Biochemical characterization of polyphenol oxidase (PPO) present in purple sweet potato (PSP) is a key step in developing efficient methodologies to control oxidative damage caused by this enzyme to the valuable components of PSP, such as caffeoylquinic acid derivatives and acylated anthocyanins. Thus, this work focused on the assessment of the effects of pH, temperature, and chemical agents on the PPO activity as well as characterization of the PPO substrate specificity towards major phenolic compounds found in PSP. The optimum conditions of enzyme activity were pH 7 and a temperature range of 20-30 °C at which phenolic substrates were oxidized with 72.5-99.8% yield. Zn ions remarkably reduced PPO activity while Cu ions improved enzyme performance. The highest substrate preference was shown for 3,4,5-tri-caffeoylquinic and 3,5-di-caffeoylquinic acid, followed by 5-caffeoylquinic and caffeic acid, 3,4- and 4,5-di-caffeoylquinic acids, peonidin-3-caffeoyl-p-hydroxybenzoyl-sophoroside-5-glucoside. The highest Km values were found for 4,5-feruloyl-caffeoylquinic acid and catechol.
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http://dx.doi.org/10.1016/j.foodchem.2021.129709 | DOI Listing |
Nutr Neurosci
January 2025
Molecular and Cell Biology Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.
Background: Recent studies have shown that ferroptosis, a newly identified regulated cell death characterized by increased lipid peroxidation and accumulation of toxic lipid peroxides, is closely related to the pathophysiological processes of nervous system diseases which can be inhibited with iron chelators, lipophilic antioxidants, and lipid peroxidation inhibitors.
Objective: To review the current evidence on the efficacy of various natural polyphenols in nervous system injury.
Methods: The data selected for this review were collected by searching the MEDLINE/PubMed, Web of Science, Scopus, and Google Scholar database for articles published in English between 2000 and 2024 using the following terms: cell death, regulated cell death, ferroptosis, lipid peroxides, iron, and glutathione peroxidase.
Int J Biol Macromol
January 2025
State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China; Department of Food Science and Engineering, College of Biological Sciences and Technology, Beijing Key Laboratory of Forest Food Processing and Safety, Beijing Forestry University, Beijing 100083, China. Electronic address:
This study aimed to compare the bioactive compounds presented in quinoa of various colors, and investigated their inhibitory effect on α-glucosidase activity and the in vitro digestibility of starch. The primary bioactive compounds identified in quinoa included betaine and polyphenols (kaempferol, quercetin, rutin, etc.), with their contents increased as the color of quinoa darkened.
View Article and Find Full Text PDFJ Fluoresc
January 2025
Department of Physics, Jnana Bharathi Campus, Bangalore University, Bengaluru, 560056, India.
This investigation delves into the extraction of polyphenols from the flowers of Tabebuia rosea using a basic maceration approach with acetone, ethanol, and methanol as solvents. The spectroscopic analysis of the dye obtained confirms the existence of functional groups in the polyphenol extract. The study also explores optoelectronic, fluorescence, and photometric characteristics associated with polyphenols.
View Article and Find Full Text PDFPlant Foods Hum Nutr
January 2025
Departamento de Investigación y Posgrado en Alimentos, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Qro., 76010, México.
Grape pomace (GP) is a by-product rich in phytochemicals, including extractable polyphenols (EPPs) and non-extractable polyphenols (NEPPs), which have distinct metabolic fates that may affect their biological activities. The benefits of GP have been reported in relation to obesity and its comorbidities, particularly when administered preventively focusing on EPPs. Therefore, the aim of this study was to investigate the effects of EPPs and NEPPs from GP as a treatment for obesity and its associated metabolic alterations.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
College of Life Science, Yangtze University, Jingzhou, China. Electronic address:
Tyrosinase is a rate-limiting enzyme for melanogenesis and abnormal melanin production can be controlled by utilizing tyrosinase inhibitory substances. To develop potent and safe inhibitors of tyrosinase, complex tannins a narrowly distributed plant polyphenols were prepared from the fruit peel of Euryale ferox (EPTs) and then structurally characterized, as well as investigated for their inhibitory effects and the involved mechanisms against tyrosinase activity and melanogenesis. The structures of EPTs were established to consist of 63.
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