MyMedR

Displaying publications 181 - 200 of 355 in total

Abstract:

Sort:

Key volatile aroma compounds of three black velvet tamarind (Dialium) fruit species

Lasekan O, See NS

Food Chem, 2015 Feb 1;168:561-5.
PMID: 25172748 DOI: 10.1016/j.foodchem.2014.07.112

Nineteen odour-active compounds were quantified in three black velvet tamarind fruit species. Calculation of the odour activity values (OAVs) of the odorants showed that differences in odour profiles of the tamarinds were mainly caused by linalool, limonene, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, nonanal, and (Z)-3-hexenal. On the basis of their high OAVs, cis-linalool oxide (furanoid), geranyl acetone, and cinnamyl acetate were identified as other potent odorants in the three tamarinds. Sensory studies revealed very distinct aroma profiles, which are characteristic of these types of fruits. While the Dialiumguineense elicited floral, flowery, caramel-like notes, the other two species were dominated by leaf-like, caramel, and green notes.

Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Biosorption and biotransformation of fluoranthene by the white-rot fungus Pleurotus eryngii F032

Hadibarata T, Kristanti RA, Hamdzah M

Biotechnol Appl Biochem, 2014 Mar-Apr;61(2):126-33.
PMID: 24033877 DOI: 10.1002/bab.1155

Major concern about the presence of fluoranthene, which consists of four fused benzene rings, in the environment has been raised in the past few years due to its toxic, mutagenic, and persistent organic pollutant properties. In this study, we investigated the removal of fluoranthene under static and agitated conditions. About 89% fluoranthene was removed within 30 days under the agitated condition, whereas under the static condition, only 54% fluoranthene was removed. We further investigated the behavior and mechanism of fluoranthene biosorption and biotransformation by Pleurotus eryngii F032 to accelerate the elimination of fluoranthene. The optimum conditions for the elimination of fluoranthene by P. eryngii F032 included a temperature of 35 °C, pH 3, 0.2% inoculum concentration, and a C/N ratio of 16. Under these conditions at the initial fluoranthene concentration of 10 mg/L, more than 95% of fluoranthene was successfully removed within 30 days. Of those factors influencing the biodegradation of fluoranthene, salinity, glucose, and rhamnolipid content were of the greatest importance. Degradation metabolites identified using gas chromatography-mass spectrometry were 1-naphthalenecarboxylic acid and salicylic acid, suggesting possible metabolic pathways. Finally, it can be presumed that the major mechanism of fluoranthene elimination by white-rot fungi is to mineralize polycyclic aromatic hydrocarbons via biotransformation enzymes like laccase.

Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Assessment of endocrine disruptors - DDTs and DEHP (plasticizer) in source water: a case study from Selangor, Malaysia

Veerasingam SA, Ali Mohd M

J Water Health, 2013 Jun;11(2):311-23.
PMID: 23708578 DOI: 10.2166/wh.2013.151

The presence of endocrine disruptors in source water is of great concern because of their suspected adverse effects on humans, even when present at very low levels. As the main source of potable water supply, rivers in Malaysia are highly susceptible to contamination by various endocrine disruptors originating from anthropogenic activities. In this study, the contamination levels of 1,1,1-trichloro-2,2-bis (4-chlorophenyl) ethane (DDT) and its metabolites and di-(2-ethylhexyl) phthalate (DEHP) in rivers of Selangor were examined using gas chromatography-mass spectrometry. Samples were collected from sites representing source water for 18 drinking water treatment plants in Selangor between July 2008 and July 2009. DDT and its metabolites were detected in only 14% of the 192 samples analysed at levels ranging from 0.6 to 14.6 ng/L. Meanwhile DEHP was detected in 96.8% of the samples at levels ranging from below quantitation level (18 ng/L) to 970 ng/L. The detected levels of DDTs and DEHP were lower than the WHO and Malaysian Guidelines for Drinking Water Quality. Data obtained from this study should also serve as a reference point for future surveillance on these endocrine disruptors.

Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Volatile constituents of roasted tigernut oil (Cyperus esculentus L.)

Lasekan O

J Sci Food Agric, 2013 Mar 30;93(5):1055-61.
PMID: 22936608 DOI: 10.1002/jsfa.5846

Volatile compounds play a key role in determining the sensory appreciation of vegetable oils. In this study a systematic evaluation of odorants responsible for the characteristic flavour of roasted tigernut oil was carried out.

Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Characterisation of calamansi (Citrus microcarpa). Part I: volatiles, aromatic profiles and phenolic acids in the peel

Cheong MW, Chong ZS, Liu SQ, Zhou W, Curran P, Bin Yu

Food Chem, 2012 Sep 15;134(2):686-95.
PMID: 23107679 DOI: 10.1016/j.foodchem.2012.02.162

Volatile compounds in the peel of calamansi (Citrus microcarpa) from Malaysia, the Philippines and Vietnam were extracted with dichloromethane and hexane, and then analysed by gas chromatography-mass spectroscopy/flame ionisation detector. Seventy-nine compounds representing >98% of the volatiles were identified. Across the three geographical sources, a relatively small proportion of potent oxygenated compounds was significantly different, exemplified by the highest amount of methyl N-methylanthranilate in Malaysian calamansi peel. Principal component analysis and canonical discriminant analysis were applied to interpret the complex volatile compounds in the calamansi peel extracts, and to verify the discrimination among the different origins. In addition, four common hydroxycinnamic acids (caffeic, p-coumaric, ferulic and sinapic acids) were determined in the methanolic extracts of calamansi peel using ultra-fast liquid chromatography coupled to photodiode array detector. The Philippines calamansi peel contained the highest amount of total phenolic acids. In addition, p-Coumaric acid was the dominant free phenolic acids, whereas ferulic acid was the main bound phenolic acid.

Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Identification of metabolites from benzo[a]pyrene oxidation by ligninolytic enzymes of Polyporus sp. S133

Hadibarata T, Kristanti RA

J Environ Manage, 2012 Nov 30;111:115-9.
PMID: 22835655 DOI: 10.1016/j.jenvman.2012.06.044

The biodegradation of benzo[a]pyrene (BaP) by using Polyporus sp. S133, a white-rot fungus isolated from oil-contaminated soil was investigated. Approximately 73% of the initial concentration of BaP was degraded within 30 d of incubation. The isolation and characterization of 3 metabolites by thin layer chromatography, column chromatography, and UV-vis spectrophotometry in combination with gas chromatography-mass spectrometry, indicated that Polyporus sp. S133 transformed BaP to BaP-1,6-quinone. This quinone was further degraded in 2 ways. First, BaP-1,6-quinone was decarboxylated and oxidized to form coumarin, which was then hydroxylated to hydroxycoumarin, and finally to hydroxyphenyl acetic acid by addition of an epoxide group. Second, Polyporus sp. S133 converted BaP-1,6-quinone into a major product, 1-hydroxy-2-naphthoic acid. During degradation, free extracellular laccase was detected with reduced activity of lignin peroxidase, manganese-dependent peroxidase and 2,3-dioxygenase, suggesting that laccase and 1,2-dioxygenase might play an important role in the transformation of PAHs compounds.

Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Fate and cometabolic degradation of benzo[a]pyrene by white-rot fungus Armillaria sp. F022

Hadibarata T, Kristanti RA

Bioresour Technol, 2012 Mar;107:314-8.
PMID: 22209445 DOI: 10.1016/j.biortech.2011.12.046

Armillaria sp. F022, a white-rot fungus isolated from a tropical rain forest in Samarinda, Indonesia, was used to biodegrade benzo[a]pyrene (BaP). Transformation of BaP, a 5-ring polycyclic aromatic hydrocarbon (PAH), by Armillaria sp. F022, which uses BaP as a source of carbon and energy, was investigated. However, biodegradation of BaP has been limited because of its bioavailability and toxicity. Five cosubstrates were selected as cometabolic carbon and energy sources. The results showed that Armillaria sp. F022 used BaP with and without cosubstrates. A 2.5-fold increase in degradation efficiency was achieved after addition of glucose. Meanwhile, the use of glucose as a cosubstrate could significantly stimulate laccase production compared with other cosubstrates and not using any cosubstrate. The metabolic pathway was elucidated by identifying metabolites, conducting biotransformation studies, and monitoring enzyme activities in cell-free extracts. The degradation mechanism was determined through the identification of several metabolites: benzo[a]pyrene-1,6-quinone, 1-hydroxy-2-benzoic acid, and benzoic acid.

Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Fulltext An antimicrobial compound isolated from Cinnamomum iners leaves with activity against methicillin-resistant Staphylococcus aureus

Mustaffa F, Indurkar J, Ismail S, Shah M, Mansor SM

Molecules, 2011 Apr 08;16(4):3037-47.
PMID: 21478819 DOI: 10.3390/molecules16043037

This study was designed to investigate the antimicrobial activity of Cinnamomum iners standardized leave methanolic extract (CSLE), its fractions and isolated compounds. CSLE and fractions were subjected to disc diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests using different Gram positive and Gram negative bacteria and yeast. Within the series of fractions tested, the ethyl acetate fraction was the most active, particularly against methicillin resistant Staphylococcus aureus (MRSA) and Escherichia coli, with MIC values of 100 and 200 µg/mL, respectively. The active compound in this fraction was isolated and identified as xanthorrhizol [5-(1, 5-dimethyl-4-hexenyl)-2-methylphenol] by various spectroscopic techniques. The overall results of this study provide evidence that Cinnamomum iners leaves extract as well as the isolated compound xanthorrhizol exhibit antimicrobial activity for both Gram negative and Gram positive pathogens, especially against MRSA strains.

Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Acetylation of glycerol to biofuel additives over sulfated activated carbon catalyst

Khayoon MS, Hameed BH

Bioresour Technol, 2011 Oct;102(19):9229-35.
PMID: 21840708 DOI: 10.1016/j.biortech.2011.07.035

Oxygenated fuel additives can be produced by acetylation of glycerol. A 91% glycerol conversion with a selectivity of 38%, 28% and 34% for mono-, di- and triacetyl glyceride, respectively, was achieved at 120 °C and 3 h of reaction time in the presence of a catalyst derived from activated carbon (AC) treated with sulfuric acid at 85 °C for 4h to introduce acidic functionalities to its surface. The unique catalytic activity of the catalyst, AC-SA5, was attributed to the presence of sulfur containing functional groups on the AC surface, which enhanced the surface interaction between the glycerol molecule and acyl group of the acetic acid. The catalyst was reused in up to four consecutive batch runs and no significant decline of its initial activity was observed. The conversion and selectivity variation during the acetylation is attributed to the reaction time, reaction temperature, catalyst loading and glycerol to acetic acid molar ratio.

Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Identification of metabolites from phenanthrene oxidation by phenoloxidases and dioxygenases of Polyporus sp. S133

Hadibarata T, Tachibana S, Askari M

J Microbiol Biotechnol, 2011 Mar;21(3):299-304.
PMID: 21464602

Phenanthrene degradation by Polyporus sp. S133, a new phenanthrene-degrading strain, was investigated in this work. The analysis of degradation was performed by calculation of the remaining phenanthrene by gas chromatography-mass spectrometry. When cells were grown in phenanthrene culture after 92 h, all but 200 and 250 mg/l of the phenanthrene had been degraded. New metabolic pathways of phenanthrene and a better understanding of the phenoloxidases and dioxygenase mechanism involved in degradation of phenanthrene were explored in this research. The mechanism of degradation was determined through identification of the several metabolites; 9,10-phenanthrenequinone, 2,2'-diphenic acid, salicylic acid, and catechol. 9,10-Oxidation and ring cleavage to give 9,10-phenanthrenequinone is the major fate of phenanthrene in ligninolytic Polyporus sp. S133. The identification of 2,2'-diphenic acid in culture extracts indicates that phenanthrene was initially attacked through dioxigenation at C9 and C10 to give cis-9,10-dihydrodiol. Dehydrogenation of phenanthrene-cis-9,10-dihydrodiol to produce the corresponding diol, followed by ortho-cleavage of the oxygenated ring, produced 2,2'-diphenic acid. Several enzymes (manganese peroxidase, lignin peroxidase, laccase, 1,2-dioxygenase, and 2,3-dioxygenase) produced by Polyporus sp. S133 was detected during the incubation. The highest level of activity was shown at 92 h of culture.

Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Sub/supercritical liquefaction of oil palm fruit press fiber for the production of bio-oil: effect of solvents

Mazaheri H, Lee KT, Bhatia S, Mohamed AR

Bioresour Technol, 2010 Oct;101(19):7641-7.
PMID: 20510608 DOI: 10.1016/j.biortech.2010.04.072

Thermal decomposition of oil palm fruit press fiber (FPF) with sub/supercritical methanol, ethanol, acetone, and 1,4-dioxane treatments were investigated using a high-pressure autoclave reactor. When FPF was decomposed with methanol, ethanol, and acetone from 483 to 603 K, the highest degree of conversion obtained were 81.5%, 77.8%, and 67.9% while the highest liquid product yield (LP) obtained were 38.0%, 36.9%, and 38.5%, respectively. For the case of 1,4-dioxane, the conversion of FPF increased from 18.30% to 80.00%, while LP yield increased dramatically from 13.30% to 50.90% (consisting of 42.3% bio-oil compounds) when the reaction temperature was increased from 483 to 563 K. However, the conversion of FPF and LP yield decreased to 69.60% and 24.10%, respectively, when the temperature was further increased to 603 K. Comparison between all the solvents, subcritical 1,4-dioxane treatment was found very effective in the degradation of FPF to produce bio-oil component.

Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Anti-angiogenic activity of Gynura segetum leaf extracts and its fractions

Seow LJ, Beh HK, Majid AM, Murugaiyah V, Ismail N, Asmawi MZ

J Ethnopharmacol, 2011 Mar 24;134(2):221-7.
PMID: 21167271 DOI: 10.1016/j.jep.2010.12.007

Gynura segetum is a popular medicinal plant in Indonesia and Malaysia, known to possess various medicinal properties especially for treatment of cancer, diabetes and hypertension.

Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Fulltext Standardization of Cassia spectabilis with respect to authenticity, assay and chemical constituent analysis

Torey A, Sasidharan S, Yeng C, Latha LY

Molecules, 2010 May 10;15(5):3411-20.
PMID: 20657490 DOI: 10.3390/molecules15053411

Quality control standardizations of the various medicinal plants used in traditional medicine is becoming more important today in view of the commercialization of formulations based on these plants. An attempt at standardization of Cassia spectabilis leaf has been carried out with respect to authenticity, assay and chemical constituent analysis. The authentication involved many parameters, including gross morphology, microscopy of the leaves and functional group analysis by Fourier Transform Infrared (FTIR) spectroscopy. The assay part of standardization involved determination of the minimum inhibitory concentration (MIC) of the extract which could help assess the chemical effects and establish curative values. The MIC of the C. spectabilis leaf extracts was investigated using the Broth Dilution Method. The extracts showed a MIC value of 6.25 mg/mL, independent of the extraction time. The chemical constituent aspect of standardization involves quantification of the main chemical components in C. spectabilis. The GCMS method used for quantification of 2,4-(1H,3H)-pyrimidinedione in the extract was rapid, accurate, precise, linear (R(2) = 0.8685), rugged and robust. Hence this method was suitable for quantification of this component in C. spectabilis. The standardization of C. spectabilis is needed to facilitate marketing of medicinal plants, with a view to promoting the export of valuable Malaysian Traditional Medicinal plants such as C. spectabilis.

Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Chemical composition and antioxidant properties of extracts of fresh fruiting bodies of Pleurotus sajor-caju (Fr.) Singer

Kanagasabapathy G, Malek SN, Kuppusamy UR, Vikineswary S

J Agric Food Chem, 2011 Mar 23;59(6):2618-26.
PMID: 21348494 DOI: 10.1021/jf104133g

The chemical composition and in vitro antioxidant activity of aqueous butanol and ethyl acetate extracts of Pleurotus sajor-caju were investigated in this study. Twenty-two compounds comprising methyl esters, hydrocarbon fatty acids, ethyl esters, and sterols were identified in ethyl acetate extracts, while cinnamic acid, nicotinamide, benzeneacetamide, and 4-hydroxybenzaldyhde were identified in butanol extracts by gas chromatography-mass spectrometry and NMR analysis. The antioxidant activity was determined by a β-carotene bleaching method, ferric reducing antioxidant power, trolox equivalent antioxidant capacity, and lipid peroxidation assays, while the total phenolic content in P. sajor-caju was assessed by Folin-Ciocalteau's method. The aqueous and butanol extracts exhibited the highest antioxidant activity, corresponding to the total phenolic content. The subfractions from the ethyl acetate extract (EP1, EP2, EP3, and EP4), however, showed moderate antioxidant activity. The regular consumption of P. sajor-caju as a part of our diet may render nutritional and nutraceuticals benefits for good health.

Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Archaeological resinous samples from Asian wrecks: Taxonomic characterization by GC-MS

Burger P, Charrié-Duhaut A, Connan J, Flecker M, Albrecht P

Anal Chim Acta, 2009 Aug 19;648(1):85-97.
PMID: 19616693 DOI: 10.1016/j.aca.2009.06.022

Plant resins, and particularly dammars from the Dipterocarpaceae family, were widely used in the past, notably as part of caulking material. The organic composition of resins, already complicated, is not always preserved over time and can be considerably affected by ageing. Hence, their occurrence in archaeological items leads to the necessity to identify them taxonomically with precision. Resinous organic materials collected near and/or on wrecks discovered in South China Sea, supposed to contain dammar resins because of their geographical excavation context, were investigated by gas chromatography-mass spectrometry (GC-MS), together with freshly collected dammars, to establish taxonomic and alteration parameters allowing to identify dammar even in very altered samples or in mixtures together with other organic materials. This study specially focuses on three samples collected within or close to the M1J wreck, a Portuguese wreck lost in the Straight of Malacca during the 16th century. Our analyses establish that all three are made of dammar, two of them in association with pitch and bitumen. In addition, biodegradation biomarkers were detected in all these three samples, indicating that they were submitted to microbial degradation processes during their ageing.

Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Degradation of DEET by ozonation in aqueous solution

Tay KS, Rahman NA, Abas MR

Chemosphere, 2009 Aug;76(9):1296-302.
PMID: 19570564 DOI: 10.1016/j.chemosphere.2009.06.007

This study was undertaken in order to understand the factors affecting the degradation of an insect repellent, N,N-diethyl-m-toluamide (DEET) by ozonation. Kinetic studies on DEET degradation were carried out under different operating conditions, such as varied ozone doses, pH values of solution, initial concentrations of DEET, and solution temperatures. The degradation of DEET by ozonation follows the pseudo-first-order kinetic model. The rate of DEET degradation increased exponentially with temperature in the range studied (20-50 degrees C) and in proportion with the dosage of ozone applied. The ozonation of DEET under different pH conditions in the presence of phosphate buffer occurred in two stages. During the first stage, the rate constant, k(obs), increased with increasing pH, whereas in the second stage, the rate constant, k(obs2), increased from pH 2.3 up to 9.9, however, it decreased when the pH value exceeded 9.9. In the case where buffers were not employed, the k(obs) were found to increase exponentially with pH from 2.5 to 9.2 and the ozonation was observed to occur in one stage. The rate of degradation decreased exponentially with the initial concentration of DEET. GC/MS analysis of the by-products from DEET degradation were identified to be N,N-diethyl-formamide, N,N-diethyl-4-methylpent-2-enamide, 4-methylhex-2-enedioic acid, N-ethyl-m-toluamide, N,N-diethyl-o-toluamide, N-acetyl-N-ethyl-m-toluamide, N-acetyl-N-ethyl-m-toluamide 2-(diethylamino)-1-m-tolylethanone and 2-(diethylcarbamoyl)-4-methylhex-2-enedioic acid. These by-products resulted from ozonation of the aliphatic chain as well as the aromatic ring of DEET during the degradation process.

Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Solid-phase microextraction for determining twelve orange flavour compounds in a model beverage emulsion

Mirhosseini H, Tan CP, Yusof S, Hamid NS

Phytochem Anal, 2008 Sep-Oct;19(5):429-37.
PMID: 18435528 DOI: 10.1002/pca.1068

Solid-phase microextraction (SPME) coupled to gas chromatography has been applied for the headspace analysis (HS) of 12 target flavour compounds in a model orange beverage emulsion. The main volatile flavour compounds studied were: acetaldehyde, ethyl acetate, alpha-pinene, ethyl butyrate, beta-pinene, myrcene, limonene, gamma-terpinene, octanal, decanal, linalool and citral (neral plus geranial). After screening the fibre type, the effect of other HS-SPME variables such as adsorption temperature (25-55 degrees C), extraction time (10-40 min), sample concentration (1-100% w/w), sample amount (5-10 g) and salt amount (0-30% w/w) were determined using a two-level fractional factorial design (2(5-2)) that was expanded further to a central composite design. It was found that an extraction process using a carboxen-polydimethylsiloxane fibre coating at 15 masculineC for 50 min with 5 g of diluted emulsion 1% (w/w) and 30% (w/w) of sodium chloride under stirring mode resulted in the highest HS extraction efficiency. For all volatile flavour compounds, the linearity values were accurate in the concentration ranges studied (r(2) > 0.97). Average recoveries that ranged from 90.3 to 124.8% showed a good accuracy for the optimised method. The relative standard deviation for six replicates of all volatile flavour compounds was found to be less than 15%. For all volatile flavour compounds, the limit of detection ranged from 0.20 to 1.69 mg/L.

Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Fulltext The effects of Secondhand Smoke (SHS) exposure on microvascular endothelial function among healthy women

Sanip Z, Hanaffi SH, Ahmad I, Yusoff SS, Rasool AH, Yusoff HM

Tob Induc Dis, 2015;13(1):32.
PMID: 26346914 DOI: 10.1186/s12971-015-0052-9

BACKGROUND: Studies have demonstrated that secondhand smoke (SHS) exposure could impair endothelial function. However, the effect of SHS exposure specifically on microvascular endothelial function is not well understood. This study aimed to determine the effects of SHS exposure on microvascular endothelial function among non-smoking, generally healthy women.
FINDINGS: We studied 127 women; and based on their hair nicotine levels measured using gas chromatography-mass spectrometry, 25 of them were categorized as having higher hair nicotine levels, 25 were grouped as having lower hair nicotine and 77 women were grouped into the non-detected group. The non-detected group did not have detectable levels of hair nicotine. Anthropometry, blood pressure (BP), lipid profile and high-sensitivity C-reactive protein (hsCRP) were measured accordingly. Microvascular endothelial function was assessed non-invasively using laser Doppler fluximetry and the process of iontophoresis involving acetylcholine and sodium nitroprusside as endothelium-dependent and endothelium-independent vasodilators respectively. The mean hair nicotine levels for higher and lower hair nicotine groups were 0.74 (1.04) and 0.05 (0.01) ng/mg respectively. There were no significant differences in anthropometry, BP, lipid profile and hsCRP between these groups. There were also no significant differences in the microvascular perfusion and endothelial function between these groups.
CONCLUSION: In this study, generally healthy non-smoking women who have higher, lower and non-detected hair nicotine levels did not show significant differences in their microvascular endothelial function. Low levels of SHS exposure among generally healthy non-smoking women may not significantly impair their microvascular endothelial function.

Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Fulltext Antihyperglycemic Effect of Methanol Extract of Syzygium polyanthum (Wight.) Leaf in Streptozotocin-Induced Diabetic Rats

Widyawati T, Yusoff NA, Asmawi MZ, Ahmad M

Nutrients, 2015 Sep;7(9):7764-80.
PMID: 26389944 DOI: 10.3390/nu7095365

Syzygium polyanthum (S. polyanthum), a plant belonging to Myrtaceae, is widely used in Indonesian and Malaysian cuisines. Diabetic patients in Indonesia also commonly use it as a traditional medicine. Hence, this study was conducted to investigate the antihyperglycemic effect of the methanol extract (ME) of S. polyanthum leaf and its possible mechanisms of action. To test for hypoglycemic activity, ME was administered orally to normal male Sprague Dawley rats after a 12-h fast. To further test for antihyperglycemic activity, the same treatment was administered to glucose-loaded (intraperitoneal glucose tolerance test, IPGTT) and streptozotocin (STZ)-induced diabetic rats, respectively. Hypoglycemic test in normal rats did not show significant reduction in blood glucose levels (BGLs) by the extract. Furthermore, IPGTT conducted on glucose-loaded normal rats also did not show significant reduction of BGLs. However, repeated administration of metformin and three doses of ME (250, 500 and 1000 mg/kg) for six days caused significant reduction of fasting BGLs in STZ-induced diabetic rats. The possible mechanisms of action of S. polyanthum antihyperglycemic activity were assessed by measurement of intestinal glucose absorption and glucose uptake by isolated rat abdominal muscle. It was found that the extract not only inhibited glucose absorption from the intestine but also significantly increased glucose uptake in muscle tissue. A preliminary phytochemical qualitative analysis of ME indicated the presence of tannins, glycosides, flavonoids, alkaloids and saponins. Additionally, Gas Chromatography-Mass Spectrometry (GC-MS) analysis detected squalene. In conclusion, S. polyanthum methanol leaf extract exerts its antihyperglycemic effect possibly by inhibiting glucose absorption from the intestine and promoting glucose uptake by the muscles.

Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Baseline distribution and sources of linear alkyl benzenes (LABs) in surface sediments from Brunei Bay, Brunei

Alkhadher SAA, Zakaria MP, Yusoff FM, Kannan N, Suratman S, Keshavarzifard M, et al.

Mar Pollut Bull, 2015 Dec 15;101(1):397-403.
PMID: 26478457 DOI: 10.1016/j.marpolbul.2015.10.011

Sewage pollution is one of major concerns of coastal and shoreline settlements in Southeast Asia, especially Brunei. The distribution and sources of LABs as sewage molecular markers were evaluated in surface sediments collected from Brunei Bay. The samples were extracted, fractionated and analyzed using gas chromatography- mass spectrometry (GC-MS). LABs concentrations ranged from 7.1 to 41.3 ng g(-1) dry weight (dw) in surficial sediments from Brunei Bay. The study results showed LABs concentrations variably due to the LABs intensity and anthropogenic influence along Brunei Bay in recent years. The ratio of Internal to External isomers (I/E ratio) of LABs in sediment samples from Brunei Bay ranged from 0.56 to 2.17 along Brunei Bay stations, indicating that the study areas were receiving primary and secondary effluents. This is the first study carried out to assess the distribution and sources of LABs in surface sediments from Brunei Bay, Brunei.

Matched MeSH terms: Gas Chromatography-Mass Spectrometry

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links