The present study was conducted to determine the antinociceptive potential of methanol extract of Muntingia calabura L. (MEMC) and to isolate and identify the bioactive compound(s) responsible for the observed antinociceptive activity. The MEMC and its partitions (petroleum ether (PEP), ethyl acetate (EAP), and aqueous (AQP) partitions), in the dose range of 100, 500, and 1000 mg/kg, were tested using the formalin-induced nociceptive test. The PEP, which exerted the most effective activity in the respective early and late phase, was further subjected to the fractionation procedures and yielded seven fractions (labelled A to G). These fractions were tested, at the dose of 300 mg/kg, together with distilled water or 10% DMSO (negative controls); morphine and aspirin (positive controls) for potential antinociceptive activity. Of all fractions, Fraction D showed the most significant antinociceptive activity, which is considered as equieffective to morphine or aspirin in the early or late phase, respectively. Further isolation and identification processes on fraction D led to the identification of three known and one new compounds, namely, 5-hydroxy-3,7,8-trimethoxyflavone (1), 3,7-dimethoxy-5-hydroyflavone (2), 2',4'-dihydroxy-3'-methoxychalcone (3), and calaburone (4). At the dose of 50 mg/kg, compound 3 exhibited the highest percentage of antinociceptive activity in both phases of the formalin test. In conclusion, the antinociceptive activity of MEMC involved, partly, the synergistic activation of the flavonoid types of compounds.
Objectives/Research Problem:Melastoma malabathricum L., (Melastomaceae) is a medicinally important plant known as “Senduduk”. Traditionally, the leaves are used to relieve diverse pain-related ailments. Present study aims to examine the antinociceptive activity of methanolic extract of M. malabathricum (MEMM) leaves and its fractions via in vivo models of nociception.
Materials and Method: Extracts (100, 250, 500 mg/kg) were administered orally 60 minutes prior to subjection to the respective test, n=6/group. Evaluation of MEMM antinociceptive activity; chemically (acetic acid-induced abdominal constriction; ACT, formalin-induced paw licking test; FT) and thermally (hot plate test; HT) models of nociception and elucidation of mechanisms of action involved; role of opioid, vanilloid receptors, glutamatergic system and NO/cGMP pathway were determined. Continuously, MEMM, partitioned into three fractions: petroleum ether (PEMM), ethyl acetate (EAMM), and aqueous (AQMM) extracts and determine the most potent fraction. Therefore, experiment ED50 and its 95% confidence intervals (CI) values were conducted, and ACT was used to screen. Calculation, obtained, PEMM, the most effective was further used to assess the antinociceptive properties. Phytochemical screening, HPLC and GC-MS analysis were performed.
Results and Discussion: First stage, MEMM exhibited significant (P
The chlorine radical is a potent atmospheric oxidant, capable of perturbing tropospheric oxidative cycles normally controlled by the hydroxyl radical. Significantly faster reaction rates allow chlorine radicals to expedite oxidation of hydrocarbons, including methane, and in polluted environments, to enhance ozone production. Here we present evidence, from the CARIBIC airborne dataset, for extensive chlorine radical chemistry associated with Asian pollution outflow, from airborne observations made over the Malaysian Peninsula in winter. This region is known for persistent convection that regularly delivers surface air to higher altitudes and serves as a major transport pathway into the stratosphere. Oxidant ratios inferred from hydrocarbon relationships show that chlorine radicals were regionally more important than hydroxyl radicals for alkane oxidation and were also important for methane and alkene oxidation (>10%). Our observations reveal pollution-related chlorine chemistry that is both widespread and recurrent, and has implications for tropospheric oxidizing capacity, stratospheric composition and ozone chemistry.
Adulteration of lard with other fats and oils in food production affects many areas including economics, religion, and health. Previous studies discriminated lard based on major components of fats, i.e. triglycerides and fatty acids. This study aimed to differentiate lard and other animal fats (beef, chicken and mutton fat) based on n-alkane profiles established by gas chromatography-mass spectrometry (GC-MS). Principal Component Analysis (PCA) and Hierarchical Clustering Analysis (HCA) were able to initiate clustering of lard and other animal fats. Good result was obtained using Random Forest (RF) and Partial Least Squares-Discriminant Analysis (PLS-DA). Statistical models propose tetracosane (C24) as a potential n-alkane marker and it was found that C24 was the major alkane with composition of 15.72% (GC-MS) of total alkanes identified. Based on this finding, more interesting study may potentially be explored for the interest of various fats and oils consumers in vast applications especially using chemometrics analysis.
To characterize the production and larvicidal activity of Xenorhabdus stockiae KUT6 Petroleum ether extracts from Luria Broth and induced Quorum sensing medium containing N-3- oxododecanoyl Homoserine Lactone inducer against dengue vector Aedes aegypti. The Galleria mellonella larvae were reared for the isolation of Steinernema saimkayi symbiont Xenorhabdus stockiae KUT6 from Cucumber field soil sample in NBTA. Then for the extraction of compounds the KUT6 strains were cultured in Luria Broth and Quorum Sensing optimized media using N-3-oxododecanoyl homoserine lactone inducer. The larvicidal activity of Xenorhabdus stockiae KUT6 of petroleum ether extracts were bioassayed against 4th instar Aedes aegypti dengue vector. The maximum rate of mortality were recorded of the samples A-24h, B-48h, C-72h, A1-24h, B1-48h, C1-72h at different concentrations 50 µg/ml, 100 µg/ml and 150 µg/ml respectively for 24h to 72h of exposure treatment. The morphological characteristics of Xenorhabdus stockiae KUT6 in NBTA were red core colonies with blue background surrounded by zone of inhibition. After 24h exposure maximum rate of 100% mortality of Aedes aegypti 4th instar larvae was attained when treated with sample C1-72h 50 µg/ml of the petroleum ether extracts of quorum sensed medium whereas the sample C 72h petroleum ether extracts of KUT6 cultured in Luria broth recorded 100% mortality at 150 µg on 24h exposure indicates enhancement in the product yield. The study assures the use of Xenorhabdus stockiae KUT6 petroleum ether extracts as biocontrol agent could be beneficial for the control of dengue vectors.
The antioxidant activity and the total phenolic content, as well as the influence of petroleum ether, chloroform and methanol extracts from the leaves of Gynotroches axillaris, on microorganisms were studied. The total phenolic contents were evaluated by using Folin-Ciocalteu reagent and the obtained values ranged from 70.0 to 620 mg GAE/g. The efficiency of antioxidation, which was identified through the scavenging of free radical DPPH, exhibited that the highest IC50 was in the methanolic extract (44.7 µg/mL) as compared to the standard ascorbic acid (25.83 µg/mL) and to standard BHT (17.2 µg/mL). In vitro antimicrobial activity of extracts was tested against Gram-negative bacteria, Gram-positive bacteria and fungi. Methanol extract showed activity in the range (225-900 μg/mL) with both types, while petroleum ether and chloroform extracts were only active with Bacillus subtilis. The three extracts strongly inhibited all fungi with activity 225-450 μg/mL. The toxicity test against brine shrimps indicated that all extracts were non-toxic with LC50 value more than 1000 µg/mL. The finding of this study supports the safety of these extracts to be used in medical treatments.
The present study aimed to determine the degradation and transformation of three-ring PAHs phenanthrene and anthracene by Cryptococcus sp. MR22 and Halomonas sp. BR04 under halophilic conditions. The growth progress of Cryptococcus sp. MR22 and Halomonas sp. BR04 on anthracene and phenanthrene was monitored by colony-forming unit (CFU) technique. The growth of the bacteria was maintained at a maximum concentration of 200 mg/L of all tested hydrocarbon, indicating that Cryptococcus sp. MR22 and Halomonas sp. BR04 significantly perform in the removal of the PAH-contaminated medium at low concentrations. The fit model to represent the biodegradation kinetics of both PAHs was first-order rate equation The extract prepared from cells supplemented with three different substrates exhibited some enzymes such as hydroxylase, dioxygenase, laccase and peroxidase. The results suggest that both strains had an impressive ability in the degradation of aromatic and aliphatic hydrocarbon but also could tolerate in the extreme salinity condition.
Different extraction procedures were evaluated to assess their potential for measuring volatile organic compounds (VOCs) from raw rubber materials. Four headspace sampling techniques (SHS, DHS, HS-SPME and µ-CTE) were studied. Each method was firstly optimised to ensure their reliability in performance. Passive sampling was also compared as a rapid identification of background VOCs. 352 VOCs were identified, 71 from passive sampling and 281 from active headspace sampling, with 62 not previously reported (hexanenitrile, octanone, decanal, indole, aniline, anisole, alpha-pinene as well as pentanol and butanol). The volatiles belonged to a broad range of chemical classes (ketones, aldehydes, aromatics, acids, alkanes, alcohol and cyclic) with their thermal effects (lower boiling points) greatly affecting their abundance at a higher temperature. Micro-chamber (µ-CTE) was found to be the most suitability for routine assessments due to its operational efficiency (rapidity, simplicity and repeatability), identifying 115 compounds from both temperatures (30 °C and 60 °C). Whereas, HS-SPME a widely applied headspace technique, only identified 75 compounds and DHS identified 74 VOCs and SHS only 17 VOCs. Regardless of the extraction technique, the highest extraction efficiency corresponded to aromatics and acids, and the lowest compound extraction were aldehyde and hydrocarbon. The interaction between techniques and temperature for all chemical groups were evaluated using two-way ANOVA (p-value is 0.000197) explaining the highly significant interactions between factors.
Chemical investigation of the stem bark of Bauhinia rufescens resulted in the isolation of a new cyanoglucoside and menisdaurin from methanol extract and oxepin from petroleum ether extract. The isolated compounds were tested for their anti-inflammatory potentials based on the cyclooxygenase-2 enzyme (COX-2) model. Cyanoglucoside exhibited the highest activity among the compounds with an inhibition activity of 49.34 % at 100 µM (IC50 0.46 µM) compared to the positive control, indomethacin (79.20 %, IC50 0.24 µM).
Sand production remains a huge obstacle in many oil and gas fields around the world, but the hazards of contaminants riding on the produced sand are often not emphasised. Improper disposal of the sand could see the toxic leaching into the environment including the food chain, endangering all living organisms. The impending sand production from an oilfield offshore Sabah also suffers from the lack of hazards identification; hence, this study was conducted to assess the contaminant on the produced sand. Sand samples were collected from multiple wells in the area, with the contaminants extracted using n-hexane and subjected to chemical and thermal analyses. FTIR and GC-MS detected traces of harmful pollutants like naphthalene, amine substances, cyclohexanol, and short-chain alkanes. It was discovered that the volatile fraction of the contaminants was able to evaporate at 33 °C, while high energy was needed to remove 100% of the contaminants from the sand. Overall, the produced sand from the oilfield was unsafe and required treatment before it could be dumped or used.
Evaporation of vaporize organic liquid has ecological consequences when the compounds are introduced into both freshwater and marine environments through industrial effluents, or introduced directly into the air from industrial unit processes such as bioreactors and cooling towers. In such cases, a rapid and simple method are needed to measure physicochemical properties of the organic liquids. The Reversed-Flow Gas Chromatography (RF-GC) sampling technique is an easy, fast and accurate procedure. It was used to measure the diffusion coefficients of vapors from liquid into a carrier gas and at the same time to determine the rate coefficients for the evaporation of the respective liquid. The mathematical expression describing the elution curves of the samples peaks was derived and used to calculate the respective parameters for the selected liquid pollutants selected such as methanol, ethanol, 1-propanol, 1-butanol, n-pentane, n-hexane, n-heptane and n-hexadecane, evaporating into the carrier gas of nitrogen. The values of diffusion coefficients found were compared
with those calculated theoretically or reported in the literature. The values of evaporation rate were used to determine the activation energy of respective samples using Arrhenius equation. An interesting finding of this work is by using an alternative mathematical analysis based on equilibrium at the liquid-gas interphase, the comparison leads to profound
agreement between theoretical values of diffusion coefficients and experimental evidence.
One of the techniques to increase oil recovery from hydrocarbon reservoirs is the injection of low salinity water. It is shown that the injection of low salinity water changes the wettability of the rock. However, there are argumentative debates concerning low salinity water effect on changing the wettability of the oil/brine/rock system in the oil reservoirs. In this regard, molecular dynamics simulation (MDS) as a tool to simulate the phenomena at the molecular level has been used for more than a decade. In this study, the Zisman plot (presented by KRUSS Company) was simulated through MDS, and then, contact angle experiments for n-decane interactions on the Bentheimer substrate in the presence of different concentrations of sodium ions were conducted. MDS was then used to simulate experiments and understand the wettability trend based on free-energy calculations. Hereafter, a new model was developed in this study to correlate free energies with contact angles. The developed model predicted the experimental results with high accuracy (R2 ∼ 0.98). A direct relation was observed between free energy and water contact angle. In contrast, an inverse relation was noticed between the ion concentration and the contact angle such that an increase in the ion concentration resulted in a decrease in the contact angle and vice versa. In other terms, increasing brine ionic concentrations in the presence of n-decane is linked to a decrease in free energies and an increase in the wetting state of a sandstone. The comparison between the developed model's predicted contact angles and experimental observations showed a maximum deviation of 14.32%, which is in satisfactory agreement to conclude that MDS can be used as a valuable and economical tool to understand the wettability alteration process.
A taxonomic study was carried out on strain A-11-3(T), which was isolated from an oil-enriched consortia from the surface seawater of Hong-Deng dock in the Straits of Malacca and Singapore. Cells were aerobic, Gram-negative, non-spore-forming irregular rods. The strain was catalase- and oxidase-negative. It grew on a restricted spectrum of organic compounds, including some organic acids and alkanes. 16S rRNA gene sequence comparisons showed that strain A-11-3(T) was most closely related to the type strains of Alcanivorax jadensis (96.8 % sequence similarity), Alcanivorax borkumensis (96.8 %), Alcanivorax dieselolei (94.8 %), Alcanivorax venustensis (94.2 %) and Alcanivorax balearicus (94.0 %). The predominant fatty acids were C(16 : 0) (31.2 %), C(18 : 1)omega7c (24.8 %), C(18 : 0) (9.6 %), C(12 : 0) (8.3 %), C(16 : 1)omega7c (8.3 %) and C(16 : 0) 3-OH (5.1 %). The G+C content of the genomic DNA was 54.7 mol%. Moreover, the strain produced lipopeptides as its surface-active compounds. According to physiological and biochemical tests, DNA-DNA hybridization results and sequence comparisons of the 16S-23S internal transcribed spacer, the gyrB gene and the alkane hydroxylase gene alkB1, strain A-11-3(T) was affiliated with the genus Alcanivorax but could be readily distinguished from recognized Alcanivorax species. Therefore strain A-11-3(T) represents a novel species of the genus Alcanivorax for which the name Alcanivorax hongdengensis sp. nov. is proposed. The type strain is A-11-3(T) (=CGMCC 1.7084(T)=LMG 24624(T)=MCCC 1A01496(T)).
Alcanivorax hongdengensis A-11-3 is a newly identified type strain isolated from the surface water of the Malacca and Singapore Straits that can degrade a wide range of alkanes. To understand the degradation mechanism of this strain, the genes encoding alkane hydroxylases were obtained by PCR screening and shotgun sequencing of a genomic fosmid library. Six genes involved in alkane degradation were found, including alkB1, alkB2, p450-1, p450-2, p450-3 and almA. Heterogeneous expression analysis confirmed their functions as alkane oxidases in Pseudomonas putida GPo12 (pGEc47ΔB) or Pseudomonas fluorescens KOB2Δ1. Q-PCR revealed that the transcription of alkB1 and alkB2 was enhanced in the presence of n-alkanes C(12) to C(24); three p450 genes were up-regulated by C(8)-C(16) n-alkanes at different levels, whereas enhanced expression of almA was observed when strain A-11-3 grew with long-chain alkanes (C(24) to C(36)). In the case of branched alkanes, pristane significantly enhanced the expression of alkB1, p450-3 and almA. The six genes enable strain A-11-3 to degrade short (C(8)) to long (C(36)) alkanes that are straight or branched. The ability of A. hongdengensis A-11-3 to thrive in oil-polluted marine environments may be due to this strain's multiple systems for alkane degradation and its range of substrates.
Alcanivorax hongdengensis A-11-3(T) was isolated from an oil-enriched consortium enriched from the surface seawater of Hong-Deng dock in the Straits of Malacca and Singapore. Strain A-11-3(T) can degrade n-alkane and produce a lipopeptide biosurfactant. Here we report the genome of A-11-3(T) and the genes associated with alkane degradation.
Methanolic extract of Clinacanthus nutans Lindau leaves (MECN) has been reported to exert antinociceptive activity. The present study aimed to elucidate the possible antinociceptive mechanisms of a lipid-soluble fraction of MECN, which was obtained after sequential extraction in petroleum ether. The petroleum ether fraction of C. nutans (PECN), administered orally to mice, was (i) subjected to capsaicin-, glutamate-, phorbol 12-myristate 13-acetate-, bradykinin-induced nociception model; (ii) prechallenged (intraperitoneal (i.p.)) with 0.15 mg/kg yohimbine, 1 mg/kg pindolol, 3 mg/kg caffeine, 0.2 mg/kg haloperidol, or 10 mg/kg atropine, which were the respective antagonist of α 2-adrenergic, β-adrenergic, adenosinergic, dopaminergic, or muscarinic receptors; and (iii) prechallenged (i.p.) with 10 mg/kg glibenclamide, 0.04 mg/kg apamin, 0.02 mg/kg charybdotoxin, or 4 mg/kg tetraethylammonium chloride, which were the respective inhibitor of ATP sensitive-, small conductance Ca2+-activated-, large conductance Ca2+-activated-, or nonselective voltage-activated-K+ channel. Results obtained demonstrated that PECN (100, 250, and 500 mg/kg) significantly (P<0.05) inhibited all models of nociception described earlier. The antinociceptive activity of 500 mg/kg PECN was significantly (P<0.05) attenuated when prechallenged with all antagonists or K+ channel blockers. However, only pretreatment with apamin and charybdotoxin caused full inhibition of PECN-induced antinociception. The rest of the K+ channel blockers and all antagonists caused only partial inhibition of PECN antinociception, respectively. Analyses on PECN's phytoconstituents revealed the presence of antinociceptive-bearing bioactive compounds of volatile (i.e., derivatives of γ-tocopherol, α-tocopherol, and lupeol) and nonvolatile (i.e., cinnamic acid) nature. In conclusion, PECN exerts a non-opioid-mediated antinociceptive activity involving mainly activation of adenosinergic and cholinergic receptors or small- and large-conductance Ca2+-activated-K+ channels.
Surface sediment samples were collected from five locations at the downstream of Klang River in January 2007 to examine the spatial distribution, composition, and sources of 19 parent polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbon (n-alkanes) using gas chromatographymass spectrometry. The total concentrations of the 19 PAHs in the sediments were found to range from 1304 to 2187 ng g-1 sediment. Meanwhile, total concentrations of n-alkanes ranged from 17008 to 27116 μg g-1 sediment. The concentration of n-alkanes in the sediment was significantly correlated (r = 0.991, p = 0.001) with the content of sediment organic carbon. In this study, all the sediments exhibited phenanthrene/anthracene (PHE/ANT >15) fluoranthene/(fluorantene+pyrene) (FLT/FLT+PYR < 0.4), ethylphenanthrenes/phenanthrene (MP/P >1), combustion PAHs/total PAHs (CombPAH/Σ19PAH
Today, insular Southeast Asia is important for both its remarkably rich biodiversity and globally significant roles in atmospheric and oceanic circulation. Despite the fundamental importance of environmental history for diversity and conservation, there is little primary evidence concerning the nature of vegetation in north equatorial Southeast Asia during the Last Glacial Period (LGP). As a result, even the general distribution of vegetation during the Last Glacial Maximum is debated. Here we show, using the stable carbon isotope composition of ancient cave guano profiles, that there was a substantial forest contraction during the LGP on both peninsular Malaysia and Palawan, while rainforest was maintained in northern Borneo. These results directly support rainforest "refugia" hypotheses and provide evidence that environmental barriers likely reduced genetic mixing between Borneo and Sumatra flora and fauna. Moreover, it sheds light on possible early human dispersal events.
Methanol extract ofMuntingia calaburaL. (family Muntingiaceae) leaf has been reported to exert various pharmacological activities including hepatoprotection. The present study was carried out to identify the most effective hepatoprotective partition derived from the extract and to determine the mechanisms of action involved. The extract was partitioned using solvents with different polarity to yield petroleum ether (PEMC), ethyl acetate (EAMC), and aqueous (AQMC) extracts. Each extract, at 250 mg/kg, was subjected to the paracetamol (PCM)-induced hepatotoxic assay and several parameters such as liver weight, liver/body weight ratio, serum liver enzymes' level, and histopathological examinations were determined. Each partition was also tested for their antioxidant and anti-inflammatory potentials. The most effective extract (AQMC) was prepared in additional dose of 50 and 500 mg/kg, and then subjected to the same liver toxicity test in addition to the endogenous antioxidant enzymes assay. Moreover, AQMC was also subjected to the phytochemical screening and HPLC analysis. Overall, from the results obtained: AQMC exerted significant (p< 0.05): (i) antioxidant activity when assessed using the DPPH, SOD and ORAC assays with high TPC detected; (ii) anti-inflammatory activity via LOX, but not XO pathway; (iii) hepatoprotective activity indicated by its ability to reverse the effect of PCM on the liver weight and liver/body weight ratio, the level of serum liver enzymes (ALT, AST, and ALP), and activity of several endogenous antioxidant enzymes (SOD and CAT). Phytochemicals analyses demonstrated the presence of several flavonoid-based bioactive compounds such as gallic acid and quercetin, which were reported to possess hepatoprotective activity. In conclusion, AQMC exerts hepatoprotective activity against the PCM-induced toxicity possibly by having a remarkable antioxidant potential and ability to activate the endogenous antioxidant system possibly via the synergistic action of its phytoconstituents.
A study has been carried out to characterize hydrocarbons emitted from the burning of three tropical wood species. The woods were burned to ember and smoke aerosols emitted were sampled using high volume sampler fitted with a pre-cleaned glass fibre filters. Hydrocarbons were extracted using ultrasonic agitation with dichloromethane-methanol (3:1 v/v) as solvent and the extracts obtained were then fractionated on silica-alumina column. Detection and quantification of aliphatic and polycyclic aromatic hydrocarbons (PAHs) compounds were carried out using GC-MS. The results indicated that the major aliphatic hydrocarbons characterized were straight chain n-alkanes in the range of C12-C35 with Cmax in the range of C27-C33. Rhizophora apiculata and Hevea brasiliensis wood smoke exhibited a weak odd to even carbon number predominance with carbon preference index (CPI) values greater than one whereas Melaleuca cajuputi wood smoke aerosols did not exhibit similar pattern with CPI obtained close to one. The results obtained also indicated that burning of these wood resulted in formation of PAHs compounds in their smoke aerosols with predominance of three to four rings PAHs over the two, five and lesser of six rings PAHs. PAH diagnostic ratios calculated except for Flan/(Flan+Py) and Indeno/(Indeno+BgP) were consistent with the ratios suggested for wood combustion source as reported in literatures. In the case of the latter, two diagnostic ratios, the values were generally lower than the range normally reported for wood combustion.