Displaying publications 121 - 140 of 162 in total

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  1. In vitro expression of Candida albicans alcohol dehydrogenase genes involved in acetaldehyde metabolism
    Bakri MM, Rich AM, Cannon RD, Holmes AR
    Mol Oral Microbiol, 2015 Feb;30(1):27-38.
    PMID: 24975985 DOI: 10.1111/omi.12064
    Alcohol consumption is a risk factor for oral cancer, possibly via its conversion to acetaldehyde, a known carcinogen. The oral commensal yeast Candida albicans may be one of the agents responsible for this conversion intra-orally. The alcohol dehydrogenase (Adh) family of enzymes are involved in acetaldehyde metabolism in yeast but, for C. albicans it is not known which family member is responsible for the conversion of ethanol to acetaldehyde. In this study we determined the expression of mRNAs from three C. albicans Adh genes (CaADH1, CaADH2 and CaCDH3) for cells grown in different culture media at different growth phases by Northern blot analysis and quantitative reverse transcription polymerase chain reaction. CaADH1 was constitutively expressed under all growth conditions but there was differential expression of CaADH2. CaADH3 expression was not detected. To investigate whether CaAdh1p or CaAdh2p can contribute to alcohol catabolism in C. albicans, each gene from the reference strain C. albicans SC5314 was expressed in Saccharomyces cerevisiae. Cell extracts from an CaAdh1p-expressing S. cerevisiae recombinant, but not an CaAdh2p-expressing recombinant, or an empty vector control strain, possessed ethanol-utilizing Adh activity above endogenous S. cerevisiae activity. Furthermore, expression of C. albicans Adh1p in a recombinant S. cerevisiae strain in which the endogenous ScADH2 gene (known to convert ethanol to acetaldehyde in this yeast) had been deleted, conferred an NAD-dependent ethanol-utilizing, and so acetaldehyde-producing, Adh activity. We conclude that CaAdh1p is the enzyme responsible for ethanol use under in vitro growth conditions, and may contribute to the intra-oral production of acetaldehyde.
    Matched MeSH terms: Saccharomyces cerevisiae/genetics
  2. Ethanol and lactic acid production using sap squeezed from old oil palm trunks felled for replanting
    Kosugi A, Tanaka R, Magara K, Murata Y, Arai T, Sulaiman O, et al.
    J Biosci Bioeng, 2010 Sep;110(3):322-5.
    PMID: 20547348 DOI: 10.1016/j.jbiosc.2010.03.001
    Old oil palm trunks that had been felled for replanting were found to contain large quantities of high glucose content sap. Notably, the sap in the inner part of the trunk accounted for more than 80% of the whole trunk weight. The glucose concentration of the sap from the inner part was 85.2g/L and decreased towards the outer part. Other sugars found in relatively low concentrations were sucrose, fructose, galactose, xylose, and rhamnose. In addition, oil palm sap was found to be rich in various kinds of amino acids, organic acids, minerals and vitamins. Based on these findings, we fermented the sap to produce ethanol using the sake brewing yeast strain, Saccharomyces cerevisiae Kyokai no.7. Ethanol was produced from the sap without the addition of nutrients, at a comparable rate and yield to the reference fermentation on YPD medium with glucose as a carbon source. Likewise, we produced lactic acid, a promising material for bio-plastics, poly-lactate, from the sap using the homolactic acid bacterium Lactobacillus lactis ATCC19435. We confirmed that sugars contained in the sap were readily converted to lactic acid with almost the same efficiency as the reference fermentation on MSR medium with glucose as a substrate. These results indicate that oil palm trunks felled for replanting are a significant resource for the production of fuel ethanol and lactic acid in palm oil-producing countries such as Malaysia and Indonesia.
    Matched MeSH terms: Saccharomyces cerevisiae/metabolism*
  3. Fulltext Isolation and Functional Characterisation of a fads2 in Rainbow Trout (Oncorhynchus mykiss) with Δ5 Desaturase Activity
    Abdul Hamid NK, Carmona-Antoñanzas G, Monroig Ó, Tocher DR, Turchini GM, Donald JA
    PLoS One, 2016;11(3):e0150770.
    PMID: 26943160 DOI: 10.1371/journal.pone.0150770
    Rainbow trout, Oncorhynchus mykiss, are intensively cultured globally. Understanding their requirement for long-chain polyunsaturated fatty acids (LC-PUFA) and the biochemistry of the enzymes and biosynthetic pathways required for fatty acid synthesis is important and highly relevant in current aquaculture. Most gnathostome vertebrates have two fatty acid desaturase (fads) genes with known functions in LC-PUFA biosynthesis and termed fads1 and fads2. However, teleost fish have exclusively fads2 genes. In rainbow trout, a fads2 cDNA had been previously cloned and found to encode an enzyme with Δ6 desaturase activity. In the present study, a second fads2 cDNA was cloned from the liver of rainbow trout and termed fads2b. The full-length mRNA contained 1578 nucleotides with an open reading frame of 1365 nucleotides that encoded a 454 amino acid protein with a predicted molecular weight of 52.48 kDa. The predicted Fads2b protein had the characteristic traits of the microsomal Fads family, including an N-terminal cytochrome b5 domain containing the heme-binding motif (HPPG), histidine boxes (HDXGH, HFQHH and QIEHH) and three transmembrane regions. The fads2b was expressed predominantly in the brain, liver, intestine and pyloric caeca. Expression of the fasd2b in yeast generated a protein that was found to specifically convert eicosatetraenoic acid (20:4n-3) to eicosapentaenoic acid (20:5n-3), and therefore functioned as a Δ5 desaturase. Therefore, rainbow trout have two fads2 genes that encode proteins with Δ5 and Δ6 desaturase activities, respectively, which enable this species to perform all the desaturation steps required for the biosynthesis of LC-PUFA from C18 precursors.
    Matched MeSH terms: Saccharomyces cerevisiae/metabolism
  4. Synthesis, in vitro evaluation and molecular docking studies of thiazole derivatives as new inhibitors of α-glucosidase
    Rahim F, Ullah H, Javid MT, Wadood A, Taha M, Ashraf M, et al.
    Bioorg Chem, 2015 Oct;62:15-21.
    PMID: 26162519 DOI: 10.1016/j.bioorg.2015.06.006
    A series of thiazole derivatives 1-21 were prepared, characterized by EI-MS and (1)H NMR and evaluated for α-glucosidase inhibitory potential. All twenty one derivatives showed good α-glucosidase inhibitory activity with IC50 value ranging between 18.23±0.03 and 424.41±0.94μM when compared with the standard acarbose (IC50, 38.25±0.12μM). Compound (8) (IC50, 18.23±0.03μM) and compound (7) (IC50=36.75±0.05μM) exhibited outstanding inhibitory potential much better than the standard acarbose (IC50, 38.25±0.12μM). All other analogs also showed good to moderate enzyme inhibition. Molecular docking studies were carried out in order to find the binding affinity of thiazole derivatives with enzyme. Studies showed these thiazole analogs as a new class of α-glucosidase inhibitors.
    Matched MeSH terms: Saccharomyces cerevisiae Proteins/chemistry
  5. Solid acid catalysts pretreatment and enzymatic hydrolysis of macroalgae cellulosic residue for the production of bioethanol
    Tan IS, Lee KT
    Carbohydr Polym, 2015 Jun 25;124:311-21.
    PMID: 25839825 DOI: 10.1016/j.carbpol.2015.02.046
    The aim of this study is to investigate the technical feasibility of converting macroalgae cellulosic residue (MCR) into bioethanol. An attempt was made to present a novel, environmental friendly and economical pretreatment process that enhances enzymatic conversion of MCR to sugars using Dowex (TM) Dr-G8 as catalyst. The optimum yield of glucose reached 99.8% under the optimal condition for solid acid pretreatment (10%, w/v biomass loading, 4%, w/v catalyst loading, 30min, 120°C) followed by enzymatic hydrolysis (45FPU/g of cellulase, 52CBU/g of β-glucosidase, 50°C, pH 4.8, 30h). The yield of sugar obtained was found more superior than conventional pretreatment process using H2SO4 and NaOH. Biomass loading for the subsequent simultaneous saccharification and fermentation (SSF) of the pretreated MCR was then optimized, giving an optimum bioethanol yield of 81.5%. The catalyst was separated and reused for six times, with only a slight drop in glucose yield.
    Matched MeSH terms: Saccharomyces cerevisiae/metabolism
  6. A novel five-step synthetic route to 1,3,4-oxadiazole derivatives with potent α-glucosidase inhibitory potential and their in silico studies
    Iftikhar M, Shahnawaz, Saleem M, Riaz N, Aziz-Ur-Rehman, Ahmed I, et al.
    Arch Pharm (Weinheim), 2019 Dec;352(12):e1900095.
    PMID: 31544284 DOI: 10.1002/ardp.201900095
    A series of new N-aryl/aralkyl derivatives of 2-methyl-2-{5-(4-chlorophenyl)-1,3,4-oxadiazole-2ylthiol}acetamide were synthesized by successive conversions of 4-chlorobenzoic acid (a) into ethyl 4-chlorobenzoate (1), 4-chlorobenzoylhydrazide (2) and 5-(4-chlorophenyl)-1,3,4-oxadiazole-2-thiol (3), respectively. The required array of compounds (6a-n) was obtained by the reaction of 1,3,4-oxadiazole (3) with various electrophiles (5a-n) in the presence of DMF (N,N-dimethylformamide) and sodium hydroxide at room temperature. The structural determination of these compounds was done by infrared, 1 H-NMR (nuclear magnetic resonance), 13 C-NMR, electron ionization mass spectrometry, and high-resolution electron ionization mass spectrometry analyses. All compounds were evaluated for their α-glucosidase inhibitory potential. Compounds 6a, 6c-e, 6g, and 6i were found to be promising inhibitors of α-glucosidase with IC50 values of 81.72 ± 1.18, 52.73 ± 1.16, 62.62 ± 1.15, 56.34 ± 1.17, 86.35 ± 1.17, 52.63 ± 1.16 µM, respectively. Molecular modeling and ADME (absorption, distribution, metabolism, excretion) predictions supported the findings. The current synthesized library of compounds was achieved by utilizing very common raw materials in such a way that the synthesized compounds may prove to be promising drug leads.
    Matched MeSH terms: Saccharomyces cerevisiae/enzymology
  7. Synthesis of indole-based-thiadiazole derivatives as a potent inhibitor of α-glucosidase enzyme along with in silico study
    Alomari M, Taha M, Rahim F, Selvaraj M, Iqbal N, Chigurupati S, et al.
    Bioorg Chem, 2021 03;108:104638.
    PMID: 33508679 DOI: 10.1016/j.bioorg.2021.104638
    A series of nineteen (1-19) indole-based-thiadiazole derivatives were synthesized, characterized by 1HNMR, 13C NMR, MS, and screened for α-glucosidase inhibition. All analogs showed varied α-glucosidase inhibitory potential with IC50 value ranged between 0.95 ± 0.05 to 13.60 ± 0.30 µM, when compared with the standard acarbose (IC50 = 1.70 ± 0.10). Analogs 17, 2, 1, 9, 7, 3, 15, 10, 16, and 14 with IC50 values 0.95 ± 0.05, 1.10 ± 0.10, 1.30 ± 0.10, 1.60 ± 0.10, 2.30 ± 0.10, 2.30 ± 0.10, 2.80 ± 0.10, 4.10 ± 0.20 and 4.80 ± 0.20 µM respectively showed highest α-glucosidase inhibition. All other analogs also exhibit excellent inhibitory potential. Structure activity relationships have been established for all compounds primarily based on substitution pattern on the phenyl ring. Through molecular docking study, binding interactions of the most active compounds were confirmed. We further studied the kinetics study of analogs 1, 2, 9 and 17 and found that they are Non-competitive inhibitors.
    Matched MeSH terms: Saccharomyces cerevisiae/enzymology
  8. Molecular Characterization of a Geranyl Diphosphate-Specific Prenyltransferase Catalyzing Stilbenoid Prenylation from Morus alba
    Zhong Z, Zhu W, Liu S, Guan Q, Chen X, Huang W, et al.
    Plant Cell Physiol, 2018 Nov 01;59(11):2214-2227.
    PMID: 30020500 DOI: 10.1093/pcp/pcy138
    Pharmaceutically active compounds from medical plants are attractive as a major source for new drug development. Prenylated stilbenoids with increased lipophilicity are valuable secondary metabolites which possess a wide range of biological activities. So far, many prenylated stilbenoids have been isolated from Morus alba but the enzyme responsible for the crucial prenyl modification remains unknown. In the present study, a stilbenoid-specific prenyltransferase (PT), termed Morus alba oxyresveratrol geranyltransferase (MaOGT), was identified and functionally characterized in vitro. MaOGT recognized oxyresveratrol and geranyl diphosphate (GPP) as natural substrates, and catalyzed oxyresveratrol prenylation. Our results indicated that MaOGT shared common features with other aromatic PTs, e.g. multiple transmembrane regions, conserved functional domains and targeting to plant plastids. This distinct PT represents the first stilbenoid-specific PT accepting GPP as a natural prenyl donor, and could help identify additional functionally varied PTs in moraceous plants. Furthermore, MaOGT might be applied for high-efficiency and large-scale prenylation of oxyresveratrol to produce bioactive compounds for potential therapeutic applications.
    Matched MeSH terms: Saccharomyces cerevisiae/genetics
  9. Fulltext Characterization of α-Glucosidase Inhibitors from Clinacanthus nutans Lindau Leaves by Gas Chromatography-Mass Spectrometry-Based Metabolomics and Molecular Docking Simulation
    Murugesu S, Ibrahim Z, Ahmed QU, Nik Yusoff NI, Uzir BF, Perumal V, et al.
    Molecules, 2018 Sep 19;23(9).
    PMID: 30235889 DOI: 10.3390/molecules23092402
    BACKGROUND: Clinacanthus nutans (C. nutans) is an Acanthaceae herbal shrub traditionally consumed to treat various diseases including diabetes in Malaysia. This study was designed to evaluate the α-glucosidase inhibitory activity of C. nutans leaves extracts, and to identify the metabolites responsible for the bioactivity.

    METHODS: Crude extract obtained from the dried leaves using 80% methanolic solution was further partitioned using different polarity solvents. The resultant extracts were investigated for their α-glucosidase inhibitory potential followed by metabolites profiling using the gas chromatography tandem with mass spectrometry (GC-MS).

    RESULTS: Multivariate data analysis was developed by correlating the bioactivity, and GC-MS data generated a suitable partial least square (PLS) model resulting in 11 bioactive compounds, namely, palmitic acid, phytol, hexadecanoic acid (methyl ester), 1-monopalmitin, stigmast-5-ene, pentadecanoic acid, heptadecanoic acid, 1-linolenoylglycerol, glycerol monostearate, alpha-tocospiro B, and stigmasterol. In-silico study via molecular docking was carried out using the crystal structure Saccharomyces cerevisiae isomaltase (PDB code: 3A4A). Interactions between the inhibitors and the protein were predicted involving residues, namely LYS156, THR310, PRO312, LEU313, GLU411, and ASN415 with hydrogen bond, while PHE314 and ARG315 with hydrophobic bonding.

    CONCLUSION: The study provides informative data on the potential α-glucosidase inhibitors identified in C. nutans leaves, indicating the plant's therapeutic effect to manage hyperglycemia.

    Matched MeSH terms: Saccharomyces cerevisiae/enzymology
  10. Synthesis, α-glucosidase inhibition and molecular docking study of coumarin based derivatives
    Taha M, Shah SAA, Afifi M, Imran S, Sultan S, Rahim F, et al.
    Bioorg Chem, 2018 04;77:586-592.
    PMID: 29477126 DOI: 10.1016/j.bioorg.2018.01.033
    We have synthesized seventeen Coumarin based derivatives (1-17), characterized by 1HNMR, 13CNMR and EI-MS and evaluated for α-glucosidase inhibitory potential. Among the series, all derivatives exhibited outstanding α-glucosidase inhibition with IC50 values ranging between 1.10 ± 0.01 and 36.46 ± 0.70 μM when compared with the standard inhibitor acarbose having IC50 value 39.45 ± 0.10 μM. The most potent derivative among the series is derivative 3 having IC50 value 1.10 ± 0.01 μM, which are many folds better than the standard acarbose. The structure activity relationship (SAR) was mainly based upon by bring about difference of substituent's on phenyl part. Molecular docking studies were carried out to understand the binding interaction of the most active compounds.
    Matched MeSH terms: Saccharomyces cerevisiae/enzymology
  11. Hydrazinyl arylthiazole based pyridine scaffolds: Synthesis, structural characterization, in vitro α-glucosidase inhibitory activity, and in silico studies
    Ali F, Khan KM, Salar U, Taha M, Ismail NH, Wadood A, et al.
    Eur J Med Chem, 2017 Sep 29;138:255-272.
    PMID: 28672278 DOI: 10.1016/j.ejmech.2017.06.041
    Acarbose, miglitol, and voglibose are the inhibitors of α-glucosidase enzyme and being clinically used for the management of type-II diabetes mellitus. However, many adverse effects are also associated with them. So, the development of new therapeutic agents is an utmost interest in medicinal chemistry research. Current study is based on the identification of new α-glucosidase inhibitors. For that purpose, hydrazinyl arylthiazole based pyridine derivatives 1-39 were synthesized via two step reaction and fully characterized by spectroscopic techniques EI-MS, HREI-MS, (1)H-, and (13)C NMR. However, stereochemistry of the iminic bond was confirmed by NOESY. All compounds were subjected to in vitro α-glucosidase inhibitory activity and found many folds active (IC50 = 1.40 ± 0.01-236.10 ± 2.20 μM) as compared to the standard acarbose having IC50 value of 856.45 ± 5.60 μM. A limited structure-activity relationship was carried out in order to make a presumption about the substituent's effect on inhibitory activity which predicted that substituents of more negative inductive effect played important role in the activity as compared to the substituents of less negative inductive effect. However, in order to have a good understanding of ligand enzyme interactions, molecular docking study was also conducted. In silico study was confirmed that substituents like halogens (Cl) and nitro (NO2) which have negative inductive effect were found to make important interactions with active site residues.
    Matched MeSH terms: Saccharomyces cerevisiae/enzymology*
  12. Fulltext Cassava brown streak virus Ham1 protein hydrolyses mutagenic nucleotides and is a necrosis determinant
    Tomlinson KR, Pablo-Rodriguez JL, Bunawan H, Nanyiti S, Green P, Miller J, et al.
    Mol Plant Pathol, 2019 08;20(8):1080-1092.
    PMID: 31154674 DOI: 10.1111/mpp.12813
    Cassava brown streak disease (CBSD) is a leading cause of cassava losses in East and Central Africa, and is currently having a severe impact on food security. The disease is caused by two viruses within the Potyviridae family: Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV), which both encode atypical Ham1 proteins with highly conserved inosine triphosphate (ITP) pyrophosphohydrolase (ITPase) domains. ITPase proteins are widely encoded by plant, animal, and archaea. They selectively hydrolyse mutagenic nucleotide triphosphates to prevent their incorporation into nucleic acid and thereby function to reduce mutation rates. It has previously been hypothesized that U/CBSVs encode Ham1 proteins with ITPase activity to reduce viral mutation rates during infection. In this study, we investigate the potential roles of U/CBSV Ham1 proteins. We show that both CBSV and UCBSV Ham1 proteins have ITPase activities through in vitro enzyme assays. Deep-sequencing experiments found no evidence of the U/CBSV Ham1 proteins providing mutagenic protection during infections of Nicotiana hosts. Manipulations of the CBSV_Tanza infectious clone were performed, including a Ham1 deletion, ITPase point mutations, and UCBSV Ham1 chimera. Unlike severely necrotic wild-type CBSV_Tanza infections, infections of Nicotiana benthamiana with the manipulated CBSV infectious clones do not develop necrosis, indicating that that the CBSV Ham1 is a necrosis determinant. We propose that the presence of U/CBSV Ham1 proteins with highly conserved ITPase motifs indicates that they serve highly selectable functions during infections of cassava and may represent a euphorbia host adaptation that could be targeted in antiviral strategies.
    Matched MeSH terms: Saccharomyces cerevisiae/metabolism
  13. Direct recovery of malate dehydrogenase from highly turbid yeast cell homogenate using dye-ligand affinity chromatography in stirred fluidized bed
    Chen KH, Lee SY, Show PL, Hong SC, Chang YK
    J Chromatogr B Analyt Technol Biomed Life Sci, 2018 Nov 15;1100-1101:65-75.
    PMID: 30292951 DOI: 10.1016/j.jchromb.2018.09.039
    Dye-ligand affinity chromatography in a stirred fluidized bed has been developed for the rapid recovery of malate dehydrogenase (MDH) from highly turbid baker's yeast cell homogenate in a single step. The most suitable dye, namely Reactive Orange 4, in its optimal immobilized concentration of 8.78 mg/mL was immobilized onto high-density STREAMLINE matrix. To further examine optimal adsorption and elution conditions, the enzyme recovery operation was carried out using unclarified cell homogenates in stirred fluidized bed system. Aiming to develop a non-specific eluent, namely NaCl, to effectively elute the MDH adsorbed, direct recovery of MDH from highly turbid cell homogenate (50% w/v) in a stirred fluidized bed adsorption system was performed. The proposed system successfully achieved a recovery yield of 73.6% and a purification factor of 73.5 in a single step by using 0.6 M NaCl as an eluent at a high liquid velocity of 200 cm/h.
    Matched MeSH terms: Saccharomyces cerevisiae/enzymology*
  14. Cyclopenta[b]benzofuran and Secodammarane Derivatives from the Stems of Aglaia stellatopilosa
    Othman N, Pan L, Mejin M, Voong JC, Chai HB, Pannell CM, et al.
    J Nat Prod, 2016 Apr 22;79(4):784-91.
    PMID: 26974604 DOI: 10.1021/acs.jnatprod.5b00810
    Four new 2,3-secodammarane triterpenoids, stellatonins A-D (3-6), together with a new 3,4-secodammarane triterpenoid, stellatonin E (7), and the known silvestrol (1), 5‴-episilvestrol (2), and β-sitosterol, were isolated from a methanol extract of the stems of Aglaia stellatopilosa through bioassay-guided fractionation. The structures of the new compounds were elucidated using spectroscopic and chemical methods. The compounds were evaluated for their cytotoxic activity against three human cancer cell lines and for their antimicrobial activity using a microtiter plate assay against a panel of Gram-positive and Gram-negative bacteria and fungi.
    Matched MeSH terms: Saccharomyces cerevisiae/drug effects
  15. Fulltext Investigation of α-Glucosidase Inhibitory Metabolites from Tetracera scandens Leaves by GC-MS Metabolite Profiling and Docking Studies
    Nokhala A, Siddiqui MJ, Ahmed QU, Ahamad Bustamam MS, Zakaria AZA
    Biomolecules, 2020 02 12;10(2).
    PMID: 32059529 DOI: 10.3390/biom10020287
    Stone leaf (Tetracera scandens) is a Southeast Asian medicinal plant that has been traditionally used for the management of diabetes mellitus. The underlying mechanisms of the antidiabetic activity have not been fully explored yet. Hence, this study aimed to evaluate the α-glucosidase inhibitory potential of the hydromethanolic extracts of T. scandens leaves and to characterize the metabolites responsible for such activity through gas chromatography-mass spectrometry (GC-MS) metabolomics. Crude hydromethanolic extracts of different strengths were prepared and in vitro assayed for α-glucosidase inhibition. GC-MS analysis was further carried out and the mass spectral data were correlated to the corresponding α-glucosidase inhibitory IC50 values via an orthogonal partial least squares (OPLS) model. The 100%, 80%, 60% and 40% methanol extracts displayed potent α-glucosidase inhibitory potentials. Moreover, the established model identified 16 metabolites to be responsible for the α-glucosidase inhibitory activity of T. scandens. The putative α-glucosidase inhibitory metabolites showed moderate to high affinities (binding energies of -5.9 to -9.8 kcal/mol) upon docking into the active site of Saccharomyces cerevisiae isomaltase. To sum up, an OPLS model was developed as a rapid method to characterize the α-glucosidase inhibitory metabolites existing in the hydromethanolic extracts of T. scandens leaves based on GC-MS metabolite profiling.
    Matched MeSH terms: Saccharomyces cerevisiae/metabolism
  16. Synthesis of indole derivatives as diabetics II inhibitors and enzymatic kinetics study of α-glucosidase and α-amylase along with their in-silico study
    Taha M, Alrashedy AS, Almandil NB, Iqbal N, Anouar EH, Nawaz M, et al.
    Int J Biol Macromol, 2021 Nov 01;190:301-318.
    PMID: 34481854 DOI: 10.1016/j.ijbiomac.2021.08.207
    In this study, we have investigated a series of indole-based compounds for their inhibitory study against pancreatic α-amylase and intestinal α-glucosidase activity. Inhibitors of carbohydrate degrading enzymes appear to have an essential role as antidiabetic drugs. All analogous exhibited good to moderate α-amylase (IC50 = 3.80 to 47.50 μM), and α-glucosidase inhibitory interactions (IC50 = 3.10-52.20 μM) in comparison with standard acarbose (IC50 = 12.28 μM and 11.29 μM). The analogues 4, 11, 12, 15, 14 and 17 had good activity potential both for enzymes inhibitory interactions. Structure activity relationships were deliberated to propose the influence of substituents on the inhibitory potential of analogues. Docking studies revealed the interaction of more potential analogues and enzyme active site. Further, we studied their kinetic study of most active compounds showed that compounds 15, 14, 12, 17 and 11 are competitive for α-amylase and non- competitive for α-glucosidase.
    Matched MeSH terms: Saccharomyces cerevisiae/enzymology
  17. Culture and molecular identification of fungal contaminants in edible bird nests
    Chen JX, Wong SF, Lim PK, Mak JW
    Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2015;32(12):2138-47.
    PMID: 26429550 DOI: 10.1080/19440049.2015.1101494
    Widespread food poisoning due to microbial contamination has been a major concern for the food industry, consumers and governing authorities. This study is designed to determine the levels of fungal contamination in edible bird nests (EBNs) using culture and molecular techniques. Raw EBNs were collected from five house farms, and commercial EBNs were purchased from five Chinese traditional medicine shops (companies A-E) in Peninsular Malaysia. The fungal contents in the raw and commercial EBNs, and boiled and unboiled EBNs were determined. Culturable fungi were isolated and identified. In this study, the use of these methods revealed that all EBNs had fungal colony-forming units (CFUs) that exceeded the limit set by Standards and Industrial Research Institute of Malaysia (SIRIM) for yeast and moulds in EBNs. There was a significant difference (p < 0.05) in the number of types of fungi isolated from raw and commercial EBNs, but no significant difference in the reduction of the number of types of fungi after boiling the EBNs (p > 0.05). The types of fungi isolated from the unboiled raw EBNs were mainly soil, plant and environmental fungi, while the types of fungi isolated from the boiled raw EBNs, unboiled and boiled commercial EBNs were mainly environmental fungi. Aspergillus sp., Candida sp., Cladosporium sp., Neurospora sp. and Penicillum sp. were the most common fungi isolated from the unboiled and boiled raw and commercial EBNs. Some of these fungi are mycotoxin producers and cause opportunistic infections in humans. Further studies to determine the mycotoxin levels and methods to prevent or remove these contaminations from EBNs for safe consumption are necessary. The establishment and implementation of stringent regulations for the standards of EBNs should be regularly updated and monitored to improve the quality of the EBNs and consumer safety.
    Matched MeSH terms: Saccharomyces cerevisiae
  18. Fulltext Microbiome of tracheoesophageal prosthesis: who are they?
    Syatirah Abdullah, Janet Quinn, Mohamed EL-Badawey, Nicholas Jakubovics
    Malaysian Journal of Medicine and Health Sciences, 2019;15(108):44-44.
    MyJurnal
    Introduction: Laryngectomy patients undergo voice rehabilitation that requires implantation of trachea-oesophagal speech valves (TESV). Usually, laryngeal cancer patients require insertion of these devices post-operatively to im-prove their quality of life. Implantation of TESV dates back to 1979 by pioneering work of Blom and Singer. There are cases of aspiration of TESV wearer reported, and obstruction of the TESV causes leakage through the valve and is suggested as a main reason for replacement of the device. The dysfunctional failure may be caused by microbial colonization on the valve or physical malfunction and requires immediate replacement is desirable. The aim of this study is to identify the microbial community members of selected TESVs using both culture-independent techniques (Next-generation sequencing) to analyse the microbiota, including unculturable species, and routine microbiology techniques (culture-dependent method) and to obtain representative isolates that can form the basis for experiments to enable increased understanding of the community. Methods: Biofilms were harvested from 16 explanted speech valves from patients visiting the ENT clinic in Freeman Hospital, Newcastle, UK. Routine microbiology techniques (culture-dependent method) including ChromeID® plates and Matrix-Assisted Laser Desorption/Ionization Time of Flight (MALDI-TOF) Mass Spectrometry were used for identification of TESV microbiome. Sequencing of the samples was performed at MR DNA (www.mrdnalab.com, USA) on a MiSeq following the manufacturer’s guidelines in order to determine the bacteria and candida composition in the biofilm community. Results: The most frequently isolated fungal species was C. albicans, which was cultured from 11 out of 16 TESVs (79%), followed by five TESVs with C. tropicalis (36%), three TESVs had C. glabrata (21%) and only one TESV contained S. cerevisiae (7%). Interestingly no biofilm communities contained more than two fungal species and 2 TESVs (12%) possessed only bacterial species. There were only 16 species of bacteria cultured and identified by MALDI-TOF MS. This was far lower than the 91 species that were detected by NGS. Species from the genus Lactobacillus were found in 10 of 16 TESVs (63%), the highest frequency of any bacterial genus isolated from TESVs followed by S. aureus found in eight TESVs of 16. S. epidermidis was identified in two TESVs (13%), Streptococcus spp., K. oxytoca and O. anthropi were both identified in five different TESVs, while the gut bacterium E. faecium was found in four TESVs. Only one TESV contained E. coli. Conclusion: TESV biofilm composition was dominated by Candida spp. and occasionally contained other types of eukaryote such as Saccharomycetes. It was not uncommon for more than one Candida species to be present. The biofilms also harboured a mixture of bacteria, with lactic acid producers (Lactobacillus sp. and Streptococcus sp.) normally accompanying Candida sp. in the biofilm.
    Matched MeSH terms: Saccharomyces cerevisiae
  19. Fulltext Pre-grafting histological studies of skin grafts cryopreserved in α helix antarctic yeast oriented antifreeze peptide (Afp1m)
    Khan MS, Ibrahim SM, Adamu AA, Rahman MBA, Bakar MZA, Noordin MM, et al.
    Cryobiology, 2020 02 01;92:26-33.
    PMID: 31580830 DOI: 10.1016/j.cryobiol.2019.09.012
    A number of living creatures in the Antarctic region have developed characteristic adaptation of cold weather by producing antifreeze proteins (AFP). Antifreeze peptide (Afp1m) fragment have been designed in the sequence of strings from native proteins. The objectives of this study were to assess the properties of Afp1m to cryopreserve skin graft at the temperature of -10 °C and -20 °C and to assess sub-zero injuries in Afp1m cryopreserved skin graft using light microscopic techniques. In the present study, a process was developed to cryopreserve Sprague-Dawley (SD) rat skin grafts with antifreeze peptide, Afp1m, α-helix peptide fragment derived from Glaciozyma antractica yeast. Its viability assessed by different microscopic techniques. This study also described the damages caused by subzero temperatures (-10 and -20 °C) on tissue cryopreserved in different concentrations of Afp1m (0.5, 1, 2, 5 and 10 mg/mL) for 72 h. Histological scores of epidermis, dermis and hypodermis of cryopreserved skin grafts showed highly significant difference (p 
    Matched MeSH terms: Saccharomyces cerevisiae
  20. Fulltext The effectiveness of betel leaves extract as antifungal agent
    Emi Norzehan Mohamad Mahbob, Nurul Huda Musa, Zaidatul Shakila Mohamad Ashari, Fathiah Abdullah, Siti Hajar Noor Alshurdin
    Jurnal Inovasi Malaysia, 2019;2(2):41-54.
    MyJurnal
    Piper betle (sirih) is a medicinal plant that has been reported for various pharmacological activities such as antifungal, antibacterial, antioxidant, anticarcinogenic and, anti-inflammatory. The researchwas carried out to study the antifungal activity of ethanolic extract from P. betle leaves. Matured leaves of P. betle were collected and processed to a fine powder before being extracted using ethanol. The first part of the research involved evaluation of antifungal activity of the ethanolic extracts using disk diffusion method at four different concentrations (5, 25, 50, 100 mg/mL) against 3 types of fungi isolated from laboratory surfaces. The sensitivities of the fungal towards the ethanolic extracts were determined by measuring the size of inhibitory zones. Results showed that highest concentration of the extract (100 mg/mL) inhibited fungal growth for all three types of isolated fungi with 0.97, 0.83, and 0.77 cm zone of inhibition for yeast, Aspergillus sp. and Penicillium sp., respectively. Low concentrations (5, 25 and 50 mg/mL) did not inhibit the fungal growth except for Penicillium sp. that showed zone of inhibition, 0.53 cm at concentration of 50 mg/mL. The second part of the research involved evaluation of fungal count utilizing effective dose of betel leaves ethanolic extract obtained from the first part of this research which is 100 mg/mL. This study found that no fungal growth on the microscope wire that has been sprayed with betel leaves ethanolic extract on Day 1, Day 4 and Day 7. For wire that been sprayed with ethanol 70%, the average of fungal count was same on Day 1 and Day 4 (5.6 x 102 cfu/mL) but increased to 9.2 x 102 cfu/mL on Day 7. In conclusion, betel leaves extract exhibit fungicidal properties that support their use as antifungal agents from natural products which are safe, easily available with no adverse effects.
    Matched MeSH terms: Saccharomyces cerevisiae
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