Displaying publications 61 - 80 of 127 in total

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  1. Fulltext Tropical plant extracts as potential antihyperglycemic agents
    Manaharan T, Palanisamy UD, Ming CH
    Molecules, 2012;17(5):5915-23.
    PMID: 22609782 DOI: 10.3390/molecules17055915
    Preliminary investigations on 14 plant extracts (obtained by ethanolic and aqueous extraction) identified those having high antioxidant and a significant total phenolic content. Antihyperglycemic, α-amylase and α-glucosidase inhibition activities were also observed. A correlation between the antihyperglycemic activity, total phenolic content and antioxidant (DPPH scavenging) activity was established. To further substantiate these findings, the possibility of tannins binding non-specifically to enzymes and thus contributing to the antihyperglycemic activity was also investigated. Our study clearly indicated that the antihyperglycemic activity observed in the plant extracts was indeed not due to non-specific tannin absorption.
    Matched MeSH terms: Phenols/chemistry
  2. Pyroligneous acid-the smoky acidic liquid from plant biomass
    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: Phenols/chemistry
  3. Fulltext Antioxidant, antityrosinase, anticholinesterase, and nitric oxide inhibition activities of three malaysian macaranga species
    Mazlan NA, Mediani A, Abas F, Ahmad S, Shaari K, Khamis S, et al.
    ScientificWorldJournal, 2013;2013:312741.
    PMID: 24319356 DOI: 10.1155/2013/312741
    The methanol extracts of three Macaranga species (M. denticulata, M. pruinosa, and M. gigantea) were screened to evaluate their total phenolic contents and activities as cholinesterase inhibitors, nitric oxide (NO) production inhibitors, tyrosinase inhibitors, and antioxidants. The bark of M. denticulata showed the highest total phenolic content (2682 mg gallic acid equivalent (GAE)/100 g) and free radical scavenging activity (IC50 = 0.063 mg/mL). All of the samples inhibited linoleic acid peroxidation by greater than 80%, with the leaves of M. gigantea exhibiting the highest inhibition of 92.21%. Most of the samples exhibited significant antioxidant potential. The bark of M. denticulata and the leaves of both M. pruinosa and M. gigantea exhibited greater than 50% tyrosinase inhibition, with the bark of M. denticulata having the highest percentage of inhibition (68.7%). The bark and leaves of M. denticulata exhibited greater than 50% inhibition (73.82% and 54.50%, resp.) of the acetylcholinesterase enzyme (AChE), while none of the samples showed any significant inhibition of butyrylcholinesterase (BChE). Only the bark of M. denticulata and M. gigantea displayed greater than 50% inhibition of nitric oxide production in cells (81.79% and 56.51%, resp.). These bioactivities indicate that some Macaranga spp. have therapeutic potential in medicinal research.
    Matched MeSH terms: Phenols/chemistry
  4. 2D Graphene oxide (GO) doped p-n type BiOI/Bi2WO6 as a novel composite for photodegradation of bisphenol A (BPA) in aqueous solutions under UV-vis irradiation
    Mengting Z, Kurniawan TA, Yanping Y, Avtar R, Othman MHD
    Mater Sci Eng C Mater Biol Appl, 2020 Mar;108:110420.
    PMID: 31924000 DOI: 10.1016/j.msec.2019.110420
    Bisphenol A (BPA) is a refractory pollutant presents in water body that possesses serious threats to living organisms. To deal with it, we investigate and evaluate the effectiveness of GO@BiOI/Bi2WO6 composite as a novel photocatalyst for BPA removal from aqueous solutions under UV-vis irradiation. To enhance its removal for BPA, the surface of BiOI/Bi2WO6 is modified with graphene oxide (GO). This composite is named as 'GO@BiOI/Bi2WO6'. Changes in its physico-chemical properties after surface modification with GO are characterized by XRD, FTIR, FESEM-EDS, XPS, PL, and BET methods. Optimized conditions of BPA degradation by the composite are determined under identical conditions. Photodegradation pathways of BPA and its removal mechanisms by the same composite are presented. It is obvious that the GO@BiOI/Bi2WO6 has demonstrated its potential as a promising photocatalyst for BPA removal under UV-vis irradiation. About 81% of BPA removal is attained by the GO@BiOI/Bi2WO6 under optimized conditions (10 mg/L of BPA, 0.5 g/L of dose, pH 7 and 5 h of reaction time). The oxidation by-products of BPA degradation include p-hydroquinone or 4-(1-hydroxy-1-methyl-ethyl)-phenol. In spite of its performance, the treated effluents are still unable to meet the maximum discharge limit of <1 mg/L set by national legislation. Therefore, subsequent biological processes are essential to maximize its biodegradation in the wastewater samples before their discharge into waterbody.
    Matched MeSH terms: Phenols/chemistry*
  5. Fulltext The Antioxidant and Xanthine Oxidase Inhibitory Activity of Plumeria rubra Flowers
    Mohamed Isa SSP, Ablat A, Mohamad J
    Molecules, 2018 Feb 13;23(2).
    PMID: 29438299 DOI: 10.3390/molecules23020400
    Plumeria rubra Linn of the family Apocynaceae is locally known in Malaysia as "Kemboja". It has been used by local traditional medicine practitioners for the treatment of arthritis-related disease. The LCMS/MS analysis of the methanol extract of flowers (PR-ME) showed that it contains 3-O-caffeyolquinic acid, 5-caffeoquinic acid, 1,3-dicaffeoquinic acid, chlorogenic acid, citric acid, 3,3-di-O-methylellagic acid, kaempferol-3-O-glucoside, kaempferol-3-rutinoside, kaempferol, quercetin 3-O-α-l-arabinopyranoside, quercetin, quinic acid and rutin. The flower PR-ME contained high amounts of phenol and flavonoid at 184.632 mg GAE/g and 203.2.2 mg QE/g, respectively. It also exhibited the highest DPPH, FRAP, metal chelating, hydrogen peroxide, nitric oxide superoxide radical scavenging activity. Similarly, the XO inhibitory activity in vitro assay possesses the highest inhibition effects at an IC50 = 23.91 μg/mL. There was no mortality or signs of toxicity in rats at a dose of 4 g/kg body weight. The administration of the flower PR-ME at doses of 400 mg/kg to the rats significantly reduced serum uric acid 43.77%. Similarly, the XO activity in the liver was significantly inhibited by flower PR-ME at doses of 400 mg/kg. These results confirm that the flower PR-ME of P. rubra contains active phytochemical compounds as detected in LCMS/MS that contribute to the inhibition of XO activity in vitro and in vivo in reducing acid uric level in serum and simultaneously scavenging the free radical to reduce the oxidative stress.
    Matched MeSH terms: Phenols/chemistry
  6. Studies on the antioxidant properties of Tualang honey of Malaysia
    Mohamed M, Sirajudeen K, Swamy M, Yaacob NS, Sulaiman SA
    Afr J Tradit Complement Altern Med, 2009 Oct 15;7(1):59-63.
    PMID: 21304614
    Honey has been used since ancient times for its nutritional as well as curative properties. Tualang honey is collected from wild honey bees' hives on Tualang trees found in the Malaysian rain forest. It has been used traditionally for the treatment of various diseases, where its therapeutic value has partly been related to its antioxidant properties. This study therefore assessed the colour intensity, total phenolic content, antioxidant activity and antiradical activity of gamma irradiated Tualang Honey. The colour intensity at ABS₄₅₀ was 489.5 ± 1.7 mAU, total phenolic content was 251.7 ± 7.9 mg (gallic acid) /Kg honey, total antioxidant activity by FRAP assay was 322.1 ± 9.7 (µM Fe(II)) and the antiradical activity by DPPH assay was 41.30 ± 0.78 (% inhibition). The data confirms that the antioxidant properties of gamma irradiated Tualang honey are similar to other types of honeys reported in the literature.
    Matched MeSH terms: Phenols/chemistry
  7. Fulltext Development of Phaleria macrocarpa (Scheff.) Boerl Fruits Using Response Surface Methodology Focused on Phenolics, Flavonoids and Antioxidant Properties
    Mohamed Mahzir KA, Abd Gani SS, Hasanah Zaidan U, Halmi MIE
    Molecules, 2018 Mar 22;23(4).
    PMID: 29565312 DOI: 10.3390/molecules23040724
    In this study, the optimal conditions for the extraction of antioxidants from the Buah Mahkota Dewa fruit (Phaleria macrocarpa) was determined by using Response Surface Methodology (RSM). The optimisation was applied using a Central Composite Design (CCD) to investigate the effect of three independent variables, namely extraction temperature (°C), extraction time (minutes) and extraction solvent to-feed ratio (% v/v) on four responses: free radical scavenging activity (DPPH), ferric ion reducing power assay (FRAP), total phenolic content (TPC) and total flavonoid content (TFC). The optimal conditions for the antioxidants extraction were found to be 64 °C extraction temperature, 66 min extraction time and 75% v/v solvent to-feed ratio giving the highest percentage yields of DPPH, FRAP, TPC and TFC of 86.85%, 7.47%, 292.86 mg/g and 3.22 mg/g, respectively. Moreover, the data were subjected to Response Surface Methodology (RSM) and the results showed that the polynomial equations for all models were significant, did not show lack of fit, and presented adjusted determination coefficients (R²) above 99%, proving that the yield of phenolic, flavonoid and antioxidants activities obtained experimentally were close to the predicted values and the suitability of the model employed in RSM to optimise the extraction conditions. Hence, in this study, the fruit from P. macrocarpa could be considered to have strong antioxidant ability and can be used in various cosmeceutical or medicinal applications.
    Matched MeSH terms: Phenols/chemistry*
  8. Fulltext Synthesis of new liquid crystalline diglycidyl ethers
    Mohammed IA, Hamidi RM
    Molecules, 2012 Jan 10;17(1):645-56.
    PMID: 22233565 DOI: 10.3390/molecules17010645
    The phenolic Schiff bases I-VI were synthesized by condensation reactions between various diamines, namely o-dianisidine, o-tolidine and ethylenediamine with vanillin or p-hydroxybenzaldehyde and subsequent reactions between these phenolic Schiff bases and epichlorohydrin to produce new diglycidyl ethers Ia-VIa. The structures of these compounds were confirmed by CHN, FT-IR, (1)H-NMR, and (13)C-NMR spectroscopy. Their thermotropic liquid crystalline behavior was studied using differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). All the diglycidyl ethers prepared exhibit nematic mesophases, except for Va and VIa, which did not show any transition mesophases, but simply flow to liquids.
    Matched MeSH terms: Phenols/chemistry
  9. Batch adsorption of phenol onto physiochemical-activated coconut shell
    Mohd Din AT, Hameed BH, Ahmad AL
    J Hazard Mater, 2009 Jan 30;161(2-3):1522-9.
    PMID: 18562090 DOI: 10.1016/j.jhazmat.2008.05.009
    The liquid-phase adsorption of phenol onto coconut shell-based activated carbon, CS850A was investigated for its equilibrium studies and kinetic modeling. Coconut shell was converted into high quality activated carbon through physiochemical activation at 850 degrees C under the influence of CO(2) flow. Beforehand, the coconut shell was carbonized at 700 degrees C and the resulted char was impregnated with KOH at 1:1 weight ratio. In order to evaluate the performance of CS850A, a series of batch adsorption experiments were conducted with initial phenol concentrations ranging from 100 to 500 mg l(-1), adsorbent loading of 0.2g and the adsorption process was maintained at 30+/-1 degrees C. The adsorption isotherms were in conformation to both Langmuir and Freundlich isotherm models. Chemical reaction was found to be a rate-controlling parameter to this phenol-CS850A batch adsorption system due to strong agreement with the pseudo-second-order kinetic model. Adsorption capacity for CS850A was found to be 205.8 mg g(-1).
    Matched MeSH terms: Phenols/chemistry
  10. Functional polysaccharides of fucoidan, laminaran and alginate from Malaysian brown seaweeds (Sargassum polycystum, Turbinaria ornata and Padina boryana)
    Mohd Fauziee NA, Chang LS, Wan Mustapha WA, Md Nor AR, Lim SJ
    Int J Biol Macromol, 2021 Jan 15;167:1135-1145.
    PMID: 33188815 DOI: 10.1016/j.ijbiomac.2020.11.067
    Brown seaweeds are rich source of functional polysaccharides that exhibit various bioactivities. However, Malaysian seaweeds are under-utilised, leading to low revenue throughout the supply chain of the seaweed industry. The aims of this study were to extract the functional polysaccharides, namely fucoidan (F), laminaran (L) and alginate (A) from Malaysian brown seaweeds (Sargassum polycystum, Turbinaria ornata and Padina boryana) and subsequently evaluate the properties of the extracted polysaccharides. P. boryana recorded the significantly (p ≤ 0.05) highest carbohydrate content (74.78 ± 1.63%) with highest fucoidan yield (Fpad = 1.59 ± 0.16%) while T. ornata contained significantly (p ≤ 0.05) highest alginate yield (Atur = 105.19 ± 3.45%). Water activities of these extracted polysaccharides varied from 0.63-0.71 with average score of browning indexes (~40). Fourier transform infrared (FTIR) spectroscopy analysis demonstrated that the extracted polysaccharides exhibited similar spectral pattern of spectra with the respective standards. Meanwhile, laminaran extracts showed the significantly highest (p ≤ 0.05) total phenolic contents (Lsar = 43.29 ± 0.43 mgGAE/g) and superoxide anion scavenging activity (Lsig = 21.7 ± 3.6%). On the other hand, the significantly highest (p ≤ 0.05) DPPH scavenging activity was recorded in alginate with Asar at 85.3 ± 0.8%. These findings reported the properties and bioactivities of natural polysaccharides from Malaysian brown seaweeds that revealed the potential to develop high-value functional ingredients from Malaysian brown seaweeds.
    Matched MeSH terms: Phenols/chemistry
  11. Fulltext Apoptosis Induction by Polygonum minus is related to antioxidant capacity, alterations in expression of apoptotic-related genes, and S-phase cell cycle arrest in HepG2 cell line
    Mohd Ghazali MA, Al-Naqeb G, Krishnan Selvarajan K, Hazizul Hasan M, Adam A
    Biomed Res Int, 2014;2014:539607.
    PMID: 24955361 DOI: 10.1155/2014/539607
    Polygonum minus (Polygonaceae) is a medicinal herb distributed throughout eastern Asia. The present study investigated antiproliferative effect of P. minus and its possible mechanisms. Four extracts (petroleum ether, methanol, ethyl acetate, and water) were prepared by cold maceration. Extracts were subjected to phytochemical screening, antioxidant, and antiproliferative assays; the most bioactive was fractionated using vacuum liquid chromatography into seven fractions (F1-F7). Antioxidant activity was measured via total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) assays. Antiproliferative activity was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Most active fraction was tested for apoptosis induction and cell cycle arrest in HepG2 cells using flow cytometry and confocal microscopy. Apoptotic-related gene expression was studied by RT-PCR. Ethyl acetate extract was bioactive in initial assays. Its fraction, F7, exhibited highest antioxidant capacity (TPC; 113.16 ± 6.2 mg GAE/g extract, DPPH; EC50: 30.5 ± 3.2 μg/mL, FRAP; 1169 ± 20.3 μmol Fe (II)/mg extract) and selective antiproliferative effect (IC50: 25.75 ± 1.5 μg/mL). F7 induced apoptosis in concentration- and time-dependent manner and caused cell cycle arrest at S-phase. Upregulation of proapoptotic genes (Bax, p53, and caspase-3) and downregulation of antiapoptotic gene, Bcl-2, were observed. In conclusion, F7 was antiproliferative to HepG2 cells by inducing apoptosis, cell cycle arrest, and via antioxidative effects.
    Matched MeSH terms: Phenols/chemistry
  12. Powdered ZELIAC augmented sequencing batch reactors (SBR) process for co-treatment of landfill leachate and domestic wastewater
    Mojiri A, Aziz HA, Zaman NQ, Aziz SQ, Zahed MA
    J Environ Manage, 2014 Jun 15;139:1-14.
    PMID: 24662109 DOI: 10.1016/j.jenvman.2014.02.017
    Sequencing batch reactor (SBR) is one of the various methods of biological treatments used for treating wastewater and landfill leachate. This study investigated the treatment of landfill leachate and domestic wastewater by adding a new adsorbent (powdered ZELIAC; PZ) to the SBR technique. ZELIAC consists of zeolite, activated carbon, lime stone, rice husk ash, and Portland cement. The response surface methodology and central composite design were used to elucidate the nature of the response surface in the experimental design and describe the optimum conditions of the independent variables, including aeration rate (L/min), contact time (h), and ratio of leachate to wastewater mixture (%; v/v), as well as their responses (dependent variables). Appropriate conditions of operating variables were also optimized to predict the best value of responses. To perform an adequate analysis of the aerobic process, four dependent parameters, namely, chemical oxygen demand (COD), color, ammonia-nitrogen (NH3-N), and phenols, were measured as responses. The results indicated that the PZ-SBR showed higher performance in removing certain pollutants compared with SBR. Given the optimal conditions of aeration rate (1.74 L/min), leachate to wastewater ratio (20%), and contact time (10.31 h) for the PZ-SBR, the removal efficiencies for color, NH3-N, COD, and phenols were 84.11%, 99.01%, 72.84%, and 61.32%, respectively.
    Matched MeSH terms: Phenols/chemistry
  13. Fulltext Two-year variations of phenolics, flavonoids and antioxidant contents in acacia honey
    Moniruzzaman M, Sulaiman SA, Azlan SA, Gan SH
    Molecules, 2013;18(12):14694-710.
    PMID: 24287998 DOI: 10.3390/molecules181214694
    Honey is a good source of several important chemical compounds and antioxidants and is harvested throughout the year. However, no study has determined how their contents change over the years. The aim of the present research was to investigate the changes in the phenolics, flavonoids and antioxidant properties, as well as other physicochemical properties, of Malaysian acacia honey collected during different months during a two year period. The DPPH (1,1-diphenyl-2-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) methods were used to determine the total antioxidant activity of the honey samples. Generally, honey samples collected in the beginning and the middle of the year tended to have higher sugar content, which may be attributed to its high acidic nature and low moisture content. There was a gradual increase in the phenolic content of the acacia honey samples collected between September 2010 and December 2010. The honey sample collected at the beginning of the year (January) showed the highest color intensity and was dark amber in color. It also contained the highest concentration of phenolic compounds (341.67 ± 2.94 mg(gallic acid)/kg), the highest flavonoid content (113.06 ± 6.18 mg(catechin)/kg) and the highest percentage of DPPH inhibition and the highest FRAP value, confirming its high antioxidant potential. There was a positive correlation between DPPH and total phenolic content, suggesting that phenolic compounds are the strongest contributing factor to the radical scavenging activity of Malaysian acacia honeys. Overall, our results indicated that there were significant seasonal variations in the antioxidant potentials of honey over the two year period and the time of honey collection affects its physicochemical properties. Therefore, acacia honey from Malaysia should ideally be collected during the dry season, particularly in the months of January, May and June.
    Matched MeSH terms: Phenols/chemistry*
  14. Fulltext Secondary Metabolites Profiling of Acinetobacter baumannii Associated with Chili (Capsicum annuum L.) Leaves and Concentration Dependent Antioxidant and Prooxidant Properties
    Monowar T, Rahman MS, Bhore SJ, Raju G, Sathasivam KV
    Biomed Res Int, 2019;2019:6951927.
    PMID: 30868071 DOI: 10.1155/2019/6951927
    Secondary bioactive compounds of endophytes are inevitable biomolecules of therapeutical importance. In the present study, secondary metabolites profiling of an endophytic bacterial strain, Acinetobacter baumannii, were explored using GC-MS study. Presence of antioxidant substances and antioxidant properties in chloroform (CHL), diethyl ether (DEE), and ethyl acetate (EA) crude extracts of the endophytic bacteria were studied. Total phenolic content (TPC), total flavonoid content (TFC), total antioxidant capacity (TAC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and ferrous ion chelating assay were evaluated. A total of 74 compounds were identified from the GC-MS analysis of the EA extract representing mostly alkane compounds followed by phenols, carboxylic acids, aromatic heterocyclic compounds, ketones, aromatic esters, aromatic benzenes, and alkenes. Among the two phenolic compounds, namely, phenol, 2,4-bis(1,1-dimethylethyl)- and phenol, 3,5-bis(1,1-dimethylethyl)-, the former was found in abundance (11.56%) while the latter was found in smaller quantity (0.14%). Moreover, the endophytic bacteria was found to possess a number of metal ions including Fe(II) and Cu(II) as 1307.13 ± 2.35 ppb and 42.38 ± 0.352 ppb, respectively. The extracts exhibited concentration dependent antioxidant and prooxidant properties at high and low concentrations, respectively. The presence of phenolic compounds and metal ions was believed to play an important role in the antioxidant and prooxidant potentials of the extracts. Further studies are suggested for exploring the untapped resource of endophytic bacteria for the development of novel therapeutic agents.
    Matched MeSH terms: Phenols/chemistry
  15. Removal of bisphenol A by adsorption mechanism using PES-SiO2 composite membranes
    Muhamad MS, Salim MR, Lau WJ, Hadibarata T, Yusop Z
    Environ Technol, 2016 Aug;37(15):1959-69.
    PMID: 26729509 DOI: 10.1080/09593330.2015.1137359
    Polyethersulphone (PES) membranes blended with silicon dioxide (SiO2) nanoparticles were prepared via a dry-jet wet spinning technique for the removal of bisphenol A (BPA) by adsorption mechanism. The morphology of SiO2 nanoparticles was analysed using a transmission electron microscopy and particle size distribution was also analysed. The prepared membranes were characterized by several techniques including field emission scanning electron microscopy, Fourier transform infrared spectroscopy and water contact angle. The adsorption mechanism of membrane towards BPA was evaluated by batch experiments and kinetic model. The influence of natural organic matter (NOM) in feed water on membrane BPA removal was also studied by filtration experiments. Results showed that BPA adsorption capacity as high as 53 µg/g could be achieved by the PES membrane incorporated with 2 wt% SiO2 in which the adsorption mechanism was in accordance with the pseudo-second-order kinetic model. The intraparticles diffusion model suggested that the rate limiting factor of membrane adsorption mechanism is governed by the diffusion of BPA into the membrane pores. The presence of 10 ppm NOM has reported to negatively reduce BPA removal by 24%, as it tended to compete with BPA for membrane adsorption. This work has demonstrated that PES-SiO2 membrane has the potential to eliminate trace amount of BPA from water source containing NOM.
    Matched MeSH terms: Phenols/chemistry
  16. Identification of Novel Sesamol Dimers with Unusual Methylenedioxy Ring-Opening Skeleton and Evaluation of Their Antioxidant and Cytotoxic Activities
    Murthy S, Hazli UHAM, Kong KW, Mai CW, Leong CO, Rahman NA, et al.
    Curr Org Synth, 2019;16(8):1166-1173.
    PMID: 31984923 DOI: 10.2174/1570179416666191003095253
    BACKGROUND: Sesamol is a widely used antioxidant for the food and pharmaceutical industries. The oxidation products of this compound may be accumulated in foods or ingested. Little is known about its effect on human health.

    OBJECTIVE: It is of great interest to identify the oxidation products of sesamol that may be beneficial to humans. This study was undertaken to identify the oxidation products of sesamol and investigate their antioxidant and cytotoxic activities.

    MATERIALS AND METHODS: Using the ferricyanide oxidation approach, four oxidation products of sesamol (2, 3, 20 & 21) have been identified. Structural elucidation of these compounds was established on the basis of their detailed NMR spectroscopic analysis, mass spectrometry and x-ray crystallography. Additionally, a formation mechanism of compound 20 was proposed based on high-resolution mass spectrometry-fragmentation method. The antioxidant activities of these compounds were determined by the DPPH, FRAP, and ABTS assays. The in vitro antiproliferative activity of these compounds was evaluated against a panel of human cancer cell lines as well as non-cancerous cells.

    RESULTS: Two oxidation products of sesamol were found to contain an unusual methylenedioxy ring-opening skeleton, as evidenced by spectroscopic and x-ray crystallographic data. Among all compounds, 20 displayed impressive antiproliferative activities against a panel of human cancer cell lines yet remained non-toxic to noncancerous cells. The antioxidant activities of compound 20 are significantly weaker than sesamol as determined by the DPPH, FRAP, and ABTS assays.

    CONCLUSION: The oxidation products of sesamol could be a valuable source of bioactive molecules. Compound 20 may be used as a potential lead molecule for cancer studies.

    Matched MeSH terms: Phenols/chemistry*
  17. Integral cross sections for electron impact excitation of vibrational and electronic states in phenol
    Neves RF, Jones DB, Lopes MC, Blanco F, García G, Ratnavelu K, et al.
    J Chem Phys, 2015 May 21;142(19):194305.
    PMID: 26001459 DOI: 10.1063/1.4921313
    We report on measurements of integral cross sections (ICSs) for electron impact excitation of a series of composite vibrational modes and electronic-states in phenol, where the energy range of those experiments was 15-250 eV. There are currently no other results against which we can directly compare those measured data. We also report results from our independent atom model with screened additivity rule correction computations, namely, for the inelastic ICS (all discrete electronic states and neutral dissociation) and the total ionisation ICS. In addition, for the relevant dipole-allowed excited electronic states, we also report f-scaled Born-level and energy-corrected and f-scaled Born-level (BEf-scaled) ICS. Where possible, our measured and calculated ICSs are compared against one another with the general level of accord between them being satisfactory to within the measurement uncertainties.
    Matched MeSH terms: Phenols/chemistry*
  18. Fulltext Botanical Origin Differentiation of Malaysian Stingless Bee Honey Produced by Heterotrigona itama and Geniotrigona thoracica Using Chemometrics
    Ng WJ, Sit NW, Ooi PA, Ee KY, Lim TM
    Molecules, 2021 Dec 16;26(24).
    PMID: 34946710 DOI: 10.3390/molecules26247628
    Stingless bee honey, specifically honeydew honey, is generally valued for its better health benefits than those of most blossom types. However, scientific studies about the differentiation of stingless bee honey based on honeydew and blossom origins are very limited. In this study, 13C NMR spectroscopy was employed to quantify the seven major sugar tautomers in stingless bee honey samples, and the major sugar compositions of both honeydew and blossom types were found not significantly different. However, several physicochemical properties of honeydew honey including moisture content, free acidity, electrical conductivity, ash content, acetic acid, diastase, hydrogen peroxide, and mineral elements levels were significantly higher; while total soluble solid, proline, and hydroxymethylfurfural were significantly lower than blossom honey. Greater antioxidant capacity in honeydew honey was proven with higher total phenolic compounds, ABTS, DPPH, superoxide radical scavenging activities, peroxyl radical inhibition, iron chelation, and ferric reducing power. Using principal component analysis (PCA), two clusters of stingless bee honey from the honeydew and blossom origin were observed. PCA also revealed that the differentiation between honeydew and blossom origin of stingless bee honey is possible with certain physicochemical and antioxidant parameters. The combination of NMR spectroscopy and chemometrics are suggested to be useful to determine the authenticity and botanical origin of stingless bee honey.
    Matched MeSH terms: Phenols/chemistry*
  19. Fulltext Phenolics, flavonoids, antioxidant activity and cyanogenic glycosides of organic and mineral-base fertilized cassava tubers
    Omar NF, Hassan SA, Yusoff UK, Abdullah NA, Wahab PE, Sinniah U
    Molecules, 2012;17(3):2378-87.
    PMID: 22370524 DOI: 10.3390/molecules17032378
    A field study was conducted to determine the effect of organic and mineral-based fertilizers on phytochemical contents in the tubers of two cassava varieties. Treatments were arranged in a split plot design with three replicates. The main plot was fertilizer source (vermicompost, empty fruit bunch compost and inorganic fertilizer) and sub-plot was cassava variety (Medan and Sri Pontian). The amount of fertilizer applied was based on 180 kg K(2)O ha-1. The tubers were harvested and analyzed for total flavonoids, total phenolics, antioxidant activity and cyanogenic glucoside content. Total phenolic and flavonoid compounds were determined using the Folin-Ciocalteu assay and aluminium chloride colorimetric method, respectively. Different sources of fertilizer, varieties and their interactions were found to have a significant effect on phytochemical content. The phenolic and flavonoid content were significantly higher (p < 0.01) in the vermicompost treatment compared to mineral fertilizer and EFB compost. The total flavonoids and phenolics content of vermicompost treated plants were 39% and 38% higher, respectively, than those chemically fertilized. The antioxidant activity determined using the DPPH and FRAP assays were high with application of organic fertilizer. Cyanogenic glycoside levels were decreased with the application of organic fertilizer. Among the two types of compost, vermicompost resulted in higher nutritional value of cassava tubers. Medan variety with application of vermicompost showed the most promising nutritional quality. Since the nutritional quality of cassava can be improved by organic fertilization, organic fertilizer should be used in place of chemical fertilizer for environmentally sustainable production of better quality cassava.
    Matched MeSH terms: Phenols/chemistry
  20. Fulltext Bioprospecting the Curculigoside-Cinnamic Acid-Rich Fraction from Molineria latifolia Rhizome as a Potential Antioxidant Therapeutic Agent
    Ooi DJ, Chan KW, Sarega N, Alitheen NB, Ithnin H, Ismail M
    Molecules, 2016 Jun 17;21(6).
    PMID: 27322226 DOI: 10.3390/molecules21060682
    Increasing evidence from both experimental and clinical studies depicts the involvement of oxidative stress in the pathogenesis of various diseases. Specifically, disruption of homeostatic redox balance in accumulated body fat mass leads to obesity-associated metabolic syndrome. Strategies for the restoration of redox balance, potentially by exploring potent plant bioactives, have thus become the focus of therapeutic intervention. The present study aimed to bioprospect the potential use of the curculigoside-cinnamic acid-rich fraction from Molineria latifolia rhizome as an antioxidant therapeutic agent. The ethyl acetate fraction (EAF) isolated from M. latifolia rhizome methanolic extract (RME) contained the highest amount of phenolic compounds, particularly curculigoside and cinnamic acid. EAF demonstrated glycation inhibitory activities in both glucose- and fructose-mediated glycation models. In addition, in vitro chemical-based and cellular-based antioxidant assays showed that EAF exhibited high antioxidant activities and a protective effect against oxidative damage in 3T3-L1 preadipocytes. Although the efficacies of individual phenolics differed depending on the structure and concentration, a correlational study revealed strong correlations between total phenolic contents and antioxidant capacities. The results concluded that enriched phenolic contents in EAF (curculigoside-cinnamic acid-rich fraction) contributed to the overall better reactivity. Our data suggest that this bioactive-rich fraction warrants therapeutic potential against oxidative stress-related disorders.
    Matched MeSH terms: Phenols/chemistry
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