Collapse
Affiliation(s)
- Ajay Mittal
- International Center of Excellence in Seafood Science and Innovation, Faculty of Agro-Industry, Prince of Songkla University, Hat Yai 90110, Thailand
| | - Avtar Singh
- International Center of Excellence in Seafood Science and Innovation, Faculty of Agro-Industry, Prince of Songkla University, Hat Yai 90110, Thailand
| | - Bin Zhang
- Key Laboratory of Health Risk Factors for Seafood of Zhejiang Province, College of Food Science and Pharmacy, Zhejiang Ocean University, Zhoushan 316022, China
| | - Qiancheng Zhao
- School of Food Science and Engineering, Dalian Ocean University, Dalian 116023, China
| | - Soottawat Benjakul
- International Center of Excellence in Seafood Science and Innovation, Faculty of Agro-Industry, Prince of Songkla University, Hat Yai 90110, Thailand
- Department of Food and Nutrition, Kyung Hee University, Seoul 02447, Republic of Korea
| |
Collapse
|
6
|
Geng Y, Liu X, Yu Y, Li W, Mou Y, Chen F, Hu X, Ji J, Ma L. From polyphenol to o-quinone: Occurrence, significance, and intervention strategies in foods and health implications. Compr Rev Food Sci Food Saf 2023; 22:3254-3291. [PMID: 37219415 DOI: 10.1111/1541-4337.13182] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 05/07/2023] [Accepted: 05/08/2023] [Indexed: 05/24/2023]
Abstract
Polyphenol oxidation is a chemical process impairing food freshness and other desirable qualities, which has become a serious problem in fruit and vegetable processing industry. It is crucial to understand the mechanisms involved in these detrimental alterations. o-Quinones are primarily generated by polyphenols with di/tri-phenolic groups through enzymatic oxidation and/or auto-oxidation. They are highly reactive species, which not only readily suffer the attack by nucleophiles but also powerfully oxidize other molecules presenting lower redox potentials via electron transfer reactions. These reactions and subsequent complicated reactions are capable of initiating quality losses in foods, such as browning, aroma loss, and nutritional decline. To attenuate these adverse influences, a variety of technologies have emerged to restrain polyphenol oxidation via governing different factors, especially polyphenol oxidases and oxygen. Despite tremendous efforts devoted, to date, the loss of food quality caused by quinones has remained a great challenge in the food processing industry. Furthermore, o-quinones are responsible for the chemopreventive effects and/or toxicity of the parent catechols on human health, the mechanisms by which are quite complex. Herein, this review focuses on the generation and reactivity of o-quinones, attempting to clarify mechanisms involved in the quality deterioration of foods and health implications for humans. Potential innovative inhibitors and technologies are also presented to intervene in o-quinone formation and subsequent reactions. In future, the feasibility of these inhibitory strategies should be evaluated, and further exploration on biological targets of o-quinones is of great necessity.
Collapse
Affiliation(s)
- Yaqian Geng
- College of Food Science and Nutritional Engineering, National Engineering Research Centre for Fruits and Vegetables Processing, Key Laboratory of Fruits and Vegetables Processing, Ministry of Agriculture, Engineering Research Centre for Fruits and Vegetables Processing, Ministry of Education, China Agricultural University, Beijing, China
| | - Xinyu Liu
- College of Food Science and Nutritional Engineering, National Engineering Research Centre for Fruits and Vegetables Processing, Key Laboratory of Fruits and Vegetables Processing, Ministry of Agriculture, Engineering Research Centre for Fruits and Vegetables Processing, Ministry of Education, China Agricultural University, Beijing, China
| | - Yiran Yu
- College of Food Science and Nutritional Engineering, National Engineering Research Centre for Fruits and Vegetables Processing, Key Laboratory of Fruits and Vegetables Processing, Ministry of Agriculture, Engineering Research Centre for Fruits and Vegetables Processing, Ministry of Education, China Agricultural University, Beijing, China
| | - Wei Li
- College of Food Science and Nutritional Engineering, National Engineering Research Centre for Fruits and Vegetables Processing, Key Laboratory of Fruits and Vegetables Processing, Ministry of Agriculture, Engineering Research Centre for Fruits and Vegetables Processing, Ministry of Education, China Agricultural University, Beijing, China
| | - Yao Mou
- College of Food Science and Nutritional Engineering, National Engineering Research Centre for Fruits and Vegetables Processing, Key Laboratory of Fruits and Vegetables Processing, Ministry of Agriculture, Engineering Research Centre for Fruits and Vegetables Processing, Ministry of Education, China Agricultural University, Beijing, China
| | - Fang Chen
- College of Food Science and Nutritional Engineering, National Engineering Research Centre for Fruits and Vegetables Processing, Key Laboratory of Fruits and Vegetables Processing, Ministry of Agriculture, Engineering Research Centre for Fruits and Vegetables Processing, Ministry of Education, China Agricultural University, Beijing, China
| | - Xiaosong Hu
- College of Food Science and Nutritional Engineering, National Engineering Research Centre for Fruits and Vegetables Processing, Key Laboratory of Fruits and Vegetables Processing, Ministry of Agriculture, Engineering Research Centre for Fruits and Vegetables Processing, Ministry of Education, China Agricultural University, Beijing, China
| | - Junfu Ji
- College of Food Science and Nutritional Engineering, National Engineering Research Centre for Fruits and Vegetables Processing, Key Laboratory of Fruits and Vegetables Processing, Ministry of Agriculture, Engineering Research Centre for Fruits and Vegetables Processing, Ministry of Education, China Agricultural University, Beijing, China
| | - Lingjun Ma
- College of Food Science and Nutritional Engineering, National Engineering Research Centre for Fruits and Vegetables Processing, Key Laboratory of Fruits and Vegetables Processing, Ministry of Agriculture, Engineering Research Centre for Fruits and Vegetables Processing, Ministry of Education, China Agricultural University, Beijing, China
| |
Collapse
|
7
|
Tang YY, Guo XN, Zhu KX. Inhibitory mechanism of sodium hexametaphosphate on enzymatic browning in yellow alkaline noodles. Food Chem 2023; 412:135533. [PMID: 36716630 DOI: 10.1016/j.foodchem.2023.135533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 12/28/2022] [Accepted: 01/19/2023] [Indexed: 01/22/2023]
Abstract
The effect and mechanism of sodium hexametaphosphate (SHMP) on polyphenol oxidase (PPO) enzymatic browning in yellow alkaline noodles (YAN) were investigated. The browning degree and PPO activity in YAN or PPO solutions decreased with the SHMP concentrations increased. Variations in pH values (pH 7-8.5) adjusted by HCl or acetic acid slightly affected the PPO activity, but SHMP inhibited PPO activity more pronounced. The inhibition of SHMP on PPO activity was irreversible. SHMP formed coordinate covalent bonds with Cu2+ to make PPO inactive. HPLC analysis revealed that SHMP reduced the browning products and led to the color of PPO-catechol systems being lightened. Furthermore, SHMP inhibited browning by hampering the auto-oxidization of intermediate products due to the change in pH value. Besides, the HPLC chromatogram, UV-vis spectrum, and mass spectrometry revealed that SHMP could convert melanin (m/z 248.97, 723.5, and 836.58) to light-colored substances (m/z 137.11).
Collapse
Affiliation(s)
- Ying-Ying Tang
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, Jiangsu Province, PR China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, Jiangsu Province, PR China
| | - Xiao-Na Guo
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, Jiangsu Province, PR China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, Jiangsu Province, PR China.
| | - Ke-Xue Zhu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, Jiangsu Province, PR China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, Jiangsu Province, PR China
| |
Collapse
|
8
|
Lv Y, Bao J, Liu D, Gao X, Yu Y, Zhu L. Synergistic effects of rice husk biochar and aerobic composting for heavy oil-contaminated soil remediation and microbial community succession evaluation. JOURNAL OF HAZARDOUS MATERIALS 2023; 448:130929. [PMID: 36860035 DOI: 10.1016/j.jhazmat.2023.130929] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 01/18/2023] [Accepted: 01/31/2023] [Indexed: 06/18/2023]
Abstract
Soil petroleum pollution is an urgent problem in modern society, which seriously threatens the ecological balance and environmental safety. Aerobic composting technology is considered economically acceptable and technologically feasible for the soil remediation. In this study, the combined experiment of aerobic composting with the addition of biochar materials was conducted for the remediation of heavy oil-contaminated soil, and treatments with 0, 5, 10 and 15 wt% biochar dosages were labeled as CK, C5, C10 and C15, respectively. Conventional parameters (temperature, pH, NH4+-N and NO3--N) and enzyme activities (urease, cellulase, dehydrogenase and polyphenol oxidase) during the composting process were systematically investigated. Remediation performance and functional microbial community abundance were also characterized. According to experimental consequences, removal efficiencies of CK, C5, C10 and C15 were 48.0%, 68.1%, 72.0% and 73.9%, respectively. The comparison with abiotic treatments corroborated that biostimulation rather than adsorption effect was the main removal mechanism during the biochar-assisted composting process. Noteworthy, the biochar addition regulated the succession process of microbial community and increased the abundance of microorganisms related to petroleum degradation at the genus level. This work demonstrated that aerobic composting with biochar amendment would be a fascinating technology for petroleum-contaminated soil remediation.
Collapse
Affiliation(s)
- Yuanfei Lv
- School of Resources & Environmental Science, Hubei International Scientific and Technological Cooperation Base of Sustainable Resource and Energy, Hubei Key Laboratory of Biomass-Resources Chemistry and Environmental Biotechnology, Wuhan University, Wuhan 430079, China
| | - Jianfeng Bao
- School of Resources & Environmental Science, Hubei International Scientific and Technological Cooperation Base of Sustainable Resource and Energy, Hubei Key Laboratory of Biomass-Resources Chemistry and Environmental Biotechnology, Wuhan University, Wuhan 430079, China
| | - Dongyang Liu
- School of Resources & Environmental Science, Hubei International Scientific and Technological Cooperation Base of Sustainable Resource and Energy, Hubei Key Laboratory of Biomass-Resources Chemistry and Environmental Biotechnology, Wuhan University, Wuhan 430079, China
| | - Xinxin Gao
- School of Resources & Environmental Science, Hubei International Scientific and Technological Cooperation Base of Sustainable Resource and Energy, Hubei Key Laboratory of Biomass-Resources Chemistry and Environmental Biotechnology, Wuhan University, Wuhan 430079, China
| | - Yunjiang Yu
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Liandong Zhu
- School of Resources & Environmental Science, Hubei International Scientific and Technological Cooperation Base of Sustainable Resource and Energy, Hubei Key Laboratory of Biomass-Resources Chemistry and Environmental Biotechnology, Wuhan University, Wuhan 430079, China; State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China.
| |
Collapse
|
9
|
New Insights into the Inhibition of Hesperetin on Polyphenol Oxidase: Inhibitory Kinetics, Binding Characteristics, Conformational Change and Computational Simulation. Foods 2023; 12:foods12040905. [PMID: 36832979 PMCID: PMC9957399 DOI: 10.3390/foods12040905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 02/07/2023] [Accepted: 02/17/2023] [Indexed: 02/22/2023] Open
Abstract
The inhibitory activity of hesperetin on polyphenol oxidase (PPO) and their interaction characteristics were investigated using multiple spectroscopic methods and computational simulation. Hesperetin, a mixed inhibitor, reversibly inhibited PPO activity, and its half-maximum inhibitory concentration (IC50) values on monophenolase and diphenolase were 80.8 ± 1.4 μM and 776.0 ± 15.5 μM, respectively. Multivariate curve resolution-alternate least squares (MCR-ALS) analysis suggested PPO interacted with hesperetin and formed PPO-hesperetin complex. Hesperetin statically quenched PPO's endogenous fluorescence, and hydrophobic interactions mainly drove their binding. Hesperetin affected the polarity of the microenvironment around the Trp residues in PPO, but had no effect on that around Tyr residues. Circular dichroism (CD) results showed that hesperetin increased α-helix content and decreased β-fold and random coil contents, thus tightening PPO's structure. Molecular docking showed that hesperetin entered the hydrophobic cavity of PPO, bound near the dinuclear copper active center, interacted with Val283, Phe264, His85, Asn260, Val248, and His263 via hydrophobic interactions, formed hydrogen bonds with Met280, His89, and His259 residues and also interacted with Phe292, His61, Phe90, Glu256, His244, Asn260, Phe264, and Gly281 via van der Waals forces. The molecular dynamics simulation results also demonstrated that the addition of hesperetin reduced the stability and hydrophobicity of PPO and increased PPO's structural denseness. Thus, the inhibition of hesperetin on PPO may be because hesperetin bound near the active center of PPO, interacted with the surrounding residues, occupied the binding site for substrate, and induced the changes in PPO's secondary structure, thus inhibiting the catalytic activity of PPO. This study may provide novel views for the inhibition of hesperetin on PPO and theoretical guidance for developing flavonoids as new and efficient PPO inhibitors.
Collapse
|