Displaying publications 61 - 80 of 128 in total

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  1. Jalil AM, Ismail A
    Molecules, 2008 Sep 16;13(9):2190-219.
    PMID: 18830150
    Cocoa and cocoa products have received much attention due to their significant polyphenol contents. Cocoa and cocoa products, namely cocoa liquor, cocoa powder and chocolates (milk and dark chocolates) may present varied polyphenol contents and possess different levels of antioxidant potentials. For the past ten years, at least 28 human studies have been conducted utilizing one of these cocoa products. However, questions arise on which of these products would deliver the best polyphenol contents and antioxidant effects. Moreover, the presence of methylxanthines, peptides, and minerals could synergistically enhance or reduce antioxidant properties of cocoa and cocoa products. To a greater extent, cocoa beans from different countries of origins and the methods of preparation (primary and secondary) could also partially influence the antioxidant polyphenols of cocoa products. Hence, comprehensive studies on the aforementioned factors could provide the understanding of health-promoting activities of cocoa or cocoa products components.
    Matched MeSH terms: Flavonoids/chemistry*
  2. Hosseinzadeh M, Hadi AH, Mohamad J, Khalilzadeh MA, Cheahd SC, Fadaeinasab M
    Comb Chem High Throughput Screen, 2013 Feb;16(2):160-6.
    PMID: 23173924
    A new linderone A, namely 2-cinnamoyl-3-hydroxy-4, 5-dimethoxycyclopenta-2, 4-dienone (5), together with three known flavonoids (1-3) and one linderone (4), were isolated from the bark of Lindera oxyphylla. Extensive spectroscopic analysis including 1D and 2D-NMR spectra determined their sturctures. In addition, the antioxidant activity of all the compounds has been determined using 2, 2-diphenyl-1-picrylhydrazyl radical scavenging (DPPH), ferric reducing antioxidant power (FRAP) and ferrous ion chelating (FIC) methods. Compound 3 showed excellent DPPH scavenging activity with IC50% value of 8.5 ± 0.004% (μg/mL) which is comparable with vitamin C. This compound, also showed an absorbance value of 1.00 ± 0.06% through FRAP test when compared with Butyl Hydroxy Aniline (BHA). However, FIC showed low activity for all the isolated compounds (chelating activity less than 50%) in comparison with ethylene diamine tetra acetic acid (EDTA). Anticancer activity for all compounds has also been measured on A375 human melanoma, HT-29 colon adenocarcinoma, MCF-7 human breast adenocarcinoma cells, WRL-68 normal hepatic cells, A549 non-small cell lung cancer cells and PC-3 prostate adenocarcinoma cell line. Compound 1 showed A549=65.03%, PC-3=30.12%, MCF-7=47.67, compound 2 showed PC-3=90.13%, compound 3 showed MCF-7=79.57 and for compound 5 MCF-7 is 96.33.
    Matched MeSH terms: Flavonoids/chemistry*
  3. Goh HH, Khairudin K, Sukiran NA, Normah MN, Baharum SN
    Plant Biol (Stuttg), 2016 Jan;18 Suppl 1:130-9.
    PMID: 26417881 DOI: 10.1111/plb.12403
    Temperature is one of the key factors in limiting the distribution of plants and controlling major metabolic processes. A series of simulated reciprocal transplant experiments were performed to investigate the effect of temperature on plant chemical composition. Polygonum minus of different lowland and highland origin were grown under a controlled environment with different temperature regimes to study the effects on secondary metabolites. We applied gas chromatography-mass spectrometry and liquid chromatography time-of-flight mass spectrometry to identify the chemical compounds. A total of 37 volatile organic compounds and 85 flavonoids were detected, with the largest response observed in the compositional changes of aldehydes and terpenes in highland plants under higher temperature treatment. Significantly less anthocyanidin compounds and larger amounts of flavonols were detected under higher temperature treatment. We also studied natural variation in the different plant populations growing under the same environment and identified compounds unique to each population through metabolite fingerprinting. This study shows that the origin of different plant populations influences the effects of temperature on chemical composition.
    Matched MeSH terms: Flavonoids/chemistry
  4. Seyedi SS, Shukri M, Hassandarvish P, Oo A, Shankar EM, Abubakar S, et al.
    Sci Rep, 2016 04 13;6:24027.
    PMID: 27071308 DOI: 10.1038/srep24027
    Chikungunya virus (CHIKV) is a mosquito-borne alphavirus that causes chikungunya infection in humans. Despite the widespread distribution of CHIKV, no antiviral medication or vaccine is available against this virus. Therefore, it is crucial to find an effective compound to combat CHIKV. We aimed to predict the possible interactions between non-structural protein 3 (nsP) of CHIKV as one of the most important viral elements in CHIKV intracellular replication and 3 potential flavonoids using a computational approach. The 3-dimensional structure of nsP3 was retrieved from the Protein Data Bank, prepared and, using AutoDock Vina, docked with baicalin, naringenin and quercetagetin as ligands. The first-rated ligand with the strongest binding affinity towards the targeted protein was determined based on the minimum binding energy. Further analysis was conducted to identify both the active site of the protein that reacts with the tested ligands and all of the existing intermolecular bonds. Compared to the other ligands, baicalin was identified as the most potential inhibitor of viral activity by showing the best binding affinity (-9.8 kcal/mol). Baicalin can be considered a good candidate for further evaluation as a potentially efficient antiviral against CHIKV.
    Matched MeSH terms: Flavonoids/chemistry
  5. Abdullah NH, Salim F, Ahmad R
    Molecules, 2016 Apr 27;21(5).
    PMID: 27128898 DOI: 10.3390/molecules21050525
    Continuing our interest in the Uncaria genus, the phytochemistry and the in-vitro α-glucosidase inhibitory activities of Malaysian Uncaria cordata var. ferruginea were investigated. The phytochemical study of this plant, which employed various chromatographic techniques including recycling preparative HPLC, led to the isolation of ten compounds with diverse structures comprising three phenolic acids, two coumarins, three flavonoids, a terpene and an iridoid glycoside. These constituents were identified as 2-hydroxybenzoic acid or salicylic acid (1), 2,4-dihydroxybenzoic acid (2), 3,4-dihydroxybenzoic acid (3), scopoletin or 7-hydroxy-6-methoxy-coumarin (4), 3,4-dihydroxy-7-methoxycoumarin (5), quercetin (6), kaempferol (7), taxifolin (8), loganin (9) and β-sitosterol (10). Structure elucidation of the compounds was accomplished with the aid of 1D and 2D Nuclear Magnetic Resonance (NMR) spectral data and Ultraviolet-Visible (UV-Vis), Fourier Transform Infrared (FTIR) spectroscopy and mass spectrometry (MS). In the α-glucosidase inhibitory assay, the crude methanolic extract of the stems of the plant and its acetone fraction exhibited strong α-glucosidase inhibition activity of 87.7% and 89.2%, respectively, while its DCM fraction exhibited only moderate inhibition (75.3%) at a concentration of 1 mg/mL. The IC50 values of both fractions were found to be significantly lower than the standard acarbose suggesting the presence of potential α-glucosidase inhibitors. Selected compounds isolated from the active fractions were then subjected to α-glucosidase assay in which 2,4-dihydroxybenzoic acid and quercetin showed strong inhibitory effects against the enzyme with IC50 values of 549 and 556 μg/mL compared to acarbose (IC50 580 μg/mL) while loganin and scopoletin only showed weak α-glucosidase inhibition of 44.9% and 34.5%, respectively. This is the first report of the isolation of 2-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid and loganin from the genus and the first report of the α-glucosidase inhibitory potential of 2,4-dihydroxybenzoic acid.
    Matched MeSH terms: Flavonoids/chemistry
  6. Lichius JJ, Thoison O, Montagnac A, Païs M, Guéritte-Voegelein F, Sévenet T, et al.
    J Nat Prod, 1994 Jul;57(7):1012-6.
    PMID: 7964782
    Bioassay-guided fractionation of the extracts of Zieridium pseudobtusifolium and Acronychia porteri led to the isolation of 5,3'-dihydroxy-3,6,7,8,4'-pentamethoxyflavone [1], which showed activity against (KB) human nasopharyngeal carcinoma cells (IC50 0.04 micrograms/ml) and inhibited tubulin assembly into microtubules (IC50 12 microM). Two other known flavonols, digicitrin [2] and 5-hydroxy-3,6,7,8,3',4'-hexamethoxyflavone [5], were also isolated together with three new ones, 3-O-demethyldigicitrin [3], 3,5,3'-trihydroxy-6,7,8,4'-tetramethoxyflavone [4], and 3,5-dihydroxy-6,7,8,3',4'-pentamethoxyflavone [6]. All of these flavonols showed cytotoxic activity against KB cells.
    Matched MeSH terms: Flavonoids/chemistry
  7. Ravishankar D, Salamah M, Akimbaev A, Williams HF, Albadawi DAI, Vaiyapuri R, et al.
    Sci Rep, 2018 06 22;8(1):9528.
    PMID: 29934595 DOI: 10.1038/s41598-018-27809-z
    Flavonoids exert innumerable beneficial effects on cardiovascular health including the reduction of platelet activation, and thereby, thrombosis. Hence, flavonoids are deemed to be a molecular template for the design of novel therapeutic agents for various diseases including thrombotic conditions. However, the structure-activity relationships of flavonoids with platelets is not fully understood. Therefore, this study aims to advance the current knowledge on structure-activity relationships of flavonoids through a systematic analysis of structurally-related flavones. Here, we investigated a panel of 16 synthetic flavones containing hydroxy or methoxy groups at C-7,8 positions on the A-ring, with a phenyl group or its bioisosteres as the B-ring, along with their thio analogues possessing a sulfur molecule at the 4th carbon position of the C-ring. The antiplatelet efficacies of these compounds were analysed using human isolated platelets upon activation with cross-linked collagen-related peptide by optical aggregometry. The results demonstrate that the hydroxyl groups in flavonoids are important for optimum platelet inhibitory activities. In addition, the 4-C=O and B ring phenyl groups are less critical for the antiplatelet activity of these flavonoids. This structure-activity relationship of flavonoids with the modulation of platelet function may guide the design, optimisation and development of flavonoid scaffolds as antiplatelet agents.
    Matched MeSH terms: Flavonoids/chemistry*
  8. Ghasemzadeh A, Jaafar HZE, Baghdadi A, Tayebi-Meigooni A
    Molecules, 2018 Jul 25;23(8).
    PMID: 30044450 DOI: 10.3390/molecules23081852
    Since α-mangostin in mangosteen fruits was reported to be the main compound able to provide natural antioxidants, the microwave-assisted extraction process to obtain high-quality α-mangostin from mangosteen pericarp (Garcinia mangostana L.) was optimized using a central composite design and response surface methodology. The parameters examined included extraction time, microwave power, and solvent percentage. The antioxidant and antimicrobial activity of optimized and non-optimized extracts was evaluated. Ethyl acetate as a green solvent exhibited the highest concentration of α-mangostin, followed by dichloromethane, ethanol, and water. The highest α-mangostin concentration in mangosteen pericarp of 121.01 mg/g dry matter (DM) was predicted at 3.16 min, 189.20 W, and 72.40% (v/v). The verification of experimental results under these optimized conditions showed that the α-mangostin value for the mangosteen pericarp was 120.68 mg/g DM. The predicted models were successfully developed to extract α-mangostin from the mangosteen pericarp. No significant differences were observed between the predicted and the experimental α-mangostin values, indicating that the developed models are accurate. The analysis of the extracts for secondary metabolites showed that the total phenolic content (TPC) and total flavonoid content (TFC) increased significantly in the optimized extracts (OE) compared to the non-optimized extracts (NOE). Additionally, trans-ferulic acid and catechin were abundant among the compounds identified. In addition, the optimized extract of mangosteen pericarp with its higher α-mangostin and secondary metabolite concentrations exhibited higher antioxidant activities with half maximal inhibitory concentration (IC50) values of 20.64 µg/mL compared to those of the NOE (28.50 µg/mL). The OE exhibited the highest antibacterial activity, particularly against Gram-positive bacteria. In this study, the microwave-assisted extraction process of α-mangostin from mangosteen pericarp was successfully optimized, indicating the accuracy of the models developed, which will be usable in a larger-scale extraction process.
    Matched MeSH terms: Flavonoids/chemistry
  9. Wongrattanakamon P, Lee VS, Nimmanpipug P, Sirithunyalug B, Chansakaow S, Jiranusornkul S
    Toxicol. Mech. Methods, 2017 May;27(4):253-271.
    PMID: 27996361 DOI: 10.1080/15376516.2016.1273428
    In this work, molecular docking, pharmacophore modeling and molecular dynamics (MD) simulation were rendered for the mouse P-glycoprotein (P-gp) (code: 4Q9H) and bioflavonoids; amorphigenin, chrysin, epigallocatechin, formononetin and rotenone including a positive control; verapamil to identify protein-ligand interaction features including binding affinities, interaction characteristics, hot-spot amino acid residues and complex stabilities. These flavonoids occupied the same binding site with high binding affinities and shared the same key residues for their binding interactions and the binding region of the flavonoids was revealed that overlapped the ATP binding region with hydrophobic and hydrophilic interactions suggesting a competitive inhibition mechanism of the compounds. Root mean square deviations (RMSDs) analysis of MD trajectories of the protein-ligand complexes and NBD2 residues, and ligands pointed out these residues were stable throughout the duration of MD simulations. Thus, the applied preliminary structure-based molecular modeling approach of interactions between NBD2 and flavonoids may be gainful to realize the intimate inhibition mechanism of P-gp at NBD2 level and on the basis of the obtained data, it can be concluded that these bioflavonoids have the potential to cause herb-drug interactions or be used as lead molecules for the inhibition of P-gp (as anti-multidrug resistance agents) via the NBD2 blocking mechanism in future.
    Matched MeSH terms: Flavonoids/chemistry
  10. Lani R, Hassandarvish P, Shu MH, Phoon WH, Chu JJ, Higgs S, et al.
    Antiviral Res, 2016 Sep;133:50-61.
    PMID: 27460167 DOI: 10.1016/j.antiviral.2016.07.009
    This study focuses on the antiviral activity of selected flavonoids against the Chikungunya virus (CHIKV), a mosquito-transmitted virus that can cause incapacitating arthritis in infected individuals. Based on the results of screening on Vero cells, the tested compounds were evaluated further with various assays, including cytotoxicity assay, virus yield assay by quantitative reverse transcription polymerase chain reaction (qRT-PCR), virus RNA replication assay with a CHIKV replicon cell line, Western blotting, and quantitative immunofluorescence assay. Baicalein, fisetin, and quercetagetin displayed potent inhibition of CHIKV infection, with 50% inhibitory concentrations [IC50] of 1.891 μg/ml (6.997 μM), 8.444 μg/ml (29.5 μM), and 13.85 μg/ml (43.52 μM), respectively, and with minimal cytotoxicity. The time-of-addition studies and various antiviral assays demonstrated that baicalein and quercetagetin mainly inhibited CHIKV binding to the Vero cells and displayed potent activity against extracellular CHIKV particles. The qRT-PCR, immunofluorescence assay, and Western blot analyses indicated that each of these flavonoids affects CHIKV RNA production and viral protein expression. These data provide the first evidence of the intracellular anti-CHIKV activity of baicalein, fisetin, and quercetagetin.
    Matched MeSH terms: Flavonoids/chemistry
  11. Sabandar CW, Jalil J, Ahmat N, Aladdin NA
    Phytochemistry, 2017 Feb;134:6-25.
    PMID: 27889244 DOI: 10.1016/j.phytochem.2016.11.010
    The genus Dillenia is comprised of about 100 species of evergreen and deciduous trees or shrubs of disjunct distribution in the seasonal tropics of Madagascar through South and South East Asia, Malaysia, North Australia, and Fiji. Species from this genus have been widely used in medicinal folklore to treat cancers, wounds, jaundice, fever, cough, diabetes mellitus, and diarrhea as well as hair tonics. The plants of the genus also produce edible fruits and are cultivated as ornamental plants. Flavonoids, triterpenoids, and miscellaneous compounds have been identified in the genus. Their extracts and pure compounds have been reported for their antimicrobial, anti-inflammatory, cytotoxic, antidiabetes, antioxidant, antidiarrheal, and antiprotozoal activities. Mucilage from their fruits is used in drug formulations.
    Matched MeSH terms: Flavonoids/chemistry
  12. Salhi N, Mohammed Saghir SA, Terzi V, Brahmi I, Ghedairi N, Bissati S
    Biomed Res Int, 2017;2017:7526291.
    PMID: 29226147 DOI: 10.1155/2017/7526291
    Aim: This study investigated the antifungal properties of aqueous extracts obtained from indigenous plants that grow spontaneously in the Northern Sahara of Algeria. The activities of these plants in controlling two fungal species that belong to Fusarium genus were evaluated in an in vitro assay.

    Materials and Methods: Fresh aerial parts of four plant species (Artemisia herba alba, Cotula cinerea, Asphodelus tenuifolius, and Euphorbia guyoniana) were collected for the preparation of aqueous extracts. Two levels of dilution (10% and 20%) of the pure extracts were evaluated against Fusarium graminearum and Fusarium sporotrichioides.

    Results: The results of this study revealed that the A. herba alba, C. cinerea, A. tenuifolius, and E. guyoniana aqueous extracts are effective at both concentrations of 10% and 20% for the Fusarium mycelia growth inhibition. In particular, A. tenuifolius extract is effective against F. graminearum, whereas F. sporotrichioides mycelium growth is strongly affected by the E. guyoniana 20% extract. The phytochemical characterization of the compositions of the aqueous extracts has revealed that the presence of some chemical compounds (tannins, flavonoids, saponins, steroids, and alkaloids) is likely to be responsible for the antifungal activities sought.

    Conclusion: The antifungal properties of A. herba alba, C. cinerea, A. tenuifolius, and E. guyoniana make these plants of potential interest for the control of fungi affecting both wheat yield and safety.

    Matched MeSH terms: Flavonoids/chemistry
  13. Hung Ho S, Wang J, Sim KY, Ee GC, Imiyabir Z, Yap KF, et al.
    Phytochemistry, 2003 Apr;62(7):1121-4.
    PMID: 12591266
    We screened more than 60 Malaysian plants against two species of insects and found that Melicope subunifoliolata (Stapf) T.G. Hartley (Rutaceae) showed strong feeding deterrent activity against Sitophilus zeamais Motsch. (Curculionidae) and very good larvicidal activity against Aedes aegypti L. (Diptera). One anti-insect compound, meliternatin (3,5-dimethoxy-3',4',6,7-bismethylendioxyflavone) (6) and six other minor polyoxygenated flavones were isolated from M. subunifoliolata.
    Matched MeSH terms: Flavonoids/chemistry*
  14. Ahmad T, Bustam MA, Irfan M, Moniruzzaman M, Asghar HMA, Bhattacharjee S
    Biotechnol Appl Biochem, 2019 Jul;66(4):698-708.
    PMID: 31172593 DOI: 10.1002/bab.1787
    Phytosynthesis of gold nanoparticles (AuNPs) has achieved an indispensable significance due to the diverse roles played by biomolecules in directing the physiochemical characteristics of biosynthesized nanoparticles. Therefore, the precise identification of key bioactive compounds involved in producing AuNPs is vital to control their tunable characteristics for potential applications. Herein, qualitative and quantitative determination of key biocompounds contributing to the formation of AuNPs using aqueous Elaeis guineensis leaves extract is reported. Moreover, roles of phenolic compounds and flavonoids in reduction of Au3+ and stabilization of AuNPs have been elucidated by establishing a reaction mechanism. Fourier-transform infrared spectroscopy (FTIR) showed shifting of O─H stretching vibrations toward longer wavenumbers and C═O toward shorter wavenumbers due to involvement of polyphenolic compounds in biosynthesis and oxidation of polyphenolic into carboxylic compounds, respectively, which cape nanoparticles to inhibit the aggregation. Congruently, pyrolysis-gas chromatography-mass spectrometry revealed the major contribution of polyphenolic compounds in the synthesis of AuNPs, which was further endorsed by reduction of total phenolic and total flavonoids contents from 48.08 ± 1.98 to 9.59 ± 0.92 mg GAE/g and 32.02 ± 1.31 to 13.8 ± 0.97 mg CE/g within 60 Min, respectively. Based on experimental results, reaction mechanism explained the roles of phenolic compounds and flavonoids in producing spherical-shaped AuNPs.
    Matched MeSH terms: Flavonoids/chemistry*
  15. Ceesay A, Nor Shamsudin M, Aliyu-Paiko M, Ismail IS, Nazarudin MF, Mohamed Alipiah N
    Biomed Res Int, 2019;2019:2640684.
    PMID: 31119160 DOI: 10.1155/2019/2640684
    The aim of the present study was to extract and characterize bioactive components from separate body organs of Holothuria leucospilota. Preliminary qualitative assessment of the crude extracts was positive for phenols, terpenoids, carbohydrates, flavonoids, saponins, glycosides, cardiac glycosides, steroids, phlobatannins, and tannins in all body organs evaluated. Phenolics were the most abundant group of bioactives accounting for approximately 80%. The extraction solvent mixtures that yielded most compounds evaluated were methanol/acetone (3:1, v:v) and methanol/distilled water (3:1, v:v). In other analyses, GC-MS data revealed diverse metabolic and biologically active compounds, where those in high concentrations included 2-Pentanone, 4-hydroxy-4-methyl- among the ketones; phenol- 2,4-bis(1,1-dimethylethyl)-, a phenol group; and 2-Chlorooctane, a hydrocarbon. Among FA and their methyl/ethyl esters, n-hexadecanoic acid, 5,8,11,14-eicosatetraenoic acid ethyl ester (arachidonic acid), and 5,8,11,14,17-eicosapentaenoic acid methyl ester (EPA) were among the most abundant FAMEs accounting for approximately 50% of the subgroups measured. Data from GC-FID analysis revealed methyl laurate (C12:0), methyl myristate (C14:0), methyl palmitate (C16:0), and methyl stearate (18:0) methyl esters as the most abundant saturated FA, whereas cis-9-oleic methyl ester (C18:1) and methyl linoleate (C18:2) were found as the major monounsaturated FA and PUFA FAMEs, respectively, in the body wall of the species. Taken together, the extraction and characterization of different categories of metabolically and biologically active compounds in various organ extracts of H. leucospilota suggest that the species is potentially a rich source of cholesterol-lowering, antioxidant, antimicrobial, and anticancer agents. These substances are known to benefit human health and assist in disease prevention. These findings justify the use of sea cucumbers in traditional folklore medication and the current interest and attention focused on the species to mine for bioactives in new drugs research.
    Matched MeSH terms: Flavonoids/chemistry
  16. Saleem H, Zengin G, Ahmad I, Lee JTB, Htar TT, Mahomoodally FM, et al.
    J Pharm Biomed Anal, 2019 Jun 05;170:132-138.
    PMID: 30921647 DOI: 10.1016/j.jpba.2019.03.027
    The current research work was conducted in order to probe into the biochemical and toxicological characterisation of methanol and dichloromethane (DCM) extracts of Bougainvillea glabra (Choisy.) aerial parts. Biological fingerprints were assessed for in vitro antioxidant, key enzyme inhibitory and cytotoxicity potential. Total bioactive contents were determined spectrophotometrically and the secondary metabolite components of methanol extract was assessed by UHPLC mass spectrometric analysis. The antioxidant capabilities were evaluated via six different in vitro antioxidant assays namely DPPH, ABTS (free radical scavenging), FRAP, CUPRAC (reducing antioxidant power), phosphomolybdenum (total antioxidant capacity) and ferrous chelating activity. Inhibition potential against key enzymes urease, α-glucosidase and cholinesterases were also determined. Methanol extract exhibited higher phenolic (24.01 mg GAE/g extract) as well as flavonoid (41.51 mg QE/g extract) contents. Phytochemical profiling of methanol extract identified a total of twenty secondary metabolites and the major compounds belonged to flavonoids, phenolics and alkaloid derivatives. The findings of antioxidant assays revealed the methanol extract to exhibit stronger antioxidant (except phosphomolybdenum) activities. Similarly, the methanol extract showed highest butyrylcholinesterase and urease inhibition. The DCM extract was most active for phosphomolybdenum and α-glucosidase inhibition assays. Moreover, both extracts exhibited significant cytotoxic potential against five (MCF-7, MDA-MB-231, CaSki, DU-145, and SW-480) human carcinoma cell lines with half maximal inhibitory concentration values of 22.09 to 257.2 μg/mL. Results from the present study highlighted the potential of B. glabra aerial extracts to be further explored in an endeavour to discover novel phytotherapeutics as well as functional ingredients.
    Matched MeSH terms: Flavonoids/chemistry
  17. Salahuddin MAH, Ismail A, Kassim NK, Hamid M, Ali MSM
    Food Chem, 2020 Nov 30;331:127240.
    PMID: 32585546 DOI: 10.1016/j.foodchem.2020.127240
    The present study focused on the phytochemical profiling along with evaluation of in vitro antioxidant, α-glucosidase and α-amylase inhibitory activities of various crudes and fractions obtained from Lepisanthes fruticosa (Roxb) Leenh fruit. Ethanolic seed crude extract exhibited the strongest radical scavenging, β-carotene bleaching activity, α-glucosidase inhibition and the highest total phenolic content (TPC). Column chromatography afforded various fractions with fraction M4 being the most potent due to the strongest radical scavenging, β-carotene bleaching, α-glucosidase inhibition and greatest amount of TPC. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of ethanolic seed crude extract and fraction M4 showed the presence of various phytochemicals with antioxidant and antidiabetic properties, which include mostly flavonoids and tannins. The results may suggest that the ethanolic crude seed extract and its fraction could be an excellent source of bioactive phytochemicals with antioxidant and antidiabetic potential.
    Matched MeSH terms: Flavonoids/chemistry
  18. Ghasemzadeh A, Nasiri A, Jaafar HZ, Baghdadi A, Ahmad I
    Molecules, 2014 Oct 30;19(11):17632-48.
    PMID: 25361426 DOI: 10.3390/molecules191117632
    In the current study, changes in secondary metabolite synthesis and the pharmaceutical quality of sabah snake grass leaves and buds were considered in relation to plant age (1 month, 6 months, and 1 year old). The activity of the enzyme chalcone synthase (CHS, EC 2.3.1.74) was measured, as it is a key enzyme for flavonoid production. Significant differences in total flavonoid (TF) production were observed between the three plant growth periods and the different plant parts. The highest contents of TF (6.32 mg/g dry weight [DW]) and total phenolic (TP) (18.21 mg/g DW) were recorded in 6-month-old buds. Among the flavonoids isolated in this study the most important ones based on concentration were from high to low as follows: catechin > quercetin > kaempferol > luteolin. Production of phenolic acids increased from 1 to 6 months, but after 6 months up to 1 year of age, they decreased significantly. The highest contents of caffeic acid (0.307 mg/g DW) and gallic acid (5.96 mg/g DW) were recorded in 1-year and 6-month-old buds, respectively. The lowest and highest activity of CHS was recorded in 1-month and 6-month-old buds with values of 3.6 and 9.5 nkat/mg protein, respectively. These results indicate that the increment in flavonoids and phenolic acids in 6-month-old buds can be attributed to an increase in CHS activity. The highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) activity was observed in the extract of 1-year-old buds followed by 6-month-old buds, with 50% of free radical scavenging (IC50) values of 64.6 and 73.5 µg/mL, respectively. Interestingly, a ferric reducing antioxidant power (FRAP) assay showed a higher activity in 6-month-old buds (488 μM of Fe(II)/g) than in 1-year-old buds (453 μM of Fe(II)/g), in contrast to the DPPH result. Significant correlations (p < 0.05) were observed between CHS enzyme activity and FRAP activity, TF, catechin, and kaempferol content. Extracts of 6-month-old bud exhibited a significant in vitro anticancer activity against HeLa cancer cells with IC50 value of 56.8 µg/mL. These results indicate that early harvesting of snake grass (6-month-old) may yield increased concentrations of secondary metabolites, which are potent antioxidant compounds.
    Matched MeSH terms: Flavonoids/chemistry
  19. Ghasemzadeh A, Jaafar HZ, Karimi E, Rahmat A
    PMID: 25169626 DOI: 10.1186/1472-6882-14-318
    Extraction prior to component analysis is the primary step in the recovery and isolation of bioactive phytochemicals from plant materials.
    Matched MeSH terms: Flavonoids/chemistry
  20. Ahmat N, Wibowo A, Mohamad SA, Low AL, Sufian AS, Yusof MI, et al.
    J Asian Nat Prod Res, 2014;16(11):1099-107.
    PMID: 25034352 DOI: 10.1080/10286020.2014.938059
    A new tetramer oligostilbenoid possessing tetrahydrofuran ring, malaysianol C (1), was isolated from the acetone extract of the stem bark of Dryobalanops lanceolata, together with four known oligostilbenoids nepalensinol E (2), ϵ-viniferin (3), laevifonol (4), and ampelopsin F (5). The structures of isolated compounds were elucidated on the basis of spectral evidence. The antibacterial activity of the isolated compounds was evaluated using resazurin microtitre-plate assay, whereas the cytotoxic activity was tested using MTT assay. The plausible biogenetic routes of the isolated compounds are also discussed.
    Matched MeSH terms: Flavonoids/chemistry
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