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Polyphenol oxidase

Chang-Qing Ding, Sophia Ng, Lu Wang, Yu-Chun Wang, Na-Na Li, Xin-Yuan Hao, Jian-Ming Zeng, Xin-Chao Wang, Ya-Jun Yang
Four typical ALTERNATIVE OXIDASE genes have been identified in tea plants, and their sequence features and gene expression profiles have provided useful information for further studies on function and regulation. Alternative oxidase (AOX) is a terminal oxidase located in the respiratory electron transport chain. AOX catalyzes the oxidation of quinol and the reduction of oxygen into water. In this study, a genome-wide search and subsequent DNA cloning were performed to identify and characterize AOX genes in tea plant (Camellia sinensis (L...
August 10, 2018: Planta
Carolina Anazco, Armando Rojas, Ileana Gonzalez, Maite A Castro, Paz Robert, Felipe Oyarzun-Ampuero
Collagen, the most abundant component in mammalian tissues, has a crucial impact at skin level. Both promotion and maintenance of cross-linked collagen at the skin, are critical to sustain the functionality and appearance of that tissue. Lysyl oxidases, also known as LOX enzymes, are the major collagen cross-linking enzymes and playing a pivotal role in homeostasis. This minireview summarizes evidence that describes an amino oxidase-like activity, which could be attributed to polyphenols, or where polyphenols could be required...
August 10, 2018: Current Topics in Medicinal Chemistry
Nobuyuki Fukuoka, Masahiro Miyata, Tatsuro Hamada, Eishin Takeshita
The mechanism underlying internal browning (IB), or brown discoloration, of the central region of tuberous roots of sweet potato (Ipomoea batatas) was examined. IB disorder begins in roots from approx. 90 days after transplanting, and the severity increases significantly with time. IB damage initially occurs in cells around the secondary vascular tissue, and the area per cell occupied by starch grains in this region was larger than in the unaffected region. High levels of reducing sugars, polyphenol oxidase (PPO) activities, chlorogenic acid, and hydrogen peroxide (H2 O2 ) were detected in cells from the IB damaged regions...
September 2018: Plant Science: An International Journal of Experimental Plant Biology
Chandrahas Vishwasrao, Laxmi Ananthanarayan
Peroxidase (POD), polyphenol oxidase (PPO), ascorbate oxidase (AO) and pectin methylesterase (PME) from 'Lalit' guava variety have been purified using BioGel P-100 and UNOsphere Q resins. POD, PPO, AO, and PME were partially purified to 28, 30, 36 and 30 fold; single band on SDS-PAGE represented a molecular weight of 21, 70, 75, 50 kDa, respectively. Optimum pH for POD and AO was 6.5 whereas, PPO and PME showed optimum pH in the alkaline range of pH 8.0 and 8.5, respectively. AO showed optimum activity at 25 °C, POD and PPO showed optimum activity at 35 °C; however, PME showed maximum activity at 55 °C...
August 2018: Journal of Food Science and Technology
Chandrahas Vishwasrao, Laxmi Ananthanarayan
Thermal inactivation kinetics of peroxidase (POD), polyphenol oxidase (PPO), pectin methyl esterase (PME) and ascorbate oxidase (AO) were studied over the temperature range of 45-85 °C along with the degradation kinetics of ascorbic acid (AA) and lycopene in Psidium guajava pulp. POD, PPO, PME and AO followed first-order kinetics whereas AA degradation data was explained by pseudo first-order kinetics. Lycopene degradation was suitably fitted in an exponential model, indicating continuous degradation of lycopene and higher degradation at higher temperature...
August 2018: Journal of Food Science and Technology
Win Yee Lim, Chen Wai Wong
Food browning is undesirable as it causes deterioration in food quality and appearance. This phenomenon was related to polyphenol oxidase (PPO), which catalyzes conversion of phenolic compounds into o -quinones. The present work evaluated the use of chemical and natural anti-browning agents to prevent the browning of ginger PPO. Sodium metabisulfite (5 mM) is a better chemical inhibitor compared to l-cysteine and sodium chloride as 55.00% of ginger PPO inhibition was achieved. The percentage of inhibition increased as the concentration of anti-browning agents increases...
August 2018: Journal of Food Science and Technology
Krystian Marszałek, Łukasz Woźniak, Francisco J Barba, Sylwia Skąpska, Jose M Lorenzo, Alessandro Zambon, Sara Spilimbergo
The impact of supercritical carbon dioxide (SCCD) (10-60 MPa/45 °C/30 min) and subsequent 10 weeks storage at 4 °C on polyphenol oxidase (PPO), peroxidase (POD) activities, phenolic profile, vitamin C, sugars, physicochemical properties of cloudy apple juices was investigated. No significant changes in sugars and total polyphenols were observed, whereas significant degradation (≈28%) of vitamin C and individual polyphenols (≈18%) was noted after SCCD treatment. After 4 weeks storage only 34% of vitamin C was retained and no vitamin C was detected after this time...
December 1, 2018: Food Chemistry
Yangyang Zheng, Xudong Wang, Siyuan Liu, Kewei Zhang, Zhibo Cai, Xiuling Chen, Yao Zhang, Jiayin Liu, Aoxue Wang
To investigate whether the ech42 gene in Clonostachysrosea can improve the biocontrol efficacy of Bacillus amyloliquefaciens and its molecular mechanism. Compared to the wild type, the B. amyloliquefaciens transformed with the ech42 gene exhibited higher chitinase activity. The B. amyloliquefaciens -ech42 also showed significantly higher biocontrol efficiency compared to Botrytiscinerea when tomato plants were pre-treated with B. amyloliquefaciens- ech42. No significant difference in biocontrol efficiency was observed between the wild type and B...
July 30, 2018: International Journal of Molecular Sciences
Xiang Gao, Shuxiang Zhang, Xiujuan Zhao, Qihua Wu
Soybean cyst nematode (SCN) is a severe soil borne disease. The control of this disease is still a worldwide problem in agriculture. In this study, we found that application of potassium (K) fertilizer could decrease the occurrence of SCN at two field sites. Furthermore, the application of K could suppress Heterodera glycines with the activation of Phenylalanine Ammonia Lyase (PAL) and Polyphenol Oxidase (PPO) expression via pot experiments in a greenhouse. The release of cinnamic, ferulic and salicylic acids was significantly enhanced by K application of 3 mM, and each of three acids can dramatically constrain Heterodera glycines in vitro...
2018: PloS One
Tao Luo, Jiajia Niu, Xiaomeng Guo, Huitao Wu, Dongmei Han, Liang Shuai, Zhenxian Wu
BACKGROUND: Zinc fertilization has been reported to improve the quality and storability of many fruits, but the mechanism had not been systematically studied. In this study, the effect of preharvest 0.2 % ZnSO4 spray on the storability of longan fruits was investigated. RESULTS: The preharvest ZnSO4 spray did not significantly influence the quality but increased the Zn content in longan pericarp by 12.5 folds. More importantly, the treatment significantly reduced the rotting rate, pericarp browning and aril breakdown of longan fruits stored at room temperature and low temperature...
July 25, 2018: Journal of the Science of Food and Agriculture
Qin Li, Shuo Chai, Yongdi Li, Jianan Huang, Yu Luo, Lizheng Xiao, Zhonghua Liu
Primary dark tea is used as raw material for compressed dark tea, such as Fu brick tea, Hei brick tea, Hua brick tea, and Qianliang tea. Pile-fermentation is the key process for the formation of the characteristic properties of primary dark tea, during which the microorganism plays an important role. In this study, the changes of major chemical compounds, enzyme activities, microbial diversity, and their correlations were explored during the pile-fermentation process. Our chemical and enzymatic analysis showed that the contents of the major compounds were decreased, while the activities of polyphenol oxidase, cellulase, and pectinase were increased during this process, except peroxidase activity that could not be generated from microbial communities in primary dark tea...
2018: Frontiers in Microbiology
Yu Qin, Dan Ju Zhang, Xun Li, Yan Zhang, Ya Ling Yuan, Li Feng Wang, Zhi Hui Pang, Jian Zhang
A field litterbag experiment was conducted to investigate dynamics of total phenols and condensed tannin in the mixed leaf litter of Pinus massoniana (P) with other three broad-leaved species, i.e., Sassafras trumu (S), Cinnamomum camphora (C), Toona sinensis (T) during decomposition in low hilly lands, Sichuan Province, China. The mass ratio of P. massoniana : S. trumu (PS) was 6:4, 7:3, 8:2, P. massoniana : C. camphora (PC) was 6:4, 7:3, 8:2 and P. massoniana : T. sinensis (PT) was 6:4, 7:3, 8:2, respectively...
July 2018: Ying Yong Sheng Tai Xue Bao, the Journal of Applied Ecology
Maria Fiorella Mazzeo, Giuseppina Cacace, Paolo Iovieno, Immacolata Massarelli, Stefania Grillo, Rosa Anna Siciliano
Constant global warming is one of the most detrimental environmental factors for agriculture causing significant losses in productivity as heat stress (HS) conditions damage plant growth and reproduction. In flowering plants such as tomato, HS has drastic repercussions on development and functionality of male reproductive organs and pollen. Response mechanisms to HS in tomato anthers and pollen have been widely investigated by transcriptomics; on the contrary, exhaustive proteomic evidences are still lacking...
2018: PloS One
Aamir Iqbal, Ayesha Murtaza, Zafarullah Muhammad, Abdeen E Elkhedir, Mingfang Tao, Xiaoyun Xu
Polyphenol oxidase (PPO) causes the browning reaction in fruits and vegetables and deteriorates the quality. Thermal treatment for enzyme inactivation may result in defects as opposed to high pressure CO₂ (HPCD) processing. In this study, the changes in activity, dissociation, aggregation and conformation of purified PPO from thermal and HPCD treated juice were investigated. HPCD exhibited inactivation of PPO at 55⁻65 °C whereas thermal processing alone at the same temperature resulted in PPO still showing activity...
July 17, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Pyung-Gang Lee, Sang-Hyuk Lee, Eun Young Hong, Stefan Lutz, Byung-Gee Kim
Tyrosinase is a type-3 copper oxygenase that catalyzes a phenol moiety into ortho-diphenol, and subsequently to ortho-quinone. Diverse tyrosinases have been observed across the kingdom including Animalia, Bacteria, Plantae, and Fungi. Among the tyrosinases, bacterial and mushroom tyrosinases have been extensively exploited to prepare melanin, ortho-hydroxy-polyphenols or novel plant secondary metabolites during the past decade. And their use as a biocatalyst to prepare various functional bio-compounds have drawn great attention worldwide...
July 16, 2018: Biotechnology and Bioengineering
De-Mei Meng, Hua-Dong Wang, Ya-Xuan Zhang, Zhi-Ai Xi, Rui Yang, Ji-Ping Sheng, Xin-Hua Zhang, Yang Ding, Jun-Ping Wang, Zhen-Chuan Fan
BACKGROUND: In the present study, we investigated the role of ornithine decarboxylase (ODC) in the methyl jasmonate (MeJA)-regulated postharvest quality maintenance of Agaricus bisporus (J.E. Kange) Imbach button mushroom by pretreatment mushrooms with a specific irreversible inhibitor called α-difluoromethylornithine (DFMO) before exposure to MeJA vapor. RESULTS: Mushrooms were treated with 0 or 100 μmol L-1 MeJA or the combination of 120 μmol L-1 DFMO and 100 μmol L-1 MeJA, respectively, before storage at 4 °C for 21 d...
July 11, 2018: Journal of the Science of Food and Agriculture
Anish Kundu, Shruti Mishra, Jyothilakshmi Vadassery
Metabolite profiling, biochemical assays, and transcript analysis revealed differential modulation of specific induced defense responses in local, older, and younger systemic leaves in Solanum lycopersicum upon Spodoptera litura herbivory. Plants reconfigure their metabolome upon herbivory to induce production of defense metabolites involved in both direct and indirect defenses against insect herbivores. Herbivory mediated leaf-to-leaf systemic induction pattern of primary and non-volatile secondary metabolites is not well studied in tomato...
July 9, 2018: Planta
Jinhua Zuo, Yunxiang Wang, Benzhong Zhu, Yunbo Luo, Qing Wang, Lipu Gao
Increasing evidence suggests that long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and microRNAs (miRNAs) have roles during biotic and abiotic stress, though their exact contributions remain unclear. To explore their biological functions in response to chilling in bell pepper, we examined their accumulation profiles by deep sequencing and identified 380 lncRNAs, 36 circRNAs, 18 miRNAs, and 4128 differentially expressed mRNAs in the chilled versus the non-chilled fruit. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed differentially expressed genes and putative ncRNA targets, including transcription factors of multiple classes, such as myeloblastosis (MYB), basic helix-loop-helix (bHLH), and ethylene response factor (ERF) transcription factors (TFs), enzymes involved in bio-oxidation and oxidative phosphorylation (serine/threonine-protein kinase, polyphenol oxidase, catalase, peroxidase, lipoxygenase, and ATPase), and cell wall metabolism-related enzymes (beta-galactosidase, pectate lyase, pectinesterase, and polygalacturonase)...
July 9, 2018: International Journal of Molecular Sciences
Hung-Te Hsu, Yu-Ting Tseng, Wen-Jhe Wong, Chi-Ming Liu, Yi-Ching Lo
BACKGROUND: Exposure to carbon black nanoparticles (CBNPs), a well-known industrial production, promotes pulmonary toxicity through inflammation and oxidative stress. Recent studies show that some polyphenols exert their antioxidant properties through regulation of protein kinase C-α (PKC-α) and NADPH oxidase (Nox) signaling. Resveratrol, a dietary polyphenol in fruits, possesses various health beneficial effects including anti-inflammatory and antioxidative properties. In this study, we aimed to elucidate the involvement of PKC-α and Nox in CBNPs-induced inflammation and oxidative stress, and to investigate the protective effects of resveratrol on CBNP-induced inflammation and oxidative stress in human lung epithelial A549 cells...
July 9, 2018: BMC Complementary and Alternative Medicine
Jiali Chen, Bing Yu, Daiwen Chen, Zhiqing Huang, Xiangbing Mao, Ping Zheng, Jie Yu, Junqiu Luo, Jun He
Intestinal barrier plays key roles in maintaining intestinal homeostasis. Inflammation and oxidative damage can severely destroy the intestinal integrity of mammals. Chlorogenic acid (CGA) is a natural polyphenol present in human diet and plants, possessing potent antioxidant and anti-inflammatory activities. This study was conducted to investigate the protective effects of CGA and its molecular mechanisms on intestinal barrier function in a porcine model. Twenty-four weaned pigs were allotted to two groups and fed with a basal diet or a basal diet containing 1000 mg/kg CGA...
June 15, 2018: Journal of Nutritional Biochemistry
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