Displaying publications 1 - 20 of 177 in total

  1. Ibrahim MH, Jaafar HZ
    Molecules, 2011 Jun 29;16(7):5514-26.
    PMID: 21716173 DOI: 10.3390/molecules16075514
    Kacip Fatimah (Labisia pumila Blume), one of the most famous and widely used herbs, especially in Southeast Asia, is found to have interesting bioactive compounds and displays health promoting properties. In this study, the antioxidant activities of the methanol extracts of leaves, stems and roots of three varieties of L. pumila (var. alata, pumila and lanceolata) were evaluated in an effort to compare and validate the medicinal potential of this indigenous Malaysian herb species. The antioxidant activity determined by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, as well as the total amount of phenolics and flavonoids were the highest in the leaves, followed by the stems and roots in all the varieties. A similar trend was displayed by the ferric reducing antioxidant potential (FRAP) activity, suggesting that the L. pumila varieties possess high foliar antioxidant properties. At low FRAP activity concentrations, the values of the leaves' inhibition activity in the three varieties were significantly higher than those of the stems and roots, with var. alata exhibiting higher antioxidant activities and total contents of phenolics and flavonoids compared to the varieties pumila and lanceolata. The high production of secondary metabolites and antioxidant activities in var. alata were firmly related to low nitrogen content and high C/N ratio in plant parts. The study also demonstrated a positive correlation between secondary metabolite content and antioxidant activities, and revealed that the consumption of L. pumila could exert several beneficial effects by virtue of its antioxidant activity.
    Matched MeSH terms: Picrates/metabolism
  2. 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: Picrates/chemistry*
  3. Mediani A, Abas F, Tan CP, Khatib A
    Antioxidants (Basel), 2014 May 07;3(2):358-70.
    PMID: 26784876 DOI: 10.3390/antiox3020358
    The present study was conducted to determine the effect of air (AD), oven (OD) and freeze drying (FD) on the free radical scavenging activity and total phenolic content (TPC) of Cosmos caudatus and the effect of storage time by the comparison with a fresh sample (FS). Among the three drying methods that were used, AD resulted in the highest free radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) (IC50 = 0.0223 mg/mL) and total phenolic content (27.4 g GAE/100 g), whereas OD produced the lowest scavenging activity and TPC value. After three months of storage, the dried samples showed a high and consistent free radical scavenging activity when compared to stored fresh material. The drying methods could preserve the quality of C. caudatus during storage and the stability of its bioactive components can be maintained.
    Matched MeSH terms: Picrates
  4. Tan, M. C., Tan, C. P., Khoo, H. E., Ho, C. W.
    This study aimed to optimise potential extraction conditions using response surface methodology (RSM) for yielding maximum levels of total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) scavenging capacity of henna (Lawsonia inermis) stems. The ranges for selected independent variables, namely acetone concentration (20−90%, v/v), extraction time (10−90 min), and extraction temperature (25−45°C) were identified by screening tests. Optimum conditions obtained for extraction of TPC were 47.0% acetone, extraction time of 47.6 min and extraction temperature of 37.3oC. The result also showed that 75.8% acetone, extraction time of 26.2 min and extraction temperature of 41oC yielded the highest DPPH• scavenging capacity. The optimized extraction conditions have resulted in TPC and DPPH• scavenging capacity of 5232.4 mg GAE/100 g DW and 6085.7 mg TE/100 g DW, respectively which similar to the predicted values. Therefore, RSM has successfully optimized the extraction conditions for TPC and radical scavenging capacity of henna stems.
    Matched MeSH terms: Picrates
  5. Jemain, S.F.P., Jamal, P., Raus, A. R., Amid, A., Jaswir, I.
    Medicinal properties of Malaysian Curcuma caesia have not been studied extensively, even though it has been used as a traditional remedy. This study examined the effects of various extraction temperatures (30, 40, 50, 60, 70oC) using a high frequency (40 kHz) ultrasonic extraction method, time (30,60,90 and 120 minutes), pH (1,2,3,4,5,6,7,8,9,10) on the extraction yield of total phenolics and DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging activities from C. caesia rhizome. Extraction was most efficient at pH 6.0, while the extraction time of 30 minutes and temperature of 60oC was the best in terms of total phenolics content and DPPH scavenging activity. This study is important due to its ability to improve extraction of total phenolics compound using ultrasonic extraction method while maintaining a relatively high DPPH scavenging activity of the extracts.
    Matched MeSH terms: Picrates
  6. 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: Picrates/chemistry
  7. Kusrini E, Saleh MI, Lecomte C
    Spectrochim Acta A Mol Biomol Spectrosc, 2009 Sep 15;74(1):120-6.
    PMID: 19560960 DOI: 10.1016/j.saa.2009.05.024
    (1)H NMR evidence for direct coordination between the Ln(III) ion and the oxygen atoms of the pentaethylene glycol (EO5) ligand and the picrate anion (Pic) in [Ln(Pic)(2)(EO5)][Pic] {Ln=Ce and Nd} complexes are confirmed by single X-ray diffraction. No dissociation of Ln-O bonds in dimethyl sulfoxide-d solution was observed in NMR studies conducted at different temperatures ranging 25-100 degrees C. The Ln(III) ion was chelated to nine oxygen atoms from the EO5 ligand in a hexadentate manner and the two Pic anions in each bidentate and monodentate modes. Both compounds are isostructural and crystallized in monoclinic with space group P2(1)/c. Coordination environment around the Ce1 and Nd1 atoms can be described as tricapped trigonal prismatic and monocapped square antiprismatic geometries, respectively. The crystal packing of the complexes have stabilized by one dimensional (1D) chains along the [001] direction to form intermolecular O-Hcdots, three dots, centeredO and C-Hcdots, three dots, centeredO hydrogen bonding. The molar conductance of the complexes in DMSO solution indicated that both compounds are ionic. The complexes had a good thermal stability. Under the UV-excitation, these complexes exhibited the red-shift emission.
    Matched MeSH terms: Picrates/pharmacology*; Picrates/chemistry
  8. 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: Picrates/antagonists & inhibitors; Picrates/chemistry*
  9. Prasad KN, Chew LY, Khoo HE, Kong KW, Azlan A, Ismail A
    PMID: 20936182 DOI: 10.1155/2010/871379
    Antioxidant capacities of ethylacetate, butanol, and water fractions of peel, pulp, and seeds of Canarium odontophyllum Miq. (CO) were determined using various in vitro antioxidant models. Ethylacetate fraction of peel (EAFPE) exhibited the highest total phenolic (TPC), total flavonoid content (TFC), and antioxidant activities compared to pulp, seeds, and other solvent fractions. Antioxidant capacities were assayed by total antioxidant capability, 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical activity, ferric reducing antioxidant power (FRAP), and hemoglobin oxidation assay. Total phenolic content of ethylacetate fractions was positively correlated with the antioxidant activity. This is the first report on the antioxidant activities from CO fruit fractions. Thus, EAFPE can be used potentially as a readily accessible source of natural antioxidants and as a possible pharmaceutical supplement.
    Matched MeSH terms: Picrates/metabolism; Picrates/chemistry
  10. Annegowda HV, Bhat R, Tze LM, Karim AA, Mansor SM
    J Food Sci Technol, 2013 Jun;50(3):535-41.
    PMID: 24425949 DOI: 10.1007/s13197-011-0370-8
    We evaluated the phenolic content and antioxidant capacities of pod and seed extracts (in methanol, ethanol, and water) of an underutilized legume, Clitoria fairchildiana (Howard). The antioxidant capacity of the extracts was determined using the ferric reducing antioxidant potential assay, and the free radical-scavenging capacity was evaluated using 2,2-diphenyl-1-picrylhydrazyl radical-scavenging and ABTS assays. In addition, the total flavonoids, flavonols, and tannin contents were also determined. Overall, the methanol extracts of the pod contained high concentration of phenolics and showed high antioxidant capacities compared to seed extracts. In addition, a positive correlation was found between total phenol and tannin versus antioxidant capacity. Results of the present study indicate pods and seeds of C. fairchildiana to possess rich amount of natural antioxidants, and can be further explored for their possible use as a natural additive in food or in pharmaceutical industries.
    Matched MeSH terms: Picrates
  11. Rahman, M.M., Fazlic, V, Saad, N.W.
    Garlic has been a favorite additive in food for many years in various cultures. It is known that garlic
    (Allium sativum) possesses antimicrobial, antiprotozoal, antimutagenic, antiplatelet and antihyperlipidemic
    properties. Allicin, a thiosulfinate extract of garlic, has been presumed to be a very strong antioxidant. High performance liquid chromatography (HPLC) analysis of raw garlic extract was not conclusive to determine allicin’s presence. However, using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging methods to determine the antioxidant activity of raw garlic extract shows a color change from deep violet to yellow, indicating antioxidant activity. Thus, raw garlic can be a source of antioxidant based on the results of the DPPH scavenging analysis.
    Matched MeSH terms: Picrates
  12. Woo, P.F., Yim, H.S., Khoo, H.E., Sia, C.M., Ang, Y.K.
    This study investigated the effects of different percentages of ethanol (0 - 100%), extraction times (1 - 5 h) and temperatures (25 - 60°C) on total phenolic content (TPC) and antioxidant activity (AA) of sapodilla pulp and peel. TPC was determined by Folin-Ciocalteu reagent method, while AA was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, 2,2-azino-bis-(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assay, ferric reducing antioxidant power (FRAP) assay and β-carotene bleaching (BCB) assay. Based on the optimal extraction conditions used, sapodilla pulp extract had TPC of 3.89 mg GAE/g, 63.20% of DPPH scavenging activity, 4.30% of ABTS scavenging activity, 19.17% of BCB activity, and FRAP value of 15.24 mg TE/g; while its peel extract had TPC of 9.23 mg GAE/g, 92.95% of DPPH scavenging activity, 5.36% of ABTS scavenging activity, 8.14% of BCB activity, and 27.85 mg TE/g (FRAP value). Using the optimal extraction conditions for sapodilla pulp (40% ethanol as extraction solvent that extracted at 60°C for 4 h) and sapodilla peel (80% ethanol and 2 h extraction time at 40°C), highest antioxidants can be extracted from the pulp and peel.
    Matched MeSH terms: Picrates
  13. Thoo, Y.Y., Ng, S.Y., Khoo, M.Z., Wan Aida, W.M., Ho, C.W.
    The effects of ethanol concentration (0-100%, v/v), extraction time (60-300 min) and extraction temperature (25-65°C) on the extraction of phenolic antioxidants from Andrographis paniculata was evaluated using single-factor experiments. The following complementary assays were used to screen the antioxidant properties of the crude extracts: total phenolic content (TPC), total flavonoid content (TFC), condensed tannin content (CTC), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical-scavenging capacity and 2,2’-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging capacity. The extraction conditions chosen had significant effects (p < 0.05) on the extraction of phenolic compounds and antioxidant capacity. The optimal conditions were 60% ethanol for 60 min at 65oC for phenolic compounds and at 25oC for antioxidant capacity. Strong negative significant (p < 0.05) correlations were observed between the phenolic compounds (TPC, TFC and CTC) and antioxidant capacity comprising ABTS (-0.924, -0.909, -0.887, respectively) and DPPH radical-scavenging capacities (-0.992, -0.938, -0.928, respectively) were determined under the influence of extraction temperature.
    Matched MeSH terms: Picrates
  14. Zuhair, R.A., Aminah, A., Sahilah, A.M., Eqbal, D.
    Papaya (Carica papaya L. cv. Hongkong) is an economically important fruit crop grown in Malaysia. During its ripening stages, (C. papaya L.) exhibits different physicochemical properties, antioxidant capacities, and sensory quality results. The objective of this study was to elucidate in detail the antioxidant capacity of C. papaya as determined by total phenol content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP),2,2-diphenyl-1-picrylhydrazyl (DPPH) and scavenging systemand (ABTS). The study also aimed to study physicochemical changes of papaya fruits based on measured pH, titratable acidity (TA), total soluble solids (TSS), moisture and fruit color at five different stages of ripening. The fruits were harvested at five different, stages RS1, RS2, RS3, RS4, and RS5 corresponding to 12, 14, 16, 18, and 20 weeks after anthesis, respectively. Significant differences were found at different stages of ripening. The pH of the fruit decreased significantly (P < 0.05), whereas TA, moisture, and TSS increased significantly (P < 0.05) during the ripening process. The redness (a*) and yellowness (b*) values of fruit color both increased significantly (P < 0.05), whereas
    lightness (L*) varied. The total phenol content TPC, TFC, FRAP, DPPH and ABTS values increased significantly (P < 0.05) with the ripening process. Sensory evaluation based on the color, sweetness, sourness, flavor, and overall acceptance for the last three maturity stages was also performed. RS5 had a better score than RS3 or RS4. The results showed the important role of the ripening stage in increasing the antioxidant content of papaya fruits.
    Matched MeSH terms: Picrates
  15. Karim, N.U., Sadzali, N.L., Hassan, M.
    The effects of squid ink at concentration of 0.10 and 0.25% on the total bacteria count and
    chemical spoilage indicator; total volatile basis nitrogen (TVBN) and trimethylamine (TMA)
    of squid (Loligo duvauceli) were analysed. The analysis were performed at interval of 5 days
    during 15 days of chilled storage (4°C). This studies also investigate the antioxidant capacity
    of the squid ink. The melanin-free squid ink were subjected to ferric reducing power (FRAP)
    and 2,2-diphenyl-1-picrylhydrazyl (DPPH) analysis. The FRAP values found in squid ink were
    0.04±0.01 µmole TE g-1 meanwhile DPPH values were recorded at 0.81±0.00 µmole TE g-1.
    The squid ink at both 0.10 and 0.25% concentration showed a significantly (p
    Matched MeSH terms: Picrates
  16. Sarini Ahmad Wakid, Nurul Syafiqah Zaharin
    The present study was conducted to evaluate the antioxidant activity of Vernonia cinerea, Peperomia
    pellucida and combination of Vernonia cinerea and Peperomia pellucida. These two herbs are pants that
    often grow at random in different environments but are not commercialized due to the fact that no
    comprehensive study of the importance of their use. The extract was prepared with methanol respectively.
    1,1-diphenyl-2-picrylhydrazyl (DPPH) assay were used to study their antioxidant activity. The extracts
    were compared with commercial antioxidant, butylated hydroxytoluene (BHT). The highest scavenging
    effect from peel extract was presented by Vernonia cinerea with the value of 76.3% scavenging activity
    (IC50 = 2.909), followed by the combination of Vernonia cinerea and Peperomia pellucida (71.21%
    scavenging activity; IC50 = 5.274) and Peperomia pellucida with value of 68.3% scavenging activity (IC50
    = 5.572). BHT showed the lowest IC50 value 1.71 with the scavenging activity 90.0%. Low IC50 value will
    indicates the strong ability of the extracts to act as DPPH scavenger.
    Matched MeSH terms: Picrates
  17. Sarini Ahmad Wakid, Hamira Azrin binti Harun
    The present study was conducted to evaluate the antioxidant activity of peel extract from three types of
    melon, Cucumis melo var cantalupensis, Cucumis melo var inodorus and Citrullus lanatus in family
    Curcurbitaceae. The extract was prepared with methanol respectively. 1,1-diphenyl-2-picrylhydrazyl
    (DPPH) assay were used to study their antioxidant activity. The extracts were compared with commercial
    antioxidant, butylated hydroxytoluene (BHT). The highest scavenging effect from peel extract was
    presented by Cucumis melo var inodorus with the value of 52.7 ± 9.1µg/ml (IC50 = 4.61). BHT showed
    the lowest IC50 value 1.71 with the scavenging activity 90.0 ± 1.7µg/ml. Low IC50 value will indicates the
    strong ability of the extracts to act as DPPH scavenger.

    Matched MeSH terms: Picrates
  18. Mohammad NA, Abang Zaidel DN, Muhamad II, Abdul Hamid M, Yaakob H, Mohd Jusoh YM
    Heliyon, 2019 Oct;5(10):e02571.
    PMID: 31667409 DOI: 10.1016/j.heliyon.2019.e02571
    Total phenolic content (TPC) and antioxidant properties of xanthone extract from mangosteen pericarp via microwave-assisted extraction (MAE) method was optimized by response surface methodology (RSM). The MAE extraction conditions to obtain optimum antioxidant-rich xanthone extract were at 2.24 min of irradiation time, 25 mL/g of solvent-to-solid ratio and 71% of ethanol concentration. The predicted results for four responses were as follows; 320.31 mg gallic acid equivalent/g extract, 83.63% and 93.77% inhibition (DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-Azino-bis-3-ethylbenzthiazoline-6-sulfonic acid) assays), and 144.56 mg Trolox equivalent/g extract (FRAP, Ferric reducing antioxidant power). The predicted and actual values were statistically insignificant (P > 0.05). Therefore, these results confirmed that the examined model was acceptable and relevant. MAE led to a slightly similar antioxidant capacity and a higher extraction of α-mangostin, a major xanthone of mangosteen pericarp as compared to water bath-maceration technique.
    Matched MeSH terms: Picrates
  19. Tan ES, Aminah Abdullah, Khalid Hamid Musa, Mohammad Yusof Maskat, Maaruf Abd Ghani
    Sains Malaysiana, 2012;41:319-324.
    The effect of solvent type in antioxidant compounds extraction from banana tissues was studied. The solvent system used was pure methanol, ethanol, acetone and their aqueous solution at 50% and 70% concentrations. Comparison among three common cultivars of banana in Malaysia (Berangan, Mas and Raja) had been done and their antioxidant activities were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging system, ferric reducing ability in plasma (FRAP)
    assays and total phenolic content (TPC) assays. Acetone 70% had the strongest antioxidant compounds extraction power as compared to other solvent. All banana samples were found to be low in primary antioxidant but powerful secondary antioxidant source of fruit. The ascending order of banana cultivars in term of their antioxidant activities in all antioxidant assays carried out were Berangan < Mas < Raja. FRAP-TPC assays were highly correlated (R2>0.70) than FRAP-DPPH
    and TPC-DPPH assays due to the same mechanism that occurred in the reaction of FRAP and TPC assays.
    Matched MeSH terms: Picrates
  20. Chew SC, Tan CP, Nyam KL
    Food Sci Biotechnol, 2017;26(1):63-69.
    PMID: 30263511 DOI: 10.1007/s10068-017-0009-2
    This study assessed the changes of antioxidant activity and bioactive compounds of crude and refined kenaf seed oil during accelerated storage at 65°C for 24 days. 2,2-Diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging assays were used to determine their antioxidant activity. The changes of phenolic, tocopherol, and phytosterol contents during the storage were also studied. The phenolic content and antioxidant activity of refined oil were significantly lower than those of crude oil after the accelerated storage. There was a decrease of 72.5% tocopherol content and 31.1% phytosterol content in the crude oil and a decrease of 67% tocopherol content and 12.1% phytosterol content in the refined oil during the accelerated storage. There was no significant difference in tocopherol and phytosterol contents for crude and refined oils after the storage. The rate of degradation of tocopherol and phytosterol contents in refined oil was slower than that in crude oil during the storage.
    Matched MeSH terms: Picrates
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