Chemical composition,antibacterial and antioxidant activities of essential oils from leaves of three Melaleuca species of Pakistani flora

This study presents essential oil composition of three Melaleuca species namely, Melaleuca bracteata F. Muell, Melaleuca fulgens R. Br. subsp. steedmanii and Melaleuca leucadendron (L.) L. collected from different regions of Pakistan. The chemical composition of essential oils was analyzed by GC-FID and GC–MS. Eugenol methyl ether was identified as a principal component in M. bracteata (82.3%), M. fulgens (87.8%) and M. leucadendron (95.4%) oils. In vitro antibacterial studies were done by agar well diffusion and microdilution method and the tested essential oils exhibited bacteriostatic and bactericidal effects against the tested foodborne pathogens at 4–8 µg/ml. Time kill assay showed significant bactericidal effect of oils for four weeks. The antioxidant potential was assessed by free radical scavenging activity and reducing power assay. The oils showed strong antioxidant activity with approximately 89.0–89.5% inhibition of 2,2-diphenyl-1-picrylhydrazyl radical and ferric reducing power in the range of 1.94 ± 0.007–2.04 ± 0.04% at 100 µg/ml.     

The effect of UV-A (352 nm) stress on chlorophyll fluorescence,chlorophyll a content,thickness of upper cortex and determinate DNA damage in Physcia semipinnata

In the present study, Physcia semipinnata samples were exposed to UV-A (352 nm) in 20 J m^?2 for 24 h, 48 h and 72 h to seek the alterations in the PSII photosynthetic quantum yield, thallus anatomy and DNA mutation rate in response to radiation. The Fv/Fm ratio decreased in P. semipinnata following exposure to UV-A for 24 h, 48 h and 72 h. The data of the present study reported that Chla degradation occurred by exposition of UV-A for 24 h, 48 h and 72 h. Photobiont size and thickness of upper cortex layer also showed a gradually decrease in P. semipinnata thallus sections during 24 h, 48 h and 72 h. The thickness of the upper cortex layer, exposed to UV-A for 72 h, of P. semipinnata thallus reduced 64%, compared with control. The random amplified polymorphic DNA (RAPD) technique was used to detect DNA damage. The main changes observed in the RAPD profiles resulted in both appearance and disappearance of different bands and variation of their intensity. According to RAPD assay, the genetic distance between the control group and 24 h, 48 h and 72 h UV-A exposed, groups was found 56%, 78% and 84%, respectively.     

Sub-critical water extraction of bitumen from Huadian oil shale lumps

Three sizes of Huadian oil shale lumps from 1 cm to 10 cm were extracted by sub-critical water at 350 °C and 16 MPa for 2–70 h. The oil shale lumps were fractured alone the shale texture in sub-critical water that greatly improved the extraction efficiency of bitumen from the large- and middle-sized sample. The extract yields of bitumen from different sized samples were similar when the extraction time is longer than 20 h and stabilized at about 18 wt.% (ad) after 50 h duration. With the increase of extraction time, asphaltene and preasphaltene extracts were gradually decomposed to maltene. The gas chromatography–mass spectrometry (GC–MS) analysis of the extracts showed that n-alkanes, n-alk-1-enes, isoprenoids, n-alk-2-ones and n-alkanoic acids were the major components. In contrast, aromatic extracts were rare and most of them were remained in the shale residue. The pyrolysis gas chromatography–mass spectrometry (Py-GC–MS) analysis of the spent shale showed that the final undecomposed organics in kerogen were some macromolecular linear hydrocarbon, n-alk-2-ones and n-alkanoic acids fragments. The comparison of the classical pyrolyzate and the sub-critical water extracts showed that the water extracts contained more long-chain alkanes than anhydrous pyrolysis and the alkene extracts could transform to alkanes in sub-critical water. Moreover, the n-alkanoic acids could be decomposed to short-chain compounds through the cleavage of carbon carbon bonds.     

Metal complexes of gliclazide: Preparation,spectroscopic and thermal characterization. Biological potential study of sulphonylurea gliclazide on the house fly,Musca domestica (Diptera – Muscidae)

Metal complexes of gliclazide (GLZ; HL) drug are prepared and characterized based on elemental analyses, IR, diffused reflectance, magnetic moment, molar conductance and thermal analyses (TG and DTG) technique. From the elemental analyses data, the complexes are proposed to have the general formulae [M(HL)Cl₃(H₂O)]·3H₂O (M = Cr(III) and Fe(III)), [M(HL)Cl₂(H₂O)₂]·yH₂O (M = Co(III), Ni(II) and Cu(II), y = 0–2) and [M(HL)Cl₂]·yH₂O (M = Mn(II) and Zn(II), y = 0–1). The molar conductance data reveal that all the metal chelates are non-electrolytes. IR spectra show that GLZ is coordinated to the metal ions in a neutral bidentate manner with ON donor sites of the amide-O and sulphonamide-OH. From the magnetic and solid reflectance spectra, it is found that the geometrical structures of these complexes are octahedral (Cr(III), Fe(III), Co(II), Ni(II) and Cu(II)) and tetrahedral (Mn(II) and Zn(II)). The thermal behaviour of these chelates is studied using thermogravimetric analysis (TG and DTG) techniques. The results obtained show that the hydrated complexes lose water molecules of hydration followed immediately by decomposition of the anions and ligand molecules in the successive unseparate steps. The activation thermodynamic parameters are calculated using Coats–Redfern method. The GLZ drug, in comparison to its metal complexes also is screened for their biological activity against house fly, Musca domestica (Diptera – Muscidae). Dose of 5 μg/insect of gliclazide is typically applied against 3 days-old larval instar of M. domestica. Survival of pupal and adult stages has been affected by the complexes of gliclazide more than larval instars. Morphogenic abnormalities of larvae, pupae and adults are studied. On the other hand, pupation and adult emergence program is deteriorated by the effect of different chemicals.     

Liquid extraction of polyhydric alcohols from water using [A336][SCN] as a solvent

This work demonstrated the possibility of hydrophobic ionic liquid tricaprylmethylammonium thiocyanate ([A336][SCN]) as a solvent in the separation by extraction of polyhydric alcohols from their mixtures with water. The knowledge of (liquid + liquid) equilibrium (LLE) of these mixtures is essential for the design of the extraction process. For this reason, the LLE data of the ternary systems {[A336][SCN] + water + glycerol, or ethylene glycol, or 1,2-propanediol, or 1,3-propanediol} were determined at T = 303.2 K and atmospheric pressure. The reliability of the tie-lines data was ascertained by applying the Othmer–Tobias equation, and the non-random two liquid (NRTL) model used to fit the experimental LLE data. The effectiveness of the extraction of polyhydric alcohols from water was evaluated using the solute distribution ratio and the selectivity. The extraction capability of [A336][SCN] was compared with that of other ILs. The results indicated that the [A336][SCN] was suitable for use as a solvent in (liquid + liquid) extraction of polyhydric alcohols from water.     

Determination of erythromycins in fermentation broth using liquid phase extraction with back extraction combined with high performance liquid chromatography

Liquid phase extraction with back extraction (LPE-BE) combined with high performance liquid chromatography-diode array detection (HPLC-DAD) was applied for the extraction and determination of erythromycin A, B and C in fermentation broths. According to this procedure, the fermentation broth with the adjustment pH at a fixed value of 10 was first mixed with organic solvent (V_broth/V_org = 1.0). After shaking, the mixture was separated into two phases by microfuging at 13,000 rpm for 15 min. Then back extraction was performed into the acidic aqueous phase with pH 5.0 (V_org/V_aq = 1.0). After centrifugation at 3000, the two phases were separated and 50 μL of the acidic aqueous phase was injected into the HPLC. The effects of different variables such as the nature of extraction solvent and the pH of samples and buffer were investigated. At the most appropriate conditions, dynamic linear ranges of 0.5–8, 0.1–0.9 and 0.1–0.9 mg mL⁻¹ and limits of detection of 0.03, 0.003 and 0.002 mg mL⁻¹ were obtained for erythromycin A, B and C, respectively. Relative standard deviations (RSDs) of the proposed method were less than 9.5%. The mean recoveries were 99.5%. The proposed method is simple and sensitive with highly clean-up effect and it can be used for monitoring the progress of erythromycin fermentation.     

Green extraction process of tannins obtained from Moroccan Acacia mollissima barks by microwave: Modeling and optimization of the process using the response surface methodology RSM

The effect of extraction conditions on polyphenols contents and condensed tannins by microwave-assisted extraction (MAE) was studied for the first time to our knowledge. Moroccan barks of Acacia mollissima was used to extract phenolic compounds. The variables studied are the following: power extraction, time extraction and solvent nature. Five powers extraction were tested: 150 W, 250 W, 300 W, 450 W and 600 W. A significant effect of power extraction on the extractable nature was proved by ANOVA and Student test. The yields were also affected by time extraction. Different solvent (water, ethanol, methanol and ethyl acetate) were tested to evaluate the best extraction solvent according to the extractable nature. Highest polyphenols contents were obtained with methanol. The proportion of this solvent, time extraction and power extraction were optimized using the response surface methodology (RSM). A face-centered composite design (FCCD) was applied to evaluate the effects of these variables on the polyphenols and condensed tannins contents. For each experiment, the extraction yield, the total polyphenolic contents and the condensed tannins contents were quantified using colorimetric essays. The extracts were characterized by their reactivity to formaldehyde and reverse phase high pressure liquid chromatography (RP-HPLC). The highest polyphenols content was obtained at 156 W using 80% of methanol during 5 min. For condensed tannins, the highest content of cyanidin was obtained at 182 W using 20% of methanol during 3.66 min. RSM applied in MAE, permitted to develop green extraction process of polyphenols and tannins extracted, using lower microwave power and methanol proportion with a shortest time extraction and in the same time improve the quantity of extractables obtained from renewable natural resource.     

Ternary (liquid + liquid) equilibria for mixtures of (methanol + aniline + n-octane or n-dodecane) at T = 298.15 K

(Liquid + liquid) equilibrium (LLE) data for the ternary mixtures of (methanol + aniline + n-octane) and (methanol + aniline + n-dodecane) at T = 298.15 K and ambient pressure are reported. The compositions of liquid phases at equilibrium were determined and the results were correlated with the UNIQUAC and NRTL activity coefficient models. The partition coefficients and the selectivity factor of methanol for the extraction of aniline from the (aniline + n-octane or n-dodecane) mixtures are calculated and compared. Based on these comparisons, the efficiency of methanol for the extraction of aniline from (aniline + n-dodecane) mixtures is higher than that for the extraction of aniline from (aniline + n-octane) mixtures. The phase diagrams for the ternary mixtures including both the experimental and correlated tie lines are presented. From the phase diagrams and the selectivity factors, it is concluded that methanol may be used as a suitable solvent in extraction of aniline from (aniline + n-octane or n-dodecane) mixtures.     

Physical properties of (jojoba oil + n-hexane) compared with other (vegetable oil + n-hexane) mixtures

Vapour pressures, densities, and viscosities of (jojoba oil + n-hexane) were measured and correlated over the temperature interval (298.15 to 318.15) K and used to calculate the activity coefficients of the components, excess thermodynamics functions, excess molar volumes, isobaric thermal expansibilities, excess viscosities, and the excess Gibbs free energies of activation for viscous flow. The reported results are compared with the corresponding values for commercial (oil + n-hexane) mixtures (cottonseed, soybean, sunflower, corn, olive, grape pip, Vaseline, and linalool oils) reported in the literature. As a by-product of this investigation, the vapour pressures of 1-methoxy-2-propanol from T = (298 to 392) K, 2-ethyl-6-methylaniline from T = (313 to 448) K, and N-methoxyisopropanol-6-ethyl-2-methylaniline from T = (407 to 535) K were measured using an ebulliometric method. A remarkable similarity between the excess properties for all oils is observed, but the behaviour of the excess thermodynamic functions in the case of (n-hexane + jojoba oil), especially in the n-hexane rich region, is quite different.     

Phosphoric-based ionic liquids as solvents to separate the azeotropic mixture of ethanol and hexane

Ethanol and hexane mixtures are present in industrial processes producing oxygenated additives for unleaded gasoline. The separation of ethanol and hexane is important but challenging due to the formation of an azeotropic mixture. This research focuses on the study of phosphoric-based ionic liquids (ILs) as green solvents for the separation of ethanol from hexane in a liquid extraction process. The knowledge of the (liquid + liquid) equilibrium (LLE) of this mixture is essential for the design of the extraction separation technique. Hence, the experimental determination of the LLE data for the ternary system {ethanol + hexane + 1,3-dimethylimidazolium dimethylphosphate ([MMIM][DMP])}, {ethanol + hexane + 1-ethyl-3-methylimidazolium diethylphosphate ([EMIM][DEP])} and {ethanol + hexane + 1-butyl-3-methylimidazolium dibutylphosphate ([BMIM][DBP])} at T = 303.2 K and atmospheric pressure was carried out. The reliability of the experimental LLE data was confirmed by applying the Othmer–Tobias and Hand equations, and the NRTL model was used to correlate the experimental results for the studied ternary system. The solute distribution ratio and selectivity, derived from the experimental LLE data, were calculated and analyzed evaluate the capacity of the investigated ILs as solvents in liquid extraction process. This capacity was also compared with that of other ILs. The experimental results show that the studied ILs can be suitable solvents in a (liquid + liquid) extraction for the separation of azeotropic mixtures of ethanol and hexane.     

(Liquid + liquid) equilibria of the (water + propionic acid + Aliquat 336 + organic solvents) at T = 298.15 K

In this work, trioctyl methyl ammonium chloride (Aliquat 336) was studied for its ability to extract propionic acid at various amine concentrations. The extraction of propionic acid with Aliquat 336 dissolved in five single solvents (cyclohexane, hexane, toluene, methyl isobutyl ketone, and ethyl acetate ) and binary solvents (hexane + MIBK, hexane + toluene, and MIBK + toluene) was investigated under various experimental conditions. The loading factors Z, extraction efficiency E and overall particular distribution coefficients were determined. All measurements were carried out at T = 298.15 K. The obtained results and the observed phenomena were discussed by taking into consideration the mechanism of extraction and the concentration of the interaction product in the aqueous phase.     

Response of oriental fruit moth,Grapholita molesta (Busck) (Lepidoptera: Tortricidae), eggs to gamma radiation

As insects increase in radiotolerance as they develop and usually several developmental stages of the pest may be present in the fresh shipped commodity, it is important to know the radiation susceptibility of the stages of the target insect before the establishment of ionizing radiation quarantine treatments. This study was performed to determine the radiotolerance of eggs of the oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), to gamma radiation. This species is considered as one of the most serious worldwide pests for temperate fruits, especially peaches. Eggs (12 h old) were exposed to 0 (control), 25, 35, 50, 75, 100, 125 and 150 Gy of gamma radiation. Surviving larvae were allowed to feed on an artificial diet. Three days after irradiation, it was verified that larvae’s cephalic capsules were significantly affected by gamma radiation, and the estimated mean LD₉₀ and LD₉₉ were 66.3 Gy and 125.8 Gy, respectively. Oriental fruit moth eggs revealed to be quite radiosensitive and very low doses as 50 Gy were sufficient to disrupt G. molesta embryogenesis. At 25 Gy, only male adults originated from the surviving larvae and, after mating with untreated fertile females, shown to be sterile.     

A multiresidue method for the determination 234 pesticides in Korean herbs using gas chromatography mass spectrometry

A rapid, specific and sensitive multiresidue method based on dispersive solid phase extraction sample preparation and gas chromatography with the mass spectrometric detection for the analysis of 234 pesticides in Korean herbs (Acanthopanax senticosus, Morus alba L., Hovenia dulcis) has been developed. Method recoveries were found to be between 62 and 119% with relative standard deviation lower than 21% for all compounds in the concentration range of 0.05 to 0.400 mg kg^? 1. Limits of quantification of most compounds are below 0.050 mg kg^? 1. The data demonstrate that this method was successfully used for analysis of 234 pesticides in Korean herbs.     

Solvent extraction of thiophene from n-alkanes (C7, C12, and C16) using the ionic liquid [C8mim][BF4]

In the last years, new strict environmental regulations to reduce sulfur content in liquid fuels have been established. Thiophene derivates can be considered as the key substances to be separated from liquid fuel oils. This paper reports the ability of the ionic liquid 1-methyl-3-octylimidazolium tetrafluoroborate to act as solvent in the (liquid + liquid) extraction of thiophene from aliphatic hydrocarbons. Tie-line data have been determined for ternary systems containing the ionic liquid, thiophene, and some n-alkanes at T = 298.15 K. Extraction process has been analyzed by means of thiophene distribution ratio and selectivity. The solute distribution coefficient decreases and the selectivity increases as the chain length of n-alkane increases. The use of 1-methyl-3-octylimidazolium tetrafluoroborate as potential solvent for separation of thiophene from n-alkanes is feasible using the necessary quantity of solvent. A correlation of the equilibrium data reported here has also been made, using the NRTL activity coefficient model, in order to facilitate their use in simulation and design processes.     

GC and GC/MS analyses of the Algerian Lantana camara leaf essential oil: Effect against Sitophilus granarius adults

The bioactivity of the essential oil extracted by hydrodistillation from Lantana camara leaves was assessed under laboratory conditions. The composition of L. camara essential oil included large amounts of sesquiterpene, mainly β-caryophyllene (35.70%) and caryophyllene oxide (10.04%). The tested essential oil showed good fumigant activity within 1 week of exposure for all tested doses. Moreover, remanence study confirmed that the oil was efficient during 2 weeks.     

Fractionation of lemon essential oil by solvent extraction: Phase equilibrium for model systems at T = 298.2 K

The fractioning of lemon essential oil can be performed by liquid–liquid extraction using hydrous ethanol as a solvent. A quaternary mixture composed of limonene, γ-terpinene, β-pinene, and citral was used to simulate lemon essential oil. In this paper, we present (liquid + liquid) equilibrium data that were experimentally determined for systems containing essential oil compounds, ethanol, and water at T = 298.2 K.The experimental data were correlated using the NRTL and UNIQUAC models, and the mean deviations between calculated and experimental data were less than 0.0053 in all systems, indicating the accuracy of these molecular models in describing our systems.The results show that as the water content in the solvent phase increased, the values of the distribution coefficients decreased, regardless of the type of compound studied. However, the oxygenated compound always showed the highest distribution coefficient among the components of the essential oil, thus making deterpenation of the lemon essential oil a feasible process.     

Microwave-assisted purge-and-trap extraction device coupled with gas chromatography and mass spectrometry for the determination of five predominant odors in sediment,fish tissues,and algal cells

Off-flavors are among the most troublesome compounds in the environment worldwide. The lack of a viable theory for studying the sources, distribution, and effect of odors has necessitated the accurate measurement of odors from environmental compartments. A rapid and flexible microwave-assisted purge-and-trap extraction device for simultaneously determining five predominant odors, namely, dimethyltrisulfide, 2-methylisoborneol, geosmin, β-cyclocitral and β-ionone, from the primary sources and sinks is demonstrated. This instrument facilitates the extraction and concentration of odors from quite different matrices simultaneously. This device is a solvent-free automated system that does not require cleaning and is timesaving. The calibration curves of the five odor compounds showed good linearity in the range of 1–500 ng/L, with correlation coefficients above 0.999 (levels = 7) and with residuals ranging from approximately 77% to 104%. The limits of detection (S/N = 3) were below 0.15 ng/L in algae sample and 0.07 ng/g in sediment and fish tissue samples. The relative standard deviations were between 2.65% and 7.29% (n = 6). Thus the proposed design is ready for rapid translation into a standard analytical tool and is useful for multiple applications in the analysis of off-flavors.     

Effects of gamma irradiation on the grape vine moth,Lobesia botrana,eggs

Eggs of the grape vine moth, Lobesia botrana (Denis and Schiffermuller), ranging in age from 1–24 to 73–96 h, were exposed, at 24 h intervals, to gamma radiation ranging from 25–600 Gy. The effects of gamma radiation on egg hatch, pupation, adult emergence, sex ratio and rate of development were examined. Results showed that the radiosensitivity of the grape vine moth eggs decreased with increasing age and increased with increasing radiation dose. Egg hatch in 1–24 h old eggs was significantly affected at 25 Gy and completely prevented at 100 Gy. At the age of 25–48 h, radiation sensitivity was only a little lower; egg hatch at 100 Gy was <1% and at 125 Gy no egg hatch was observed. Egg sensitivity to gamma irradiation decreased significantly in the 49–72 h age group; egg hatch was 66% at 100 Gy, and 500 Gy did not completely stop egg hatch (<1%). Eggs irradiated a few hours before egg hatch (73–96 h old) were the most resistant; 150 Gy had no significant effect on egg hatch and at 600 Gy over 33% of the eggs hatched. When pupation or adult emergence was used as a criterion for measuring effectiveness, however, the effects of gamma radiation were very severe. In the most resistant age group (73–96 h old), 150 Gy completely prevented pupation and adult emergence and all larvae resulting from eggs irradiated <49 h old died before pupation. In addition, the rate of development of immature stages resulting from irradiated eggs was negatively affected and sex ratio was skewed in favor of males.     

Analysis of hydrocarbon contamination with membrane-assisted solvent extraction: Comparison of agitation and sonication methods

Membrane-assisted solvent extraction (MASE) coupled to large volume injection was applied to the determination of (gasoline-type) hydrocarbon contamination in water samples. Hexane was used as acceptor phase. 50 μL extract was injected in the programmed temperature vaporizer injector using combined split–splitless evaporation. The extraction conditions were optimized both for MASE with agitation and for MASE with sonication. In the course of optimization the effect of extraction time, extraction temperature, agitation speed, solvent volume, pH, ionic strength and the addition of methanol were tested. Over 75% recovery was accomplished in the range of diesel oil hydrocarbons (n-C₉–n-C₂₄). The developed method was validated. Linearity, accuracy and precision were tested. The method showed excellent linearity between 1 and 1000 μg L^?1 for n-alkanes and between 0.05 and 50 mg L^?1 for gasoline. The method was tested with comprehensive GC × GC as well and found to be non-discriminative to all major compounds of diesel oil.