Displaying publications 1 - 20 of 102 in total

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  1. Antimicrobial activity of Cassia alata from Malaysia
    Ibrahim D, Osman H
    J Ethnopharmacol, 1995 Mar;45(3):151-6.
    PMID: 7623478
    Ethanolic extract of Cassia alata leaves was investigated for its antimicrobial activities on several microorganisms including bacteria, yeast, dermatophytic fungi and non-dermatophytic fungi. In vitro, the extract exhibited high activity against various species of dermatophytic fungi but low activity against non-dermatophytic fungi. However, bacterial and yeast species showed resistance against in vitro treatment with the extract. The minimum inhibitory concentration (MIC) values of the extract revealed that Trichophyton mentagorphytes var. interdigitale, Trichophyton mentagrophytes var. mentagorophytes, Trichophyton rubrum and Microsporum gypseum had the MIC of 125 mg/ml, whereas Microsporum canis had the MIC of 62.5 mg/ml. The inhibition can be observed on the macroconidia of Microsporum gypseum which resulted in structural degeneration beyond repair. The mechanism of inhibition can be related to the cell leakage as observed by irregular, wrinkle shape and loss in rigidity of the macroconidia.
  2. Fulltext Physicochemical and antioxidant studies on oven-dried, freeze-dried and spray-dried agaro oligosaccharide powders
    Kang, O.L., Yong, P.F., Ma’aruf, A.G., Osman, H., Nazaruddin, R.
    International Food Research Journal, 2014;21(6):2363-2367.
    MyJurnal
    In this work, oven-dried, freeze-dried and spray-dried agaro-oligosaccharide powders were characterized to investigate their physicochemical and antioxidant properties. Agaro-oligosaccharide powders were shown to exhibit high water solubility index (88.73 – 95.88%), water absorption capacity (0.96 – 2.57 g/g) and oil absorption capacity (0.40 – 0.45 g/g). Agaro-oligosaccharide powders were shown to possess moderate DPPH radical scavenging activity (10.65 – 14.59%), ABTS radical scavenging activity (44 .47 – 65.61%) and ferric reducing antioxidant activity (0.165 – 0.353). Agaro-oligosaccharide powders were further characterized with respect to thermal and pH stability. Agaro-oligosaccharide powders were shown to exhibit high temperature resistance (≤ 100oC) and acid/alkaline resistance.
  3. Fulltext Relating descriptive sensory analysis to gas chromatography/mass spectrometry of palm sugars using partial least squares regression
    Wan Aida, W.M., Ho, C.W., Maskat, M.Y., Osman, H.
    International Food Research Journal, 2008;15(1):35-45.
    MyJurnal
    Sensory attributes of four different palm sugars were related to gas chromatography/mass spectrometry (GC/MS) analysis using partial least squares regression (PLS). The sweet caramel and burnt-like sensory attributes were strongly associated with 2-furfural and 2-furan methanol volatile compounds. The sensory scores for roasty and nutty were also associated with the GC/MS ratings for roasty and nutty-like aroma by its highest scores obtained from 2-ethyl-5-methyl pyrazine, 2,5-dimethyl pyrazine and 2,3-dimethyl pyrazine volatile compounds along the PC1 dimension. PLS analysis did not show correlation for the character impact compound furaneol, 2-ethyl-3,5-dimethyl pyrazine (EDMP) and 2,3-diethyl-5-methyl pyrazine (DEMP), which are perceived to be responsible for the sweet caramel-like and roasty/nutty attributes of palm sugars, respectively. This lack of relationship could partially be explained by covariance among the sensory ratings for the samples.
  4. Fulltext Physicochemical analysis of cholesterol-reduced egg yolk powder and its application in mayonnaise
    Fauziah, C.I., Zaibunnisa, A.H., Osman, H., Wan Aida, W.M.
    International Food Research Journal, 2016;23(2):575-582.
    MyJurnal
    The aim of this study were to find out the physicochemical characteristics of cholesterol-reduced egg yolk powder and its application in the production of mayonnaises. Cholesterol-reduced egg yolk powder (CREYP) were prepared from removal of cholesterol by formation of cholesterol:β-cyclodextrin inclusion complex. The physicochemical characteristics of CREYP and NEYP were foaming capacity (FC): 1.96%, 4%; foaming stability (FS): 96.48%, 94.55%; emulsion capacity (EC): 59.82%, 58.43% and emulsion stability (ES): 43.94%, 41.48% respectively. Whereas the viscosity of CREY, NEY and commercial mayonnaises were 8000, 4768 and 6747 cP respectively. The lightness (L*), redness (a*), yellowness (b*), saturation (C*) and hue angle (h°) values for CREYP and NEYP results showed significantly different (p>0.05) for all chroma values with CREYP showed higher L* and h° values but lower in a*, b* and C* values showing that the yellow colour of NEYP lessened. Commercial mayonnaise appeared to be lighter and less yellowish than CREY mayonnaises with L* and b* values of
    commercial to CREY mayonnaises were L*: 78.34; 63.78% and b*: 8.29; 14.98% respectively. It can be concluded that CREYP can be used as replace to the NEYP and whole liquid egg yolk
    with enhance nutritional values. The results obtained from this study will be very useful for producing CREYP.
  5. Physico-chemical compositions of the red seedless watermelons (Citrullus Lanatus)
    Yau, E.W., Rosnah, S., Noraziah, M., Chin, N.L., Osman, H.
    International Food Research Journal, 2010;17(2):327-334.
    MyJurnal
    Changes of physico-chemical properties such as size, weight, moisture content, total soluble solid
    (TSS), colour, pH, total acidity and sugar content of red seedless watermelon during storage at room temperature (± 28ºC; 70-80% RH) were investigated. The average weight, diameter and length of red seedless watermelon were 5.94 kg, 22.0 cm and 21.8 cm respectively. The length to diameter ratio was 1.02. The statistical analysis indicated that total soluble solids of fruit decreased significantly (p
  6. Fulltext Chemical composition changes of two water apple (Syzygium samaragense)
    Rosnah, S., Wong, W.K., Noraziah, M., Osman, H.
    International Food Research Journal, 2012;19(1):167-174.
    MyJurnal
    Changes in physical properties (weight, size, colour and weight loss) and chemical properties (proximate analysis, TSS, pH, freezing point, total acidity and sugar content) of two water apple (Syzgium samaragense) cultivars, Semarang Rose and Kristal Taiwan were evaluated during ripening at 10°C and 50% RH. The results showed that the Kristal Taiwan cultivar was larger in size and weight but smaller in length compared to Semarang Rose. The Semarang Rose cultivar was sweeter than Kristal Taiwan. In this study, data obtained suggests that the water apple fruit can be stored at cold storage until 19 days.
  7. Optimization of deacidification process for Morinda citrifolia extracts using packed column of calcium carbonate
    Nur Hafiza, Z., Maskat, M.Y., Wan Aida, W.M., Osman, H.
    International Food Research Journal, 2010;17(4):1051-1066.
    MyJurnal
    A study was carried out to optimize the deacidification process for noni (Morinda citrifolia L.) extract using packed column of calcium carbonate. The experiments were based on a 3-level factorial design to study the optimum process of deacidification for M. citrifolia extract. The M. citrifolia extract was treated with CaCO3 packed in different column diameter (20, 25 and 30 mm), height of calcium carbonate (0, 0.5 and 1 cm) and feed rate (10, 30 and 50 ml/min). Physico-chemical characteristics which include pH, titratable acidity, turbidity, total polyphenol content and total soluble solids were measured. Results showed that only pH, titratable acidity and turbidity could be well represented using statistical models. For pH, only the effect of height of CaCO3 was found to be significant. While for titratable acidity and turbidity, effects of diameter column and height of CaCO3 were significant. The optimum conditions for the deacidification of M. citrifolia extract was by using a column diameter of 30 mm, CaCO3 height of 1 cm, and a feed rate of 50 ml/min.
  8. Fulltext Anticonvulsant activity of α-terpineol isolated from myristica fragrans in GAERS model of absence epilepsy
    Islam, M.R., Muthuraju, S., Tarmizi, C.H., Zulkifli, M.M., Osman, H., Mohamad, H., et al.
    ASM Science Journal, 2012;6(2):95-102.
    MyJurnal
    Epilepsy is a neurological disorder characterized by recurrent seizures resulting from excessive abnormal electrical discharges in the brain. Medicinal plants may play an invaluable role to discover the new antiepileptic drugs. The aim of the present study was to investigate the anticonvulsant activity of α-terpineol isolated from Myristica fragrans Hountt. The α-terpineol showed a significant inhibition of the seizure episodes and spikes in absence seizures model of Genetic Absence Epilepsy Rats from Strasbourg (GAERS) rats by using electroencephalography records. It showed dose-dependent anticonvulsant activity that was comparable to the known antiepileptic drug of diazepam. It showed a rapid onset and relatively short duration of anticonvulsant effects. The present findings suggest that α-terpineol might possess antiepileptic activities against the partial seizures of human because it prevented seizures in well-established genetic absence seizure animal model of GAERS rats.
  9. Fulltext Optimization of vanillin production using isoeugenol as substrate by Aspergillus niger I-1472
    Tan, M. C., Liew, S. L., Wan Aida, W. M., Osman, H., Maskat, M. Y.
    International Food Research Journal, 2015;22(4):1651-1656.
    MyJurnal
    Response Surface Methodology (RSM) was used in the study to optimize the production of vanillin from isoeugenol through fermentation by Aspergillus niger I-1472. Three factors were studied which include amount of isoeugenol, resin (Amberlite XAD-4) and Span 80. During fermentation, isoeugenol as substrate were vortexed with Span 80 and added into the culture on Day 4. Resin (Amberlite XAD-4) was added into the medium the following day. The predicted optimum medium combination consisted of 3.61 g/L of isoeugenol, 5.8% (g/ mL) of Amberlite XAD-4 resin and 0.37% of Span 80 with an expected vanillin production of 0.137 g/L. Verification test showed that the model produced similar predicted and experimental values.
  10. The immobilization of 3-(chloropropyl)triethoxysilane onto silica by a simple one-pot synthesis
    Adam F, Osman H, Hello KM
    J Colloid Interface Sci, 2009 Mar 1;331(1):143-7.
    PMID: 19095242 DOI: 10.1016/j.jcis.2008.11.048
    Sodium silicate from rice husk ash (RHA) was transformed to functionalized silica with 3-(chloropropyl)triethoxysilane (CPTES) via a simple sol-gel technique in a one-pot synthesis. The (29)Si MAS NMR of the organo-silica complex (RHACCl) showed the presence of T(2), T(3), Q(3) and Q(4) silicon centers. The (13)C MAS NMR showed that RHACCl had three chemical shifts at 10.37, 26.70 and 47.69 ppm consistent with the three carbon atoms of the CPTES moiety. The presence of carbon, silicon and chlorine was determined by a combination of elemental analysis and EDX study.
  11. Cholinesterase inhibitory triterpenoids from the bark of Garcinia hombroniana
    Jamila N, Khairuddean M, Yeong KK, Osman H, Murugaiyah V
    J Enzyme Inhib Med Chem, 2015 Feb;30(1):133-9.
    PMID: 24666300 DOI: 10.3109/14756366.2014.895720
    Context: Garcinia hombroniana Pierre, known as manggis hutan in Malaysia is a rich source of xanthones and benzophenones.
  12. Ionic liquid mediated synthesis of mono- and bis-spirooxindole-hexahydropyrrolidines as cholinesterase inhibitors and their molecular docking studies
    Kia Y, Osman H, Kumar RS, Basiri A, Murugaiyah V
    Bioorg Med Chem, 2014 Feb 15;22(4):1318-28.
    PMID: 24461561 DOI: 10.1016/j.bmc.2014.01.002
    One pot, three-component reaction of 1-acryloyl-3,5-bisarylmethylidenepiperidin-4-ones with isatin and sarcosine in molar ratios of 1:1:1 and 1:2:2 furnished to mono- and bis-spiropyrrolidine heterocyclic hybrids comprising functionalized piperidine, pyrrolidine and oxindole structural motifs. Both mono and bis-spiropyrrolidines displayed good inhibitory activity against acetylcholinesterase (AChE) with IC₅₀ values of 2.36-9.43 μM. For butyrylcholinesterase (BChE), mono-cycloadducts in series 8 with IC₅₀ values of lower than 10 μM displayed better inhibitory activities than their bis-cycloadduct analogs in series 9 with IC₅₀ values of 7.44-19.12 μM. The cycloadducts 9j and 8e were found to be the most potent AChE and BChE inhibitors with IC₅₀ values of 2.35 and 3.21 μM, respectively. Compound 9j was found to be competitive inhibitor of AChE while compound 8e was a mixed-mode inhibitor of BChE with calculated Ki values of 2.01 and 6.76 μM, respectively. Molecular docking on Torpedo californica AChE and human BChE showed good correlation between IC₅₀ values and free binding energy values of the synthesized compounds docked into the active site of the enzymes.
  13. Enhanced photocatalytic activity of fish scale loaded TiO2 composites under solar light irradiation
    Ho LN, Ong SA, Osman H, Chong FM
    J Environ Sci (China), 2012;24(6):1142-8.
    PMID: 23505883
    Fish scale (FS) loaded TiO2 composites were investigated as photocatalysts in degradation of Methyl Orange under solar light irradiation. Composites were prepared through sol-gel method by varying mass ratio of TiO2/FS at 90:10, 70:30 and 50:50, respectively. The catalysts prepared in this study were characterized by using XRD, SEM, FT-IR and nitrogen sorption. The effects of solar irradiation, mass ratio of TiO2/FS composites, irradiation time and catalyst loadings were studied. Synergistic effect was found in TiO2/FS of 90:10 composite which performed higher photocatalytic degradation than synthesized TiO2 under solar light irradiation. However, further increasing fish scale content in the composites reduced the photocatalytic activity drastically. Under solar light irradiation, all the catalysts in this study exhibited photocatalytic activity, except TiO2/FS of 50:50 composite that only acted as a weak biosorbent without performing any photocatalytic property. Photocatalytic degradation increased with increasing catalyst loading and irradiation time but decreased with increased of initial dye concentration.
  14. Fulltext Antioxidant activity and phenolic content of Paederia foetida and Syzygium aqueum
    Osman H, Rahim AA, Isa NM, Bakhir NM
    Molecules, 2009;14(3):970-8.
    PMID: 19305354 DOI: 10.3390/molecules14030970
    The antioxidant activity of fresh and dried plant extracts of Paederia foetida and Syzygium aqueum were studied using beta-carotene bleaching and the 2,2'-azinobis(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) radical cation assay. The percentage of antioxidant activity for all extract samples using both assays was between 58 and 80%. The fresh samples of both plants had higher antioxidant activity than the dried samples. The results of the beta-carotene bleaching assay were correlated (R(2) = 0.9849) with those of the ABTS assay.
  15. Synthesis and discovery of highly functionalized mono- and bis-spiro-pyrrolidines as potent cholinesterase enzyme inhibitors
    Kia Y, Osman H, Suresh Kumar R, Basiri A, Murugaiyah V
    Bioorg Med Chem Lett, 2014 Apr 1;24(7):1815-9.
    PMID: 24594354 DOI: 10.1016/j.bmcl.2014.02.019
    Novel mono and bis spiropyrrolidine derivatives were synthesized via an efficient ionic liquid mediated, 1,3-dipolar cycloaddition methodology and evaluated in vitro for their AChE and BChE inhibitory activities in search for potent cholinesterase enzyme inhibitors. Most of the synthesized compounds displayed remarkable AChE inhibitory activities with IC50 values ranging from 1.68 to 21.85 μM, wherein compounds 8d and 8j were found to be most active inhibitors against AChE and BChE with IC50 values of 1.68 and 2.75 μM, respectively. Molecular modeling simulation on Torpedo californica AChE and human BChE receptors, showed good correlation between IC50 values and binding interaction template of the most active inhibitors docked into the active site of their relevant enzymes.
  16. Fulltext Metabolomics approach for multibiomarkers determination to investigate dengue virus infection in human patients
    Shahfiza N, Osman H, Hock TT, Abdel-Hamid AZ
    Acta Biochim. Pol., 2017;64(2):215-219.
    PMID: 28350402 DOI: 10.18388/abp.2015_1224
    BACKGROUND: Dengue is one of the major public health problems in the world, affecting more than fifty million cases in tropical and subtropical region every year. The metabolome, as pathophysiological end-points, provide significant understanding of the mechanism and progression of dengue pathogenesis via changes in the metabolite profile of infected patients. Recent developments in diagnostic technologies provide metabolomics for the early detection of infectious diseases.

    METHODS: The mid-stream urine was collected from 96 patients diagnosed with dengue fever at Penang General Hospital (PGH) and 50 healthy volunteers. Urine samples were analyzed with proton nuclear magnetic resonance (1H NMR) spectroscopy, followed by chemometric multivariate analysis. NMR signals highlighted in the orthogonal partial least square-discriminant analysis (OPLS-DA) S-plots were selected and identified using Human Metabolome Database (HMDB) and Chenomx Profiler. A highly predictive model was constructed from urine profile of dengue infected patients versus healthy individuals with the total R2Y (cum) value 0.935, and the total Q2Y (cum) value 0.832.

    RESULTS: Data showed that dengue infection is related to amino acid metabolism, tricarboxylic acid intermediates cycle and β-oxidation of fatty acids. Distinct variations in certain metabolites were recorded in infected patients including amino acids, various organic acids, betaine, valerylglycine, myo-inositol and glycine.

    CONCLUSION: Metabolomics approach provides essential insight into host metabolic disturbances following dengue infection.

  17. Fulltext Straightforward synthesis of novel 1-(2'-α-O-D-glucopyranosyl ethyl) 2-arylbenzimidazoles
    Arumugam N, Abdul Rahim AS, Abd Hamid S, Osman H
    Molecules, 2012 Aug 17;17(8):9887-99.
    PMID: 22902883 DOI: 10.3390/molecules17089887
    A series of novel 1-(2'-α-O-D-glucopyranosyl ethyl) 2-arylbenzimidazoles has been prepared via one-pot glycosylation of ethyl-1-(2'-hydroxyethyl)-2-arylbenzimidazole-5-carboxylate derivatives. Synthesis of the 2-arylbenzimidazole aglycones from 4-fluoro-3-nitrobenzoic acid was accomplished in four high-yielding steps. The reduction and cyclocondensation steps for the aglycone synthesis proceeded efficiently under microwave irradiation to afford the appropriate benzimidazoles in excellent yields within 2-3 min. Glycosylation of the hydroxyethyl aglycones with the perbenzylated 1-hydroxy- glucopyranose, pretreated with the Appel-Lee reagent, followed by catalytic hydrogenolysis delivered the desired 1-(2'-α-O-D-glucopyranosyl ethyl) 2-aryl-benzimidazoles in a simple and straightforward manner.
  18. Fulltext Microwave-assisted synthesis and antioxidant properties of hydrazinyl thiazolyl coumarin derivatives
    Osman H, Arshad A, Lam CK, Bagley MC
    Chem Cent J, 2012 Apr 17;6(1):32.
    PMID: 22510146 DOI: 10.1186/1752-153X-6-32
    BACKGROUND: Coumarin derivatives exhibit a wide range of biological properties including promising antioxidant activity. Furthermore, microwave-assisted organic synthesis has delivered rapid routes to N- and O-containing heterocycles, including coumarins and thiazoles. Combining these features, the use of microwave-assisted processes will provide rapid access to a targeted coumarin library bearing a hydrazino pharmacophore for evaluation of antioxidant properties

    RESULTS: Microwave irradiation promoted 3 of the 4 steps in a rapid, convergent synthesis of a small library of hydrazinyl thiazolyl coumarin derivatives, all of which exhibited significant antioxidant activity comparable to that of the natural antioxidant quercetin, as established by DPPH and ABTS radical assays

    CONCLUSIONS: Microwave dielectric heating provides a rapid and expedient route to a series of hydrazinyl thiazolyl coumarins to investigate their radical scavenging properties. Given their favourable properties, in comparison with known antioxidants, these coumarin derivatives are promising leads for further development and optimization.

  19. Effects of hydraulic retention time and cultivation on nutrients removal and biomass production in wastewater by membrane photobioreactor: Modeling and optimization by machine learning and response surface methodology
    Hua H, Zahmatkesh S, Osman H, Tariq A, Zhou JL
    Chemosphere, 2024 Feb 05.
    PMID: 38325614 DOI: 10.1016/j.chemosphere.2024.141394
    Discharge of excess nutrients in wastewater can potentially cause eutrophication and poor water quality in the aquatic environment. A new approach of nutrients removal in wastewater is by utilizing microalgae which grow by absorbing CO2 from air. Furthermore, the use of membrane photo-bioreactor (MPBR) that combines membranes and photo-bioreactor has emerged as a novel wastewater treatment method. This research sought to model, forecast, and optimize the behavior of dry biomass, dissolved inorganic nitrogen (DIN), and dissolved inorganic phosphorus (DIP) in MPBR by response surface methodology (RSM) and artificial neural network (ANN) algorithms, which saved time and resources of experimental work. The independent variables that have been used for modeling were hydraulic retention time (HRT) and cultivation. For this purpose, the dry biomass of algal production, DIN and DIP behavior were modeled by RSM and ANN algorithms, to identify the optimum mode of processing. RSM modeling has shown good agreement with experimental data. According to RSM optimization, the optimum mode for DIN and DIP occurred at 1.15 days of HRT and 1.92 days of cultivation. The ANN showed better performance than the RSM model, with the margin of deviation being less than 10%. Furthermore, the ANN algorithm showed higher accuracy than RSM method in predicting the dry biomass, DIN and DIP behavior in MPBR.
  20. Effect of thermal processing of palm sap on the physico-chemical composition of traditional palm sugar
    Ho CW, Aida WM, Maskat MY, Osman H
    Pak J Biol Sci, 2008 Apr 01;11(7):989-95.
    PMID: 18810967
    During the production of palm sugar, the palm sap (Arenga pinnata) is heated up to 150 degrees C. Besides the hydrolysis of carbohydrate to generate reducing sugars and degradation of amino acid, many physicochemical changes produced at all these temperatures, having a significant impact on the overall quality of palm sugar. In this study, changes in physico-chemical properties of the palm sap due to heat processing were investigated. Analysis of colour, soluble solid, pH, temperature, sugar and amino acid concentration was determinant. The results showed clearly that the heating process at these high temperatures was necessary to create an environment which was rich in essential precursors for subsequent reactions such as Maillard reaction. Chemical compounds that showed drastic changes in concentration were polar side chain amino acids especially glutamine, asparagine and arginine as well as sucrose and pH value. Other quality characteristics of palm sugar based on colour and soluble solids (Brix) shared an increase in concentration as a function of time.
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