GC-MS analysis of volatile compounds of Perilla frutescens Britton var. Japonica accessions: morphological and seasonal variability

Objective: To investigate the composition of volatile compounds in the different accessions of Perilla frutescens(P. frutescens) collected from various habitats of China and Japan. Methods: In the present study, the essential oil from the leaves of P. frutescens cultivars from China and Japan was extracted by hydro-distillation and the chemical composition and concentration of the volatile components present in the oils were determined by gas chromatography–mass spectrometry(GC–MS) analysis. Results: Among the volatile components, the major proportion was of perilla ketone, which was followed by elemicin and beta-caryophyllene in the Chinese Perilla cultivars. The main component in the oil extracted from the Japanese accessions was myristicin, which was followed by perilla ketone and beta-caryophyllene. We could distinguish seven chemotypes, namely the perilla ketone(PK) type, perilla ketone, myristicin(PM) type, perilla ketone, unknown(PU) type, perilla ketone, beta-caryophyllene, myristicine(PB) type, perilla ketone, myristicin, unknown(PMU) type, perilla ketone, elemicine, myristicin, beta-caryophyllene(PEMB) type, and the perilla ketone, limonene, betacryophyllene, myristicin(L) type. Most of the accessions possessed higher essential oil content before the flowering time than at the flowering stage. The average plant height, leaf length, leaf width of the Chinese accessions was higher than those of the Japanese accessions. Conclusion:The results revealed that the harvest time and geographical origin caused polymorphisms in the essential oil composition and morphological traits in the Perilla accessions originating from China and Japan. Therefore, these chemotypes with desirable characters might be useful for industrial exploitation and for determining the harvest time.

GC/MS Analysis of Organic Compounds in Hot Water-Extractable Fraction from Shenfu Coal

Shenfu Coal was extracted with hot pure water and slurry was isolated. The concentrated benzene-soluble fraction (CBSF) was analyzed with GC/MS and four types of organic compounds (OCs) were detected: HACOCs,DTEs,DMDT and LCAs. The amount of benzyl benzoate which is the most abundant OC was calculated by an inter-nal standard method with an indicated amount of BP. The broken hydrogen bonds and ether bonds were responsible for the extraction of OCs from the coal .DTEs,DMDT and LCAs are essentially insoluble in water,whereas they are soluble,probably owing to intermolecular interaction of OCs with HACOCs.

Component analysis of volatile oil from Illicium Verum Hook. f.

Volatile oil was extracted from Illicium Verum Hook. f. by using steam distillation. 41 kinds of compounds were separated and identified by GC/MS, and their relative contents were determined by normalization method. Among 41 identified compounds, there are 14 hydrocarbon components and 22 oxygenated hydrocarbon derivatives, and a small amount of nitrogenous compounds. The main component is anethole, accoun ting for 76.23%, and the other components such as anisyl acetone, anisaldehyde, p allylanisole, p cumic aldehyde and p allylpen take up more than 10%.

GC–MS analysis of bioactive compounds present in different extracts of an endemic plant Broussonetia luzonica (Blanco) (Moraceae) leaves

Objective: To investigate and characterize the chemical composition of the different crude extracts from the leaves of Broussonetia luzonica(Blanco)(Moraceae)(B. luzonica), an endemic plant in the Philippines.Methods: The air dried leaves were powdered and subjected to selective sequential extraction using solvents of increasing polarity through percolation, namely, n-hexane,ethyl acetate and methanol to obtain three different extracts. Then, each of the extracts was further subjected to gas chromatography–mass spectrometry.Results: Qualitative determination of the different biologically active compounds from crude extracts of B. luzonica using gas chromatography–mass spectrometry revealed different types of high and low molecular weight chemical entities with varying quantities present in each of the extracts. These chemical compounds are considered biologically and pharmacologically important. Furthermore, the three different extracts possess unique physicochemical characteristics which may be attributed to the compounds naturally present in significant quantities in the leaves of B. luzonica.Conclusions: The three extracts possess major bioactive compounds that were identified and characterized spectroscopically. Thus, identification of different biologically active compounds in the extracts of B. luzonica leaves warrants further biological and pharmacological studies.

LOCATION OF DOUBLE BOND POSITION OF INSECT SEX PHEROMONE BY GC/MS ANALYSIS WITH CHEMICAL IONIZATION

Ozonolysis products of four lepidopteral pheromone were identified by methane CI-MS.The spectra obtained were notably simpler than those of EI-MS,the peak of molecular ion was normally close to the base peak,and the characteristic fragment ions were high in m/z,thereby the interpretation was facilitated.

Antibacterial, Antioxidant Activities and GC-MS Analysis of Dichrostachys cinera (L.) Ethanolic Leaves Extract

Traditional medicinal plants are one of the potential sources of antimicrobial drugs and there is a great concern in the use and development of herbal medicine for the treatment of various infections. This study aimed to evaluate the antibacterial, and antioxidant activities of Dichrostachys cinera ethanolic leaves extract and to determine the components of the crude extract. D. cinera extract was evaluated against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 27853. The antibacterial, antioxidant activities and active constituents were determined using standard methods. Antibacterial activity of the crude extract findings showed that all bacterial candidates were susceptible where S. aureus represent MIC at 12.5 mg/ml and MBC at 25 mg/ml, E. coli and P. aeruginosa both showed MIC 25 mg/ml and MBC 50 mg/ml. In the free radical scavenging assay of the extract and the standard quercetin at concentrations of 250 μg/ml, 125 μg/ml, 50 μg/ml, 10 μg/ml, and 5 μg/ml. The radical scavenging activity for the extract was about 92%, 89.6%, 86.8%, 82.8% and 37.8% respectively, compared to quercetin which gave 89.7%, 85.8%, 62.1%, 55.5%, and 45% radical scavenging activity. The GC-Ms analysis of the total constituents demonstrated that 1,6-Anhydro-2,4-dideoxy-.beta.-D-ribo-hexo (21.26%) with different peaks, followed by Glycerin (11.56%), 1,2,3-Cyclopentanetriol (10.18%), 8,11,14-Eicosatrienoic acid, (Z,Z,Z)-(6.18%), 1H-Pyrrole, 1-methyl-(6.08%), Phytol (5.91%) and 7-Bromo-6-(2-diethylaminoethoxy)-2,3-dihyd (5.44%) as major components in the extract. Finally, this study provided useful information on the therapeutic potential of D. cinera as an antibacterial agent and recommended to be evaluated against a wide range of Bacterial and fungal strains using different solvents and different parts from the plant.

Natural isothiocyanates of the genus Capparis as potential agonists of apoptosis and antitumor agents:Mechanisms and implications

In this editorial,we comment on a recent publication,which highlights the important findings from the study,including the antitumor and anti-inflammatory effects of isothiocyanates,their underlying mechanisms,and implications.Additionally,a related perspective is discussed.

Thermal oxidation of two aviation synthetic lubricant base oils

The thermal degradation of two synthetic lubricants base oils, poly-a-olefins （PAO） and di-esters （DE）, was investigated under oxidative pyrolysis condition and their properties were characterized in simulated ＂areo-engine＂ by comparing the thermal stability and identifying the products of thermal decomposition as a function of exposure temperature. The characterization of the products were performed by means of Fourier transform infrared spectrometry （FTIR）, gas chromatography/mass spectrometry （GC/MS） and viscosity experiments. The results show that PAO has the lower thermal stability, being degraded at 200℃ different from 300 ℃ for DE. Several by-products are identified during the thermal degradation of two lubricant base oils. The majority of PAO products consist of alkenes and olefins, while more oxygen-contained organic compounds are detected in DE samples based on GC/MS analysis. The related reaction mechanisms are discussed based on the experimental results.

固相微萃取-气相色谱-质谱联用鉴别荚醚N,N,N',N'-四丁基-3-氧-戊二酰胺辐射产物

N,N,N′,N′-四丁基-3-氧-戊二酰胺(TBOPDA)是一种新合成的萃取剂,它可以在高酸度情况下萃取铀等锕系元素[1],在高废液的萃取处理中具有良好的应用前景.曾有报道采用GC方法分析辐照后的气相产物[2],本文采用固相微萃取技术萃取TBOPDA部分挥发性和半挥发性液相辐照产物,结合GC-MS进行鉴定,确定了其液相辐照产物主要为二丁胺、二正丁基甲酰胺、二正丁基乙酰胺.……

Microwave-assisted extraction of Shenfu coal and its macromolecule structure

Coals consist of some molecules trapped within an organic matrix from which some organic compounds can be extracted by solvents. The Soxhlet technique has been widely used for extracting organic compounds. Microwave heating methods may be successfully applied in the field of coal science. Acetone extraction yields and the chemical composition of the extract were investigated using a typical Chinese coal, Shenfu coal, with microwave-assisted extraction. The acetone extract and residue were analyzed by GC/MS and carbon-13 nuclear magnetic resonance spectroscopy respectively. The carbon spectra were converted into several numerical parameters, fa, Ha, Xb, which indicate the difference in macromolecular structure between Shenfu coal and its residue. Furthermore, a hybrid genetic algorithm was employed using these parameters to approximate a coal macromolecule by assembling the structural fragments or functional groups into a large and complicated structure.

Study on microwave-assisted extraction of coal

The effect of different factors on coal extraction yield-temperature, solvent, coal type and irradiation time were investigated for different China coals under microwave-assisted extraction（MAE）. The results show that the optimum temperature for ethanol, acetone and THF are 393,373 and 373 K respectively and the extraction yield of THF is higher than that of other two solvents under MAE. Extraction with several single organic solvents were conducted for the 5 typical China coals-Shenfu, Tongchuan, Panzhihua, Yitai and Huating coal under microwave-assisted extraction and Soxhlet extraction. Results indicat that extraction yield of ethylenediamine, ethanol, acetone, tetrahydrofuran under MAE are all higher than that of Soxhlet extraction and MAE required less time. Tongchuan coal extracts of ethanol and acetone which were extracted by MAE and Soxhlet extraction were analyzed by GC/MS.

Chemical composition of the essential oil from Rabdosia lophanthoides

Gas chromatography/mass spectrometry (GC MS) of the essential oil from the aerial parts of Rabdosia lophanthoides resulted in the identification of 108 compounds representing 78.120% of the oil. Hydro distillation of Rabdosia lophanthoides yielded a pale yellow oil. The compounds identified and their relative proportions are listed in Table 1 according to their order of elution on an HP 5MS capillary column. .

Effective and inexpensive gas chromatography method for detection of trace level SO_2 in H_2 fuel

Gas chromatography （GC） analysis of sulfer dioxide is challenging because SO2 is a highly mobile and chemically active molecule. For the conventional GC method with flame photometric detector （FPD） and direct-injection, it is often ineffective particularly when the SO2 level is as low as on the trace level. In this paper, a modified GC system integrated with an adsorption-desorption device was developed to detect the trace SO2 impurity in H2 fuel. Adsorbent GDX-502 is used in the adsorber to adsorb/collect SO2 from the sample gas and desorb/release it in a concentrated flow so that the conventional GC at downstream could detect it with an acceptable accuracy.

Rgwo performances of submerged membrane bioreactor treating brewery wastewater: A laboratory study

Performances of submerged membrane bioreactor （SMBR） treating brewery wastewater were investigated in this study. With little variation of COD：TN：TP ratio （100：5：1） in influent, SMBR showed high removal efficiency （ 〉 90% ） for both COD and NH4^＋ - N, and it also showed a strong resistive ability for shock organics loading rate, evidenced by no obvious fluctuation for COD in the effluent when the organics loading rate suddenly increased from 0. 27 g/（ gMLSS · d） to 0. 54 g/（ gMLSS · d）. Comparatively different with the COD removal, TN and TP removal showed a strong correlation with the growth stage of the sludge in SMBR. When the sludge was in the multiplication stage, about 45% of TN was removed and an average removal efficiency of 30% for TP was also observed. However, when the activated sludge was in the steady stage, the removal efficiency for TN decreased to about 30% , whereas, the removal efficiency for TP was very low, and sometimes even below zero. The results of GC/MS indicated that the residual organic matters in the effluent were mainly alkyl hydrocarbon with high molecular weight, and coupling with the results of electroseopic scanning, it is speculated that biomass formed at external and internal membrane fibers played an important role for the removal of small organics.

Study on the removal of toxic substance from river water using O_3-GAC process

This paper studied on the removal of toxic substance from river water using O3-GAC process. The result of GC/MS analysis indicated that the number of organic compound species was decreased by 55.1%. The species of toxic substance of raw water also decreased from 16 to 5. The total removal rate of CODMn andUV254 were 45%～72% and 60%～80% following O3-GAC treatment. It reflected that this process had a good effective on removing unsaturation organic which absorb UV and toxic organic containing nitrogen. The results of Ames test indicated that raw water had a relatively strong mutagicity on TA 98. The O3-GAC process had a good ability in removing mutagen in water. The effluent water’s mutagicity is minus. The results of the study indicated that the effluent of the O3-GAC process was meet the demand of drinking water.

Smashing Tissue Extraction and GC Analysis of Active Fatty Acids from Oil Cake of Perilla Seeds

Objective To optimize the extraction technology of perilla seeds oil from the oil cake of perilla seeds(OCPS)by using the contents of active fatty acids as evaluation standard.Methods The fatty acids were extracted from OCPS,the residue of perilla seeds after cold-press,by smashing tissue extraction(STE),the new technology selected through comparing with classical leaching extraction(LE),Soxhlet extraction(SE),ultrasonic extraction(UE),and supercritical-CO2 fluid extraction(SFE).For optimized condition of STE,orthogonal test was designed and completed.The contents of five fatty acids in extracted oil and OCPS were determined by GC.Results The optimized extraction parameters were smashing for 1.5 min under extraction power of 150 W and 1:6 of the material/solvent ratio.The contents of five fatty acids in the oils extracted by five techniques from OCPS and determined by GC were as follows:α-linolenic acid(41.12%-51.81%),linoleic acid(15.38%-16.43%),oleic acid (18.93%-27.28%),stearic acid(2.56%-4.01%),and palmitic acid(7.38%-10.77%).Conclusion The results show that STE is the most efficient technology with the highest yield(LE:0.57%;SE:1.03%;UE:0.61%;SFE:0.80%;STE: 1.17%)and shortest time(LE:720 min;SE:360 min;UE:30 min;SFE:120 min;STE:1.5 min)among five tested extraction technologies.It is first reported using STE to extract herbal oil enriched with active fatty acids.

Determination of particulate polycyclic aromatic hydrocarbons in ambient air by gas chromatography-mass spectrometry after molecularly imprinted polymer extraction

A solid phase extraction procedure(SPE)is described for the quantitative analysis of polycyclic aromatic hydrocarbons(PAHs)in atmospheric particulate matter(PM),as ubiquitous environmental pollutants routinely measured in air qualitymonitoring.A SPE cartridge was used based on a molecular imprinted polymer(MIP-SPE)properly tailored for selective retention of PAHs with 4 and more benzene fused rings.The performance of the clean-up procedure was evaluated with the specific concern of selective purification towards saturated hydrocarbons,which are the PM components mostly interfering GC analysis of target PAHs.Under optimized operative conditions,the MIP-SPE provided analyte recovery close to 95%for heavier PAHs,from benzo(α)pyrene to benzo(ghi)perylene,and close to 90%for four benzene rings PAHs,with good reproducibility(RSDs:2.5%-5.9%).Otherwise,C_(17)-C_(32) n-alkanes were nearly completely removed.The proposed method was critically compared with Solid Phase Micro Extraction(SPME)using a polyacrylate fiber.Both methods were successfully applied to the analysis of ambient PM2.5 samples collected at an urban polluted site.Between the two procedures,the MIP-SPE provided the highest recovery(R%≥93%)for PAHs with 5 and more benzene rings,but lower for lighter PAHs.In contrast,SPME showed a mean acceptable R%value(∼80%)for all the investigated PAHs,except for the heaviest PAHs in the most polluted samples(R%:110%-138%),suggesting an incomplete purification from the interfering n-hydrocarbons.

Insights for integrative medicinal potentials of Ethiopian Kale(Brassica carinata): Investigation of antibacterial, antioxidant potential and phytocompounds composition of its leaves

Objective:To compare the phytochemical and antimicrobial activity of Ethiopian Kale leaves infusions,investigate the antioxidant activity and profile the major phytochemicals existing in the better solvent system.Methods:Ethiopian Kale leaves were collected from Addis Ababa,Ethiopia,and extracted using different solvents.The qualitative phytochemical analysis,antibacterial assays,and Fourier Transform Infrared(FTIR) analysis are executed for all extracts.Antioxidant assay and Gas Chromatography-Mass Spectrometry(GC-MS) analysis are carried out for the solvent system,which showed better activity in preliminary studies.Results:The qualitative phytochemical analysis exposed the presence of different classes of phytoconstituents in most of the tested extracts.The broad spectrum of antibacterial activity(7-15 mm) was noted against the tested bacterial species.The functional groups of the extracts are reported by FTIR analysis.The antioxidant ability of ethanol extract was found to be(62.92±0.34)% for 2,2-diphenyl-1-picrylhydrazyl(DPPH*) assay and(71.12±0.41)% for 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS) assay.More than 17 major phytocompounds in ethanol extract were profiled by GC-MS analysis.Conclusion:The ethanol extract of Ethiopian Kale leaves contain a good source of phytochemicals and it can be a significant source for various functional applications.

Biopolymer-based powders with encapsulated thyme oil: Characterization and comparison with free oil regarding thermal stability and antimicrobial activity

The prevention of food contamination by pathogenic microorganisms is a very important factor for food safety and security during storage time. The essential oils have the potential to be used as antimicrobial agents, but their full potential is limited due to the sensitivity and volatility of bioactive compounds. This study aimed to characterize Thymus vulgaris essential oil, free and nano-encapsulated in alginate-whey protein concentrate carriers using the freeze-drying technique. GC/MS analysis was done to identify the oil composition. The investigation of the antimicrobial effect of free and encapsulated oil was performed on Escherichia coli, Staphylococcus aureus, and Candida albicans, by microdilution method. The free thyme oil exhibited antimicrobial activity against all tested microorganisms in the range of 0.71–1.43 mg/ml. Interestingly, encapsulated oil was more effective at lower concentrations (0.625–1.25 mg/ml), as a consequence of a nano-size carrier (0.25 ± 0.5 μm) together with other properties (encapsulation efficiency of 86.04%). TGA pointed out a significant effect of encapsulation, in comparison to free oil, on the stability of thyme oil at temperatures from 25 to 500 °C. The results indicated a high potential of thyme oil powder carriers as natural antimicrobial additives in food products.