Displaying publications 1 - 20 of 511 in total

  1. Tan LL, Musa Ahmad
    Analisis kuantitatif telah dilakukan untuk menentukan kepekatan ion aluminium (Al3+) dalam larutan dengan menggunakan kaedah spektrofotometri UL-Nampak dan jaringan neural tiruan (ANN). Reagen morin telah digunakan untuk membentuk kompleks morin-Al(III). Pencirian terhadap reagen dalam larutan termasuk analisis kestabilan foto reagen, kesan pH, kesan kepekatan, masa rangsangan, julat kepekatan dinamik dan kebolehulangan telah dilakukan. Penggunaan ANN telah berupaya memanjangkan julat kepekatan dinamik ion Al3+ sehingga julat kepekatan 1-13 ppm.
    Matched MeSH terms: Flavonoids
  2. Lalani S, Poh CL
    Viruses, 2020 Jun 30;12(7).
    PMID: 32630136 DOI: 10.3390/v12070712
    We have recently been made aware by Mr. Saravanan (National University of Singapore) thatthe structure of prunin flavonoid used in their study was different to the one that we reported [...].
    Matched MeSH terms: Flavonoids
  3. Khalilpourfarshbafi M, Gholami K, Murugan DD, Abdul Sattar MZ, Abdullah NA
    European journal of nutrition, 2019 Feb;58(1):5-25.
    PMID: 29541908 DOI: 10.1007/s00394-018-1663-8
    PROPOSE: Obesity is a fast growing epidemic worldwide. During obesity, the increase in adipose tissue mass arise from two different mechanisms, namely, hyperplasia and hypertrophy. Hyperplasia which is the increase in adipocyte number is characteristic of severe obese patients. Recently, there has been much interest in targeting adipogenesis as therapeutic strategy against obesity. Flavonoids have been shown to regulate several pathways and affect a number of molecular targets during specific stages of adipocyte development.

    METHODS: Presently, we provide a review of key studies evaluating the effects of dietary flavonoids in different stages of adipocyte development with a particular emphasis on the investigations that explore the underlying mechanisms of action of these compounds in human or animal cell lines as well as animal models.

    RESULTS: Flavonoids have been shown to regulate several pathways and affect a number of molecular targets during specific stages of adipocyte development. Although most of the studies reveal anti-adipogenic effect of flavonoids, some flavonoids demonstrated proadipogenic effect in mesenchymal stem cells or preadipocytes.

    CONCLUSION: The anti-adipogenic effect of flavonoids is mainly via their effect on regulation of several pathways such as induction of apoptosis, suppression of key adipogenic transcription factors, activation of AMPK and Wnt pathways, inhibition of clonal expansion, and cell-cycle arrest.

    Matched MeSH terms: Flavonoids/pharmacology*
  4. Matsuura S, Kunii T, Iinuma M
    Yakugaku Zasshi, 1973 Nov;93(11):1517-9.
    PMID: 4798539
    Matched MeSH terms: Flavonoids/isolation & purification*
  5. Ghasemzadeh A, Jaafar HZ, Rahmat A
    Int J Mol Sci, 2010;11(11):4539-55.
    PMID: 21151455 DOI: 10.3390/ijms11114539
    The relationship between phenolics and flavonoids synthesis/accumulation and photosynthesis rate was investigated for two Malaysian ginger (Zingiber officinale) varieties grown under four levels of glasshouse light intensity, namely 310, 460, 630 and 790 μmol m(-2)s(-1). High performance liquid chromatography (HPLC) was employed to identify and quantify the polyphenolic components. The results of HPLC analysis indicated that synthesis and partitioning of quercetin, rutin, catechin, epicatechin and naringenin were high in plants grown under 310 μmol m(-2)s(-1). The average value of flavonoids synthesis in leaves for both varieties increased (Halia Bentong 26.1%; Halia Bara 19.5%) when light intensity decreased. Photosynthetic rate and plant biomass increased in both varieties with increasing light intensity. More specifically, a high photosynthesis rate (12.25 μmol CO(2) m(-2)s(-1) in Halia Bara) and plant biomass (79.47 g in Halia Bentong) were observed at 790 μmol m(-2)s(-1). Furthermore, plants with the lowest rate of photosynthesis had highest flavonoids content. Previous studies have shown that quercetin inhibits and salicylic acid induces the electron transport rate in photosynthesis photosystems. In the current study, quercetin was an abundant flavonoid in both ginger varieties. Moreover, higher concentration of quercetin (1.12 mg/g dry weight) was found in Halia Bara leaves grown under 310 μmol m(-2)s(-1) with a low photosynthesis rate. Furthermore, a high content of salicylic acid (0.673 mg/g dry weight) was detected in Halia Bara leaves exposed under 790 μmol m(-2)s(-1) with a high photosynthesis rate. No salicylic acid was detected in gingers grown under 310 μmol m(-2)s(-1). Ginger is a semi-shade loving plant that does not require high light intensity for photosynthesis. Different photosynthesis rates at different light intensities may be related to the absence or presence of some flavonoid and phenolic compounds.
    Matched MeSH terms: Flavonoids/biosynthesis; Flavonoids/metabolism*
  6. Rajudin E, Ahmad F, Sirat HM, Arbain D, Aboul-Enein HY
    Nat Prod Res, 2010 Mar;24(4):387-90.
    PMID: 20221945 DOI: 10.1080/14786410903421826
    Seven flavonoid compounds have been isolated from the aerial parts of tiger's betel (Piper porphyrophyllum), which were identified as 5,7-dimethoxyflavone, 4',5,7-trimethoxy-flavone, 3',4',5,7-tetramethoxyflavone, 4'-hydroxy-3',5,7-trimethoxyflavone, 5-hydroxy-3',4',7-trimethoxyflavone, 4',5-dihydroxy-3',7-dimethoxyflavone and 5-hydroxy-7-methoxyflavanone. The identification of all compounds was achieved by physical properties and spectroscopically. These data were also confirmed by comparison with previously reported spectral data. Flavonoid compounds with high content in P. porphyrophyllum can probably be used as a chemical marker for this Piper species.
    Matched MeSH terms: Flavonoids/isolation & purification*; Flavonoids/chemistry
  7. Chemah T, Aminah A, Wan Aida W, Noriham A
    Sisa puri pitaya merah bersama biji telah digunakan dalam penyediaan mufin yang dicampurkan dengan 10%, 15% dan 20% puri dalam formulasi bater. Ujian warna, kandungan jumlah polifenol, jumlah flavonoid, ujian antioksida; pemerangkapan radikal bebas 2,2-difenil-1-pikrilhidrazil (DPPH) dan ujian penurunan ferrik (FRAP) telah dijalankan. Warna bater 3 jenis mufin tersebut berwarna merah jambu violet. Warna merah jambu (nilai a) meningkat dengan signifikan (p<0.05) selaras peningkatan peratus kandungan puri manakala kecerahan (nilai L) menurun dengan peningkatan puri. Apabila dimasak, semua warna merah jambu daripada bater hilang. Permukaan mufin adalah lebih gelap (nilai L), dengan mufin 20% puri paling signifikan (p<0.05). Isi kesemua mufin berwarna kuning dan kecerahan (nilai L) didapati berkurang secara signifikan (p<0.05) dengan pertambahan peratus puri. Jumlah polifenol sampel mufin menunjukkan mufin 10% puri pitaya ekstrak air mengandungi jumlah polifenol yang paling tinggi (29.0 mg GAE/100 g sampel). Kandungan flavonoid menunjukkan mufin 20% puri pitaya mengandungi flavonoid yang paling signifikan (p<0.05) 15.3 mg katekin/100 g sampel berbanding mufin kawalan 11.0 mg katekin. Bagi ujian antioksida DPPH, semua mufin dengan puri pitaya menunjukkan peratus pemerangkapan yang lebih baik berbanding kawalan. Ujian FRAP menunjukkan pola yang serupa dengan keputusan mufin 10% (17.4), mufin 15% (15.4) dan mufin 20% (17.5 mg trolox/100 g sampel). Warna merah jambu bater mufin hilang semasa proses memasak namun nilai antioksida masih diperolehi dalam mufin masak.
    Matched MeSH terms: Flavonoids
  8. Abdallah HH, Mavri J, Repič M, Lee VS, Wahab HA
    Int J Mol Sci, 2012;13(2):1269-83.
    PMID: 22408390 DOI: 10.3390/ijms13021269
    Genistein, daidzein, glycitein and quercetin are flavonoids present in soybean and other vegetables in high amounts. These flavonoids can be metabolically converted to more active forms, which may react with guanine in the DNA to form complexes and can lead to DNA depurination. We assumed two ultimate carcinogen forms of each of these flavonoids, diol epoxide form and diketone form. Density functional theory (DFT) and Hartree-Fock (HF) methods were used to study the reaction thermodynamics between active forms of flavonoids and DNA guanine. Solvent reaction field method of Tomasi and co-workers and the Langevin dipoles method of Florian and Warshel were used to calculate the hydration free energies. Activation free energy for each reaction was estimated using the linear free energy relation. Our calculations show that diol epoxide forms of flavonoids are more reactive than the corresponding diketone forms and are hence more likely flavonoid ultimate carcinogens. Genistein, daidzein and glycitein show comparable reactivity while quercetin is less reactive toward DNA.
    Matched MeSH terms: Flavonoids/chemistry*
  9. Ghasemzadeh A, Jaafar HZ, Rahmat A, Wahab PE, Halim MR
    Int J Mol Sci, 2010;11(10):3885-97.
    PMID: 21152306 DOI: 10.3390/ijms11103885
    Nowadays, phytochemicals and antioxidants in plants are raising interest in consumers for their roles in the maintenance of human health. Phenolics and flavonoids are known for their health-promoting properties due to protective effects against cardiovascular disease, cancers and other disease. Ginger (Zingiber officinale) is one of the traditional folk medicinal plants and it is widely used in cooking in Malaysia. In this study, four levels of glasshouse light intensities (310, 460, 630 and 790 μmol m(-2)s(-1)) were used in order to consider the effect of light intensity on the production, accumulation and partitioning of total phenolics (TP), total flavonoids (TF) and antioxidant activities in two varieties of Malaysian young ginger (Zingiber officinale). TF biosynthesis was highest in the Halia Bara variety under 310 μmol m(-2)s(-1) and TP was high in this variety under a light intensity of 790 μmol m(-2)s(-1). The highest amount of these components accumulated in the leaves and after that in the rhizomes. Also, antioxidant activities determined by the 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) assay in both of varieties, increased significantly (p ≤ 0.01) with increasing TF concentration, and high antioxidant activity was observed in the leaves of Halia Bara grown under 310 μmol m(-2)s(-1). The ferric reducing (FRAP) activity of the rhizomes was higher than that of the leaves in 310 μmol m(-2)s(-1) of sun light. This study indicates the ability of different light intensities to enhance the medicinal components and antioxidant activities of the leaves and young rhizomes of Zingiber officinale varieties. Additionally, this study also validated their medicinal potential based on TF and TP contents.
    Matched MeSH terms: Flavonoids/biosynthesis*; Flavonoids/metabolism
  10. Lukaseder B, Vajrodaya S, Hehenberger T, Seger C, Nagl M, Lutz-Kutschera G, et al.
    Phytochemistry, 2009 May;70(8):1030-7.
    PMID: 19535116 DOI: 10.1016/j.phytochem.2009.05.007
    Fifteen prenylated or geranylated flavanones and flavanonols were isolated from the leaf extracts of different Glycosmis species collected in Thailand and Malaysia. All structures were elucidated by spectroscopic methods, especially 1D and 2D NMR. Six compounds were described for the first time and two were only known so far as synthetic products. The chemotaxonomic significance of flavanoid accumulation within the genus Glycosmis is highlighted.
    Matched MeSH terms: Flavonoids/isolation & purification*; Flavonoids/chemistry
  11. Aziz Z, Huin WK, Badrul Hisham MD, Tang WL, Yaacob S
    Complement Ther Med, 2018 Aug;39:49-55.
    PMID: 30012392 DOI: 10.1016/j.ctim.2018.05.011
    OBJECTIVE: To present a systematic review of randomised controlled trials (RCTs) examining the effects of MPFF in the management of haemorrhoid symptoms.

    METHODS: Electronic databases including CENTRAL, CINAHL, EMBASE, MEDLINE were searched up to April 2018 for relevant RCTs. Journal and conference proceedings were also searched. Two review authors independently selected trials, extracted data, assessed the risks of bias in included trials and graded the quality of evidence. Meta-analyses were conducted for studies presenting similar outcomes.

    RESULTS: Ten RCTs involving 1164 participants were included. These RCTs varied in terms of patients' grade of haemorrhoids, length of trials, and outcome assessed. Most of the studies did not describe adequately the process of randomisation and allocation concealment. The pooled analysis of data from three studies indicated that there was significant difference between groups for the bleeding outcome, favoring the MPFF group (RR 1.46; 95% CI 1.10-1.93; p = 0.008). Except for bleeding, the current evidence did not show MPFF has significant effects on all the other outcomes examined when compared with placebo. Even then, the quality of evidence for bleeding was judged as low due to the small number and inconsistent results among the included studies.

    CONCLUSION: This review highlights the need for further rigorous research if MPFF was to be routinely used for the treatment of haemorrhoid symptoms.

    Matched MeSH terms: Flavonoids/adverse effects*; Flavonoids/therapeutic use*
  12. Hong FJ, Low YY, Chong KW, Thomas NF, Kam TS
    J. Org. Chem., 2014 May 16;79(10):4528-43.
    PMID: 24754525 DOI: 10.1021/jo500559r
    A systematic study of the electrochemical oxidation of 1,2-diarylalkenes was carried out with the focus on detailed product studies and variation of product type as a function of aromatic substitution. A reinvestigation of the electrochemical oxidation of 4,4'-dimethoxystilbene under various conditions was first carried out, and all products formed were fully characterized and quantitated. This was followed by a systematic investigation of the effect of aromatic substitution on the nature and distribution of the products. The aromatic substituents were found to fall into three main categories, viz., substrates in which the nature and position of the aromatic substituents gave rise to essentially the same products as 4,4'-dimethoxystilbene, for example, tetraaryltetrahydrofurans, dehydrotetralins, and aldehydes (p-MeO or p-NMe2 on one ring and X on the other ring, where X = o-MeO or p-alkyl, or m- or p-EWG; e.g., 4-methoxy-4'-trifluoromethylstilbene); those that gave rise to a mixture of indanyl (or tetralinyl) acetamides and dehydrotetralins (or pallidols) (both or one ring substituted by alkyl groups, e.g., 4,4'-dimethylstilbene); and those where strategic placement of donor groups, such as OMe and OH, led to the formation of ampelopsin F and pallidol-type carbon skeletons (e.g., 4,3',4'-trimethoxystilbene). Reaction pathways to rationalize the formation of the different products are presented.
    Matched MeSH terms: Flavonoids/chemistry
  13. Wiart C
    Food Chem. Toxicol., 2014 Feb;64:410.
    PMID: 24316313 DOI: 10.1016/j.fct.2013.11.052
    Matched MeSH terms: Flavonoids/pharmacology*
  14. Salvamani S, Gunasekaran B, Shaharuddin NA, Ahmad SA, Shukor MY
    Biomed Res Int, 2014;2014:480258.
    PMID: 24971331 DOI: 10.1155/2014/480258
    Atherosclerosis is the process of hardening and narrowing the arteries. Atherosclerosis is generally associated with cardiovascular diseases such as strokes, heart attacks, and peripheral vascular diseases. Since the usage of the synthetic drug, statins, leads to various side effects, the plants flavonoids with antiartherosclerotic activity gained much attention and were proven to reduce the risk of atherosclerosis in vitro and in vivo based on different animal models. The flavonoids compounds also exhibit lipid lowering effects and anti-inflammatory and antiatherogenic properties. The future development of flavonoids-based drugs is believed to provide significant effects on atherosclerosis and its related diseases. This paper discusses the antiatherosclerotic effects of selected plant flavonoids such as quercetin, kaempferol, myricetin, rutin, naringenin, catechin, fisetin, and gossypetin.
    Matched MeSH terms: Flavonoids/therapeutic use*
  15. Ghasemzadeh A, Jaafar HZ, Rahmat A
    Molecules, 2010 Jun 14;15(6):4324-33.
    PMID: 20657444 DOI: 10.3390/molecules15064324
    Ginger (Zingiber officinale Roscoe) is a well known and widely used herb, especially in Asia, which contains several interesting bioactive constituents and possesses health promoting properties. In this study, the antioxidant activities of methanol extracts from the leaves, stems and rhizomes of two Zingiber officinale varieties (Halia Bentong and Halia Bara) were assessed in an effort to compare and validate the medicinal potential of the subterranean part of the young ginger. The antioxidant activity and phenolic contents of the leaves as determined by the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay and the total amounts of phenolics and flavonoids were higher than those of the rhizomes and stems. On the other hand, the ferric reducing/antioxidant potential (FRAP) activity of the rhizomes was higher than that of the leaves. At low concentration the values of the leaves' inhibition activity in both varieties were significantly higher than or comparable to those of the young rhizomes. Halia Bara had higher antioxidant activities as well as total contents of phenolic and flavonoid in comparison with Halia Bentong. This study validated the medicinal potential of the leaves and young rhizome of Zingiber officinale (Halia Bara) and the positive relationship between total phenolics content and antioxidant activities in Zingiber officinale.
    Matched MeSH terms: Flavonoids/chemistry*
  16. Ali DM, Wong KC, Lim PK
    Fitoterapia, 2005 Jan;76(1):128-30.
    PMID: 15664477
    3,4',5-Trihydroxy-3',7-dimethoxyflavanone was isolated from the ligroin extract of the leaves of Blumea balsamifera, while the acetone extract yielded 3',4',5-trihydroxy-7-methoxyflavanone and a new biflavonoid identifed as 3-O-7''-biluteolin (1). The isolation of 1 is significant since a biflavonoid with a C-O-C linkage of the type [I-3-O-II-7] has not been previously reported from a plant.
    Matched MeSH terms: Flavonoids/chemistry
  17. Meng CC, Jalil AM, Ismail A
    Molecules, 2009;14(1):200-9.
    PMID: 19127248 DOI: 10.3390/molecules14010200
    Chocolate contains a wide range of antioxidants that includes soluble phenolic compounds (phenolic acids, catechin, epicatechin, and proanthocyanidins), insoluble polymeric phenolics and methylxanthines. The objective of this study was to determine phenolic and theobromine contents in dark (DC), milk (MC), and white (WC) chocolates commonly found in the Malaysian marketplace. Total phenolic and flavonoids were determined by means of a spectrometric assay, while catechin, epicatechin and theobromine were quantified using a reverse-phase HPLC method. Dark chocolates exhibited the highest phenolics and flavonoids contents, followed by milk and white chocolates. Catechin and epicatechin were major flavonoids detected in dark chocolates. Theobromine was detected in dark and milk chocolates, but not in white chocolates. A high correlation (r= 0.93) between total phenolic and flavonoid contents, indicating that the major phenolic compounds in dark chocolates belong to the flavonoid class. When nutrition and health promotion are of concern, dark chocolates would be recommended over milk and white chocolates owing to their higher contents of antioxidant phenolic compounds.
    Matched MeSH terms: Flavonoids/analysis*
  18. 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: Flavonoids/chemistry*
  19. Sarian MN, Ahmed QU, Mat So'ad SZ, Alhassan AM, Murugesu S, Perumal V, et al.
    Biomed Res Int, 2017;2017:8386065.
    PMID: 29318154 DOI: 10.1155/2017/8386065
    The best described pharmacological property of flavonoids is their capacity to act as potent antioxidant that has been reported to play an important role in the alleviation of diabetes mellitus. Flavonoids biochemical properties are structure dependent; however, they are yet to be thoroughly understood. Hence, the main aim of this work was to investigate the antioxidant and antidiabetic properties of some structurally related flavonoids to identify key positions responsible, their correlation, and the effect of methylation and acetylation on the same properties. Antioxidant potential was evaluated through dot blot, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ABTS+ radical scavenging, ferric reducing antioxidant power (FRAP), and xanthine oxidase inhibitory (XOI) assays. Antidiabetic effect was investigated through α-glucosidase and dipeptidyl peptidase-4 (DPP-4) assays. Results showed that the total number and the configuration of hydroxyl groups played an important role in regulating antioxidant and antidiabetic properties in scavenging DPPH radical, ABTS+ radical, and FRAP assays and improved both α-glucosidase and DPP-4 activities. Presence of C-2-C-3 double bond and C-4 ketonic group are two essential structural features in the bioactivity of flavonoids especially for antidiabetic property. Methylation and acetylation of hydroxyl groups were found to diminish the in vitro antioxidant and antidiabetic properties of the flavonoids.
    Matched MeSH terms: Flavonoids/chemistry*
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