Displaying publications 1 - 20 of 73 in total

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  1. Determination of DPPH free radical scavenging activity: application of artificial neural networks
    Musa KH, Abdullah A, Al-Haiqi A
    Food Chem, 2016 Mar 1;194:705-11.
    PMID: 26471610 DOI: 10.1016/j.foodchem.2015.08.038
    A new computational approach for the determination of 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity (DPPH-RSA) in food is reported, based on the concept of machine learning. Trolox standard was mix with DPPH at different concentrations to produce different colors from purple to yellow. Artificial neural network (ANN) was trained on a typical set of images of the DPPH radical reacting with different levels of Trolox. This allowed the neural network to classify future images of any sample into the correct class of RSA level. The ANN was then able to determine the DPPH-RSA of cinnamon, clove, mung bean, red bean, red rice, brown rice, black rice and tea extract and the results were compared with data obtained using a spectrophotometer. The application of ANN correlated well to the spectrophotometric classical procedure and thus do not require the use of spectrophotometer, and it could be used to obtain semi-quantitative results of DPPH-RSA.
    Matched MeSH terms: Biphenyl Compounds/chemistry*
  2. Fulltext Synthesis, evaluation of antioxidant activity and crystal structure of 2,4-dimethylbenzoylhydrazones
    Taha M, Ismail NH, Jamil W, Yousuf S, Jaafar FM, Ali MI, et al.
    Molecules, 2013 Sep 05;18(9):10912-29.
    PMID: 24013406 DOI: 10.3390/molecules180910912
    2,4-Dimethylbenzoylhydrazones 1-30 were synthesized by condensation reactions of 2,4-dimethylbenzoylhydrazide with various aromatic aldehydes and characterized. The assigned structures of compounds 10, 15 and 22 were further supported by single-crystal X-ray diffraction data. The synthesized compounds were evaluated for their in vitro DPPH radical scavenging activity. They exerted varying degree of scavenging activity toward DPPH radical with IC₅₀ values between 25.6-190 µM. Compounds 1, 4, 2, 3, 7, and 6 have IC₅₀ values of 25.6, 28.1, 29.3, 29.8, 30.0 and 30.1 µM respectively, showing better activity than an n-propyl gallate standard (IC₅₀ value = 30.30 µM). For super oxide anion scavenging activity compounds 1, 2 and 3 with IC₅₀ values of 98.3, 102.6, and 105.6, respectively, also showed better activity than the n-propyl gallate standard (IC₅₀ value = 106.34 µM).
    Matched MeSH terms: Biphenyl Compounds/chemistry
  3. Fulltext Design of three-component essential oil extract mixture from Cymbopogon flexuosus, Carum carvi, and Acorus calamus with enhanced antioxidant activity
    Assaggaf H, Jeddi M, Mrabti HN, Ez-Zoubi A, Qasem A, Attar A, et al.
    Sci Rep, 2024 Apr 22;14(1):9195.
    PMID: 38649707 DOI: 10.1038/s41598-024-59708-x
    The development of novel antioxidant compounds with high efficacy and low toxicity is of utmost importance in the medicine and food industries. Moreover, with increasing concerns about the safety of synthetic components, scientists are beginning to search for natural sources of antioxidants, especially essential oils (EOs). The combination of EOs may produce a higher scavenging profile than a single oil due to better chemical diversity in the mixture. Therefore, this exploratory study aims to assess the antioxidant activity of three EOs extracted from Cymbopogon flexuosus, Carum carvi, and Acorus calamus in individual and combined forms using the augmented-simplex design methodology. The in vitro antioxidant assays were performed using DPPH and ABTS radical scavenging approaches. The results of the Chromatography Gas-Mass spectrometry (CG-MS) characterization showed that citral (29.62%) and niral (27.32%) are the main components for C. flexuosus, while D-carvone (62.09%) and D-limonene (29.58%) are the most dominant substances in C. carvi. By contrast, β-asarone (69.11%) was identified as the principal component of A. calamus (30.2%). The individual EO exhibits variable scavenging activities against ABTS and DPPH radicals. These effects were enhanced through the mixture of the three EOs. The optimal antioxidant formulation consisted of 20% C. flexuosus, 53% C. carvi, and 27% A. calamus for DPPHIC50. Whereas 17% C. flexuosus, 43% C. carvi, and 40% A. calamus is the best combination leading to the highest scavenging activity against ABTS radical. These findings suggest a new research avenue for EOs combinations to be developed as novel natural formulations useful in food and biopharmaceutical products.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  4. Microwave-assisted extraction of polysaccharides from Micromelum minutum leaves using citric acid monohydrate-glycerol based deep eutectic solvents and evaluation of biological activities
    Md Yusoff MH, Shafie MH
    Anal Chim Acta, 2024 Dec 01;1331:343351.
    PMID: 39532430 DOI: 10.1016/j.aca.2024.343351
    BACKGROUND: The extraction of polysaccharides using an acidic extraction media has been extensively reported, highlighting its effectiveness in yielding high-quality polysaccharides. A higher concentration of acidic solution could hydrolyze the structure of polysaccharide, while a low concentration reduces the extraction efficiency. Despite this challenges, deep eutectic solvents (DES) were introduced as an alternative extraction medium due to additional interactions such as inter and intra-molecular interactions, Van de Waals, hydrogen bond, and electrostatic interactions, which could improve the polysaccharide extraction efficiency and biological activities. Furthermore, the extraction conditions such as extraction medium and extraction parameters could affect the properties of polysaccharides as well as influence their structure-activity relationship for biological activities.

    RESULTS: The result showed that the microwave-assisted extraction of Micromelum minutum leaf polysaccharide (MMLP) using DES as an extraction media (MMLP-DES) gave a higher yield (improvement of 101.20 %) than citric acid monohydrate (CAM) (MMLP-CAM) and required a lower percentage of microwave power (19.83 % less) and time (0.78 min less). The properties of MMLPs significantly differ based on their pH, molecular weight, viscosity, degree of esterification and monosaccharide molar ratio which influenced the biological activities. Compared to MMLP-CAM, MMLP-DES had a more branched and less linear structure. The bioactivities study revealed that MMLP-DES exhibited higher antioxidant and anti-α-amylase activities (i.e.

    , DPPH: 74.52 %, FRAP: 2.87 mM FeSO4 and α-amylase inhibition: 86.23 %) compared to MMLP-CAM (i.e.

    , DPPH: 49.33 %, FRAP: 1.49 mM FeSO4, and α-amylase inhibition: 81.76 %). The mechanism and structure-activity relationship of MMLPs on bioactivities were also hypothesized.

    SIGNIFICANCE: Based on our previous study, the citric acid monohydrate-glycerol based DES as an extraction medium has enhanced the extraction yield of polysaccharides from M. minutum. This study highlights the DES combined with microwave-assisted extraction to improve the yield of MMLP and evaluate the biological activities compared to CAM as a classical solvent. In conclusion, the DES showed the advantages for extraction of polysaccharides with desired biological activities.

    Matched MeSH terms: Biphenyl Compounds/chemistry
  5. Syntheses, in vitro, and in silico studies of rhodanine-based schiff bases as potential α-amylase inhibitors and radicals (DPPH and ABTS) scavengers
    Egu SA, Ali I, Khan KM, Chigurupati S, Qureshi U, Salar U, et al.
    Mol Divers, 2023 Apr;27(2):767-791.
    PMID: 35604512 DOI: 10.1007/s11030-022-10454-0
    A two-step reaction method was used to synthesize a series of rhodanine-based Schiff bases (2-33) that were characterized using spectroscopic techniques. All compounds were assessed for α-amylase inhibitory and radical scavenging (DPPH and ABTS) activities. In comparison to the standard acarbose (IC50 = 9.08 ± 0.07 µM), all compounds demonstrated good to moderate α-amylase inhibitory activity (IC50 = 10.91 ± 0.08-61.89 ± 0.102 µM). Compounds also demonstrated significantly higher DPPH (IC50 = 10.33 ± 0.02-96.65 ± 0.03 µM) and ABTS (IC50 = 12.01 ± 0.12-97.47 ± 0.13 µM) radical scavenging activities than ascorbic acid (DPPH, IC50 = 15.08 ± 0.03 µM; ABTS, IC50 = 16.09 ± 0.17 µM). The limited structure-activity relationship (SAR) suggests that the position and nature of the substituted groups on the phenyl ring have a vital role in varying inhibitory potential. Among the series, compounds with an electron-withdrawing group at the para position showed the highest potency. Kinetic studies revealed that the compounds followed a competitive mode of inhibition. Molecular docking results are found to agree with experimental findings, showing that compounds reside in the active pocket due to the main rhodanine moiety.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  6. Antioxidant and anticancer activities of hesperetin and its novel formulations in KB cells
    Chauhan A, Salwa, Shedgaonkar GG, Kumar L, Karmakar A, Khajuria S, et al.
    Naunyn Schmiedebergs Arch Pharmacol, 2025 May;398(5):5213-5236.
    PMID: 39531045 DOI: 10.1007/s00210-024-03581-y
    This study aimed to formulate the hesperetin nanostructured lipid carriers (NLCs) containing oro-mucosal gel for its activity assessment on the KB cell line. NLCs were prepared with glyceryl monostearate, oleic acid, and lecithin using a modified constant-temperature emulsification technique. The particle size analysis, in vitro drug release studies, etc., of prepared NLCs were evaluated. The formulated gels were analyzed with respect to spreadability, extrudability, swelling index, texture analysis, etc. The particle size, polydispersity index, zeta potential, and drug entrapment of nanocarriers were recorded to be 221.733 ± 61.536 nm, 0.381 ± 0.091, - 51.433 ± 4.143 mV, and 89.29%, respectively. The optimized NLCs in 24 h released 87.14 ± 6.62% of the drug. The round shape of NLCs was noticed with scanning electron microscopy. The pH, spreadability, extrudability, swelling index, content uniformity, and drug release studies of hesperetin NLCs-containing gel (HNG) were found to be 6.81 ± 0.04, 2.49 ± 0.04 cm.mg/s, 539.04 ± 32.88 g/cm2, 4.27 ± 0.47, 107.98 ± 1.93%, and 90.17 ± 6.67% (in 48 h), respectively. The developed formulations showed promising in vitro anticancer and antioxidant activities. HNP results authorize that the formulation may be beneficial for the treatment of oral cancer.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  7. Fulltext Subcritical Water Technology for Extraction of Phenolic Compounds from Chlorella sp. Microalgae and Assessment on Its Antioxidant Activity
    Zakaria SM, Kamal SMM, Harun MR, Omar R, Siajam SI
    Molecules, 2017 Jul 03;22(7).
    PMID: 28671617 DOI: 10.3390/molecules22071105
    Chlorella sp. microalgae is a potential source of antioxidants and natural bioactive compounds used in the food and pharmaceutical industries. In this study, a subcritical water (SW) technology was applied to determine the phenolic content and antioxidant activity of Chlorella sp. This study focused on maximizing the recovery of Chlorella sp. phenolic content and antioxidant activity measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay as a function of extraction temperature (100-250 °C), time (5-20 min) and microalgae concentration (5-20 wt. %) using response surface methodology. The optimal operating conditions for the extraction process were found to be 5 min at 163 °C with 20 wt. % microalgae concentration, which resulted in products with 58.73 mg gallic acid equivalent (GAE)/g phenolic content and 68.5% inhibition of the DPPH radical. Under optimized conditions, the experimental values were in close agreement with values predicted by the model. The phenolic content was highly correlated (R² = 0.935) with the antioxidant capacity. Results indicated that extraction by SW technology was effective and that Chlorella sp. could be a useful source of natural antioxidants.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  8. The influence of microwave cooking on the nutritional composition and antioxidant activity of the underutilized perah seed
    Li KS, Ali A, Muhammad II
    Acta Sci Pol Technol Aliment, 2017 Jul-Sep;16(3):283-292.
    PMID: 29055976 DOI: 10.17306/J.AFS.0497
    BACKGROUND: Perah seed is one of the most underutilized oilseeds, containing high nutritional values and high percentage of α-linoleneic acid, which may have a high potential in food and pharmaceutical applica- tions. The main objective of this study was to evaluate the influence of microwave (MW) cooking on the proximate composition and antioxidant activity of perah seeds.

    METHODS: In this study, the proximate composition and amygdalin concentration of MW ir- radiated perah seeds were determined. The total phenolic content (TPC), Maillard reaction products (MRPs) and antioxidant activity of methanol (PME), 70% methanol in water (PMW), ethanol (PEE), 70% ethanol  in water (PEW) extracts and methanol extract of oil (PMO) were evaluated during MW cooking. The anti- oxidant activity was evaluated using multiple assays, namely DPPH radical scavenging activity, β-Carotene bleaching assay, and reducing power.

    RESULTS: Microwave cooking did not significantly increase crude lipid and carbohydrate content, and the amounts of other nutrients such as ash, crude protein and fibre remained almost unchanged. As evaluated  by HPLC, the amygdalin concentration in the seeds was reduced by MW cooking. The TPC, MRP and anti- oxidant activity of the solvent extracts of perah seeds increased significantly with increasing roasting time. Of all the extracts, PMW at all MW cooking times displayed the highest antioxidant effectiveness. However, thermal treatment significantly reduced the antioxidant properties of PMO. The values for TPC, MRP and antioxidant effectiveness of the samples were ranked in the following order: PMW > PEW > PME > PEE > PMO, in both control and microwaved samples.

    CONCLUSIONS: In determining the overall quality of the products, MW cooking time was found to be a critical factor. Solubilization of phenolic compounds and formation of MRPs during MW cooking could have caused the increase in antioxidant activity of the perah seeds.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  9. Isolation of antioxidative compounds from Micromelum minutum guided by preparative thin layer chromatography-2,2-diphenyl-1-picrylhydrazyl (PTLC-DPPH) bioautography method
    Kassim NK, Lim PC, Ismail A, Awang K
    Food Chem, 2019 Jan 30;272:185-191.
    PMID: 30309531 DOI: 10.1016/j.foodchem.2018.08.045
    The application of preparative thin layer chromatography-2,2-diphenyl-1-picrylhydrazyl (PTLC-DPPH) bioautography technique successfully isolated a lignan sesamin (1), two prenylated coumarins (2 and 3) and a marmesin glycosides (4) from Micromelum minutum methanol bark extract. Compounds 2 and 3 were identified as new compounds whereas 1 and 4 were first isolated from Micromelum genus. Structural identification of all compounds were done by detailed spectroscopic analyses and comparison with literature data. Antioxidant capacities of extract, active fraction and compounds were measured based on DPPH free radical savenging activity, oxygen radical absorbance capacity (ORAC) and β-carotene bleaching. The DPPH activity of methanol extract and its fraction present the IC50 values of 54.3 and 168.9 µg/mL meanwhile the β-carotene bleaching results were 55.19% and 5.75% respectively. The ORAC measurements of M. minutum extract, compounds 2 and 4 showed potent antioxidant activity with the values of 5123, 5539 and 4031 µmol TE/g respectively.
    Matched MeSH terms: Biphenyl Compounds/chemistry*
  10. Fulltext A Kinetic Approach of DPPH Free Radical Assay of Ferulate-Based Protic Ionic Liquids (PILs)
    Ahmad NA, Jumbri K, Ramli A, Abd Ghani N, Ahmad H, Lim JW
    Molecules, 2018 Dec 05;23(12).
    PMID: 30563037 DOI: 10.3390/molecules23123201
    The antiradical efficiency (AE) and kinetic behavior of a new ferulate-based protic ionic liquids (PILs) were described using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay. The reduction of the DPPH free radical (DPPH•) was investigated by measuring the decrease in absorbance at 517 nm. The time to reach steady state for the reaction of parent acid (ferulic acid) and synthesized PILs with DPPH• was continuously recorded for 1 h. Results revealed that the AE of 2-butylaminoethanol ferulate (2BAEF), 3-dimethylaminopropanol ferulate (3DMAPF) and 3-diethylaminopropanol ferulate (3DEAPF) PILs have improved compared to ferulic acid (FA) as the reaction class changes from low to medium. This attributed to the strong hydrogen abstraction occurred in the PILs. Furthermore, these PILs were found to have a good kinetic behavior compared to FA due to the high rate constant (k₂) (164.17, 242.84 and 244.73 M-1 s-1, respectively). The alkyl chain length and more alkyl substituents on the nitrogen atom of cation were believed to reduce the cation-anion interaction and speed up the hydrogen atom transfer (HAT) and electron transfer (ET) mechanisms; hence, increased rate constant was observed leading to a strong antioxidant activity of the synthesized PILs.
    Matched MeSH terms: Biphenyl Compounds/chemistry*
  11. Chemical investigation and biological activities of the essential oil of Knema kunstleri Warb. from Malaysia
    Salleh WMNHW, Anuar MZA, Khamis S, Nafiah MA, Sul'ain MD
    Nat Prod Res, 2021 Jul;35(13):2279-2284.
    PMID: 31544509 DOI: 10.1080/14786419.2019.1669027
    The chemical composition of the essential oil of Knema kunstleri Warb. (Myristicaceae) was investigated for the first time. The essential oil was obtained by hydrodistillation and fully characterized by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). In total, 36 components were identified in the essential oil, which made up 91.7% of the total oil. The essential oil is composed mainly of β-caryophyllene (23.2%), bicyclogermacrene (9.6%), δ-cadinene (7.3%), α-humulene (5.7%), and germacrene D (4.3%). The essential oil showed moderate activity towards DPPH free-radical scavenging and lipoxygenase inhibition. To the best of our knowledge, this is the first study of the composition and bioactivities of the essential oil report concerning the genus Knema.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  12. Assessment of antioxidant activity in Victorian marine algal extracts using high performance thin-layer chromatography and multivariate analysis
    Agatonovic-Kustrin S, Morton DW, Ristivojević P
    J Chromatogr A, 2016 Oct 14;1468:228-235.
    PMID: 27670751 DOI: 10.1016/j.chroma.2016.09.041
    The aim of this study was to develop and validate a rapid and simple high performance thin layer chromatographic (HPTLC) method to screen for antioxidant activity in algal samples. 16 algal species were collected from local Victorian beaches. Fucoxanthin, one of the most abundant marine carotenoids was quantified directly from the HPTLC plates before derivatization, while derivatization either with 2,2-diphenyl-1-picrylhydrazyl (DPPH) or ferric chloride (FeCl3) was used to analyze antioxidants in marine algae, based on their ability to scavenge non biological stable free radical (DPPH) or to chelate iron ions. Principal component analysis of obtained HPTLC fingerprints has classified algae species into 5 groups according to their chemical/antioxidant profiles. The investigated brown algae samples were found to be rich in non-and moderate-polar compounds and phenolic compounds with antioxidant activity. Most of the phenolic iron chelators also have shown free radical scavenging activity. Strong positive and significant correlations between total phenolic content and DPPH radical scavenging activity showed that, phenolic compounds, including flavonoids are the main contributors of antioxidant activity in these species. The results suggest that certain brown algae possess significantly higher antioxidant potential when compared to red or green algae and could be considered for future applications in medicine, dietary supplements, cosmetics or food industries. Cystophora monilifera extract was found to have the highest antioxidant concentration, followed by Zonaria angustata, Cystophora pectinate, Codium fragile, and Cystophora pectinata. Fucoxanthin was found mainly in the brown algae species. The proposed methods provide an edge in terms of screening for antioxidants and quantification of antioxidant constituents in complex mixtures. The current application also demonstrates flexibility and versatility of a standard HPTLC system in the drug discovery. Proposed methods could be used for the bioassay-guided isolation of unknown natural antioxidants and subsequent identification if combined with spectroscopic identification.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  13. Fulltext Antioxidant Activity Evaluation of FlexirubinType Pigment from Chryseobacterium artocarpi CECT 8497 and Related Docking Study
    Mogadem A, Almamary MA, Mahat NA, Jemon K, Ahmad WA, Ali I
    Molecules, 2021 Feb 12;26(4).
    PMID: 33673263 DOI: 10.3390/molecules26040979
    The current research is focused on studying the biological efficacy of flexirubin, a pigment extracted from Chryseobacterium artocarpi CECT 8497.Different methods such as DPPH, H2O2, NO•, O2•-, •OH, lipid peroxidation inhibition by FTC and TBA, ferric reducing and ferrous chelating activity were carried out to evaluate the antioxidant activity of flexirubin. Molecular docking was also carried out, seeking the molecular interactions of flexirubin and a standard antioxidant compound with SOD enzyme to figure out the possible flexirubin activity mechanism. The new findings revealed that the highest level of flexirubin exhibited similar antioxidant activity as that of the standard compound according to the H2O2, •OH, O2•-, FTC and TBA methods. On the other hand, flexirubin at the highest level has shown lower antioxidant activity than the positive control according to the DPPH and NO• and even much lower when measured by the FRAP method. Molecular docking showed that the interaction of flexirubin was in the binding cavity of the SOD enzyme and did not affect its metal-binding site. These results revealed that flexirubin has antioxidant properties and can be a useful therapeutic compound in preventing or treating free radical-related diseases.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  14. Fulltext Gamma irradiation increases the antioxidant properties of Tualang honey stored under different conditions
    Khalil MI, Sulaiman SA, Alam N, Moniruzzaman M, Bai'e S, Man CN, et al.
    Molecules, 2012 Jan 11;17(1):674-87.
    PMID: 22237682 DOI: 10.3390/molecules17010674
    This study was conducted to evaluate the effects of evaporation, gamma irradiation and temperature on the total polyphenols, flavonoids and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activities of Tualang honey samples (n = 14) following storage over three, six or twelve months. The mean polyphenol concentrations of the six gamma irradiated honey samples at three, six and twelve months, respectively, were 96.13%, 98.01% and 102.03% higher than the corresponding values of the eight non-gamma irradiated samples. Similarly, the mean values for flavonoids at three, six and twelve months were 111.52%, 114.81% and 110.04% higher, respectively, for the gamma irradiated samples. The mean values for DPPH radical-scavenging activities at three, six and twelve months were also 67.09%, 65.26% and 44.65% higher, respectively, for the gamma irradiated samples. These data indicate that all gamma irradiated honey samples had higher antioxidant potential following gamma irradiation, while evaporation and temperature had minor effects on antioxidant potential.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  15. Fulltext Synthesis, crystal structure, DFT studies and evaluation of the antioxidant activity of 3,4-dimethoxybenzenamine schiff bases
    Aziz AN, Taha M, Ismail NH, Anouar el H, Yousuf S, Jamil W, et al.
    Molecules, 2014 Jun 19;19(6):8414-33.
    PMID: 24950444 DOI: 10.3390/molecules19068414
    Schiff bases of 3,4-dimethoxybenzenamine 1-25 were synthesized and evaluated for their antioxidant activity. All the synthesized compounds were characterized by various spectroscopic techniques. In addition, the characterizations of compounds 13, 15 and 16 were supported by crystal X-ray determinations and their geometrical parameters were compared with theoretical DFT calculations at the B3LYP level of theory. Furthermore, the X-ray crystal data of two non-crystalline compounds 8 and 18 were theoretically calculated and compared with the practical values of compounds 13, 15, 16 and found a good agreement. The compounds showed good DPPH scavenging activity ranging from 10.12 to 84.34 μM where compounds 1-4 and 6 showed stronger activity than the standard n-propyl gallate. For the superoxide anion radical assay, compounds 1-3 showed better activity than the standard.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  16. Fulltext Nutritional content and in vitro antioxidant potential of Garcinia atroviridis (Asam gelugor) leaves and fruits
    Nursakinah I, Zulkhairi HA, Norhafizah M, Hasnah B, Zamree MS, Farrah SI, et al.
    Malays J Nutr, 2012 Dec;18(3):363-71.
    PMID: 24568077 MyJurnal
    The objective of this study was to determine antioxidant potential of Garcinia atroviridis leaves and fruits extracts in vitro.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  17. Fulltext The improvement of the endogenous antioxidant property of stone fish (Actinopyga lecanora) tissue using enzymatic proteolysis
    Bordbar S, Ebrahimpour A, Abdul Hamid A, Abdul Manap MY, Anwar F, Saari N
    Biomed Res Int, 2013;2013:849529.
    PMID: 23586061 DOI: 10.1155/2013/849529
    The stone fish (Actinopyga lecanora) ethanolic and methanolic tissue extracts were investigated for total phenolic contents (TPCs) as well as antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH(•)) radical scavenging activity and ferric reducing antioxidant power (FRAP) assays. Both extracts showed low amount of phenolics (20.33 to 17.03 mg of gallic acid equivalents/100 g dried sample) and moderate antioxidant activity (39% to 34% DPPH(•) radical scavenging activity and 23.95 to 22.30 mmol/100 mL FeSO4 FRAP value). Enzymatic proteolysis was carried out in order to improve the antioxidant activity using six commercially available proteases under their optimum conditions. The results revealed that the highest increase in antioxidant activity up to 85% was obtained for papain-generated proteolysate, followed by alcalase (77%), trypsin (75%), pepsin (68%), bromelain (68%), and flavourzyme (50%) as measured by DPPH(•) radical scavenging activity, whilst for the FRAP value, the highest increase in the antioxidant activity up to 39.2 mmol/100 mL FeSO4 was obtained for alcalase-generated proteolysate, followed by papain (29.5 mmol/100 mL FeSO4), trypsin (23.2 mmol/100 mL FeSO4), flavourzyme (24.7 mmol/100 mL FeSO4), bromelain (22.9 mmol/100 mL FeSO4), and pepsin (20.8 mmol/100 mL FeSO4). It is obvious that proteolysis of stone fish tissue by proteolytic enzymes can considerably enhance its antioxidant activity.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  18. Exploring the antioxidant potential of lignin isolated from black liquor of oil palm waste
    Bhat R, Khalil HP, Karim AA
    C. R. Biol., 2009 Sep;332(9):827-31.
    PMID: 19748457 DOI: 10.1016/j.crvi.2009.05.004
    This study was conducted to evaluate the potential antioxidant activity of lignin obtained from black liquor, a hazardous waste product generated during the extraction of palm oil. Antioxidant potential of the extracted lignin was evaluated by dissolving the extracted samples in 2 different solvent systems, namely, 2-methoxy ethanol and DMSO. Results revealed high percent inhibition of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical in the lignin sample dissolved in 2-methoxy ethanol over DMSO (concentration range of 1-100 microg/ml). Lignin extracted in 2-methoxy ethanol exhibited higher inhibition percentage (at 50 microg/ml, 84.2%), whereas a concentration of 100 microg/ml was found to be effective in the case of the DMSO solvent (69.8%). Fourier transform infrared (FTIR) spectrometry revealed that the functional groups from the extracted lignin and commercial lignin were highly similar, indicating the purity of the lignin extracted from black liquor. These results provide a strong basis for further applications of lignin in the food industry and also illustrate an eco-friendly approach to utilize oil palm black liquor.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  19. Fulltext Ultrasound-assisted extraction of antioxidants in Misai Kucing (Orthosiphon stamineus)
    Ho SK, Tan CP, Thoo YY, Abas F, Ho CW
    Molecules, 2014 Aug 19;19(8):12640-59.
    PMID: 25153876 DOI: 10.3390/molecules190812640
    Ultrasound-assisted extraction (UAE) with ethanol was used to extract the compounds responsible for the antioxidant activities of Misai Kucing (Orthosiphon stamineus). Response surface methodology (RSM) was used to optimize four independent variables: ethanol concentration (%), amplitude (%), duty cycle (W/s) and extraction time (min). Antioxidant compounds were determined by total phenolic content and total flavonoid content to be 1.4 g gallic acid equivalent/100 g DW and 45 g catechin equivalent/100 g DW, respectively. Antioxidant activities were evaluated using the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) radical scavenging capacity assay and the 2,2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging capacity assay to be 1,961.3 and 2,423.3 µmol Trolox Equivalent Antioxidant Capacity (TEAC)/100 g DW, respectively. Based on the optimal conditions, experimental values were reported to be close to the predicted value by RSM modeling (p>0.05), indicating the suitability of UAE for extracting the antioxidants of Misai Kucing. Rosmarinic acid, kaempferol-rutinoside and sinesetine were identified by high performance liquid chromatography-mass spectrometry.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  20. Fulltext Report: antioxidant and nutraceutical value of wild medicinal Rubus berries
    Ahmad M, Masood S, Sultana S, Hadda TB, Bader A, Zafar M
    Pak J Pharm Sci, 2015 Jan;28(1):241-7.
    PMID: 25553701
    Nutritional quality and antioxidant capacity of three edible wild berries (Rubus ellipticus Smith, Rubus niveus Thunb, Rubus ulmifolius L.) from Lesser Himalayan Range (LHR) were evaluated. Their edible portion was assayed for moisture, fats, ash, carbohydrates, proteins, fibers, essential minerals (Ca, P, Mg, K, Na, Cl, S, Mn, Zn, Fe, Cu, Se, Co, Ni) and DPPH free radical scavenging activity was applied to determine the antioxidant potential. The fruit of Rubus ulmifolius L. (blackberry) possessed the highest values of energy (403.29 Kcal), total protein (6.56g/100 g), Nitrogen (N) content (1500mg/100g), K (860.17mg/100g), Ca (620.56mg/100g), Zn (17.509mg/100g) and the strongest antioxidant activity (98.89% inhibition). While the raspberries (Rubus ellipticus Smith, Rubus niveus Thunb.) exhibited more significant contents of dietary fiber (5.90g/100g), carbohydrates (86.4 g/100 g) and Fe (4.249mg/100g). Significant variation was observed among the tested samples in all the investigated features. The combination of bio elements and active antioxidants clearly showed the applicability of these berries as a nutraceutical supplement.
    Matched MeSH terms: Biphenyl Compounds/chemistry
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