Displaying publications 1 - 20 of 458 in total

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  1. Maiangwa J, Hamdan SH, Mohamad Ali MS, Salleh AB, Zaliha Raja Abd Rahman RN, Shariff FM, et al.
    J Mol Graph Model, 2021 06;105:107897.
    PMID: 33770705 DOI: 10.1016/j.jmgm.2021.107897
    Critical to the applications of proteins in non-aqueous enzymatic processes is their structural dynamics in relation to solvent polarity. A pool of mutants derived from Geobacillus zalihae T1 lipase was screened in organic solvents (methanol, ethanol, propanol, butanol and pentanol) resulting in the selection of six mutants at initial screening (A83D/K251E, R21C, G35D/S195 N, K84R/R103C/M121I/T272 M and R106H/G327S). Site-directed mutagenesis further yielded quadruple mutants A83D/M121I/K251E/G327S and A83D/M121I/S195 N/T272 M, both of which had improved activity after incubation in methanol. The km and kcat values of these mutants vary marginally with the wild-type enzyme in the methanol/substrate mixture. Thermally induced unfolding of mutants was accompanied with some loss of secondary structure content. The root mean square deviations (RMSD) and B-factors revealed that changes in the structural organization are intertwined with an interplay of the protein backbone with organic solvents. Spatially exposed charged residues showed correlations between the solvation dynamics of the methanol solvent and the hydrophobicity of the residues. The short distances of the radial distribution function provided the required distances for hydrogen bond formation and hydrophobic interactions. These dynamic changes demonstrate newly formed structural interactions could be targeted and incorporated experimentally on the basis of solvent mobility and mutant residues.
    Matched MeSH terms: Methanol
  2. Li D, Faiza M, Ali S, Wang W, Tan CP, Yang B, et al.
    Appl Biochem Biotechnol, 2018 Apr;184(4):1061-1072.
    PMID: 28948493 DOI: 10.1007/s12010-017-2594-1
    A highly efficient process for reducing the fatty acid (FA) content of high-acid rice bran oil (RBO) was developed by immobilized partial glycerides-selective lipase SMG1-F278N-catalyzed esterification/transesterification using methanol as a novel acyl acceptor. Molecular docking simulation indicated that methanol was much closer to the catalytic serine (Ser-171) compared with ethanol and glycerol, which might be one of the reasons for its high efficiency in the deacidification of high-acid RBO. Additionally, the reaction parameters were optimized to minimize the FA content of high-acid RBO. Under the optimal conditions (substrate molar ratio of methanol to FAs of 1.8:1, enzyme loading of 40 U/g, and at 30 °C), FA content decreased from 25.14 to 0.03% after 6 h of reaction. Immobilized SMG1-F278N exhibited excellent methanol tolerance and retained almost 100% of its initial activity after being used for ten batches. After purification by molecular distillation, the final product contained 97.86% triacylglycerol, 2.10% diacylglycerol, and 0.04% FA. The acid value of the final product was 0.09 mg KOH/g, which reached the grade one standard of edible oil. Overall, methanol was a superior acyl acceptor for the deacidification of high-acid RBO and the high reusability of immobilized SMG1-F278N indicates an economically attractive process.
    Matched MeSH terms: Methanol/chemistry*
  3. Bhardwaj R, Sharma T, Nguyen DD, Cheng CK, Lam SS, Xia C, et al.
    J Environ Manage, 2021 Jul 01;289:112468.
    PMID: 33823414 DOI: 10.1016/j.jenvman.2021.112468
    A continuous increase in the amount of greenhouse gases (GHGs) is causing serious threats to the environment and life on the earth, and CO2 is one of the major candidates. Reducing the excess CO2 by converting into industrial products could be beneficial for the environment and also boost up industrial growth. In particular, the conversion of CO2 into methanol is very beneficial as it is cheaper to produce from biomass, less inflammable, and advantageous to many industries. Application of various plants, algae, and microbial enzymes to recycle the CO2 and using these enzymes separately along with CO2-phillic materials and chemicals can be a sustainable solution to reduce the global carbon footprint. Materials such as MOFs, porphyrins, and nanomaterials are also used widely for CO2 absorption and conversion into methanol. Thus, a combination of enzymes and materials which convert the CO2 into methanol could energize the CO2 utilization. The CO2 to methanol conversion utilizes carbon better than the conventional syngas and the reaction yields fewer by-products. The methanol produced can further be utilized as a clean-burning fuel, in pharmaceuticals, automobiles and as a general solvent in various industries etc. This makes methanol an ideal fuel in comparison to the conventional petroleum-based ones and it is advantageous for a safer and cleaner environment. In this review article, various aspects of the circular economy with the present scenario of environmental crisis will also be considered for large-scale sustainable biorefinery of methanol production from atmospheric CO2.
    Matched MeSH terms: Methanol*
  4. Seng NT
    Med J Malaysia, 1978 Sep;33(1):13-6.
    PMID: 750888
    Matched MeSH terms: Methanol/poisoning*
  5. Kai T, Mak GL, Wada S, Nakazato T, Takanashi H, Uemura Y
    Bioresour Technol, 2014 Jul;163:360-3.
    PMID: 24813567 DOI: 10.1016/j.biortech.2014.04.030
    In this study, a novel method for the production of biodiesel under mild conditions using fine particles of sodium methoxide formed in dimethyl carbonate (DMC) is proposed. Biodiesel is generally produced from vegetable oils by the transesterification of triglycerides with methanol. However, this reaction produces glycerol as a byproduct, and raw materials are not effectively utilized. Transesterification with DMC has recently been studied because glycerol is not formed in the process. Although solid-state sodium methoxide has been reported to be inactive for this reaction, the catalytic activity dramatically increased with the preparation of fine catalyst powders by crystallization. The transesterification of canola oil with DMC was studied using this catalyst for the preparation of biodiesel. A conversion greater than 96% was obtained at 65°C for 2h with a 3:1M ratio of DMC and oil and 2.0 wt% catalyst.
    Matched MeSH terms: Methanol/chemistry*
  6. Syam AM, Hamid HA, Yunus R, Rashid U
    ScientificWorldJournal, 2013;2013:268385.
    PMID: 24363616 DOI: 10.1155/2013/268385
    Many kinetics studies on methanolysis assumed the reactions to be irreversible. The aim of the present work was to study the dynamic modeling of reversible methanolysis of Jatropha curcas oil (JCO) to biodiesel. The experimental data were collected under the optimal reaction conditions: molar ratio of methanol to JCO at 6 : 1, reaction temperature of 60°C, 60 min of reaction time, and 1% w/w of catalyst concentration. The dynamic modeling involved the derivation of differential equations for rates of three stepwise reactions. The simulation study was then performed on the resulting equations using MATLAB. The newly developed reversible models were fitted with various rate constants and compared with the experimental data for fitting purposes. In addition, analysis of variance was done statistically to evaluate the adequacy and quality of model parameters. The kinetics study revealed that the reverse reactions were significantly slower than forward reactions. The activation energies ranged from 6.5 to 44.4 KJ mol⁻¹.
    Matched MeSH terms: Methanol/chemistry*
  7. Annegowda HV, Bhat R, Min-Tze L, Karim AA, Mansor SM
    J Food Sci Technol, 2012 Aug;49(4):510-4.
    PMID: 23904662 DOI: 10.1007/s13197-011-0435-8
    The present study was conducted to examine the effects of sonication treatments (time intervals of 0, 15, 30, 45 and 60 min.) on phenolics and other antioxidant compounds in starfruits extracted in methanol and water. Overall, methanolic extracts exhibited significantly higher extractability, percentage inhibition of DPPH radicals, ferric reducing antioxidant property (FRAP) value, antioxidant capacity, flavonoids, total phenolics and tannins (p Methanolic extract obtained after 30 min of sonication proved to be the best treatment with regard to various parameters evaluated. Results of the present study clearly indicated sonication treatments to be effective in enhancing the antioxidant compounds in starfruit extracts and could be further explored for commercial purposes to benefit the consumers.
    Matched MeSH terms: Methanol
  8. Rajeh MA, Kwan YP, Zakaria Z, Latha LY, Jothy SL, Sasidharan S
    Pharmacognosy Res, 2012 Jul;4(3):170-7.
    PMID: 22923956 DOI: 10.4103/0974-8490.99085
    The methanol extract of Euphorbia hirta L (Euphorbiaceae), which is used in traditional medicines, was tested for in vivo toxicity.
    Matched MeSH terms: Methanol
  9. Zyoud SH, Al-Jabi SW, Sweileh WM, Awang R, Waring WS
    J Occup Med Toxicol, 2015;10:17.
    PMID: 25949270 DOI: 10.1186/s12995-015-0062-9
    BACKGROUND: Methanol poisoning is on the rise and has been associated with high morbidity and mortality; it has resulted in growing research in the field of toxicology. The aim of this study was to reveal underlying patterns in scientific outputs related to methanol poisoning at the global level by evaluating different bibliometric indices.

    METHODS: We searched for publications that contained specific words regarding methanol poisoning in Scopus database.

    RESULTS: A total of 912 articles, with 8,317 citations and with an average of 9.1 citations per document, were retrieved on methanol poisoning, and the bulk of the articles were published from the USA (20.9%), followed by Spain (4.4%), Canada (4.3%), India (3.1%), and France (3.0%). The articles were published belonging to 57 countries. No data related to methanol poisoning were published from 155 (73.1%) out of 212 countries. Twenty-one documents (2.3%) were published in Clinical Toxicology, whereas 18 (2.0%) were published in The Lancet.

    CONCLUSIONS: Scientific production related to methanol poisoning is increasing. articles have been published in a wide range of journals with a variety of subject areas, most notably clinical toxicology; and the country with the greatest production was the USA.

    Matched MeSH terms: Methanol
  10. Azrina, A., Nurul Nadiah, M.N., Amin, I.
    MyJurnal
    The antioxidant properties of skin, flesh and kernel of Canarium odontophyllum fruit were determined. The methanolic extracts of the fruit were screened for their total phenolic content and antioxidant properties. The averaged antioxidant properties (mM TE/g FM) in skin, flesh, and kernel of Canarium odontophyllum were 16.46 ± 0.24, 20.54 ± 0.35, and 8.89 ± 0.29, respectively by DPPH assay; 151.24 ± 9.75, 70.58 ± 2.98, and 5.65 ± 0.02, respectively by FRAP assay; and 47.9 ± 0.00, 11.61 ± 1.14, and 3.00 ± 0.00, respectively by β-Carotene bleaching method. The averaged OH scavenging activity (mg DMSOE/mg FM) in skin, flesh, and kernel of Canarium odontophyllum were 43.33 ± 13.85, 7.81 ± 1.42, and 3.31 ± 0.80, respectively. While averaged total phenolic content (mg GAE/100g FM) were 387.5 ± 33.23, 267.0 ± 4.24, and 51.0 ± 0.00 for skin, flesh, and kernel respectively. Antioxidant activities were positively correlated with the total phenolic content (0.71 ≤ r ≤ 0.84).
    Matched MeSH terms: Methanol
  11. Yeo CI, Tan SL, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2016 Oct 1;72(Pt 10):1446-1452.
    PMID: 27746938
    The title compound, [Au(C9H10NOS)(C18H15P)], features a near linear P-Au-S arrangement defined by phosphane P and thiol-ate S atoms with the minor distortion from the ideal [P-Au-S is 177.61 (2)°] being traced in part to the close intra-molecular approach of an O atom [Au⋯O = 3.040 (2) Å]. The packing features supra-molecular layers lying parallel to (011) sustained by a combination of C-H⋯π and π-π [inter-centroid distance = 3.8033 (17) Å] inter-actions. The mol-ecular structure and packing are compared with those determined for a previously reported hemi-methanol solvate [Kuan et al. (2008 ▸). CrystEngComm, 10, 548-564]. Relatively minor differences are noted in the conformations of the rings in the Au-containing mol-ecules. A Hirshfeld surface analysis confirms the similarity in the packing with the most notable differences relating to the formation of C-H⋯S contacts between the constituents of the solvate.
    Matched MeSH terms: Methanol
  12. 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
  13. 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
  14. 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*
  15. 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*
  16. 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*
  17. 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*
  18. 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*
  19. 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*
  20. 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*
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