Methanol Residues Research Articles

Simultaneous production of biofuel, and removal of heavy metals using marine alga Turbinaria turbinata as a feedstock in NEOM Region, Tabuk

Depletion of fossil fuel and pollution by heavy metals are two major global issues. The cell wall of algae consists of polymers of polysaccharides such as cellulose, hemicellulose, alginate, starch, and many others that are readily hydrolyzed to monosaccharides and hence are amenable to fermentation into bioethanol. Moreover, algae contain lipids that may undergo trans-esterification to biodiesel, and can be absorbed by heavy metals. In this study, extraction of lipids from Turbinaria turbinata (common brown alga) from the beach of Sharma, NEOM, Tabuk, Saudi Arabia by different solvents hexane, methanol, and hexane: methanol (1:1), and trans-esterification was performed to obtain biodiesel and investigated by GC.MS. The alga residue after fats extractions by different solvents was used in bioremediation synthetic wastewater containing 50 ppm of As−3, Co+2, Cu+2, Fe+2, Mn+2, and Zn+2. The residue of defatted alga was hydrolyzed by 2% H2SO4 and then fermented to obtain bioethanol. The combination of hexane: methanol (1:1) gave the greatest amount of petroleum hydrocarbons, which contain Tetradecane, 5-methyl, Octacosane, Pentatriacontane, and a small amount of Cyclotrisiloxane, Hexamethyl. The most effective removal % was obtained with alga residue defatted by hexane: methanol (1:1), and methanol, 100% removal of As−3, 83% Co+2, 95% Cu+2, 97.25% Fe+2, Mn+2 79.69%, Zn+2 90.15% with 2 g alga /L at 3 hours. The lowest value of sugar was obtained with hexane: methanol residue but gave the highest bioethanol efficiency. Thus, it is possible to use Turbinaria turbinata, or brown alga as a feedstock to produce bio-diesel, and bioethanol, and to remove heavy metals from wastewater, which may have a great economic and environmental significance.

Extracts of Trichilia heudelotii (Meliaceae) Planch, a Nigerian Medicinal Plant have Antibacterial and Antifungal Activity

There is no overemphasizing the need for novel phytotherapeutic agents to combat the menace of drug resistance in microbial pathogens. Many plant species so far, have yielded some bioactive compounds with great promise for such drugs. Trichilia heudelotii (Meliaceae) is commonly used in traditional medicine in Nigeria for the treatment of many microbial infections ranging from gastrointestinal infections to gonorrhea. This study is thus designed to determine the phytochemicals present in T. heudeloti and evaluate the plant’s extracts' antimicrobial activity on some bacterial and fungal isolates.
 The phytochemical screening was done using standard procedures. Soxhlet extracts using n-hexane and methanol were drying in vacuo. The methanol extract was partitioned into petroleum ether, chloroform, and aqueous fractions. The antibacterial and antifungal activity of the extracts determined using the agar-well diffusion method. The MICs were determined for the extracts using the agar dilution method.
 The qualitative phytochemical screening revealed the presence of tannins, saponins, alkaloids, cardenolides, and anthraquinones in the leaf, stem bark, and root bark of T. heudelotii. The extracts showed considerable activity against Gram-positive and Gram-negative organisms, and fungi with dermatophytes including Klebsiella spp, Escherichia coli, Proteus spp, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Neisseria gonorrhoeae, Mycobacterium smegmatis, Candida albicans, Aspergillus niger, Rhizopus stolonifer, Penicillium spp, Microsporium canis, and Trichophyton mentagrophytes. The mean diameter of zones of inhibition exhibited by the extracts ranged between 10mm+ 0.5 and 32+ 0.33mm. The methanol extracts compared favourably with the gentamycin (standard control). The minimum inhibitory concentration (MIC) ranged between 0.157mg/mL and 20mg/mL. The crude methanol extracts and methanol residue showed the highest activity of all the extracts while the hexane extract showed the lowest activity and the Petroleum ether fraction was inactive.
 These results showed the potential of T. heudelotii as a possible candidate for bioactive compounds for the discovery and development of new drugs for the treatment of diseases caused by test pathogens.

Effect of removal of inhibitors on microbial communities and biogas yield of Jatropha curcas seeds during continuous anaerobic digestion

Jatropha curcas seeds, as an abundant lignocellulosic biomass, offer a highly promising and ideal alternative for producing energy in the form of methane. Use of J. curcas seeds has the potential to significantly bolster the biofuel sector, fostering a more sustainable circular economy. In the current study, different fractions of processed J. curcas seeds were investigated for biogas production. J. curcas seed pressed cake, a by-product of biodiesel production, was subjected to methanolic extraction. The remaining solids, referred to as methanolic residues, yielded more biogas in batch experiments than pressed cake and residues from aqueous and n-hexane extractions. The compounds extracted with methanol inhibited hydrolysis and reduced biogas production by 35.5% compared to the same setup without extracts. In continuous reactors fed with methanolic residues, the highest biogas yield occurred at an organic loading rate (OLR) of 1 g VS L−1 day−1 and a hydraulic retention time (HRT) of 20 days. The relative abundance of acetogenic bacteria was higher in reactors fed with methanolic residues than in those fed with seed pressed cake, seed oil, and whole seed. Jatropha seed oil and whole seed did not inhibit methanogens. A higher relative abundance of methanogenic communities was observed in all reactors at HRT of 20 days compared to those at HRTs at 15 and 10 days. These findings can be used to increase biogas production during anaerobic digestion of J. curcas seed components and suggests a zero-waste biorefinery production route for value added compounds derived from the removal of biogas-inhibiting components.

Structure and Reactivity of Metal-Oxide-Supported Noble Metal Nanoparticles: Electrooxidation of Simple Organic Molecules

There has been growing interest in utilizing small (simple) organic molecules, as alternative fuels to hydrogen, in electrochemical energy conversion systems. In addition to ethanol (biofuel), that can be ideally oxidized to carbon dioxide thus delivering twelve electrons, recent important systems include dimethyl ether as well. But realistically the respective reaction is rather slow at ambient conditions. Obviously, there is a need to develop novel electrocatalytic materials.Platinum has been recognized as the most active catalytic metal towards oxidation of ethanol at low and moderate temperatures. But Pt anodes are readily poisoned by the strongly adsorbed intermediates, namely by CO-type species, requiring fairly high overpotentials for their removal. To enhance activity of Pt catalysts towards methanol and ethanol oxidation, additional metals including ruthenium, tin, molybdenum, tungsten or rhodium are usually introduced as the alloying component. More recently it has been demonstrated that catalytic activity of platinum-based nanoparticles towards electrooxidation of ethanol has been significantly enhanced through interfacial modification with ultra-thin monolayer-type films of metal oxo species of tungsten, titanium or zirconium.We pursue a concept of utilization of mixed metal (e.g. zirconium/tungsten or titanium/tungsten) oxide matrices for supporting and activating noble metal nanoparticles (e.g. PtRu) during electrooxidation of methanol, ethanol, formic acid and dimethyl ether. Among important issues is incorporation of Rh nanostructures capable of weakening, or even breaking, the C-C bond in the ethanol molecules. On the other hand, rhodium itself is not directly electrocatalytic toward oxidation of ethanol. The oxides and noble metal nanoparticles have been deposited in a controlled manner using the layer-by-layer method. Remarkable increases of electrocatalytic currents measured under voltammetric and chronoamperometric conditions have been observed. The most likely explanation takes into account possibility of specific interactions of noble metals with transition metal oxide species as well as existence of active hydroxyl groups in the vicinity of catalytic noble metal sites. In addition, formation of “nanoreactors” where ethanol is partitioned (at Rh) to methanolic residues further oxidized at PtRu cannot be excluded.

Identification of neurotherapeutic constituents in Ocimum gratissimum with cholinesterase and mono amine oxidase inhibitory activities, using GC-MS analysis, in vitro, and in silico approaches

Neuroprotective activities of various extracts of Ocimum gratissimum (OG), have been reported, but there is paucity of information on its neurotherapeutic constituents. This study is aimed at identifying the neurotherapeutic constituents in OG leaves using in vitro assays, GC-MS chemical investigation and in silico studies including molecular docking, ensemble-based docking, molecular dynamics (MD) simulation, clustering and ADMET filtering analysis. Methanol extract of O gratissimum (MEOG) and solvent-partition (n-hexane, ethylacetate, and methanol residue fraction) of MEOG were investigated for in vitro acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and monoamine oxidase B (MAO-B) inhibition at concentration of 0.65, 12.5, 2.5, 5, and 10 mg/mL, using donepezil, phenazine methosulfate and selegiline as reference inhibitors for AChE, BChE and MAO B respectively. n-hexane solvent partition fraction was further investigated using GC-MS analysis. Identified compounds were screened against human AChE, BChE and MAO-B activities using molecular docking and molecular dynamics. The lead phytochemicals were further analysed for ADMET in silico analysis. MEOG and the 3 fractions (n-hexane, ethylacetate, and methanol residue fraction) inhibited the activities of AChE, BChE and MAO-B in a concentration-dependent manner with AChE (IC50 = 2.380, 2.022, 2.066 and 1.079 mg/mL respectively), BChE (IC50 = 2.261, 2.126, 2.630 and 1.465 mg/mL respectively) and MAO-B (IC50 = 2.345, 1.584, 2.933 and 2.935 mg/mL respectively). From the 38 GC-MS identified compounds, 7 hit compounds were further subjected to ensemble-docking, the lead phytochemicals (LP): cholestane and 3-methoxy-morphanin presented highest multiple binding tendencies to the three enzymes. Cholestane had the highest binding energies of −9.9, −9.0 and −11 kcal/mol, while 3-methoxy-morphanin presented the second-best binding energies of −9.3, −8.2 and −10.1 kcal/mol respectively. When compared with the binding pattern of reference inhibitors of the enzyme, lead phytochemicals were orientated in the catalytic sites of the enzyme and interacted with important catalytic residues. The LP-enzyme complexes were stable during the MD simulation analysis. Cholestane and 3-methoxy-morphanin presented favorable ADMET properties over several molecular descriptors and filters, with druggable properties and ability to cross the blood-brain barrier. Hence, cholestane and 3-methoxy-morphanin, in part, or in synergy with other hit phytochemicals, may be responsible for the neurotherapeutic activities of MEOG leaves.

Effect of blending ratio of biofuel from used cooking oil with Dexlite

Indonesia is committed to accelerating the clean energy transition through the biodiesel policy to achieve net zero emission. The commitment to use palm oil as a biofuel base material will support Indonesia in achieving its energy security and energy mix target of 23% in 2025. This article discussed the characteristics of the blended fuel between biofuel from used cooking oil and Dexlite from PERTAMINA products. The blending process is carried out with the biofuel: Dexlite ratio as follows: 5:95, 10:90, 15:85 20:80, 25:75 and 30:70. The results revealed that the best experiments for acid number were obtained at the B5 blending ratio of 0.039 mgKOH/(g sample), saponification number at the B5 blending ratio of 1.066 mgKOH/(g sample), flash point at the B20 blending ratio at a temperature of 101°C, 90% distillation at the B10 blending ratio at a temperature of 213°C, and the density at the blending ratio B15 is 837 kg/m3. From these results, only the density parameter does not meet the biodiesel quality standards based on SNI 7182:2015. These results indicate that the addition of 30% biofuel to Dexlite can still be used as a fuel for diesel vehicles by applying a better washing method for KOH catalyst residue and unreacted methanol residue.

Herrmananes A and B, two new sulfated hydrocarbons from the sea cumber Stichopus herrmanni

AbstractUsing various chromatographic separations, two new sulfated hydrocarbons namely herrmananes A and B (1 and 2) were isolated from the aqueous fraction of the methanol residue of the sea cucumber Stichopus herrmanni. Their chemical structures were elucidated by extensive analysis of the 1D, 2D NMR and HR‐QTOF mass spectra. In addition, compound 1 showed significant cytotoxicity on SK‐Mel‐2 cell line with IC50 value of 23.12 ± 1.87 μM, whereas 2 exhibited moderate effect on this cell line with IC50 value of 55.28 ± 4.17 μM.

(Invited) Enhancement of Oxidation of Dimethyl Ether through Applicationof Metal-Oxide-Supported Noble Metal Catalytic Nanoparticles: Comparison to Behavior of Other Simple Organic Fuels

There has been growing interest in utilizing small (simple) organic molecules, as alternative fuels to hydrogen, in electrochemical energy conversion systems. In addition to ethanol (biofuel), that can be ideally oxidized to carbon dioxide thus delivering twelve electrons, recent important systems include dimethyl ether as well. But realistically the respective reaction is rather slow at ambient conditions. Obviously, there is a need to develop novel electrocatalytic materials.Platinum has been recognized as the most active catalytic metal towards oxidation of ethanol at low and moderate temperatures. But Pt anodes are readily poisoned by the strongly adsorbed intermediates, namely by CO-type species, requiring fairly high overpotentials for their removal. To enhance activity of Pt catalysts towards methanol and ethanol oxidation, additional metals including ruthenium, tin, molybdenum, tungsten or rhodium are usually introduced as the alloying component. More recently it has been demonstrated that catalytic activity of platinum-based nanoparticles towards electrooxidation of ethanol has been significantly enhanced through interfacial modification with ultra-thin monolayer-type films of metal oxo species of tungsten, titanium or zirconium.We pursue a concept of utilization of zirconia nad mixed metal (e.g. zirconium/tungsten or titanium/tungsten) oxide matrices for supporting and activating noble metal nanoparticles (e.g. PtRu) during electrooxidation of dimethyl ether relative to methanol, formic acid and ethanol. Among important issues is incorporation of additional metal (e.g. Rh or Pt) nanostructures capable of weakening, or even breaking, the C-C and C-O bonds in the ethanol and dimethyl ether molecules. On the other hand, rhodium itself is not directly electrocatalytic toward oxidation of ethanol. The oxides and noble metal nanoparticles have been deposited in a controlled manner using the layer-by-layer method. Remarkable increases of electrocatalytic currents measured under voltammetric and chronoamperometric conditions have been observed. The most likely explanation takes into account possibility of specific interactions of noble metals with transition metal oxide species as well as existence of active hydroxyl groups in the vicinity of catalytic noble metal sites. In addition, formation of “nanoreactors” where ethanol and dimethyl ether are partitioned (at Rh, Pt or Pd) to methanolic residues and further oxidized at PtRu cannot be excluded.

Assessment of Paronychia Argentea Extraction on Kidney Stone by Using Calcium Oxalate Method

Urinary calculi are stones (urolithiasis) that can form anywhere in urinary tract outside of the kidneys and mostly composed of calcium oxalate and phosphate, additionally with elevated throughout the last two decades in the world. Chemical composition plays a major part in nephrolithiasis. Therefore, the high concentrations of lithogenic substances in urine enhance the crystallization method in urine tract system. The most kidney stones form from calcium oxalate, the present study was inspected the effect of the crude aqueous extract as well as the fractionated methanol extract (ethyl acetate, isopropanol, acetone and methanol residue) of paronychia argentea on the crystallization of calcium oxalate salts. The effect of aqueous extract and fractionated methanol extract on the size, number, type of calcium oxalate crystals. Paronychia argentea both the crude aqueous and the fractionated extract, especially ethyl acetate fraction have antiurolithic activity via reducing crystal size as well as activate the formation of calcium oxalate dihydrate (COD) crystals out from calcium oxalate monohydrate (COM) with increasing concentration of extract. The shifting of crystallization process to producing calcium oxalate dihydrate (COD) rather than oxalate monohydrate (COM) and the reducing the crystal size and calcium ion concentration, in addition to the diuretic action of extract plays an important role in controlling urolithiasis.

Treatment of perfluoroalkyl acids in concentrated wastes from regeneration of spent ion exchange resin by electrochemical oxidation using Magnéli phase Ti4O7 anode

This study investigated the treatment of perfluoroalkyl acids (PFAAs) in still bottoms during electrochemical oxidation using Magnéli phase titanium suboxide (Ti4O7) as the anode. Still bottoms are wastes produced from regeneration of saturated ion exchange resin (IXR) by a solution containing high salt content and methanol followed by distillation to remove the methanol. All 10 monitored PFAAs were effectively degraded by electrochemical oxidation (EO) on a Magnéli phase Ti4O7 anode, and the removal was 61.1% after 40 h EO treatment of a still bottoms sample that was produced from the use of a typical regenerant containing 2% NaCl and 80% methanol by mass. Total Organic Carbon (TOC) destruction exceeded 79% in this treatment. Chlorate (ClO3−) and perchlorate (ClO4−) were formed after 8 h and reached a maximum of 2.3 mM and 2.2 mM, respectively, after 40 h. To minimize perchlorate generation by EO, five other salts were also tested instead of NaCl to regenerate IXR that had treated groundwater containing PFAAs. The regenerant containing NaI exhibited the greatest PFAAs elution, comparable to that of NaCl. EO treatment of the still bottoms produced from the NaI regenerant for 200 h led to a total of 98.1% removal of all 10 monitored PFAAs. No ClO3− or ClO4− was detected after 100 h of EO treatment. It was found that the methanol residue in still bottoms effectively suppressed the formation of ClO3− and ClO4− during electrooxidation by scavenging chlorine radicals. The results of this study demonstrate the promise of coupling regenerable IXR technology and EO for removing PFAAs from water and destroying them onsite.

Bioactivities, heavy metal contents and toxicity effect of macroalgae from two sites in Madura, Indonesia

Abstract Sargassum duplicatum and Padina tetrastromatica seaweed species collected from oil and a non-oil extraction site at Madura Island were investigated in this study for selected bioactivities, heavy metals and toxicity effects. The collected seaweeds were evaluated for their phytochemical constituents, total phenolic contents (TPC), antioxidant activities, antidiabetic activities, anticancer activities, toxicities and heavy metals using Folin-Ciocalteus method, the 2,2-diphernyl-1 picrylhydrazyl (DPPH), α-glucosidase enzyme, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), Brine Shrimp Lethality Test (BSLT) and atomic absorption spectrophotometer, respectively. The crude extracts (C), normal hexane (N), ethyl acetate (E), and methanol residue fractions (M) were studied. The highest TPC (589.79 ± 7.14 mg GAE/g) was observed in ethyl acetate fraction of P. tetrastromatica from the non-oil extraction site. Meanwhile, the crude extracts and all fractions showed potent antioxidant, antidiabetic, and cytotoxic activities with ethyl acetate fraction of P. tetrastromatica from non-oil extraction site displaying the highest effects (IC50 25.25 ± 5.15, 249.12 ± 1.77 and 70.56 ± 2.56 µg/mL: antioxidant, antidiabetic, cytotoxic activities respectively). In the brine shrimp assay, the crude extracts and all fractions of both species from the two sites were non-toxic with exception of the hexane fraction of P. tetrastromatica from oil site which was very toxic after 24 h incubation. However, the crude extract of S. duplicatum and ethyl acetate fraction of P. tetrastromatica from oil extraction site were mildly toxic except the hexane fraction of P. tetrastromatica from oil site which was very toxic after 48 h incubation while samples of both species from the non-oil site were nontoxic. In each species, the concentration of Cd from the oil extraction site was higher than those of the non-oil site with the values of P. tetrastromatica leading and a similar observation occurred Cu in P. tetrastromatica but the same Cu was negligible in S. duplicatum as Pb was negligible in both species. According to the findings of this current study, it is safe to conclude that both S. duplicatum and P. tetrastromatica from Madura Island have antioxidant, antidiabetic and cytotoxic activity, we therefore recommend these species from the non-oil extraction site for drug candidates against the various health abnormally they seem to inhibit.

(Invited) Enhancement of Oxidation of Dimethyl Ether at Nanostructured-Metal-Oxide-Supported Noble Metal Catalytic Nanoparticles: Comparison to Behavior of Other Simple Organic Fuels

There has been growing interest in utilizing small (simple) organic molecules, as alternative fuels to hydrogen, in electrochemical energy conversion systems. In addition to ethanol (biofuel), that can be ideally oxidized to carbon dioxide thus delivering twelve electrons, recent important systems include dimethyl ether as well. But realistically the respective reaction is rather slow at ambient conditions. Obviously, there is a need to develop novel electrocatalytic materials.Platinum has been recognized as the most active catalytic metal towards oxidation of ethanol at low and moderate temperatures. But Pt anodes are readily poisoned by the strongly adsorbed intermediates, namely by CO-type species, requiring fairly high overpotentials for their removal. To enhance activity of Pt catalysts towards methanol and ethanol oxidation, additional metals including ruthenium, tin, molybdenum, tungsten or rhodium are usually introduced as the alloying component. More recently it has been demonstrated that catalytic activity of platinum-based nanoparticles towards electrooxidation of ethanol has been significantly enhanced through interfacial modification with ultra-thin monolayer-type films of metal oxo species of tungsten, titanium or zirconium.We pursue a concept of utilization of zirconia nad mixed metal (e.g. zirconium/tungsten or titanium/tungsten) oxide matrices for supporting and activating noble metal nanoparticles (e.g. PtRu) during electrooxidation of dimethyl ether relative to methanol, formic acid and ethanol. Among important issues is incorporation of additional metal (e.g. Rh or Pt) nanostructures capable of weakening, or even breaking, the C-C and C-O bonds in the ethanol and dimethyl ether molecules. On the other hand, rhodium itself is not directly electrocatalytic toward oxidation of ethanol. The oxides and noble metal nanoparticles have been deposited in a controlled manner using the layer-by-layer method. Remarkable increases of electrocatalytic currents measured under voltammetric and chronoamperometric conditions have been observed. The most likely explanation takes into account possibility of specific interactions of noble metals with transition metal oxide species as well as existence of active hydroxyl groups in the vicinity of catalytic noble metal sites. In addition, formation of “nanoreactors” where ethanol and dimethyl ether are partitioned (at Rh, Pt or Pd) to methanolic residues and further oxidized at PtRu cannot be excluded.

Determination of methanol residues in crude glycerol for animal feed by gas chromatography

ABSTRACT: Crude glycerol is a major by-product of biodiesel production and is an economical additive feed for ruminants. However, residual methanol in crude glycerol can be harmful to animal health. Several methods exist for quantifying methanol residues in biodiesel, yet few have been described that identify the methanol level in crude glycerol. We propose a method for determining the methanol level in crude glycerol destined for animal feed. Crude glycerol was extracted from the headspace and quantified by gas chromatography using a flame ionization detector (GC-FID). The method was linear up to 0.5 % of methanol. The limits of detection (LOD) and quantification (LOQ) were 0.015 and 0.031 %, respectively. No significant matrix effects were observed. Precision was 2 % at the 0.05 and 0.5 % levels. The average percentage of recovery was 90 %. Three analyzed samples of crude glycerol had methanol residues of 0.027-7.802 %. Furthermore, this methanol quantification method may be externally or internally calibrated using a GC manual injector. A reduction of at least 20 % in running time was obtained with good resolution between the peaks. Thus, this method can be applied to determine the methanol level in crude glycerol according to the upper limits for animal feed (5,000 ppm) and for human consumption (150 ppm). Finally, this method is useful for the quality control of crude glycerol intended for use in animal feed, enabling the alternative use of this by-product to add value to the biodiesel production chain.

Halide adsorption effect on methanol electro-oxidation reaction studied by dynamic instabilities

The effect of halide anion adsorption on methanol electro-oxidation reaction in acid media was studied by means of thermal effects on both cyclic voltammograms (CV) and oscillations in galvanostatic time series (GTS). While increasing the chloride concentration we observed a monotonically current decrease followed by an increase of apparent activation energy (Ea) in CV, GTS increases the maximum potential (Emax) and decreases both the oscillation frequency (w) and Ea. Poisoning/Freeing rates (dE/dt) increase for a very small Cl− amount but decreases for higher concentrations. Changing Cl− by Br−, albeit observing similar behaviors for currents on CV and w, Emax and Ea changes suggest that Br− probably plays a dual role, i.e. poisoning the surface by its adsorption but also interacting with adsorbed methanol residues. Finally, increasing the pH to 5.6 in a nonadsorbing electrolyte (HClO4/NaF) several oscillations patterns were mapped with a lesser Cl− influence on both CV and GTS.

Lavandula dentata Solid Residue from Essential Oil Industry

Essential oil industry produces a considerable amount of solid residues during the distillation process. These wastes are very rich in high added-value compounds like polyphenols. In this work, we have tentatively identified the polyphenols present in solid residues from the steam distillation and non-distilled extract of Lavandula dentata, and assessed for it total phenols and total flavonoid content. The antioxidant activity was estimated using tree different methods. The antimicrobial activity has been evaluated against sex bacterial strains. Both remarkably high phenolic content and radical scavenging activities were found in the metanolic and ethanolic extracts. In general, the residue material was found to exhibit higher phenolic content as well as antioxidant and radical scavenging activities than the non-distilled material. Finally, We concluded that the methanolic and ethanol residue extracts were a promising source of antioxidant and antimicrobial agents that can be exploited as health-promoting compounds in food or in cosmetic products.

Antidiabetic Activity of the Methanolic Extracts of Thuja occidentalis Twings in Alloxan-induced Rats

Objective and Background: In hyperglycemic and alloxan-induced diabetic rats, the effect of Thuja occidentalis methanolic residue extract on blood glucose levels and some biochemical parameters were investigated. Methods: Significantly decreased blood glucose level by 22.85% and 27.66%, in hyperglycemic rats, respectively after 3 h, were seen in a single oral administration of the extract at a dose of 200 and 400 mg/kg. Blood glucose level was decreased by 50% in alloxan-induced diabetic rats within three weeks of daily treatment of Thuja occidentalis methanolic residue extract (200 and 400 mg/kg p.o). Alloxan-induced diabetic rats showed significant hypercholesterolemia in comparison with the control in alloxan induced rats. Results: In both normal and diabetic rats, there was also a significant decrease of elevated serum cholesterol and triglycerides. Hypertriglyceridemia was also shown to be prevented by treatment with plant extract (200 and 400mg/kg p.o) (p<0. 05). As compared with the control animals, diabetic control rats did not show any change in a level of creatinine and urea. Conclusion: Thuja occidentalis treatment may improve glucose homeostasis in alloxaninduced diabetes and alleviate kidney and liver function. Thuja occidentalis twigs could be a potential source of the new oral antidiabetic drug.

(Invited) Nanostructured-Metal-Oxide Functionalized-Supports for Noble Metal Catalytic Nanoparticles: Enhancement of Electrooxidation of Simple Organic Fuels

There has been growing interest in utilizing small (simple) organic molecules, as alternative fuels to hydrogen, in electrochemical energy conversion systems. In addition to ethanol (biofuel), that can be ideally oxidized to carbon dioxide thus delivering twelve electrons, recent important systems include dimethyl ether as well. But realistically the respective reaction is rather slow at ambient conditions. Obviously, there is a need to develop novel electrocatalytic materials. Platinum has been recognized as the most active catalytic metal towards oxidation of ethanol at low and moderate temperatures. But Pt anodes are readily poisoned by the strongly adsorbed intermediates, namely by CO-type species, requiring fairly high overpotentials for their removal. To enhance activity of Pt catalysts towards methanol and ethanol oxidation, additional metals including ruthenium, tin, molybdenum, tungsten or rhodium are usually introduced as the alloying component. More recently it has been demonstrated that catalytic activity of platinum-based nanoparticles towards electrooxidation of ethanol has been significantly enhanced through interfacial modification with ultra-thin monolayer-type films of metal oxo species of tungsten, titanium or zirconium. We pursue a concept of utilization of mixed metal (e.g. zirconium/tungsten or titanium/tungsten) oxide matrices for supporting and activating noble metal nanoparticles (e.g. PtRu) during electrooxidation of methanol and ethanol. Among important issues is incorporation of Rh nanostructures capable of weakening, or even breaking, the C-C bond in the ethanol molecules. On the other hand, rhodium itself is not directly electrocatalytic toward oxidation of ethanol. The oxides and noble metal nanoparticles have been deposited in a controlled manner using the layer-by-layer method. Remarkable increases of electrocatalytic currents measured under voltammetric and chronoamperometric conditions have been observed. The most likely explanation takes into account possibility of specific interactions of noble metals with transition metal oxide species as well as existence of active hydroxyl groups in the vicinity of catalytic noble metal sites. In addition, formation of “nanoreactors” where ethanol is partitioned (at Rh) to methanolic residues further oxidized at PtRu cannot be excluded.

LC-MS/MS-based determination of chloramphenicol, thiamphenicol, florfenicol and florfenicol amine in poultry meat from the Punjab-Pakistan

ABSTRACTA simple, reliable and sensitive liquid chromatography-tandem mass spectrometry-based confirmatory method was redeveloped and validated for the simultaneous determination of chloramphenicol, thiamphenicol, florfenicol and florfenicol amine in chicken muscles. The analytes were extracted from minced chicken muscle with acetonitrile and ammoniated water mixture. A second extraction with ethyl acetate was followed by evaporation and dissolution of the residue in ammoniated methanol before defatting with n-hexane. Finally, the extract was further cleaned up by dispersive solid phase extraction using C-18 end-capped dispersive material. The validation protocol was adapted from the European Commission Decision 2002/657/EC and all the performance characteristics were successfully satisfied. The recoveries of all the analytes were found to be in the range of 86.4–108.1% and the precision values, within day and between days, ranged from 2.7% to 11% and 4.4% to 16.3%, respectively. The method was tested in various incurred samples and applied to analyse a wide range of random poultry market samples (n = 120) collected from three cities of the Punjab, Pakistan. Chloramphenicol and florfenicol residues were detected at low levels in less than 11% of the samples. Chloramphenicol was detected only in 4 samples with the concentration range of 0.17–0.477 µg kg–1, whereas the levels of florfenicol/florfenicol amine residues detected in 9 samples ranged from 8.7 to 32.8 µg kg–1. Moreover, most of the florfenicol residues were identified as tissue bound, extractable only after strong acid hydrolysis.

English

The phytochemical screening of Citharexylum spinosum L. aerial parts resulted in the presence of flavonoids, tannins, carbohydrates and/or glycosides, triterpenes and/or sterols and saponins. The percentage of hydrocarbons and sterols in C. spinosum petroleum ether extract were 99.57 and 0.3%, respectively. In petroleum ether extract, saturated fatty acids (78.76%) and unsaturated fatty acids (9.14%) were found. Chromatographic fractionation of 80% aqueous, methanol and chloroform extracts of C. spinosum resulted in isolation of 10 compounds; β-Sitosterol, β-Sitosterol 3-O-β-D-glucopyranoside, Oleanolic acid, Gallic acid, Quercetin, 6-Methoxy acacetin 7-O-β-D-glucopyranoside, Naringenin, Quercetin 3-O-α-L-rhamnopyranoside (Quercetrin), 1, 2, 6-tri-O-galloyl-β-D-glucopyranoside and Rutin. The antipyretic activity of aqueous methanolic residue using Brewer's yeast-induced pyrexia in rats was significant at dose 300 mg/kg. All tested samples had no analgesic activity. The major isolated compounds were quercetin and quercetrin, their biological activities, antimicrobial and cytotoxic activities, were determined parallel to the extracts. It was found that the aqueous methanolic residue, chloroform extract, quercetin and quercetrin exerted significant antimicrobial activity. From 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell proliferation assay on A2780 human ovarian cell line, quercetrin showed moderate cytotoxic activity, whereas quercetin showed significant cytotoxic activity.   Key words: Citharexylum spinosum, lipoidal matter, phenolics, antipyretic, antimicrobial.

Supercritical methanol as an effective medium for producing asphaltenes-free light fraction oil from vacuum residue

The upgrading of vacuum residue (VR) in supercritical methanol (scMeOH) was investigated without using catalysts. Various process parameters, including temperature (350–425°C), reaction time (30–90min), and additives (toluene and hydrogen) were explored to optimize the yield of light fraction oil (LFO) with few impurities. At a 400°C, 16.7wt% of VR in methanol for 60min, the LFO produced in scMeOH contained very low asphaltene content (0.74wt%) and a very low amount of heteroatom/metallic impurities (S, 3.58wt%;N, non-detectable; Ni, 10.4ppm;V, 36.9ppm, Fe, 7.3ppm). In addition, the naptha-to-diesel fraction increased from 1wt% (VR feed) to 15wt% and the saturate+aromatic content increased from 43.7 area% (VR feed) to 59.6 area% in the LFO. When the reaction time was extended to 90min at 400°C, a complete removal of asphaltenes could be achieved.