Displaying publications 81 - 100 of 138 in total

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  1. Fulltext Reduced photoinhibition under low irradiance enhanced Kacip Fatimah (Labisia pumila Benth) secondary metabolites, phenyl alanine lyase and antioxidant activity
    Ibrahim MH, Jaafar HZ
    Int J Mol Sci, 2012;13(5):5290-306.
    PMID: 22754297 DOI: 10.3390/ijms13055290
    A randomized complete block design experiment was designed to characterize the relationship between production of total flavonoids and phenolics, anthocyanin, photosynthesis, maximum efficiency of photosystem II (Fv/Fm), electron transfer rate (Fm/Fo), phenyl alanine lyase activity (PAL) and antioxidant (DPPH) in Labisia pumila var. alata, under four levels of irradiance (225, 500, 625 and 900 μmol/m(2)/s) for 16 weeks. As irradiance levels increased from 225 to 900 μmol/m(2)/s, the production of plant secondary metabolites (total flavonoids, phenolics and antocyanin) was found to decrease steadily. Production of total flavonoids and phenolics reached their peaks under 225 followed by 500, 625 and 900 μmol/m(2)/s irradiances. Significant positive correlation of production of total phenolics, flavonoids and antocyanin content with Fv/Fm, Fm/Fo and photosynthesis indicated up-regulation of carbon-based secondary metabolites (CBSM) under reduced photoinhibition on the under low light levels condition. At the lowest irradiance levels, Labisia pumila extracts also exhibited a significantly higher antioxidant activity (DPPH) than under high irradiance. The improved antioxidative activity under low light levels might be due to high availability of total flavonoids, phenolics and anthocyanin content in the plant extract. It was also found that an increase in the production of CBSM was due to high PAL activity under low light, probably signifying more availability of phenylalanine (Phe) under this condition.
    Matched MeSH terms: Flavonoids/chemistry
  2. Fulltext Involvement of nitrogen on flavonoids, glutathione, anthocyanin, ascorbic acid and antioxidant activities of Malaysian medicinal plant Labisia pumila Blume (Kacip Fatimah)
    Ibrahim MH, Jaafar HZ, Rahmat A, Rahman ZA
    Int J Mol Sci, 2012;13(1):393-408.
    PMID: 22312260 DOI: 10.3390/ijms13010393
    A split plot 3 by 4 experiment was designed to characterize the relationship between production of gluthatione (GSH), oxidized gluthatione (GSSG), total flavonoid, anthocyanin, ascorbic acid and antioxidant activities (FRAP and DPPH) in three varieties of Labisia pumila Blume, namely the varieties alata, pumila and lanceolata, under four levels of nitrogen fertilization (0, 90, 180 and 270 kg N/ha) for 15 weeks. The treatment effects were solely contributed by nitrogen application; there was neither varietal nor interaction effects observed. As the nitrogen levels decreased from 270 to 0 kg N/ha, the production of GSH and GSSG, anthocyanin, total flavonoid and ascorbic acid increased steadily. At the highest nitrogen treatment level, L. pumila exhibited significantly lower antioxidant activities (DPPH and FRAP) than those exposed to limited nitrogen growing conditions. Significant positive correlation was obtained between antioxidant activities (DPPH and FRAP), total flavonoid, GSH, GSSG, anthocyanin and ascorbic acid suggesting that an increase in the antioxidative activities in L. pumila under low nitrogen fertilization could be attributed to higher contents of these compounds. From this observation, it could be concluded that in order to avoid negative effects on the quality of L. pumila, it is advisable to avoid excessive application of nitrogen fertilizer when cultivating the herb for its medicinal use.
    Matched MeSH terms: Flavonoids/chemistry*
  3. Fulltext Effects of nitrogen fertilization on synthesis of primary and secondary metabolites in three varieties of Kacip Fatimah (Labisia pumila Blume)
    Ibrahim MH, Jaafar HZ, Rahmat A, Rahman ZA
    Int J Mol Sci, 2011;12(8):5238-54.
    PMID: 21954355 DOI: 10.3390/ijms12085238
    A split plot 3 by 4 experiment was designed to examine the impact of 15-week variable levels of nitrogen fertilization (0, 90, 180 and 270 kg N/ha) on the characteristics of total flavonoids (TF), total phenolics (TP), total non structurable carbohydrate (TNC), net assimilation rate, leaf chlorophyll content, carbon to nitrogen ratio (C/N), phenyl alanine lyase activity (PAL) and protein content, and their relationships, in three varieties of Labisia pumila Blume (alata, pumila and lanceolata). The treatment effects were solely contributed by nitrogen application; there was neither varietal nor interaction effect observed. As nitrogen levels increased from 0 to 270 kg N/ha, the production of TNC was found to decrease steadily. Production of TF and TP reached their peaks under 0 followed by 90, 180 and 270 kg N/ha treatment. However, net assimilation rate was enhanced as nitrogen fertilization increased from 0 to 270 kg N/ha. The increase in production of TP and TF under low nitrogen levels (0 and 90 kg N/ha) was found to be correlated with enhanced PAL activity. The enhancement in PAL activity was followed by reduction in production of soluble protein under low nitrogen fertilization indicating more availability of amino acid phenyl alanine (phe) under low nitrogen content that stimulate the production of carbon based secondary metabolites (CBSM). The latter was manifested by high C/N ratio in L. pumila plants.
    Matched MeSH terms: Flavonoids/chemistry
  4. Fulltext Impact of organic and inorganic fertilizers application on the phytochemical and antioxidant activity of Kacip Fatimah (Labisia pumila Benth)
    Ibrahim MH, Jaafar HZ, Karimi E, Ghasemzadeh A
    Molecules, 2013 Sep 05;18(9):10973-88.
    PMID: 24013410 DOI: 10.3390/molecules180910973
    A study was conducted to compare secondary metabolites and antioxidant activity of Labisia pumila Benth (Kacip Fatimah) in response to two sources of fertilizer [i.e., organic (chicken dung; 10% N:10% P₂O₅:10% K₂O) and inorganic fertilizer (NPK green; 15% N, 15% P₂O₅, 15% K₂O)] under different N rates of 0, 90, 180 and 270 kg N/ha. The experiment was arranged in a randomized complete block design replicated three times. At the end of 15 weeks, it was observed that the application of organic fertilizer enhanced the production of total phenolics, flavonoids, ascorbic acid, saponin and gluthathione content in L. pumila, compared to the use of inorganic fertilizer. The nitrate content was also reduced under organic fertilization. The application of nitrogen at 90 kg N/ha improved the production of secondary metabolites in Labisia pumila. Higher rates in excess of 90 kg N/ha reduced the level of secondary metabolites and antioxidant activity of this herb. The DPPH and FRAP activity was also highest at 90 kg N/ha. The results indicated that the use of chicken dung can enhance the production of secondary metabolites and improve antioxidant activity of this herb.
    Matched MeSH terms: Flavonoids/chemistry
  5. Modulation of lipid metabolism by Centella asiatica in oxidative stress rats
    Hussin M, Hamid AA, Mohamad S, Saari N, Bakar F, Dek SP
    J Food Sci, 2009 Mar;74(2):H72-8.
    PMID: 19323754 DOI: 10.1111/j.1750-3841.2009.01045.x
    A study was carried out to investigate the effects of Centella asiatica leaf on lipid metabolism of oxidative stress rats. The rats were fed 0.1% hydrogen peroxide (H(2)O(2)) with either 0.3% (w/w) C. asiatica extract, 5%C. asiatica powder (w/w), or 0.3% (w/w) alpha-tocopherol for 25 wk. Results of the study showed that C. asiatica powder significantly (P < 0.05) lowered serum low-density lipoprotein compared to that of control rats (rats fed H(2)O(2) only). At the end of the study C. asiatica-fed rats were also found to have significantly (P < 0.05) higher high-density lipoprotein and lower triglyceride level compared to rats fed only normal diet. However, cholesterol level of rats fed both C. asiatica extract and powder was found to be significantly (P < 0.05) higher compared to that of control rats. It was interesting to note that consumption of C. asiatica significantly decreased body and liver weights of the rats. Histological examinations revealed no obvious changes in all rats studied. Quantitative analysis of C. asiatica leaf revealed high concentration of total phenolic compounds, in particular, catechin, quercetin, and rutin.
    Matched MeSH terms: Flavonoids/chemistry
  6. Meliternatin: a feeding deterrent and larvicidal polyoxygenated flavone from Melicope subunifoliolata
    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*
  7. Flavonoids and linderone from Lindera oxyphylla and their bioactivities
    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*
  8. Biomimetic oxidative dimerization of anodically generated stilbene radical cations: effect of aromatic substitution on product distribution and reaction pathways
    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
  9. Fulltext Flavonoid analyses and antimicrobial activity of various parts of Phaleria macrocarpa (Scheff.) Boerl fruit
    Hendra R, Ahmad S, Sukari A, Shukor MY, Oskoueian E
    Int J Mol Sci, 2011;12(6):3422-31.
    PMID: 21747685 DOI: 10.3390/ijms12063422
    Phaleria macrocarpa (Scheff.) Boerl (Thymelaceae) is commonly known as 'Crown of God', 'Mahkota Dewa', and 'Pau'. It originates from Papua Island, Indonesia and it grows in tropical areas. Empirically, it is potent in treating the hypertensive, diabetic, cancer and diuretic patients. It has a long history of ethnopharmacological usage, and the lack of information about its biological activities led us to investigate the possible biological activities by characterisation of flavonoids and antimicrobial activity of various part of P. macrocarpa against pathogenic bacteria and fungi. The results showed that kaempferol, myricetin, naringin, and rutin were the major flavonoids present in the pericarp while naringin and quercetin were found in the mesocarp and seed. Furthermore, the antibacterial activity of different parts of P. macrocarpa fruit showed a weak ability to moderate antibacterial activity against pathogenic tested bacteria (inhibition range: 0.93-2.17 cm) at concentration of 0.3 mg/disc. The anti fungi activity was only found in seed extract against Aspergillus niger (1.87 cm) at concentration of 0.3 mg/well. From the results obtained, P. macrocarpa fruit could be considered as a natural antimicrobial source due to the presence of flavonoid compounds.
    Matched MeSH terms: Flavonoids/chemistry*
  10. Fulltext Antioxidant, α-Glucosidase, and Nitric Oxide Inhibitory Activities of Six Algerian Traditional Medicinal Plant Extracts and 1H-NMR-Based Metabolomics Study of the Active Extract
    Hellal K, Maulidiani M, Ismail IS, Tan CP, Abas F
    Molecules, 2020 Mar 10;25(5).
    PMID: 32164186 DOI: 10.3390/molecules25051247
    Claims of effective therapy against diabetes using plants including Peganum harmala L., Zygophyllum album, Anacyclus valentinus L., Ammodaucus leucotrichus, Lupinus albus, and Marrubium vulgare in Algerian empirical medicine prompted our interest in evaluating their antidiabetic activity by screening their free radical scavenging (DPPH), α-glucosidase, and nitric oxide (NO) inhibitory activities as well as the total phenolic content (TPC). Extracts of the selected plants were prepared using different ratios of ethanol (0, 50, 80, and 100%). In this study, 100%, and 80% ethanol extracts of L. albus were found to be the most potent, in inhibiting α-glucosidase activity with IC50 values of 6.45 and 8.66 μg/mL, respectively. The 100% ethanol extract of A. leucotrichus exhibited the highest free radical scavenging activity with an IC50 value of 26.26 μg/mL. Moreover, the highest TPC of 612.84 μg GAE/mg extract was observed in M. vulgare, extracted with 80% ethanol. Metabolite profiling of the active extract was conducted using 1H-NMR metabolomics. Partial least square analysis (PLS) was used to assess the relationship between the α-glucosidase inhibitory activity of L. albus and the metabolites identified in the extract. Based on the PLS model, isoflavonoids (lupinoisoflavone G, lupisoflavone, lupinoisolone C), amino acids (asparagine and thiamine), and several fatty acids (stearic acid and oleic acid) were identified as metabolites that contributed to the inhibition of α-glucosidase activity. The results of this study have clearly strengthened the traditional claim of the antihyperglycemic effects of L. albus.
    Matched MeSH terms: Flavonoids/chemistry
  11. Colorectal, Prostate and Pancreas Human Cancers Targeted Bioassay-guided Isolations and Characterization of Chemical Constituents from Tephrosia apollinea
    Hassan LEA, Iqbal MA, Dahham SS, Tabana YM, Ahamed MBK, Majid AMSA
    Anticancer Agents Med Chem, 2017;17(4):590-598.
    PMID: 27671298 DOI: 10.2174/1871520616666160926113711
    BACKGROUND: Cancer is characterized by uncontrolled cell division caused by dysregulation of cell proliferation. Therefore, agents that impair cancer cell proliferation could have potential therapeutic value. Higher plants are considered to be a good source of anticancer agents, and several clinically tested chemotherapeutic agents have been isolated from plants or derived from constituents of plant origin.

    METHODS: In the present study, a prenylated flavone (isoglabratephrin) was isolated from aerial parts of Tephrosia apollinea using a bioassay-guided technique. Chemical structure of the isolated compound was elucidated using spectroscopic techniques (NMR, IR, and LC-MC), elemental analysis and confirmed by using single crystal X-ray analysis. The antiproliferative effect of isoglabratephrin was tested using three human cancer cell lines (prostate (PC3), pancreatic (PANC-1), and colon (HCT-116) and one normal cell line (human fibroblast).

    RESULTS: Isoglabratephrin displayed selective inhibitory activity against proliferation of PC3 and PANC-1 cells with median inhibitory concentration values of 20.4 and 26.6 μg/ml, respectively. Isoglabratephrin demonstrated proapoptotic features, as it induced chromatin dissolution, nuclear condensation, and fragmentation. It also disrupted the mitochondrial membrane potential in the treated cancer cells.

    CONCLUSION: Isoglabratephrin could be a new lead to treat human prostate (PC3) and pancreatic (PANC-1) malignancies.

    Matched MeSH terms: Flavonoids/chemistry
  12. Modulation of age related protein expression changes by gelam honey in cardiac mitochondrial rats
    Hasenan SM, Karsani SA, Jubri Z
    Exp Gerontol, 2018 11;113:1-9.
    PMID: 30248357 DOI: 10.1016/j.exger.2018.09.001
    Aging is characterized by progressive decline in biochemical and physiological functions. According to the free radical theory of aging, aging results from oxidative damage due to the accumulation of excess reactive oxygen species (ROS). Mitochondria are the main source of ROS production and are also the main target for ROS. Therefore, a diet high in antioxidant such as honey is potentially able to protect the body from ROS and oxidative damage. Gelam honey is higher in flavonoid content and phenolic compounds compared to other local honey. This study was conducted to determine the effects of gelam honey on age related protein expression changes in cardiac mitochondrial rat. A total of 24 Sprague-Dawley male rats were divided into two groups: the young group (2 months old), and aged group (19 months old). Each group were then subdivided into two groups: control group (force-fed with distilled water), and treatment group (force-fed with gelam honey, 2.5 g/kg), and were treated for 8 months. Comparative proteomic analysis of mitochondria from cardiac tissue was then performed by high performance mass spectrometry (Q-TOF LCMS/MS) followed by validation of selected proteins by Western blotting. Proteins were identified using Spectrum Mill software and were subjected to stringent statistical analysis. A total of 286 proteins were identified in the young control group (YC) and 241 proteins were identified in the young gelam group (YG). In the aged group, a total of 243 proteins were identified in control group (OC), and 271 proteins in gelam group (OG). Comparative proteome profiling identified 69 proteins with different abundance (p 
    Matched MeSH terms: Flavonoids/chemistry
  13. Fulltext Corn silk (Stigma maydis) in healthcare: a phytochemical and pharmacological review
    Hasanudin K, Hashim P, Mustafa S
    Molecules, 2012 Aug 13;17(8):9697-715.
    PMID: 22890173 DOI: 10.3390/molecules17089697
    Corn silk (Stigma maydis) is an important herb used traditionally by the Chinese, and Native Americans to treat many diseases. It is also used as traditional medicine in many parts of the world such as Turkey, United States and France. Its potential antioxidant and healthcare applications as diuretic agent, in hyperglycemia reduction, as anti-depressant and anti-fatigue use have been claimed in several reports. Other uses of corn silk include teas and supplements to treat urinary related problems. The potential use is very much related to its properties and mechanism of action of its plant's bioactive constituents such as flavonoids and terpenoids. As such, this review will cover the research findings on the potential applications of corn silk in healthcare which include its phytochemical and pharmacological activities. In addition, the botanical description and its toxicological studies are also included.
    Matched MeSH terms: Flavonoids/chemistry
  14. Fulltext Fabrication of an electrochemical sensor based on gold nanoparticles/carbon nanotubes as nanocomposite materials: determination of myricetin in some drinks
    Hajian R, Yusof NA, Faragi T, Shams N
    PLoS One, 2014;9(5):e96686.
    PMID: 24809346 DOI: 10.1371/journal.pone.0096686
    In this paper, the electrochemical behavior of myricetin on a gold nanoparticle/ethylenediamine/multi-walled carbon-nanotube modified glassy carbon electrode (AuNPs/en/MWCNTs/GCE) has been investigated. Myricetin effectively accumulated on the AuNPs/en/MWCNTs/GCE and caused a pair of irreversible redox peaks at around 0.408 V and 0.191 V (vs. Ag/AgCl) in 0.1 mol L-1 phosphate buffer solution (pH 3.5) for oxidation and reduction reactions respectively. The heights of the redox peaks were significantly higher on AuNPs/en/MWNTs/GCE compare with MWCNTs/GC and there was no peak on bare GC. The electron-transfer reaction for myricetin on the surface of electrochemical sensor was controlled by adsorption. Some parameters including pH, accumulation potential, accumulation time and scan rate have been optimized. Under the optimum conditions, anodic peak current was proportional to myricetin concentration in the dynamic range of 5.0×10-8 to 4.0×10-5 mol L-1 with the detection limit of 1.2×10-8 mol L-1. The proposed method was successfully used for the determination of myricetin content in tea and fruit juices.
    Matched MeSH terms: Flavonoids/chemistry
  15. Fulltext Modulation of glucose transporter protein by dietary flavonoids in type 2 diabetes mellitus
    Hajiaghaalipour F, Khalilpourfarshbafi M, Arya A
    Int J Biol Sci, 2015;11(5):508-24.
    PMID: 25892959 DOI: 10.7150/ijbs.11241
    Diabetes mellitus (DM) is a metabolic diseases characterized by hyperglycemia due to insufficient or inefficient insulin secretory response. This chronic disease is a global problem and there is a need for greater emphasis on therapeutic strategies in the health system. Phytochemicals such as flavonoids have recently attracted attention as source materials for the development of new antidiabetic drugs or alternative therapy for the management of diabetes and its related complications. The antidiabetic potential of flavonoids are mainly through their modulatory effects on glucose transporter by enhancing GLUT-2 expression in pancreatic β cells and increasing expression and promoting translocation of GLUT-4 via PI3K/AKT, CAP/Cb1/TC10 and AMPK pathways. This review highlights the recent findings on beneficial effects of flavonoids in the management of diabetes with particular emphasis on the investigations that explore the role of these compounds in modulating glucose transporter proteins at cellular and molecular level.
    Matched MeSH terms: Flavonoids/chemistry
  16. Antioxidant activity, total phenolics and flavonoids contents: Should we ban in vitro screening methods?
    Granato D, Shahidi F, Wrolstad R, Kilmartin P, Melton LD, Hidalgo FJ, et al.
    Food Chem, 2018 Oct 30;264:471-475.
    PMID: 29853403 DOI: 10.1016/j.foodchem.2018.04.012
    As many studies are exploring the association between ingestion of bioactive compounds and decreased risk of non-communicable diseases, the scientific community continues to show considerable interest in these compounds. In addition, as many non-nutrients with putative health benefits are reducing agents, hydrogen donors, singlet oxygen quenchers or metal chelators, measurement of antioxidant activity using in vitro assays has become very popular over recent decades. Measuring concentrations of total phenolics, flavonoids, and other compound (sub)classes using UV/Vis spectrophotometry offers a rapid chemical index, but chromatographic techniques are necessary to establish structure-activity. For bioactive purposes, in vivo models are required or, at the very least, methods that employ distinct mechanisms of action (i.e., single electron transfer, transition metal chelating ability, and hydrogen atom transfer). In this regard, better understanding and application of in vitro screening methods should help design of future research studies on 'bioactive compounds'.
    Matched MeSH terms: Flavonoids/chemistry
  17. Metabolite profiling reveals temperature effects on the VOCs and flavonoids of different plant populations
    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
  18. Fulltext Variation of the Phytochemical Constituents and Antioxidant Activities of Zingiber officinale var. rubrum Theilade Associated with Different Drying Methods and Polyphenol Oxidase Activity
    Ghasemzadeh A, Jaafar HZ, Rahmat A
    Molecules, 2016 Jun 17;21(6).
    PMID: 27322227 DOI: 10.3390/molecules21060780
    The effects of different drying methods (freeze drying, vacuum oven drying, and shade drying) on the phytochemical constituents associated with the antioxidant activities of Z. officinale var. rubrum Theilade were evaluated to determine the optimal drying process for these rhizomes. Total flavonoid content (TFC), total phenolic content (TPC), and polyphenol oxidase (PPO) activity were measured using the spectrophotometric method. Individual phenolic acids and flavonoids, 6- and 8-gingerol and shogaol were identified by ultra-high performance liquid chromatography method. Ferric reducing antioxidant potential (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays were used for the evaluation of antioxidant activities. The highest reduction in moisture content was observed after freeze drying (82.97%), followed by vacuum oven drying (80.43%) and shade drying (72.65%). The highest TPC, TFC, and 6- and 8-shogaol contents were observed in samples dried by the vacuum oven drying method compared to other drying methods. The highest content of 6- and 8-gingerol was observed after freeze drying, followed by vacuum oven drying and shade drying methods. Fresh samples had the highest PPO activity and lowest content of flavonoid and phenolic acid compounds compared to dried samples. Rhizomes dried by the vacuum oven drying method represent the highest DPPH (52.9%) and FRAP activities (566.5 μM of Fe (II)/g DM), followed by freeze drying (48.3% and 527.1 μM of Fe (II)/g DM, respectively) and shade drying methods (37.64% and 471.8 μM of Fe (II)/g DM, respectively) with IC50 values of 27.2, 29.1, and 34.8 μg/mL, respectively. Negative and significant correlations were observed between PPO and antioxidant activity of rhizomes. Vacuum oven dried rhizomes can be utilized as an ingredient for the development of value-added food products as they contain high contents of phytochemicals with valuable antioxidant potential.
    Matched MeSH terms: Flavonoids/chemistry
  19. Fulltext Changes in phytochemical synthesis, chalcone synthase activity and pharmaceutical qualities of sabah snake grass (Clinacanthus nutans L.) in relation to plant age
    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
  20. Fulltext Optimization of ultrasound-assisted extraction of flavonoid compounds and their pharmaceutical activity from curry leaf (Murraya koenigii L.) using response surface methodology
    Ghasemzadeh A, Jaafar HZ, Karimi E, Rahmat A
    BMC Complement Altern Med, 2014;14:318.
    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
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