Displaying publications 1 - 20 of 40 in total

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  1. Zainudin MAM, Jongberg S, Lund MN
    Food Chem, 2021 Jan 01;334:127611.
    PMID: 32712493 DOI: 10.1016/j.foodchem.2020.127611
    Plant polyphenols applied as natural antioxidant ingredients, are known to bind to cysteine residues on meat proteins. The aim of this study was to examine the effect of light exposure on the formation of cysteine-phenol adduct in meat added 4-methylcatechol (4MC), a model polyphenol, during storage through quantitative LC-MS/MS-based analysis. Cysteine-4-methylcatechol adduct (Cys-4MC) formation in meat added 1500 ppm 4-MC increased significantly (by 50%) when stored under light in oxygen at 4 °C for 7 days as compared to storage in the dark. This was reflected by a significant decrease in thiol concentrations in the same sample. Gel electrophoresis showed loss in myosin heavy chain (MHC), and a resulting increase in cross-linked MHC (CL-MHC) and larger protein polymers in samples added 4MC. Protein blots stained with nitroblue tetrazolium (NBT) showed intensive protein-polyphenol binding in the meat samples added 4MC, but no major differences between storage conditions.
    Matched MeSH terms: Catechols/chemistry*
  2. Yusof KM, Makpol S, Jamal R, Harun R, Mokhtar N, Ngah WZ
    Molecules, 2015 Jun 03;20(6):10280-97.
    PMID: 26046324 DOI: 10.3390/molecules200610280
    Numerous bioactive compounds have cytotoxic properties towards cancer cells. However, most studies have used single compounds when bioactives may target different pathways and exert greater cytotoxic effects when used in combination. Therefore, the objective of this study was to determine the anti-proliferative effect of γ-tocotrienol (γ-T3) and 6-gingerol (6G) in combination by evaluating apoptosis and active caspase-3 in HT-29 and SW837 colorectal cancer cells. MTS assays were performed to determine the anti-proliferative and cytotoxicity effect of γ-T3 (0-150 µg/mL) and 6G (0-300 µg/mL) on the cells. The half maximal inhibitory concentration (IC50) value of 6G+ γ-T3 for HT-29 was 105 + 67 µg/mL and for SW837 it was 70 + 20 µg/mL. Apoptosis, active caspase-3 and annexin V FITC assays were performed after 24 h of treatment using flow cytometry. These bioactives in combination showed synergistic effect on HT-29 (CI: 0.89 ± 0.02,) and SW837 (CI: 0.79 ± 0.10) apoptosis was increased by 21.2% in HT-29 and 55.4% in SW837 (p < 0.05) after 24 h treatment, while normal hepatic WRL-68 cells were unaffected. Increased apoptosis by the combined treatments was also observed morphologically, with effects like cell shrinkage and pyknosis. In conclusion, although further studies need to be done, γ-T3 and 6G when used in combination act synergistically increasing cytotoxicity and apoptosis in cancer cells.
    Matched MeSH terms: Catechols/pharmacology*
  3. Yusof KM, Makpol S, Fen LS, Jamal R, Wan Ngah WZ
    J Nat Med, 2019 Sep;73(4):745-760.
    PMID: 31177355 DOI: 10.1007/s11418-019-01323-6
    Our previous study reported that combined treatment of γ-tocotrienol with 6-gingerol showed promising anticancer effects by synergistically inhibiting proliferation of human colorectal cancer cell lines. This study aimed to identify and elucidate molecular mechanisms involved in the suppression of SW837 colorectal cancer cells modulated by combined treatment of γ-tocotrienol and 6-gingerol. Total RNA from both untreated and treated cells was prepared for transcriptome analysis using RNA sequencing techniques. We performed high-throughput sequencing at approximately 30-60 million coverage on both untreated and 6G + γT3-treated cells. The results showed that cancer-specific differential gene expression occurred and functional enrichment pathway analysis suggested that more than one pathway was modulated in 6G + γT3-treated cells. Combined treatment with 6G + γT3 augmented its chemotherapeutic effect by interfering with the cell cycle process, downregulating the Wnt signalling pathway and inducing apoptosis mainly through caspase-independent programmed cell death through mitochondrial dysfunction, activation of ER-UPR, disruption of DNA repair mechanisms and inactivation of the cell cycle process through the downregulation of main genes in proliferation such as FOXM1 and its downstream genes. The combined treatment exerted its cytotoxic effect through upregulation of genes in stress response activation and cytostatic effects demonstrated by downregulation of main regulator genes in the cell cycle. Selected genes involved in particular pathways including ATF6, DDIT3, GADD34, FOXM1, CDK1 and p21 displayed concordant patterns of gene expression between RNA sequencing and RT-qPCR. This study provides new insights into combined treatment with bioactive compounds not only in terms of its pleiotropic effects that enhance multiple pathways but also specific target genes that could be exploited for therapeutic purposes, especially in suppressing cancer cell growth.
    Matched MeSH terms: Catechols/pharmacology*
  4. Yudthavorasit S, Wongravee K, Leepipatpiboon N
    Food Chem, 2014 Sep 01;158:101-11.
    PMID: 24731320 DOI: 10.1016/j.foodchem.2014.02.086
    Chromatographic fingerprints of gingers from five different ginger-producing countries (China, India, Malaysia, Thailand and Vietnam) were newly established to discriminate the origin of ginger. The pungent bioactive principles of ginger, gingerols and six other gingerol-related compounds were determined and identified. Their variations in HPLC profiles create the characteristic pattern of each origin by employing similarity analysis, hierarchical cluster analysis (HCA), principal component analysis (PCA) and linear discriminant analysis (LDA). As results, the ginger profiles tended to be grouped and separated on the basis of the geographical closeness of the countries of origin. An effective mathematical model with high predictive ability was obtained and chemical markers for each origin were also identified as the characteristic active compounds to differentiate the ginger origin. The proposed method is useful for quality control of ginger in case of origin labelling and to assess food authenticity issues.
    Matched MeSH terms: Catechols/chemistry*
  5. Xing M, Akowuah GA, Gautam V, Gaurav A
    J Biomol Struct Dyn, 2017 Oct;35(13):2910-2924.
    PMID: 27608741 DOI: 10.1080/07391102.2016.1234417
    Phosphodiesterase 4 (PDE4) has been established as a drug target for inflammatory diseases of respiratory tract like asthma and chronic obstructive pulmonary disease. The selective inhibitors of PDE4B, a subtype of PDE4, are devoid of adverse effects like nausea and vomiting commonly associated with non-selective PDE4B inhibitors. This makes the development of PDE4B subtype selective inhibitors a desirable research goal. Thus, in the present study, molecular docking, molecular dynamic simulations and binding free energy were performed to explore potential selective PDE4B inhibitors based on ginger phenolic compounds. The results of docking studies indicate that some of the ginger phenolic compounds demonstrate higher selective PDE4B inhibition than existing selective PDE4B inhibitors. Additionally, 6-gingerol showed the highest PDE4B inhibitory activity as well as selectivity. The comparison of binding mode of PDE4B/6-gingerol and PDE4D/6-gingerol complexes revealed that 6-gingerol formed additional hydrogen bond and hydrophobic interactions with active site and control region 3 (CR3) residues in PDE4B, which were primarily responsible for its PDE4B selectivity. The results of binding free energy demonstrated that electrostatic energy is the primary factor in elucidating the mechanism of PDE4B inhibition by 6-gingerol. Dynamic cross-correlation studies also supported the results of docking and molecular dynamics simulation. Finally, a small library of molecules were designed based on the identified structural features, majority of designed molecules showed higher PDE4B selectivity than 6-gingerol. These results provide important structural features for designing new selective PDE4B inhibitors as anti-inflammatory drugs and promising candidates for synthesis and pre-clinical pharmacological investigations.
    Matched MeSH terms: Catechols/chemistry
  6. Tan BS, Kang O, Mai CW, Tiong KH, Khoo AS, Pichika MR, et al.
    Cancer Lett, 2013 Aug 9;336(1):127-39.
    PMID: 23612072 DOI: 10.1016/j.canlet.2013.04.014
    6-Shogaol has been shown to possess many antitumor properties including inhibition of cancer cell growth, inhibition of cancer metastasis, induction of apoptosis in cancer cells and induction of cancer cell differentiation. Despite its prominent antitumor effects, the direct molecular target of 6-shogaol has remained elusive. To identify the direct targets of 6-shogaol, a comprehensive antitumor profile of 6-shogaol (NSC752389) was tested in the NCI-60 cell line in an in vitro screen. The results show that 6-shogaol is COMPARE negative suggesting that it functions via a mechanism of action distinct from existing classes of therapeutic agents. Further analysis using microarray gene profiling and Connectivity Map analysis showed that MCF-7 cells treated with 6-shogaol display gene expression signatures characteristic of peroxisome proliferator activated receptor γ (PPARγ) agonists, suggesting that 6-shogaol may activate the PPARγ signaling pathway for its antitumor effects. Indeed, treatment of MCF-7 and HT29 cells with 6-shogaol induced PPARγ transcriptional activity, suppressed NFκB activity, and induced apoptosis in breast and colon cancer cells in a PPARγ-dependent manner. Furthermore, 6-shogaol is capable of binding to PPARγ with a binding affinity comparable to 15-delta prostaglandin J2, a natural ligand for PPARγ. Together, our findings suggest that the antitumor effects of 6-shogaol are mediated through activation of PPARγ and imply that activation of PPARγ might be beneficial for breast and colon cancer treatment.
    Matched MeSH terms: Catechols/pharmacology*
  7. Song S, Dang M, Kumar M
    Inflammopharmacology, 2019 Dec;27(6):1243-1254.
    PMID: 30826930 DOI: 10.1007/s10787-019-00569-6
    P38 mitogen-activated protein kinase (p38 MAPK), a tissue inflammatory factor can be activated under oxidative stress and in conditions associated with hyperglycemia. Gingerol containing various natural herbs has been extensively studied for its pharmacological actions both in reducing the inflammation and as immunity booster. The aim of the current investigation was to examine the renal protective effect of gingerol in high-fat diet/streptozotocin-induced type II diabetes mellitus in a rat model.NRK 52E cells were divided into normal and high glucose group treated with gingerol. The methylthiazotetrazolium assay was used to establish the cell proliferation progress. Streptozotocin-inducted diabetes in rats was treated with gingerol for 16 weeks. The blood glucose, serum creatinine, body weight, food intake, biochemical, antioxidant and haematological parameters were assayed to establish the correlation. Pro-inflammatory cytokines including Il-1β, IL-6, TNF-α; inflammatory mediator COX-2, PGE2, NF-kB, p38MAPK, and TGF-β, were also determined to assess the molecular mechanism. Gingerol exhibited the protective effect on the high glucose level induced NRK 52E cells and did not show any effect on the normal cells. Gingerol significantly (P 
    Matched MeSH terms: Catechols/pharmacology*; Catechols/therapeutic use
  8. Seow SLS, Hong SL, Lee GS, Malek SNA, Sabaratnam V
    BMC Complement Altern Med, 2017 Jun 24;17(1):334.
    PMID: 28646880 DOI: 10.1186/s12906-017-1837-6
    BACKGROUND: Ginger is a popular spice and food preservative. The rhizomes of the common ginger have been used as traditional medicine to treat various ailments. 6-Shogaol, a pungent compound isolated from the rhizomes of jahe gajah (Zingiber officinale var officinale) has shown numerous pharmacological activities, including neuroprotective and anti-neuroinflammatory activities. The aim of this study was to investigate the potential of 6-shogaol to mimic the neuritogenic activity of nerve growth factor (NGF) in rat pheochromocytoma (PC-12) cells.

    METHODS: The cytotoxic effect of 6-shogaol was determined by 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The neuritogenic activity was assessed by neurite outgrowth stimulation assay while the concentration of extracellular NGF in cell culture supernatant was assessed by enzyme-linked immunosorbent assay (ELISA). Involvement of cellular signaling pathways, mitogen-activated protein kinase kinase/extracellular signal-regulated kinase1/2 (MEK/ERK1/2) and phosphoinositide-3-kinase/protein kinase B (PI3K/AKT) in 6-shogaol-stimulated neuritogenesis were examined by using specific pharmacological inhibitors.

    RESULTS: 6-Shogaol (500 ng/ml) induced neuritogenesis that was comparable to NGF (50 ng/ml) and was not cytotoxic towards PC-12 cells. 6-Shogaol induced low level of NGF biosynthesis in PC-12 cells, showing that 6-shogaol stimulated neuritogenesis possibly by inducing NGF biosynthesis, and also acting as a substitute for NGF (NGF mimic) in PC-12 cells. The inhibitors of Trk receptor (K252a), MEK/ERK1/2 (U0126 and PD98059) and PI3K/AKT (LY294002) attenuated the neuritogenic activity of both NGF and 6-shogaol, respectively.

    CONCLUSIONS: The present findings demonstrated that 6-shogaol induced neuritogenic activity in PC-12 cells via the activation MEK/ERK1/2 and PI3K/AKT signaling pathways. This study suggests that 6-shogaol could act as an NGF mimic, which may be beneficial for preventive and therapeutic uses in neurodegenerative diseases.

    Matched MeSH terms: Catechols/isolation & purification; Catechols/pharmacology*; Catechols/chemistry
  9. Senusi F, Nasuha N, Husain A, Ismail S
    Environ Sci Pollut Res Int, 2023 Dec;30(60):124585-124595.
    PMID: 35604600 DOI: 10.1007/s11356-022-20167-4
    Recently, the plant polyphenols have attracted much attention for membrane modification, especially in surface coating application. In this study, the synthesis of catechol-amine coating solutions was evaluated at different pH conditions and with different concentrations of tannic acid and tetraethylenepentamine in order to determine the relationship between chemical structure and mechanism in the oxidation reaction. The reactivity of catechol and amine groups in the formulation was measured using UV-Vis spectroscopy and observation of the change in colour of the coating solutions. Then, the deposition of catechol-amine coating solutions was applied onto the hydrophobic polyvinylidene fluoride (PVDF) membrane. The formulation results show significant differences in alkaline conditions, revealing the role of catechol groups in the oxidation of polyphenolics. The reactions of quinone and amines to form crosslinks by Michael addition and Schiff base reactions were observed at different concentrations of each compound in coating solution. In addition, the negative charge of hydrophilic and underwater oleophobic-coated PVDF membrane was confirmed by surface zeta potential analysis. The morphological surface of modified membrane is rougher due to that coating deposition was also examined using scanning electron microscopy (SEM). Furthermore, the performance of modified membrane is comparable with the commercial hydrophilic membrane in terms of fluxes and separation efficiency of emulsion solution.
    Matched MeSH terms: Catechols
  10. Rahman AA, Makpol S, Jamal R, Harun R, Mokhtar N, Ngah WZ
    Molecules, 2014 Sep 12;19(9):14528-41.
    PMID: 25221872 DOI: 10.3390/molecules190914528
    Plant bioactives [6]-gingerol (GING), epigallocatechin gallate (EGCG) and asiaticoside (AS) and vitamin E, such as tocotrienol-rich fraction (TRF), have been reported to possess anticancer activity. In this study, we investigated the apoptotic properties of these bioactive compounds alone or in combination on glioma cancer cells. TRF, GING, EGCG and AS were tested for cytotoxicity on glioma cell lines 1321N1 (Grade II), SW1783 (Grade III) and LN18 (Grade IV) in culture by the (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxy-phenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) (MTS) assay. With the exception of AS, combinations of two compounds were tested, and the interactions of each combination were evaluated by the combination index (CI) using an isobologram. Different grades of glioma cancer cells showed different cytotoxic responses to the compounds, where in 1321N1 and LN18 cells, the combination of EGCG + GING exhibited a synergistic effect with CI = 0.77 and CI = 0.55, respectively. In contrast, all combinations tested (TRF + GING, TRF + EGCG and EGCG + GING) were found to be antagonistic on SW1783 with CI values of 1.29, 1.39 and 1.39, respectively. Combined EGCG + GING induced apoptosis in both 1321N1 and LN18 cells, as evidenced by Annexin-V FITC/PI staining and increased active caspase-3. Our current data suggests that the combination of EGCG + GING synergistically induced apoptosis and inhibits the proliferation 1321N1 and LN18 cells, but not SW1783 cells, which may be due to their different genetic profiles.
    Matched MeSH terms: Catechols/administration & dosage*
  11. Ng, A.W.R., Wong, C.W.
    MyJurnal
    Polyphenol oxidase (PPO) catalyzes the conversion of phenolic compounds into o-quinones which will lead to food browning. This phenomenon causes huge implications on food industries, as it degrades food quality over time. By combining both ammonium sulphate precipitation and gel filtration chromatography, PPO was partially purified up to 5.26-fold with 11.23% yield. The enzyme activity was 5120 EU/mL using 4-methylcatechol as substrate. Maximal PPO activity was found at 30oC, pH 5.0 for 4-methylcatechol and 40°C, pH 6.0 for catechol. The PPO showed a higher affinity towards 4-methylcatechol but higher thermal stability when reacting with catechol. The Km and Vmax values were 5.00 mM, 2000 EU/ml for 4-methylcatechol and 10.79 mM, 526.32 EU/ml for catechol. Energy for inactivation (Ea) obtained using 4-methylcatechol and catechol were 12.57 kJ/mol and 14.23 kJ/mol from respective substrates. Sodium disulfite was a better inhibitor where 79.17% of PPO inhibition was achieved. The isolation and characterization of round brinjal PPO serves as a guideline to predict the behavior of enzyme, leading to effective prevention of its browning during processing and storage.
    Matched MeSH terms: Catechols
  12. Mulyati S, Muchtar S, Arahman N, Syamsuddin Y, Mat Nawi NI, Yub Harun N, et al.
    Polymers (Basel), 2020 Sep 09;12(9).
    PMID: 32916778 DOI: 10.3390/polym12092051
    Polydopamine has been widely used as an additive to enhance membrane fouling resistance. This study reports the effects of two-step dopamine-to-polydopamine modification on the permeation, antifouling, and potential anti-UV properties of polyethersulfone (PES)-based ultrafiltration membranes. The modification was performed through a two-step mechanism: adding the dopamine additive followed by immersion into Tris-HCl solution to allow polymerization of dopamine into polydopamine (PDA). The results reveal that the step of treatment, the concentration of dopamine in the first step, and the duration of dipping in the Tris solution in the second step affect the properties of the resulting membranes. Higher dopamine loadings improve the pure water flux (PWF) by more than threefold (15 vs. 50 L/m2·h). The extended dipping period in the Tris alkaline buffer leads to an overgrowth of the PDA layer that partly covers the surface pores which lowers the PWF. The presence of dopamine or polydopamine enhances the hydrophilicity due to the enrichment of hydrophilic catechol moieties which leads to better anti-fouling. Moreover, the polydopamine film also improves the membrane resistance to UV irradiation by minimizing photodegradation's occurrence.
    Matched MeSH terms: Catechols
  13. Mojani, M.S., Ghasemzadeh, A., Rahmat, A., Loh, S.P., Ramasamy, R.
    MyJurnal
    In current work, the nutritional composition, bioactive compounds, total phenolic contents and anti-oxidant activity of young Malaysian ginger rhizome were investigated. Proximate analysis and high performance liquid chromatography (HPLC) recruited to determine nutritional composition and bioactive compounds. The total flavonoid (TF) and total phenolic contents (TPC) of ginger rhizome were determined by aluminium chloride calorimetric assay and Folin-Ciocalteau reagent, respectively. 2,2’-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method were used to measure antioxidant capacity. The rhizome contained high moisture content and low level of carbohydrate and energy. 6-gingerol was the most abundant component in the selected ginger, and total flavonoid and phenolic content were reported to be 3.66±0.45 mg gallic acid/g and 10.22±0.87 mg quercetin/g of dry weight of rhizome, respectively. The rhizome also showed lower antioxidant activity than controls, with the IC 50 value of 46.5 vs. 15.5 for α-tocopherol and 22 for BHT. The results of this study predicted that the young ginger rhizome originated from Malaysia may exhibit anti-oxidative and anti-inflammatory potentials due to high levels of gingerols, total flavonoid and phenolic compounds and antioxidant capacity.
    Matched MeSH terms: Catechols
  14. Mohd Yusof YA
    Adv Exp Med Biol, 2016;929:177-207.
    PMID: 27771925
    Since antiquity, ginger or Zingiber officinale, has been used by humans for medicinal purposes and as spice condiments to enhance flavor in cooking. Ginger contains many phenolic compounds such as gingerol, shogaol and paradol that exhibit antioxidant, anti-tumor and anti-inflammatory properties. The role of ginger and its constituents in ameliorating diseases has been the focus of study in the past two decades by many researchers who provide strong scientific evidence of its health benefit. This review discusses research findings and works devoted to gingerols, the major pungent constituent of ginger, in modulating and targeting signaling pathways with subsequent changes that ameliorate, reverse or prevent chronic diseases in human studies and animal models. The physical, chemical and biological properties of gingerols are also described. The use of ginger and especially gingerols as medicinal food derivative appears to be safe in treating or preventing chronic diseases which will benefit the common population, clinicians, patients, researchers, students and industrialists.
    Matched MeSH terms: Catechols/isolation & purification; Catechols/therapeutic use*; Catechols/chemistry
  15. Mohd Sahardi NFN, Jaafar F, Mad Nordin MF, Makpol S
    PMID: 32419792 DOI: 10.1155/2020/1787342
    Background: Ageing resulted in a progressive loss of muscle mass and strength. Increased oxidative stress in ageing affects the capacity of the myoblast to differentiate leading to impairment of muscle regeneration. Zingiber officinale Roscoe (ginger) has potential benefits in reversing muscle ageing due to its antioxidant property. This study aimed to determine the effect of ginger in the prevention of cellular senescence and promotion of muscle regeneration.

    Methods: Myoblast cells were cultured into young and senescent state before treated with different concentrations of ginger standardised extracts containing different concentrations of 6-gingerol and 6-shogaol. Analysis on cellular morphology and myogenic purity was carried out besides determination of SA-β-galactosidase expression and cell cycle profile. Myoblast differentiation was quantitated by determining the fusion index, maturation index, and myotube size.

    Results: Treatment with ginger extracts resulted in improvement of cellular morphology of senescent myoblasts which resembled the morphology of young myoblasts. Our results also showed that ginger treatment caused a significant reduction in SA-β-galactosidase expression on senescent myoblasts indicating prevention of cellular senescence, while cell cycle analysis showed a significant increase in the percentage of cells in the G0/G1 phase and reduction in the S-phase cells. Increased myoblast regenerative capacity was observed as shown by the increased number of nuclei per myotube, fusion index, and maturation index.

    Conclusions: Ginger extracts exerted their potency in promoting muscle regeneration as indicated by prevention of cellular senescence and promotion of myoblast regenerative capacity.

    Matched MeSH terms: Catechols
  16. Mohd Sahardi NFN, Makpol S
    PMID: 31531114 DOI: 10.1155/2019/5054395
    Currently, the age of the population is increasing as a result of increased life expectancy. Ageing is defined as the progressive loss of physiological integrity, which can be characterized by functional impairment and high vulnerability to various types of diseases, such as diabetes, hypertension, Alzheimer's disease (AD), Parkinson's disease (PD), and atherosclerosis. Numerous studies have reported that the presence of oxidative stress and inflammation contributes to the development of these diseases. In general, oxidative stress could induce proinflammatory cytokines and reduce cellular antioxidant capacity. Increased oxidative stress levels beyond the production of antioxidant agents cause oxidative damage to biological molecules, including DNA, protein, and carbohydrates, which affects normal cell signalling, cell growth, differentiation, and apoptosis and leads to disease pathogenesis. Since oxidative stress and inflammation contribute to these diseases, ginger (Zingiber officinale Roscoe) is one of the potential herbs that can be used to reduce the level of oxidative stress and inflammation. Ginger consists of two major active components, 6-gingerol and 6-shogaol, which are essential for preventing oxidative stress and inflammation. Thus, this paper will review the effects of ginger on ageing and degenerative diseases, including AD, PD, type 2 diabetes mellitus (DM), hypertension, and osteoarthritis.
    Matched MeSH terms: Catechols
  17. Mathew S, Zakaria ZA
    Appl Microbiol Biotechnol, 2015 Jan;99(2):611-22.
    PMID: 25467926 DOI: 10.1007/s00253-014-6242-1
    Pyroligneous acid (PA) is a complex highly oxygenated aqueous liquid fraction obtained by the condensation of pyrolysis vapors, which result from the thermochemical breakdown or pyrolysis of plant biomass components such as cellulose, hemicellulose, and lignin. PA produced by the slow pyrolysis of plant biomass is a yellowish brown or dark brown liquid with acidic pH and usually comprises a complex mixture of guaiacols, catechols, syringols, phenols, vanillins, furans, pyrans, carboxaldehydes, hydroxyketones, sugars, alkyl aryl ethers, nitrogenated derivatives, alcohols, acetic acid, and other carboxylic acids. The phenolic components, namely guaiacol, alkyl guaiacols, syringol, and alkyl syringols, contribute to the smoky odor of PA. PA finds application in diverse areas, as antioxidant, antimicrobial, antiinflammatory, plant growth stimulator, coagulant for natural rubber, and termiticidal and pesticidal agent; is a source for valuable chemicals; and imparts a smoky flavor for food.
    Matched MeSH terms: Catechols/chemistry
  18. Manoj D, Gnanasekaran L, Rajendran S, Jalil AA, Siddiqui MN, Gracia F, et al.
    Environ Res, 2023 Apr 01;222:115358.
    PMID: 36702188 DOI: 10.1016/j.envres.2023.115358
    The subject of water contamination and how it gets defiled to the society and humans is confabulating from the past decades. Phenolic compounds widely exist in the water sources and it is emergent to determine the toxicity in natural and drinking water, because it is hazardous to the humans. Among these compounds, catechol has sought a strong concern because of its rapid occurrence in nature and its potential toxicity to humans. The present work aims to develop an effective electrochemical sensing of catechol using mesoporous structure of Fe3O4-TiO2 decorated on glassy carbon (GC) electrode. The creation of pure TiO2 using the sol-gel technique was the first step in the synthesis protocol for binary nanocomposite, which was then followed by the loading of Fe3O4 nanoparticles on the surface of TiO2 using the thermal decomposition method. The resultant Fe3O4-TiO2 based nanocomposite exhibited mesoporous structure and the cavities were occupied with highly active magnetite nanoparticles (Fe3O4) with high specific surface area (90.63 m2/g). When compared to pure TiO2, catechol showed a more prominent electrochemical response for Fe3O4-TiO2, with a significant increase in anodic peak current at a lower oxidation potential (0.387 V) with a detection limit of 45 μM. Therefore, the prepared magnetite binary nanocomposite can serve as an efficient electroactive material for sensing of catechol, which could also act as a promising electrocatalyst for various electrocatalytic applications.
    Matched MeSH terms: Catechols
  19. Lin H, Ng AWR, Wong CW
    Food Sci Biotechnol, 2016;25(Suppl 1):91-96.
    PMID: 30263491 DOI: 10.1007/s10068-016-0103-x
    Purification and characterization of polyphenol oxidase (PPO) from Chinese parsley (Coriandrum sativum) were achieved. Crude PPO exhibited an enzyme activity of 1,952.24 EU/mL. PPO was partially purified up to 6.52x with a 10.89% yield using gel filtration chromatography. Maximal PPO activity was found at 35°C, pH 8.0 for 4-methylcatechol and at 40°C, pH 7.0 for catechol. PPO showed a higher affinity towards 4-methylcatechol, but a higher thermal stability when reacting with catechol. LCysteine was a better inhibitor than citric acid for reducing PPO activity at concentrations of 1 and 3mM in the presence of either substrate. Two 46 kDa isoenzymes were identified using SDS-PAGE. Isolation and characterization of Chinese parsley serves as a guideline for prediction of enzyme behavior leading to effective prevention of enzymatic browning during processing and storage, including inhibition and inactivation of PPO.
    Matched MeSH terms: Catechols
  20. Lim YY, Liew LP
    J Colloid Interface Sci, 2002 Nov 15;255(2):425-7.
    PMID: 12505092
    The rate of autooxidation of 3,5-di-tert-butylcatechol (3,5-DTBC) in the presence of micelles formed from mixing equal concentrations of [Cu(C(12)-tmed)Br(2)] (where C(12)-tmed is N,N,N'-trimethyl-N'-dodecylethylenediamine) and several amino acids has been investigated. It was found that the rate in air-saturated solution is very much dependent on pH, which affects the availability of copper(II) coordination site for the catechol and the degree of micellization. At a given pH, the rates in [Cu(C(12)-tmed)Br(2)] micellar media are greatly enhanced in the presence sodium halide.
    Matched MeSH terms: Catechols/chemistry*
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