Displaying publications 1 - 20 of 21 in total

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  1. Cation-stimulated drug delivery via lipid assembly comprising macrocyclized disaccharides - A DFT study
    Mazlee MTF, Heidelberg T, Ariffin A, Zain SM
    Carbohydr Res, 2023 Oct;532:108923.
    PMID: 37598565 DOI: 10.1016/j.carres.2023.108923
    In the attempt to create a delivery system for an alkali-cation stimulated drug release, a computational study was conducted, aiming for the evaluation of synthetic access towards glycolipid crown ethers analogs and their potential for coordination-induced changes of packing constraints for molecular assemblies. The results disfavor amide-linkages for the creation of macrocycles around the inter-glycosidic bond of a disaccharide. Conformational changes upon cation coordination of the macrocycle decrease the intersection area for easily accessible macrocycles based on lactose. This leads to shrinking intersection areas upon alkali complexation. Maltose-based analogs, on the other hand, exhibited the targeted increase of the glycolipid intersection area and, hence, may be considered as a promising resource.
    Matched MeSH terms: Disaccharides*
  2. Fulltext Stingless bee honey, a novel source of trehalulose: a biologically active disaccharide with health benefits
    Fletcher MT, Hungerford NL, Webber D, Carpinelli de Jesus M, Zhang J, Stone ISJ, et al.
    Sci Rep, 2020 07 22;10(1):12128.
    PMID: 32699353 DOI: 10.1038/s41598-020-68940-0
    Stingless bee (Meliponini) honey has long been considered a high-value functional food, but the perceived therapeutic value has lacked attribution to specific bioactive components. Examination of honey from five different stingless bee species across Neotropical and Indo-Australian regions has enabled for the first time the identification of the unusual disaccharide trehalulose as a major component representing between 13 and 44 g per 100 g of each of these honeys. Trehalulose is an isomer of sucrose with an unusual α-(1 → 1) glucose-fructose glycosidic linkage and known acariogenic and low glycemic index properties. NMR and UPLC-MS/MS analysis unambiguously confirmed the identity of trehalulose isolated from stingless bee honeys sourced across three continents, from Tetragonula carbonaria and Tetragonula hockingsi species in Australia, from Geniotrigona thoracica and Heterotrigona itama in Malaysia and from Tetragonisca angustula in Brazil. The previously unrecognised abundance of trehalulose in stingless bee honeys is concrete evidence that supports some of the reported health attributes of this product. This is the first identification of trehalulose as a major component within a food commodity. This study allows the exploration of the expanded use of stingless bee honey in foods and identifies a bioactive marker for authentication of this honey in associated food standards.
    Matched MeSH terms: Disaccharides/analysis*; Disaccharides/isolation & purification
  3. Unique physicochemical properties and rare reducing sugar trehalulose mandate new international regulation for stingless bee honey
    Zawawi N, Zhang J, Hungerford NL, Yates HSA, Webber DC, Farrell M, et al.
    Food Chem, 2022 Mar 30;373(Pt B):131566.
    PMID: 34823933 DOI: 10.1016/j.foodchem.2021.131566
    Stingless bee honey (SBH) of four stingless bee species (Heterotrigona itama, Geniotrigona thoracica, Tetragonula carbonaria, and Tetragonula hockingsi) from two geographic regions (Malaysia and Australia, n = 36) were studied for their physicochemical parameters, including total phenolic and multi-elemental contents. Sugar analysis confirmed the prominent presence of trehalulose in all samples. All SBH failed to meet the CODEX Standard for honey moisture, free acidity, and total fructose plus glucose levels. One-way ANOVA, principal component analysis (PCA) and hierarchical component analysis (HCA) confirm distinctive differences between Australian and Malaysian SBH with Australian SBH having significantly (P 
    Matched MeSH terms: Disaccharides
  4. Can we predict who will respond to a low-FODMAP diet in irritable bowel syndrome?
    Chuah KH, Mahadeva S
    J Gastroenterol Hepatol, 2024 Feb;39(2):217-218.
    PMID: 38238032 DOI: 10.1111/jgh.16487
    Matched MeSH terms: Disaccharides
  5. Biochemical and nutritional components of selected honey samples
    Chua LS, Adnan NA
    Acta Sci Pol Technol Aliment, 2014 Apr-Jun;13(2):169-79.
    PMID: 24876312
    The purpose of this study was to investigate the relationship of biochemical (enzymes) and nutritional components in the selected honey samples from Malaysia. The relationship is important to estimate the quality of honey based on the concentration of these nutritious components. Such a study is limited for honey samples from tropical countries with heavy rainfall throughout the year.
    Matched MeSH terms: Disaccharides/analysis
  6. Molecular dynamics study of anhydrous lamellar structures of synthetic glycolipids: effects of chain branching and disaccharide headgroup
    Achari VM, Nguan HS, Heidelberg T, Bryce RA, Hashim R
    J Phys Chem B, 2012 Sep 27;116(38):11626-34.
    PMID: 22967067
    Glycolipids form materials of considerable potential for a wide range of surfactant and thin film applications. Understanding the effect of glycolipid covalent structure on the properties of their thermotropic and lyotropic assemblies is a key step toward rational design of new glycolipid-based materials. Here, we perform molecular dynamics simulations of anhydrous bilayers of dodecyl β-maltoside, dodecyl β-cellobioside, dodecyl β-isomaltoside, and a C(12)C(10) branched β-maltoside. Specifically, we examine the consequences of chain branching and headgroup identity on the structure and dynamics of the lamellar assemblies. Chain branching of the glycolipid leads to measurable differences in the dimensions and interactions of the lamellar assembly, as well as a more fluid-like hydrophobic chain region. Substitution of the maltosyl headgroup of βMal-C(12) by an isomaltosyl moiety leads to a significant decrease in bilayer spacing as well as a markedly altered pattern of inter-headgroup hydrogen bonding. The distinctive simulated structures of the two regioisomers provide insight into the difference of ~90 °C in their observed clearing temperatures. For all four simulated glycolipid systems, with the exception of the sn-2 chain of the branched maltoside, the alkyl chains are ordered and exhibit a distinct tilt, consistent with recent crystallographic analysis of a branched chain Guerbet glycoside. These insights into structure-property relationships from simulation provide an important molecular basis for future design of synthetic glycolipid materials.
    Matched MeSH terms: Disaccharides/chemistry*
  7. Crystal structure of a neoagarobiose-producing GH16 family β-agarase from Persicobacter sp. CCB-QB2
    Teh AH, Fazli NH, Furusawa G
    Appl Microbiol Biotechnol, 2020 Jan;104(2):633-641.
    PMID: 31784792 DOI: 10.1007/s00253-019-10237-y
    PdAgaC from the marine bacterium Persicobacter sp. CCB-QB2 is a β-agarase belonging to the glycoside hydrolase family 16 (GH16). It is one of only a handful of endo-acting GH16 β-agarases able to degrade agar completely to produce neoagarobiose (NA2). The crystal structure of PdAgaC's catalytic domain, which has one of the highest Vmax value at 2.9 × 103 U/mg, was determined in order to understand its unique mechanism. The catalytic domain is made up of a typical β-jelly roll fold with two additional insertions, and a well-conserved but wider substrate-binding cleft with some minor changes. Among the unique differences, two unconserved residues, Asn226 and Arg286, may potentially contribute additional hydrogen bonds to subsites -1 and +2, respectively, while a third, His185 from one of the additional insertions, may further contribute another bond to subsite +2. These additional hydrogen bonds may probably have enhanced PdAgaC's affinity for short agaro-oligosaccharides such as neoagarotetraose (NA4), rendering it capable of binding NA4 strongly enough for rapid degradation into NA2.
    Matched MeSH terms: Disaccharides/metabolism
  8. Fulltext Effects of partial sugar replacement on the physicochemical and sensory properties of low sugar cookies
    Ho, L. H., Pulsawat, M. M.
    International Food Research Journal, 2020;27(3):557-567.
    MyJurnal
    The aim of the present work was to produce low sugar cookies by partial substitution with a
    sugar replacer (i.e. maltitol, sorbitol, and isomalt) for sucrose. Four different types of cookies
    were prepared. Sucrose was replaced by maltitol, sorbitol, and isomalt at 50% level (based on
    relative degree of sweetness of sucrose) to produce CMAL50, CSOR50, and CISO50, respectively. Cookies that contained sucrose represented the control. All the cookies produced were
    analysed for chemical properties, physical properties, and sensorial acceptance. The chemical
    analysis results indicated that CMAL50, CSOR50, and CISO50 had higher moisture, crude
    fibre, and the total carbohydrate content, but with lower ash, crude protein, crude fat, calories,
    and total sugar content than the control. CSOR50 showed the lowest total sugar content; thus,
    could be denoted as ‘low sugar’ cookies. Cookies containing maltitol and isomalt presented
    good physical quality. The hardness value of cookies decreased with 50% substitution of
    sorbitol and isomalt for sucrose. CISO50 showed the lowest lightness and yellowness values
    than other cookie samples. The sensory evaluation results showed that the cookies incorporated with maltitol and isomalt did not influence the overall acceptability of cookies. In conclusion, the replacement of sucrose with maltitol, sorbitol, and isomalt could reduce sugar and
    daily calorie intake. However, sorbitol substitution at 50% level is feasible to produce ‘low
    sugar’ cookies, and this cookie could provide benefits to weight and health-conscious
    consumers.
    Matched MeSH terms: Disaccharides
  9. Fulltext Effect of different types of low sweetness sugar on physicochemical properties of threadfin bream surimi (Nemipterus spp.) during frozen storage
    Nopianti, R., Huda, N., Fazilah, A., Ismail, N., Easa, A. M.
    International Food Research Journal, 2012;19(3):1011-1021.
    MyJurnal
    The effects of different types of low-sweetness sugar (lactitol, maltodexrin, palatinit, polydextrose,
    trehalose) on the physicochemical properties of threadfin bream (Nemipterus spp.) surimi during six months of frozen storage were investigated. The characteristics analyzed were moisture content, pH, water-holding capacity, whiteness, folding test, gel strength, expressible moisture, and texture profile analyses. Generally, the cryoprotective effectiveness decreased as the storage time increased. Polydextrose was able to maintain a water-holding capacity of 77.0%, 98.6% whiteness, a folding test value of 100%, and a gel strength of 53.6% compared with its initial value during six months of frozen storage. Meanwhile, sucrose was able to maintain a water-holding capacity of 80.3%, 98.6% whiteness, a folding test value of 75%, and a gel strength of 56.8%
    compared with its initial value. Raw surimi was able to maintain water holding capacity of 62.2%, 98.7% whiteness, a folding test value of 75%, and a gel strength of 36.0% compared with its initial value. It is suggested that, polydextrose as a potential alternative cryoprotectant to replace other low-sweetness sugars.
    Matched MeSH terms: Disaccharides
  10. Characterization of two novel bacterial type A exo-chitobiose hydrolases having C-terminal 5/12-type carbohydrate-binding modules
    Jamek SB, Nyffenegger C, Muschiol J, Holck J, Meyer AS, Mikkelsen JD
    Appl Microbiol Biotechnol, 2017 Jun;101(11):4533-4546.
    PMID: 28280871 DOI: 10.1007/s00253-017-8198-4
    Type A chitinases (EC 3.2.1.14), GH family 18, attack chitin ((1 → 4)-2-acetamido-2-deoxy-β-D-glucan) and chito-oligosaccharides from the reducing end to catalyze release of chitobiose (N,N'-diacetylchitobiose) via hydrolytic cleavage of N-acetyl-β-D-glucosaminide (1 → 4)-β-linkages and are thus "exo-chitobiose hydrolases." In this study, the chitinase type A from Serratia marcescens (SmaChiA) was used as a template for identifying two novel exo-chitobiose hydrolase type A enzymes, FbalChi18A and MvarChi18A, originating from the marine organisms Ferrimonas balearica and Microbulbifer variabilis, respectively. Both FbalChi18A and MvarChi18A were recombinantly expressed in Escherichia coli and were confirmed to exert exo-chitobiose hydrolase activity on chito-oligosaccharides, but differed in temperature and pH activity response profiles. Amino acid sequence comparison of the catalytic β/α barrel domain of each of the new enzymes showed individual differences, but ~69% identity of each to that of SmaChiA and highly conserved active site residues. Superposition of a model substrate on 3D structural models of the catalytic domain of the enzymes corroborated exo-chitobiose hydrolase type A activity for FbalChi18A and MvarChi18A, i.e., substrate attack from the reducing end. A main feature of both of the new enzymes was the presence of C-terminal 5/12 type carbohydrate-binding modules (SmaChiA has no C-terminal carbohydrate binding module). These new enzymes may be useful tools for utilization of chitin as an N-acetylglucosamine donor substrate via chitobiose.
    Matched MeSH terms: Disaccharides/genetics*; Disaccharides/metabolism
  11. Fulltext Fructooligosaccharides in honey and effects of honey on growth of Bifidobacterium longum BB 53
    International Food Research Journal, 2010;17(3):557-561.
    MyJurnal
    This research was carried out to determine the fructooligosaccharides content in local honey samples, namely the wild Malaysian Tualang honey and common wild honey obtained from Tapah, Perak and a commercial Tualang honey. Local wild honeys were found to contain a higher concentration of fructooligosaccharides (FOS) compared to the commercial Tualang honey. The FOS quantified from local wild honeys was inulobiose, kestose and nystose. Nystoses were found at a very low amount in the commercial Tualang honey. The effects of honey on the growth of Bifidobacterium longum BB 536 were investigated. Both wild and commercial honey samples including FOS standard were found to support the growth of B. longum. The pH value of the skim milk + honey inoculated with the probiotic strain decreases as expected. Addition of honey was found to support the growth of B. longum BB 536.
    Matched MeSH terms: Disaccharides
  12. Ethanol production capability of Candida shehatae in mixed sugars and rice straw hydrolysate
    Yuvadetkun P, Boonmee M
    Sains Malaysiana, 2016;45:581-587.
    Ethanol fermentations by Candida shehatae TISTR 5843 at low (20 g/L) and high (80 g/L) sugar concentrations with various glucose to xylose ratios were investigated. Glucose was a preferred substrate as it was consumed first at a faster consumption rate. The type of sugar and ratio between glucose and xylose did not have an effect on ethanol produced. The average ethanol concentrations were 7.99 g/L when using 20 g/L sugar and 27.82 g/L when using 80 g/L sugar. Small amounts of xylitol and glycerol as by-products were presented when using 20 g/L sugar. Xylitol appeared to be the main by-product at high xylose concentration with elevated concentrations as xylose is increased. When using rice straw hydrolysate containing 34.75 g/L glucose and 21.29 g/L xylose, 19.37 g/L ethanol was produced with the ethanol yield and ethanol productivity at 0.49 g/g and 0.20 g/L.h, respectively. However, xylose was not completely consumed after fermentation was complete.
    Matched MeSH terms: Disaccharides
  13. Enhanced fermentable sugar production from kitchen waste using various pretreatments
    Hafid HS, Rahman NA, Md Shah UK, Baharudin AS
    J Environ Manage, 2015 Jun 1;156:290-8.
    PMID: 25900092 DOI: 10.1016/j.jenvman.2015.03.045
    The kitchen waste fraction in municipal solid waste contains high organic matter particularly carbohydrate that can contribute to fermentable sugar production for subsequent conversion to bioethanol. This study was carried out to evaluate the influence of single and combination pretreatments of kitchen waste by liquid hot water, mild acid pretreatment of hydrochloric acid (HCl) and sulphuric acid (H2SO4) and enzymatic hydrolysis (glucoamylase). The maximum total fermentable sugar produced after combination pretreatment by 1.5% HCl and glucoamylase consisted of 93.25 g/L glucose, 0.542 g/L sucrose, 0.348 g/L maltose, and 0.321 g/L fructose. The glucose released by the combination pretreatment method was 0.79 g glucose/g KW equivalent to 79% of glucose conversion. The effects of the pre-treatment on kitchen waste indicated that the highest solubilization was 40% by the combination method of 1.5% HCl and glucoamylase. The best combination pre-treatment gave concentrations of lactic acid, acetic acid, and propionic acid of 11.74 g/L, 6.77 g/L, and 1.02 g/L, respectively. The decrease of aliphatic absorbance bands of polysaccharides at 2851 and 2923 cm(-1) and the increase on structures of carbonyl absorbance bands at 1600 cm(-1) reflects the progress of the kitchen waste hydrolysis to fermentable sugars. Overall, 1.5% HCl and glucoamylase treatment was the most profitable process as the minimum selling price of glucose was USD 0.101/g kitchen waste. Therefore, the combination pretreatment method was proposed to enhance the production of fermentable sugar, particularly glucose from kitchen waste as the feedstock for bioethanol production.
    Matched MeSH terms: Disaccharides/isolation & purification*
  14. Effects of pectinase clarification treatment on phenolic compounds of pummelo (Citrus grandis l. Osbeck) fruit juice
    Shah NN, Rahman RA, Shamsuddin R, Adzahan NM
    J Food Sci Technol, 2015 Aug;52(8):5057-65.
    PMID: 26243926 DOI: 10.1007/s13197-014-1554-9
    The purpose of this study is to investigate the changes occured on phenolic compounds between two Malaysian varieties of pummelo fruit juice: Ledang (PO55) and Tambun (PO52) post-enzymatic clarification. The changes in polyphenols composition were monitored using High Performance Liquid Chromatography Diode Array Detection and Folin Ciocalteu's method. Clarification treatment of pummelo fruit juice with a commercial pectinase was optimized based on incubation temperature, time and enzyme concentration. Both varieties of pummelo fruit juice were treated with different optimized variables which produced the highest clarities with the least effect to the juice physical quality. Tambun variety was found to have significantly more total phenolic compounds (p <0.05) in comparison to Ledang variety, possibly due to the amount of naringin. Three types of hydroxycinnamic acids (chlorogenic, caffeic and coumaric acid) and three compounds of flavanones (naringin, hesperidin and narirutin) were found in both fruit juices, where naringin and chlorogenic acid were the major contributor to the total phenolic content. Naringin, which gave out bitter aftertaste to the juice, was found to decrease, 1.6 and 0.59 % reduction in Ledang and Tambun respectively, post-enzymatic treatment. The decrease in naringin, albeit nominal, could be a potential benefit to the juice production in reducing the bitterness of the juice. Post-enzymatic analysis furthermore resulted in no significance differences (p <0.05) on the total phenolic compounds of both varieties. This study in summary provides a compositional database for Malaysian pummelo fruit juice of various phenolic compounds, which can provide useful information for evaluating the authenticity and the health benefits from the juice.
    Matched MeSH terms: Disaccharides
  15. Low FODMAP diet significantly improves IBS symptoms: an Irish retrospective cohort study
    Nawawi KNM, Belov M, Goulding C
    Eur J Nutr, 2020 Aug;59(5):2237-2248.
    PMID: 31520160 DOI: 10.1007/s00394-019-02074-6
    INTRODUCTION: There is growing evidence that a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) improves symptoms in irritable bowel syndrome (IBS) patients. We aimed to retrospectively investigate the effects of this diet in Irish IBS cohort over a 12-month follow-up period, including after re-introduction of the high FODMAP foods.

    METHODS: All the tertiary referrals seen by an FODMAP-trained dietician were reviewed (2013-2016). Patients were evaluated for IBS symptoms by a questionnaire (four-point Likert scale). Subsequently, advice regarding the low FODMAP diet was given. Symptoms' response was assessed at 3-, 6-, and 12-month follow-up, by use of the same questionnaire. Re-introduction of high FODMAP foods was aimed to commence at the subsequent follow-up.

    RESULTS: A total of 164 patients were identified. Thirty-seven patients were excluded due to failure to attend for follow-up. Hundred and twenty-seven patients (77% patients, of which 85% were female) completed the initial 3-month follow-up. Forty-five percent (74/164) and twenty-five percent (41/164) of the patients had continued follow-up at 6 and 12 months, respectively. Of the 127 patients who returned for follow-up, their commonest baseline symptoms were lethargy (92%), bloating (91%), flatulence (91%), and abdominal pain (89%). All symptoms were significantly improved at the initial follow-up (p 

    Matched MeSH terms: Disaccharides
  16. Fulltext Cellular Metabolic Profiling of CrFK Cells Infected with Feline Infectious Peritonitis Virus Using Phenotype Microarrays
    Ng SW, Selvarajah GT, Cheah YK, Mustaffa Kamal F, Omar AR
    Pathogens, 2020 May 25;9(5).
    PMID: 32466289 DOI: 10.3390/pathogens9050412
    Feline infectious peritonitis (FIP) is a fatal feline immune-mediated disease caused by feline infectious peritonitis virus (FIPV). Little is known about the biological pathways associated in FIP pathogenesis. This is the first study aiming to determine the phenotypic characteristics on the cellular level in relation to specific metabolic pathways of importance to FIP pathogenesis.

    METHODS: The internalization of type II FIPV WSU 79-1146 in Crandell-Rees Feline Kidney (CrFK) cells was visualized using a fluorescence microscope, and optimization prior to phenotype microarray (PM) study was performed. Then, four types of Biolog Phenotype MicroArray™ plates (PM-M1 to PM-M4) precoated with different carbon and nitrogen sources were used to determine the metabolic profiles in FIPV-infected cells.

    RESULTS: The utilization of palatinose was significantly low in FIPV-infected cells; however, there were significant increases in utilizing melibionic acid, L-glutamine, L-glutamic acid and alanyl-glutamine (Ala-Gln) compared to non-infected cells.

    CONCLUSION: This study has provided the first insights into the metabolic profiling of a feline coronavirus infection in vitro using PMs and deduced that glutamine metabolism is one of the essential metabolic pathways for FIPV infection and replication. Further studies are necessary to develop strategies to target the glutamine metabolic pathway in FIPV infection.

    Matched MeSH terms: Disaccharides
  17. Interaction of Artocarpus lectins with human IgA does not involve asparagine-linked oligosaccharide of the immunoglobulin
    Hashim OH, Kobayashi K, Taniguchi N
    Biochem. Int., 1992 Jul;27(3):423-9.
    PMID: 1417879
    In view of the controversy with respect to the interaction of jacalin with human IgA2, a study was undertaken to assess the reactivity of the Artocarpus heterophyllus lectin, as well as the lectin from Artocarpus integer (lectin C), with subclasses of human immunoglobulin A by ELISA. Our data is consistent with the view that Artocarpus lectins have no affinity for the IgA2 immunoglobulins. In further support of the findings, we have established that N-linked oligosaccharide moieties of IgA have no significant bearing in the lectin-immunoglobulin binding. Interaction was also not affected in the presence of 1% (w/v) BSA.
    Matched MeSH terms: Disaccharides/metabolism
  18. Fulltext Sulfated galactans from red seaweeds and their potential applications
    Lim, Yi-Yi, Lee, Wei-Kang, Leow, Adam Thean-Chor, Parameswari Namasivayam, Janna-Ong Abdullah, Ho, Chai-Ling
    The Pertanika Journal of Scholarly Research Reviews, 2018;4(2):1-17.
    MyJurnal
    Red seaweeds (Rhodophyta) produce a variety of sulfated galactans in their cell wall matrix and intercellular space, contributing up to 50-60 % of their total dry weight. These sulfated polysaccharides are made up of galactose disaccharides substituted with sulfate, methoxyl, pyruvic acid, or non-galactose monosaccharides (e.g. xylose, glucose and mannose). They are required by the Rhodophytes for protection against pathogen, desiccation, tidal waves and extreme changes in pH, temperature and salinity. Since ancient times, sulfated galactans from red seaweeds, such as agar and carrageenan, have been consumed as human foods and later being used in traditional medicine. Nowadays, some red seaweeds are cultivated and exploited for commercial uses in various fields. In this review, different types of sulfated galactans found in red seaweeds and their current and potential uses in food, biotechnology, medical and pharmaceutical industries are discussed.
    Matched MeSH terms: Disaccharides
  19. First Report of Ralstonia solanacearum Race 2 Biovar 1 Causing Moko Disease of Banana in Malaysia
    Zulperi D, Sijam K
    Plant Dis, 2014 Feb;98(2):275.
    PMID: 30708756 DOI: 10.1094/PDIS-03-13-0321-PDN
    During March 2011 to June 2012, 50 banana plants of cultivar Musa × paradisiaca 'Horn' with Moko disease symptoms were randomly sampled in 12 different locations of 5 outbreak states in Peninsular Malaysia comprising Kedah, Selangor, Pahang, Negeri Sembilan, and Johor, with disease incidence exceeding 90% in some severely affected plantations. The disease symptoms observed in the infected plants included yellowing and wilting of the oldest leaves, which became necrotic, and eventually led to their dieback or collapse. The pulp of banana fruits also became discolored and exuded bacterial ooze. Vascular tissues in pseudostems were discolored. Fragments from symptomatic plant samples were excised and cultured on Kelman's-tetrazolium salt (TZC) medium. Twenty positive samples produced fluidal colonies that were either entirely white or white with pink centers after incubation for 24 to 48 h at 28°C on Kelman's-TZC medium and appeared as gram-negative rods after Gram staining. They were also positive for potassium hydroxide (KOH), Kovacs oxidase, and catalase tests, but negative for utilization of disaccharides and hexose alcohols, which are characteristics of biovar 1 Ralstonia solanacearum. For the pathogenicity test, 30 μl of 108 CFU/ml bacterial suspension of three selected virulent strains were injected into banana (Musa × paradisiaca 'Horn') leaves explants grown in plastic pots of 1,440 cm3 volume in a greenhouse, with temperature range from 26 to 35°C. Leaves that were infiltrated with sterile distilled water served as a negative control. Inoculations with all isolates were performed in three replications, as well as the uninoculated control leaves explants. The inoculated plants produced the same symptoms as observed on naturally diseased samples, whereas control plants remained asymptomatic. Strain cultures were re-isolated and possessed the morphological and biochemical characteristics as previously described. PCR amplification using race 2 R. solanacearum primers ISRso19-F (5'-TGGGAGAGGATGGCGGCTTT-3') and ISRso19-R (5'-TGACCCGCCTTTCGGTGTTT-3') (3) produced a 1,900-bp product from DNA of all bacterial strains. BLAST searches resulted that the sequences were 95 to 98% identical to published R. solanacearum strain race 2 insertion sequence ISRso19 (GenBank Accession No. AF450275). These genes were later deposited in GenBank (KC812051, KC812052, and KC812053). Phylotype-specific multiplex PCR (Pmx-PCR) and Musa-specific multiplex PCR (Mmx-PCR) were performed to identify the phylotype and sequevar of all isolates (4). Pmx-PCR showed that all isolates belonged to phylotype II, whereas Mmx-PCR showed that they belonged to phylotype II sequevar 4 displaying 351-bp amplicon. Although there were previously extensive studies on R. solanacearum associated with bacterial wilt disease of banana crops in Malaysia, none related to Moko disease has been reported (1,2). The result has a great importance to better understand and document R. solanacearum race 2 biovar 1, since banana has been identified as the second most important commercial fruit crop with a high economic value in Malaysia. References: (1) R. Khakvar et al. Plant Pathol. J. 7:162, 2008. (2) R. Khakvar et al. Am. J. Agri. Biol. Sci. 3:490, 2008. (3) Y. A. Lee and C. N. Khor. Plant Pathol. Bull. 12:57, 2003. (4) P. Prior et al. Pages 405-414 in: Bacterial Wilt Disease and the Ralstonia solanacearum Species Complex. The American Phytopathological Society, St. Paul, MN, 2005.
    Matched MeSH terms: Disaccharides
  20. The effect of tocotrienol-rich fraction on the expression of glutathione s-transferase isoenzymes in mice liver
    Ahmed Atia, Nadia Salem Alrawaiq, Azman Abdullah
    Sains Malaysiana, 2018;47:2799-2809.
    Glutathione S-transferase isoenzymes (GSTs) catalyze the conjugation reaction between glutathione and electrophilic
    compounds. GSTs are involved in the detoxification of toxic and carcinogenic compounds, thus protecting the body from
    toxic injuries. Tocotrienols are part of the vitamin E family and is believed to possess potent antioxidant activity. The
    objective of this study was to determine the effect of increasing doses of tocotrienol rich fraction (TRF) supplementation
    on liver GSTs gene and protein expression. A total of 30 male ICR white mice were divided into five groups (n=6 for each
    group) and given treatment for 14 days through oral supplementation. Groups were divided as follows: - three groups
    administered with TRF at doses of 200, 500 and 1000 mg/kg, respectively, a positive control group administered with 100
    mg/kg butylated hydroxyanisole (BHA) and a control group administered with only the vehicle (corn oil). At day 15, the
    mice were sacrificed and their livers isolated. Total RNA was extracted from the liver and quantitative real-time polymerase
    chain reaction (qPCR) assays were performed to analyze GSTs gene expression. Total liver protein was also extracted
    and the protein expression of GSTs was determined by Western blotting. The results showed that TRF oral supplementation
    caused a significant dose-dependent increase in liver GST isoenzymes gene and protein expression, compared to controls.
    In conclusion, TRF oral supplementation for 14 days resulted in increased gene and protein expression of GST isoenzymes
    in mice liver dose-dependently, with the highest expression seen in mice treated with 1000 mg/kg TRF.
    Matched MeSH terms: Disaccharides
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