Displaying publications 21 - 40 of 448 in total

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  1. H-E. Khoo, Azlan A, Ismail A, Abas F
    Sains Malaysiana, 2013;42:949-954.
    This study aimed to determine the total phenolics and antioxidant capacity of defatted dabai parts based on liquid extraction and optimized using response surface methodology (RSM). A two-level factorial design was applied to determine the effect of two independent variables (extraction time: X1 and % methanol: X2) on three response variables (total phenolic content: Y1, total flavonoid/anthocyanin content: Y2 and Trolox equivalent antioxidant capacity: Y3). The optimum conditions for extraction time and percent methanol were 36 min or 1 min and 62.25% or 53% for the defatted dabai pulp or peel, respectively. The RSM optimized extraction was compared with sonication-assisted extraction. Optimization results showed that defatted dabai parts had high total phenolic content and antioxidant capacity. Sonication-assisted extraction utilized the optimized extraction conditions had further increased the total phenolic content and antioxidant capacity of defatted dabai peel, but not in the pulp. Therefore, optimization of different extraction methods for the defatted fruit parts is recommended for future studies.
    Matched MeSH terms: Methanol
  2. Iqbal A, Smida A, Saraereh OA, Alsafasfeh QH, Mallat NK, Lee BM
    Sensors (Basel), 2019 Mar 08;19(5).
    PMID: 30857265 DOI: 10.3390/s19051200
    A compact, cylindrical dielectric resonator antenna (CDRA), using radio frequency signals to identify different liquids is proposed in this paper. The proposed CDRA sensor is excited by a rectangular slot through a 3-mm-wide microstrip line. The rectangular slot has been used to excite the CDRA for H E M 11 mode at 5.25 GHz. Circuit model values (capacitance, inductance, resistance and transformer ratios) of the proposed CDRA are derived to show the true behaviour of the system. The proposed CDRA acts as a sensor due to the fact that different liquids have different dielectric permittivities and, hence, will be having different resonance frequencies. Two different types of CDRA sensors are designed and experimentally validated with four different liquids (Isopropyl, ethanol, methanol and water).
    Matched MeSH terms: Methanol
  3. Ariffin NHM, Hasham R, Hamzah MAAM, Park CS
    Fitoterapia, 2024 Jan;172:105755.
    PMID: 38000761 DOI: 10.1016/j.fitote.2023.105755
    Ficus deltoidea was known for its potent antioxidant, anti-melanogenic and photoprotective skin barrier activities. These properties are contributed by its biomarkers which are vitexin and isovitexin. This study aims to optimize the yield of methanolic extraction of Ficus deltoidea leaves (EFD) and evaluate their effects on skin barrier function and hydration. For optimization, Box-Behnken design was utilized to investigate the effects of methanol concentration, sonication time, and solvent-to-sample ratio on the yields of vitexin and isovitexin in EFD. The optimal yields obtained were 32.29 mg/g for vitexin and 35.87 mg/g for isovitexin. The optimum extraction conditions were 77.66% methanol concentration, 20.03 min sonication time, and 19.88 mL/g solvent-to-sample ratio. The quantitative real-time polymerase chain reaction was utilized to measure variant marker genes of transglutaminase-1, caspase 14, ceramide synthase 3, involucrin, and filaggrin of EFD-induced keratinocyte differentiation by in vitro study. Exposure to EFD has elevated the mRNA levels of all tested marker genes by 0.7-9.2 folds. Then, in vivo efficacy study was conducted on 20 female subjects for 14 days to evaluate skin biophysical assessment of hydration. EFD topical formulation treatment successfully increased skin hydration on day 7 (43.74%) and day 14 (47.23%). In silico study by molecular docking was performed to identify intermolecular binding interactions of vitexin and isovitexin with the interested proteins of tested marker genes. The result of molecular docking to the interested proteins revealed a similar trend with real-time PCR data. In conclusion, EFD potentially enhanced the skin barrier function and hydration of human skin cells.
    Matched MeSH terms: Methanol
  4. Lim S, Lee KT
    Bioresour Technol, 2013 Aug;142:121-30.
    PMID: 23735793 DOI: 10.1016/j.biortech.2013.05.010
    In this study, optimization of supercritical reactive extraction directly from Jatropha seeds in a high pressure batch reactor using Response Surface Methodology (RSM) coupled with Central Composite Rotatable Design (CCRD) was performed. Four primary variables (methanol to solid ratio (SSR), reaction temperature, time and CO2 initial pressure) were investigated under the proposed constraints. It was found that all variables had significant effects towards fatty acid methyl esters (FAME) yield. Moreover, three interaction effects between the variables also played a major role in influencing the final FAME yield. Optimum FAME yield at 92.0 wt.% was achieved under the following conditions: 5.9 SSR, 300°C, 12.3 min and 20 bar CO2. Final FAME product was discovered to fulfil existing international standard. Preliminary characterization analysis proved that the solid residue can be burnt as solid fuel in the form of biochar while the liquid product can be separated as specialty chemicals or burned as bio-oil for energy production.
    Matched MeSH terms: Methanol/chemistry*
  5. Yaakob Z, Sukarman IS, Narayanan B, Abdullah SR, Ismail M
    Bioresour Technol, 2012 Jan;104:695-700.
    PMID: 22113069 DOI: 10.1016/j.biortech.2011.10.058
    Transesterification reaction of Jatropha curcas oil with methanol was carried out in the presence of ash generated from Palm empty fruit bunch (EFB) in a heterogeneous catalyzed process. The ash was doped with KOH by impregnation to achieve a potassium level of 20 wt.%. Under optimum conditions for the EFB-catalyzed (65 °C, oil/methanol ratio of 15, 90 min, 20 wt.% EFB ash catalyst) and the KOH-EFB-catalyzed reactions (65 °C, oil/methanol ratio of 15, 45 min, 15 wt.% of KOH doped EFB ash), biodiesel (>98%) with specifications higher than those stipulated by European biodiesel quality standard EN 14214 was obtained.
    Matched MeSH terms: Methanol/chemistry*
  6. Syahmi AR, Vijayarathna S, Sasidharan S, Latha LY, Kwan YP, Lau YL, et al.
    Molecules, 2010 Nov;15(11):8111-21.
    PMID: 21072022 DOI: 10.3390/molecules15118111
    Elaeis guineensis (Arecaceae) is widely used in West African traditional medicine for treating various ailments. An evaluation on the toxicity of extracts of this plant is crucial to support the therapeutic claims. The acute oral toxicity and brine shrimp lethality of a methanolic extract of this plant was tested. Oral administration of crude extract at the highest dose of 5,000 mg/kg resulted in no mortalities or evidence of adverse effects, implying that E. guineensis is nontoxic. Normal behavioral pattern, clinical signs and histology of vital organs confirm this evidence. The E. guineensis extracts screened for toxicity against brine shrimp had 50% lethal concentration (LC₅₀) values of more than 1.0 mg/mL (9.00 and 3.87 mg/mL, at 6 and 24 h, respectively), confirming that the extract was not toxic. Maximum mortalities occurred at 100 mg/mL concentration while the least mortalities happened to be at 0.195 mg/mL concentration. The results of both tests confirm that E. guineensis is nontoxic and hence safe for commercial utilization.
    Matched MeSH terms: Methanol/chemistry*
  7. Atkins MP, Earle MJ, Seddon KR, Swadźba-Kwaśny M, Vanoye L
    Chem Commun (Camb), 2010 Mar 14;46(10):1745-7.
    PMID: 20177636 DOI: 10.1039/b923250h
    Selected Brønsted acidic ionic liquids were tested as homogeneous catalysts for the dehydration of methanol to dimethyl ether. Ionic liquids incorporating an alkanesulfonic acid as a part of the cation, a complex acidic anion, [A(2)H](-), or both, proved to be good catalysts for this process, providing high conversions and selectivities. Homogeneous catalysis in the liquid state represents a novel approach to dimethyl ether synthesis.
    Matched MeSH terms: Methanol/chemistry*
  8. Kumar SR, Mohd Ramli ES, Abdul Nasir NA, Mohd Ismail N, Mohd Fahami NA
    Molecules, 2021 Jun 29;26(13).
    PMID: 34210097 DOI: 10.3390/molecules26133985
    Obesity and hyperlipidemia are metabolic dysregulations that arise from poor lifestyle and unhealthy dietary intakes. These co-morbidity conditions are risk factors for vascular diseases. Piper sarmentosum (PS) is a nutritious plant that has been shown to pose various phytochemicals and pharmacological actions. This study aimed to investigate the effect of PS on obesity and hyperlipidemia in an animal model. Forty male Wistar rats were randomly divided into five experimental groups. The groups were as follows: UG-Untreated group; CTRL-control; FDW-olive oil + 20% fructose; FDW-PS-PS (125 mg/kg) + 20% fructose; FDW-NGN-naringin (100 mg/kg) + 20% fructose. Fructose drinking water was administered daily for 12 weeks ad libitum to induce metabolic abnormality. Treatment was administered at week 8 for four weeks via oral gavage. The rats were sacrificed with anesthesia at the end of the experimental period. Blood, liver, and visceral fat were collected for further analysis. The consumption of 20% fructose water by Wistar rats for eight weeks displayed a tremendous increment in body weight, fat mass, percentage fat, LDL, TG, TC, HMG-CoA reductase, leptin, and reduced the levels of HDL and adiponectin as well as adipocyte hypertrophy. Following the treatment period, FDW-PS and FDW-NGN showed a significant reduction in body weight, fat mass, percentage fat, LDL, TG, TC, HMG-CoA reductase, and leptin with an increment in the levels of HDL and adiponectin compared to the FDW group. FDW-PS and FDW-NGN also showed adipocyte hypotrophy compared to the FDW group. In conclusion, oral administration of 125 mg/kg PS methanolic extract to fructose-induced obese rats led to significant amelioration of obesity and hyperlipidemia through suppressing the adipocytes and inhibiting HMG-CoA reductase. PS has the potential to be used as an alternative or adjunct therapy for obesity and hyperlipidemia.
    Matched MeSH terms: Methanol/chemistry*
  9. Low QJ, Lee KT, Lim TH, Siaw C, Cheo SW, Tan NE, et al.
    Med J Malaysia, 2020 07;75(4):442-444.
    PMID: 32724013
    There are increasing reports of methanol poisoning (MP) incidence worldwide. In Malaysia, the largest first methanol poisoning was reported in Selangor in 2013 with a total of 41 patients and cluster of cases been reported from the country since then. Often MP involved adulterated alcohol containing more than the legal permissible concentration of methanol. Methanol is rapidly absorbed and metabolised into formic acid which causes variable symptoms of the central nervous system such as blindness, seizure, coma and gastrointestinal disturbances. Mortality could reach up to 83% as reported using the coma state, pH and pCO2 level in the worst-case scenario.
    Matched MeSH terms: Methanol/poisoning*
  10. Al-Adhroey AH, Nor ZM, Al-Mekhlafi HM, Amran AA, Mahmud R
    Molecules, 2010 Dec 28;16(1):107-18.
    PMID: 21189459 DOI: 10.3390/molecules16010107
    The need for new compounds active against malaria parasites is made more urgent by the rapid spread of drug-resistance to available antimalarial drugs. The crude methanol extract of Piper betle leaves (50-400 mg/kg) was investigated for its antimalarial activity against Plasmodium berghei (NK65) during early and established infections. The phytochemical and antioxidant potentials of the crude extract were evaluated to elucidate the possibilities of its antimalarial effects. The safety of the extract was also investigated in ICR mice of both sexes by the acute oral toxicity limit test. The leaf extract demonstrated significant (P < 0.05) schizonticidal activity in all three antimalarial evaluation models. Phytochemical screening showed that the leaf extract contains some vital antiplasmodial chemical constituents. The extract also exhibited a potent ability to scavenge the free radicals. The results of acute toxicity showed that the methanol extract of Piper betle leaves is toxicologically safe by oral administration. The results suggest that the Malaysian folklorical medicinal application of the extract of Piper betle leaf has a pharmacological basis.
    Matched MeSH terms: Methanol/chemistry*
  11. Wong SK, Lim YY, Ling SK, Chan EW
    Pharmacognosy Res, 2014 Jan;6(1):67-72.
    PMID: 24497746 DOI: 10.4103/0974-8490.122921
    Three compounds isolated from the methanol (MeOH) leaf extract of Vallaris glabra (Apocynaceae) were those of caffeoylquinic acids (CQAs). This prompted a quantitative analysis of their contents in leaves of V. glabra in comparison with those of five other Apocynaceae species (Alstonia angustiloba, Dyera costulata, Kopsia fruticosa, Nerium oleander, and Plumeria obtusa), including flowers of Lonicera japonica (Japanese honeysuckle), the commercial source of chlorogenic acid (CGA).
    Matched MeSH terms: Methanol
  12. Baharara J, Amini E, Namvar F
    Avicenna J Med Biotechnol, 2016 Jan-Mar;8(1):29-35.
    PMID: 26855733
    Marine organisms provide appreciable source of novel bioactive compounds with pharmacological potential. There is little information in correlation with anti-cancer activities of brittle star. In the present study, anti-neoplastic efficacy of Ophiocoma erinaceus methanol extract against human cervical cancer cells was investigated.
    Matched MeSH terms: Methanol
  13. Lange E, Lozano AI, Jones NC, Hoffmann SV, Kumar S, Śmiałek MA, et al.
    J Phys Chem A, 2020 Sep 30.
    PMID: 32941031 DOI: 10.1021/acs.jpca.0c06615
    We investigate the methanol absorption spectrum in the range 5.5-10.8 eV to provide accurate and absolute cross-sections values. The main goal of this study is to provide a comprehensive analysis of methanol electronic-state spectroscopy by employing high-resolution vacuum ultraviolet (VUV) photoabsorption measurements together with state-of-the-art quantum chemical calculation methods. The VUV spectrum reveals several new features that are not previously reported in literature, for n > 3 in the transitions (nsσ(a') ← (2a″)) (1A' ← X̃1A') and (nsσ, npσ, npσ', ndσ ← (7a')) (1A' ← X̃1A'), and with particular relevance to vibrational progressions of the CH3 rocking mode, v11'(a″), mode in the (3pπ(a″) ← (2a″)) (21A' ← X̃1A') absorption band at 8.318 eV. The measured absolute photoabsorption cross-sections have subsequently been used to calculate the photolysis lifetime of methanol in the Earth's atmosphere from the ground level up to the limit of the stratosphere (50 km altitude). This shows that solar photolysis plays a negligible role in the removal of methanol from the lower atmosphere compared with competing sink mechanisms. Torsional potential energy scans, as a function of the internal rotation angle for the ground and first Rydberg states, have also been calculated as part of this investigation.
    Matched MeSH terms: Methanol
  14. Zahidah Ayob, Shajarahtunnur Jamil, Siti Pauliena Mohd Bohari, Farediah Ahmad, Azman Abd Samad
    Sains Malaysiana, 2017;46:457-461.
    Justicia gendarussa methanolic leaves extract from four different locations in Southern region of Malaysia and distribution
    of two flavonoids, naringenin and kaempferol in plant organs (young and mature leaves) were determined using gas
    chromatography-flame ionization detector (GC-FID) analysis. Naringenin and kaempferol contents were detected
    and quantified in leaves extract. The results indicated that mature leaves contained more naringenin and kaempferol
    compared to young leaves. The highest concentration of naringenin and kaempferol were recorded in mature leaves from
    Skudai and Muar regions which were 507.692 and 1226.964 mgkg-1, respectively. Data analysis showed that naringenin
    content was directly proportional to the amount of kaempferol in the leaf extracts. In conclusion, this study suggested
    geographical variation among plant samples and physiological stage of organ parts could contribute to variation in
    flavonoids concentration in a plant species.
    Matched MeSH terms: Methanol
  15. Teh AA, Ahmad R, Kara M, Rusop M, Awang Z
    J Nanosci Nanotechnol, 2012 Oct;12(10):8201-4.
    PMID: 23421197
    We report the use of a new precursor as active agents to promote the growth of carbon nanotubes (CNT) in methane ambient using a simple thermal chemical vapour deposition method. The agents consist of ammonia and methanol mixed at different ratios and was found to enhance the growth of CNTs. The optimum methanol to ammonia ratio was found to be 8 to 5, whereby longer and denser CNTs were produced compared to other ratios. The result was found otherwise when the experiment was done solely in methane ambient. In addition, CNT growth on substrates coated with double layer Ni catalyst was improved in terms of quality and density compared to a single coated substrates. This finding is supported by Raman spectrometry analysis.
    Matched MeSH terms: Methanol
  16. Poh-Hwa, T., Yoke-Kqueen, C., Indu Bala, J., Son, R.
    MyJurnal
    The aim of this work was to investigate the antioxidant and antimicrobial of Phyllanthus amarus, Phyllanthus niruri and Phyllanthus urinaria. P. niruri was found to possess the highest antioxidant activity, the activity decreased in the order P. niruri > P. amarus > P. urinaria for water extract. However, the activity decreased in the order P. niruri > P. urinaria > P. amarus for methanol extract. The result correlation between the antioxidant activity and total phenolic content revealed a positive correlation of 0.954 < r 2 < 1.000 for both water and methanol extract. Methanol extract showed higher total phenolic content and antioxidant activity as compared with water extract. Lowest Minimum Inhibitory Concentration (MIC) value for water extract against the selected microorganism was >2.5 mg/mL meanwhile, for methanol extract was 2.5 mg/mL and >0.625 mg/mL were the value for water and methanol extract. Methanol extract showed better inhibition potential than water extract
    Matched MeSH terms: Methanol
  17. MohanRaj, T., Kumar, K. Murugu Mohan, Kumar, Perumal
    MyJurnal
    Vegetable oil has become more attractive recently because of its environmental benefits and better
    quality exhaust emission. A well-known transesterification process made biodiesel, pungam seed oil was selected for biodiesel production. Pungam seed oil is non-edible oil, thus, food versus fuel conflict will not arise if this is used for biodiesel production. A maximum of 75% biodiesel was produced with 20% methanol in the presence of 0.5% sodium hydroxide. The experimental investigations were carried out in an engine that is coupled with an eddy current dynamometer. The engine is a single cylinder water-cooled, direct injection diesel engine developing a power output of 3.7 kW at 1500 rev/min. The crank angle encoder measured the engine speed, whereas the piezo electric sensors measured the cylinder pressure and the fuel injection pressure. The experimental investigations were carried out for bio-diesel and diesel and the results were compared. From the experimental results, it is concluded that the use of bio-diesel as an alternative fuel leads to significant reduction in emissions and improved performance of diesel engines. This paper discusses the production process of biodiesel from Pungam seed oil and its performance in the compression ignition engine.
    Matched MeSH terms: Methanol
  18. Rabeta MS, Lin S
    Sains Malaysiana, 2015;44:275-280.
    This study aimed to assess the effects of fresh, thermal drying method (vacuum oven drying), and nonthermal drying method (freeze drying) on the antioxidant activities of leaves and berries of Cayratia trifolia using ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-1-picrylhydrazyl radical scavenging capacity (DPPH) assays. The total phenolic content (TPC) and flavonoid content (TFC) of the leaves and berries of C. trifolia were also measured. Based on the results obtained, the TPC, TFC, and antioxidant activities of the leaves and berries were arranged in the following order: freeze-dried sample with methanol extraction > vacuum-dried sample with methanol extraction > freeze-dried sample with water extraction > vacuum-dried sample with water extraction > fresh sample with methanol extraction > fresh sample with water extraction. The results showed a significant difference (p<0.05) between the fresh and dried samples. In conclusion, freeze drying was found to be a good method for maintaining TPC, TFC, and antioxidant activities by FRAP and DPPH methods in the leaves and berries of C. trifolia.
    Matched MeSH terms: Methanol
  19. Mohammad Hafizuddin Jumali, Norhashimah Ramli, Izura Izzuddin, Muhammad Yahaya, Muhamad Mat Salleh
    The influence of PANI additions on methanol sensing properties of ZnO thin films at room temperature had been investigated. Commercial polyaniline powder (PANI) was mixed into 3 mL ZnO solution in five different weight percentages namely 1.25, 2.50, 3.75, 5.00 and 6.25% to obtain ZnO/PANI composite solutions. These solutions were spin coated onto glass substrate to form thin films. Microstructural studies by FESEM indicated that ZnO/PANI films showed porous structures with nanosize grains. The thickness of the film increased from 55 to 256 nm, proportionate to increment of PANI. The presence of 2 adsorption peaks at ~310 nm and ~610 nm in UV-Vis spectrum proved that addition of PANI has modified the adsorption peak of ZnO film. Methanol vapour detection showed that addition of PANI into ZnO dramatically improved the sensing properties of the sensor. The sensors also exhibited good repeatability and reversibility. Sensor with the amount of PANI of 3.75 wt% exhibited the highest sensitivity with response and recovery time was about 10 and 80 s, respectively. The possible sensing mechanism of the sensor was also discussed in this article.
    Matched MeSH terms: Methanol
  20. Wong Y, Taufiq-Yap YH, Ramli I
    Sains Malaysiana, 2015;44:281-290.
    Biodiesel was produced via transesterification of palm oil with methanol in the presence of CaO-Nb2O5 mixed oxide catalyst. Response surface methodology (RSM) with central composite design (CCD) was performed to determine the optimum operating conditions and to optimize the biodiesel yield. In this study, the reaction variables being optimized were reaction time, catalyst loading and methanol to oil molar ratio. From the analysis of variance (ANOVA), the most influential parameter on biodiesel production was reaction time. The predicted yield was found in good agreement with the experimental value, with R2= 0.9902. The optimum biodiesel yield of 97.67% was achieved at 2.67 h reaction time, with 3.60 wt. % of catalyst and with methanol to oil molar ratio of 13.04. The high biodiesel yield can be correlated to the synergic effect of basicity between the metallic ions of CaO-Nb2O5 shown in the physicochemical analysis.
    Matched MeSH terms: Methanol
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