Gas Chromatography-mass Spectometry Research Articles

Phyto-constituents of the Dichloromethane Extracts of the Bulbs of Selected Genera in the Family Amaryllidaceae

The analysis of phytoconstituents present in the dichloromethane extract of the bulb of Hippeastrum vittatum (L’Her.) Herb., Proiphys amboinensis (L.) Herb., Urceolina amazonica (Linden) Christenh. & Byng., Hymenocallis littoralis (Jacq.) Salisb., Crinum jagus (J. Thomps.) Dandy and Zephyranthes carinata Herb. by Gas Chromatography-Mass Spectometry (GC-MS) analysis was carried out using standard methods. The Results of the GC-MS analysis of Hippeastrum vittatum, Proiphys amboinensis, Urceolina amazonica, Hymenocallis littoralis, Crinum jagus and Zephyranthes carinata revealed the presence of 50, 66, 61, 57, 56 and 61 peaks indicating the presence of the number of phytochemical constituents respectively. Phytol was present in Hymennocallis littoralis (0.41%) and Urceolina amazonica (0.79%) only. N-hexadecanoic acid, Di mevalonic acid lactone, Hexadecanoic acid methyl ester and Stigmasterol were present in all. Apiol and Xanthoxylin were absent in H. littoralis and P. amboniensis respectively. Oleic acid was present in Z. carinata (2.01%), P. amboniensis (1.85%) and U. amazonica (2.03%). Sakuranin was found in H. littoralis (3.42%), C. jagus (1.38%) and U. amazonica (4.43%). Linoleic acid ethyl ester was present in P. amboniensis (1.49%), U. amazonica (0.16%), H. littoralis (11.91%) and Z. carinata (0. 8 8%). The major components that delimited the species were as follows; In Hymenocallis littoralis was Liriodendromin (14.03%), Linoleic acid ethyl ester (11.91%) and Ethyl oleate (9.38%); in Zephranthes carinata; Phthalic acid, 4-methoxybenzyl methyl ester (15.34%) Gatanthamine, 3-O-acetyl-1, 2, dihydro (8.87%) Stigmasterol (5.87%); in Hippeastrum vittatum; N-benzyl-2-[1-(4-methoxyl-phenyl 1) – 1 H-tetrazo (14.94%), Benzaminde, 2-amino-N-(4-ethoxyphenyl) (12.65%) and 1-(5-methyl-2-hydroxyphenyl)-3-phenyl propane (10.49%); in Crinum jagus; 2H-1-Benzopyran-7-ol, 3,4-dihydro-3-(2-hyrdo) (19.87%), Benzamide, 2-amino-N- (4-ethoxyphenyl) (9.92%) and Stigmasterol (4.04%); in Proiphys amboniensis; Gamma-sitosterol (16.98%), Stigmasterol (11.49%) and N-Hexadecanoic acid(5.05%); in U. amazonica; 3-Furanacetic acid, 4-hexyl-2, 5-dihydro-2, 5 (12.73%), Benzamide, 2-amino-N- (4-ethoxyphenyl) (8.18%) and Phenyl, 2-(3,4-dihydro 2-methoxyl-2H-1-benzopy) (6.40%). The presence of various bioactive compounds may be responsible for the application of these species in the treatment and management of various ailments in folklore medicine. However, in vitro and in vivo studies, isolation of individual phytoconstituents and their mechanism of action may proceed to find a novel drug or lead compound for use as medicine.

The aroma profile of butter produced using different starter cultures

The aroma of fermented dairy products is greatly influenced by starter cultures and by the lactic acid bacteria strains that are used as starter cultures. Experimental butter samples were produced using no starter culture, by a commercial starter culture (Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. cremoris, Lactococcus lactis subsp. lactis biovar. diacetylactis, Leuconostoc mesenteroides), by a prepared bacteria mix (Lactococcus lactis subsp. lactis EM1, Lactococcus lactis subsp. cremoris EM28, Lactococcus lactis subsp. lactis biovar. diacetylactis G49, Leuconostoc mesenteroides B3), and by a prepared bacteria mix fortified with Lactobacillus rhamnosus B19 (L. rhamnosus B19). The aroma profile of the butter samples was investigated using a gas chromatography mass spectometry method (GC-MS). A total of 92 components were determined in the butter samples, including acids (12), alcohols (20), aldehydes (9), alkanes (6), esters (8), ketones (19) and several other aroma compounds (18). The sample containing the prepared starter culture had the most detectable aroma components, while the lowest number of aromatic components were found in the sample without a starter culture. 2,3-butanedione (diacetyl) was not detected in the sample without a starter culture. 2-Butanone 3-hydroxy- (acetoin) content was the highest in the sample containing the commercial starter culture and the lowest in the sample without a starter culture.

Extraction and evaluation of α-glucosidase inhibitory activity of polysaccharide from Urena lobata L. roots

Polysaccharides are compounds found in the roots of Urena lobata L. Polysaccharides are of interest due to many valuable biological activities such as immunomodulatory, anti-cancer, diabetes treatment, anti-inflammatory and antioxidant. In this research, polysaccharides extracted from Urena lobata L. roots were analyzed by GC-MS (Gas Chromatography Mass Spectometry) and GPC (Gel Permeation Chromatography). The results show that the polysaccharide from Urena lobata L. natural roots is a heteropolysaccharide. This polysaccharide has two peaks with the weighted average molecular weights (Mw) as 1.823 x 107 g/mol and 1.139 x 105 g/mol. The monosaccharide composition of this polysaccharide includes rhamnose, arabinose, xyloza, mannose, glucose and galactose with the composition ratios of 13.927, 16.579, 3.174, 5.442, 27.659 and 33.219% respectively. In addition, when investigating the α-glucosidase inhibitory activity of polysaccharide from three types of Urena lobata L. roots cultured under different conditions: natural, in vitro and aeroponics, the results showed that the activity of in vitro hairy root polysaccharide was the best. This shows the potential for the development of biologically active polysaccharide sources by in vitro hairy root culture of Urena lobata L.

Combined bioreduction and volatilization of SeVI by Stenotrophomonas bentonitica: Formation of trigonal selenium nanorods and methylated species

Nowadays, metal pollution due to the huge release of toxic elements to the environment has become one of the world's biggest problems. Bioremediation is a promising tool for reducing the mobility and toxicity of these contaminants (e.g. selenium), being an efficient, environmentally friendly, and inexpensive strategy. The present study describes the capacity of Stenotrophomonas bentonitica to biotransform SeVI through enzymatic reduction and volatilization processes. HAADF-STEM analysis showed the bacterium to effectively reduce SeVI (200 mM) into intra- and extracellular crystalline Se0 nanorods, made mainly of two different Se allotropes: monoclinic (m-Se) and trigonal (t-Se). XAS analysis appears to indicate a Se crystallization process based on the biotransformation of amorphous Se0 into stable t-Se nanorods. In addition, results from headspace analysis by gas chromatography-mass spectometry (GC–MS) revealed the formation of methylated volatile Se species such as DMSe (dimethyl selenide), DMDSe (dimethyl diselenide), and DMSeS (dimethyl selenenyl sulphide). The biotransformation pathways and tolerance are remarkably different from those reported with this bacterium in the presence of SeIV. The formation of crystalline Se0 nanorods could have positive environmental implications (e.g. bioremediation) through the production of Se of lower toxicity and higher settleability with potential industrial applications.

A Comparative Study of Healthy and American Foulbrood-Infected Bee Brood (Apis mellifera L.) through the Investigation of Volatile Compounds

American Foulbrood (AFB) is a major endemic disease affecting the bee brood and the absence of chemical therapeutic treatments leads beekeepers to develop alternative management plans, based mainly on the prevention and accurate diagnosis of symptoms. One of the main symptoms of the disease is the unpleasant odor caused by the rot of dead larvae. In the present comparative study, we analyzed the odor profile of bee larvae and the presence of characteristic volatile compounds (Gas Chromatography-Mass Spectometry), in an effort to discriminate healthy and AFB-infected brood. A greater number of volatile compounds was identified in the affected brood than the healthy. The presence of (Ε)-β-ocimene was prominent in healthy brood samples in percentages from 85.25 to 99.14%, a compound also detected in all samples of infected brood but in lower percentages (37%). The compounds toluene, xylene, 1,3-dimethylbenzene, 2-nonanone, dimethyl disulfide, and dimethyl trisulfide were detected in 100% of the diseased brood samples, with the latter three being absent from the healthy brood, while 2-undecanone was found in some samples of diseased brood (40.0%). Further investigation of volatile markers may contribute significantly to the successful diagnosis of the disease, aiming at its rapid treatment.

Acute toxicity of bioplastic leachates to Paracentrotus lividus sea urchin larvae

In an attempt to ensure that bioplastics, progressively replacing petrochemical-derived plastics, do not release any harmful compound to the environment, the study assessed the toxic effects of three innovative bioplastic products: polyhydroxybutyrate resin (PHB), polylactic acid cups (PLA) and a polylactic acid/polyhydroxyalkanoate 3D printing filament (PLA/PHA), together with a synthetic polyvinyl chloride (PVC) toy in Paracentrotus lividus sea urchin larvae. PVC toy was the most toxic material, likely due to the added plasticizers; remarkably, even if PHB is conceived as a nontoxic polymer, it showed a slight toxicity and Gas Chromatography-Mass Spectometry analysis (GC-MS) revealed the presence of a wide range of additives. Conversely, PLA cups and PLA/PHA filament were innocuous for the larvae, a positive outcome for these renewable solutions. Proven that additives are also used in some bioplastic formulations, they should be carefully addressed to ensure that they are as safe as regarded.

A push-pull strategy for controlling the tea green leafhopper (Empoasca flavescens F.) using semiochemicals from Tagetes erecta and Flemingia macrophylla.

The tea green leafhopper, Empoasca flavescens is the most important pest in Chinese tea plantations. For decades its control has been executed almost exclusively through pesticide applications. A semiochemical-based 'push-pull' strategy was tested on the leafhopper in the study. The odors released from Tagetes erecta and Flemingia macrophylla significantly repelled and attracted leafhoppers, respectively. These volatile compounds (46 from T.erecta and 53 F.macrophylla) were identified and quantified via gas chromatography-mass spectometry (GC-MS) analysis. Y-tube olfactometer assays indicated that thymol anisole, thymol and camphor had significant repellent effects on the leafhoppers, resulting in a ternary repellent blend at a 4:3:13 ratio. Cis-3-hexen-1-ol, cis-3-hexenyl acetate, nonanal and α-farnesene were significantly attractive to the leafhoppers, making an attractant blend at a 17:4:1:1 ratio. In the field, the push-pull strategy with the repellent dispensers placed within the tea bushes and the attractant-baited sticky traps hung 15 cm above the tea plants showed a significant control efficacy, reaching 69% and 55% at two and 14 days post-treatment, respectively, similar to those in the insecticide control plots. Additionally, the leafhopper density in the push-pull intercropping plot was 63.2 leafhoppers/100 tea shoots/visit, much lower than those in the pull intercropping plot and nonintercropping plot. Application of the push-pull strategy using both synthetic repellent and attractant, or intercropping T.erecta and F.macrophylla with tea plants, can effectively reduce the leafhopper population. This approach might have great potential as an environmentally safe control strategy against the leafhopper. © 2022 Society of Chemical Industry.

Heavy Oil Seapage Characteristic in Cipari Area, Banyumas Central Java

Oil seepage in Cipari, Banyumas, Central Java, has long been known. Although, Its occurrence had been reported in several publications, it's properties and characteristic, have not been explained in detail. Therefore, through field geology observation and laboratory analysis, this paper attempts to describe the oil seep characteristic, possible source rock origin, and its relationship with geological features in the surrounding area. Picnometer analysis resulted that this oil seep can be classified as heavy oil with 12n API Gravity. Gas Chromatography (GC) Gas Chromatography Mass Spectometry (GCMS) analysis revealed that Cipari oil seep is heavily biodegraded. Possible source rock of the oil seep was interpreted based on bicadinane and oleanane biomarkers, which indicated that source was deposited in fluvio-deltaic/transitional environment. Based on regional geology reference of Banyumas sub-Basin, it is inferred that the source rocks possibly shale or claystone of Paleogene sediment which was thermally mature, and deposited in transition to marine environment. Deep seated fault that extent from Majenang to Karangbolong areas is probably the main migration pathway of the oil seepage from the kitchen or deep reservoir to the surface. The Cipari anticline outcrop, which associated with faults and fractures, become the place where the oil seep occurs in the surface. Heavy biodegradation of the oil seep may possibly be accelerated by hydrothermal system during migration from the reservoir/kitchen area to the surface.

The Hepatoprotective Activity of the Methanol Leaf Extract of Lasimorpha Senegalensis against Liver Injury Induced by Paracetamol (Acetaminophen) in Albino Wistar Rats

The leaf extract of Lasimorpha senegalensis is used in Nigerian traditional medicine for the treatment of liver disease. The aim of this investigation was to evaluate the hepatoprotective ability of Lasimorpha senegalensis methanol leaf extracts on paracetamol-induced toxicity in order to validate or invalidate its traditional use in the treatment of liver disease. Gas Chromatography-Mass Spectometry analysis of the extract revealed the presence of Cycloheptasiloxane tetradecamethyl- and 3, 4-Dihydroxyphenylglycol, a strong antioxidant capable of protecting the cell membrane from assaults. Thirty Wistar rats of mixed sexes were randomly assigned to six groups of five rats each. Group 1, which was the normal control received only normal saline. Groups 2-4 were pre-treated with the extract at various doses, twice daily for 4 days. Silymarin, a known hepatoprotective drug was administered in the same manner to group 5 at 100 mg/kg body weight for 4 days. One hour after the last pre-treatment on the fourth day, groups 2-6 received 2500 mg/kg of paracetamol (PCM) orally in order to induce hepatotoxicity. Eighteen hours after PCM intoxication, blood samples were collected for haematology and biochemical analyses. All the animals were sacrificed and the liver cells were harvested for histopathological examinations. The liver function markers (ALT, AST, ALP), total and direct bilirubin were estimated. This present study has shown that the extract under investigation exhibits hepatoprotective activities since they reduce cell membrane disturbances induced by PCM in the isolated liver cells of the rats. These activities were comparable with that of silymarin, a reference hepatoprotective drug.

A Preliminary Study of Chemical Profiles of Honey, Cerumen, and Propolis of the African Stingless Bee Meliponula ferruginea.

Recently, the honey and propolis of stingless bees have been attracting growing attention because of their health-promoting properties. However, studies on these products of African Meliponini are still very scarce. In this preliminary study, we analyzed the chemical composition of honey, two cerumen, and two resin deposits (propolis) samples of Meliponula ferruginea from Tanzania. The honey of M. ferruginea was profiled by NMR and indicated different long-term stability from Apis mellifera European (Bulgarian) honey. It differed significantly in sugar and organic acids content and had a very high amount of the disaccharide trehalulose, known for its bioactivities. We suggested trehalulose to be a potential marker for African stingless bee honey analogously to the recent proposal for Meliponini honey from Asia, South America, and Australia and demonstrated its easy discrimination by 13C NMR. Propolis and cerumen were studied by GC-MS (gas chromatography-mass spectometry). The samples contained mainly terpenoids (di-and triterpenes) but demonstrated qualitative and quantitative differences. This fact was an indication that possibly M. ferruginea has no strict preferences for resins used to construct and protect their nests. The antimicrobial and anti-quorum sensing properties of the two materials were also tested. These first results demonstrated that the honey, cerumen, and propolis of African stingless bees were rich in biologically active substances and deserved further research.

Esterification of Glycerol with Acetic Acid in Bioadditive Triacetin with Fe<sub>2</sub>O<sub>3</sub>/Activated Carbon Catalyst

Esterification and transesterification processes for biodiesel production generate glycerol which is possible to be converted into triacetin. It is an actractive bioadditive for increasing octane number of fuel. The production of this bioadditive in a biodiesel plant also increases the revenue as raw material comes from biodiesel process production as by-product.This study examines the effects of catalyst concentration and temperature on triacetin production using glycerol from esterification process and acetic acid at volume ratio of 1:3 as raw materials. An activated charcoal as catalyst is activated with sulfuric acid at concentration of 2% and 3% (w/w). The esterification temperatures are varied at 90 and 100°C and the reaction time is set for 3 hours. The samples are taken frequently at certain interval times of 15, 30, and 60 minutes for chemical analysis using Gas Chromatography Mass Spectometry. It is observed that using 2% and 3% (w/w) of catalysts at 90°C and 60 minutes reaction time converts 41.037% and 57.441% of glycerol respectively.

Authentication of Wistar rat fats with gas chromatography mass spectometry combined by chemometrics

Indonesia is a country with the largest Muslim population in the world, which is very concerned about halal food. The most problem that’s very concerning nowadays was that food products were contaminated by unclean meat, such as rat meat. The purpose of this study was to authenticate rat fat using Gas Chromatography-Mass Spectrophotometry (GC-MS) combined with chemometrics. In this study, rat fat were heated in oven at 90 °C – 100 °C for approximately one hour until the oil came out. After that, the derivatization process was carried out to convert fat into methyl ester compounds using NaOCH3 and BF3. Methyl ester compound than injected into the GCMS instrument system. In addition to rat fat, other fat extraction were carried out, such as pigs, cows, chickens, wild boars, dogs, and goats. The combination of chemometrics Principal Component Analysis (PCA) was used to classify rat fat with other animal fat. Based on the results of the study showed that fatty acids in rats using GCMS produced 6 types of fatty acids, namely: myristat (0.15 ±0.09%), palmitoleate (0.73 ±0.54%), palmitate (19.08 ±3.54%), linoleate (30.14 ±16.90%), oleate (40.48 ±2.74%), and stearate (2.55 ±0.01%). Total content of rat fatty acids was 93.13%, with unsaturated fatty acids 71.35% and saturated fatty acids 21.78%. Chemometrics PCA from rat fat can be grouped with other animal fats.

Gas chromatography mass spectometry analysis of Volatile compounds in ethanolic extract of propolis from geniotrigonathoracica of Malaysian stingless bees species

Gas chromatography mass spectometry analysis of Volatile compounds in ethanolic extract of propolis from geniotrigonathoracica of Malaysian stingless bees species

Chemical Composition Variability of Essential Oils in Different Parts of the Spice Plant Heracleum rawianum During Ontogenesis

Heracleum rawianum with the local name of ´Baldirqań is used as flavoring agent, spice and food additive in Azerbaijan province of Iran. In present study, the essential oil of this species at different phenological stages including vegetative (leaves), full flowering (leaves, flower stalk and flowers) and fruit set (unripe and ripe fruit) were obtained by hydrodistillation and analyzed by gas chromatography (GC) and gas chromatography-mass spectometry (GC-MS). There were qualitative and quantitative differences in the chemical composition among these essential oils. The essential oils isolated from vegetative stages’ leaf, flowering stages’ leaf and flower stalk were dominated by monoterpene hydrocarbons, while essential oils of flower, unripe and ripe fruit were rich in aliphatic esters. In the present study, p-cymene and β-pinene in leaf of vegetative phase, β-bisabolene and (Z)-β-ocimene in leaf sample at flowering stage, (E)-β-ocimene and β-bisabolene in flower stalk, hexyl butyrate and β-bisabolene in flowering umbels, hexyl butyrate and octanol in unripe and ripe fruit essential oils were detected as major compounds.

The composite water and solute transport of barley (Hordeum vulgare) roots: effect of suberized barriers.

Background and Aims Roots have complex anatomical structures, and certain localized cell layers develop suberized apoplastic barriers. The size and tightness of these barriers depend on the growth conditions and on the age of the root. Such complex anatomical structures result in a composite water and solute transport in roots. Methods Development of apoplastic barriers along barley seminal roots was detected using various staining methods, and the suberin amounts in the apical and basal zones were analysed using gas chromatography–mass spectometry (GC-MS). The hydraulic conductivity of roots (Lpr) and of cortical cells (Lpc) was measured using root and cell pressure probes. Key Results When grown in hydroponics, barley roots did not form an exodermis, even at their basal zones. However, they developed an endodermis. Endodermal Casparian bands first appeared as ‘dots’ as early as at 20 mm from the apex, whereas a patchy suberin lamellae appeared at 60 mm. The endodermal suberin accounted for the total suberin of the roots. The absolute amount in the basal zone was significantly higher than in the apical zone, which was inversely proportional to the Lpr. Comparison of Lpr and Lpc suggested that cell to cell pathways dominate for water transport in roots. However, the calculation of Lpr from Lpc showed that at least 26 % of water transport occurs through the apoplast. Roots had different solute permeabilities (Psr) and reflection coefficients (σsr) for the solutes used. The σsr was below unity for the solutes, which have virtually zero permeability for semi-permeable membranes. Conclusions Suberized endodermis significantly reduces Lpr of seminal roots. The water and solute transport across barley roots is composite in nature and they do not behave like ideal osmometers. The composite transport model should be extended by adding components arranged in series (cortex, endodermis) in addition to the currently included components arranged in parallel (apoplastic, cell to cell pathways).

Transformation of toxic and allelopathic lantana into a benign organic fertilizer through vermicomposting

In a first study of its kind, the composition of vermicompost derived solely from the toxic and allelopathic weed lantana has been investigated using UV–visible and Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric (TG) and differential scanning calorimetry (DSC), gas chromatography–mass spectometry (GC–MS), and scanning electron microscopy (SEM). The studies reveal that a sharp reduction in humification index, substantial mineralization of organic matter and degradation of complex aromatics such as lignin and polyphenols into simpler carbohydrates and lipids occur in the course of vermicomposting. GC–MS analysis shows significant fragmentation, bio-oxidation and molecular rearrangements of chemical compounds in vermicompost in comparison to those in lantana. SEM micrographs of vermicompost reflect strong disaggregation of material compared to the much better formed lantana matrices. The phenols and sesquiterpene lactones which are specifically responsible for the toxicity and allelopathy of lantana are seen to get significantly degraded in the course of vermicomposting — turning it into a plant-friendly organic fertilizer. The study leads to the possibility that the millions of tons of phytomass that is generated annually by lantana can be gainfully utilized in producing organic fertilizer via vermicomposting.

Pollination of Specklinia by nectar-feeding Drosophila: the first reported case of a deceptive syndrome employing aggregation pheromones in Orchidaceae.

The first documented observation of pollination in Pleurothallidinae was that of Endrés, who noticed that the 'viscid sepals' of Specklinia endotrachys were visited by a 'small fly'. Chase would later identify the visiting flies as being members of the genus Drosophila. This study documents and describes how species of the S. endotrachys complex are pollinated by different Drosophila species. Specimens of Specklinia and Drosophila were collected in the field in Costa Rica and preserved in the JBL and L herbaria. Flies were photographed, filmed and observed for several days during a 2-year period and were identified by a combination of non-invasive DNA barcoding and anatomical surveys. Tissue samples of the sepals, petals and labellum of Specklinia species were observed and documented by SEM, LM and TEM. Electroantennogram experiments were carried out on Drosophila hydei using the known aggregation pheromones ethyl tiglate, methyl tiglate and isopropyl tiglate. Floral compounds were analysed by gas chromatography-mass spectometry using those same pheromones as standards. Flowers of S. endotrachys, S. pfavii, S. remotiflora and S. spectabilis are visited and pollinated by several different but closely related Drosophila species. The flies are arrested by aggregation pheromones, including ethyl tiglate, methyl tiglate and isopropyl tiglate, released by the flowers, and to which at least D. hydei is very sensitive. Visible nectar drops on the adaxial surface of sepals are secreted by nectar-secreting stomata, encouraging male and female Drosophila to linger on the flowers for several hours at a time. The flies frequently show courtship behaviour, occasionally copulating. Several different Drosophila species can be found on a single Specklinia species. Species of the S. endotrachys group share a similar pollination syndrome. There seem to be no species-specific relationships between the orchids and the flies. It is not expected that Specklinia species will hybridize naturally as their populations do not overlap geographically. The combination of pheromone attraction and nectar feeding is likely to be a generalized pollination syndrome in Pleurothallidinae.

Determination of Eight Volatile Nitrosamines in Meat Products by Ultrasonic Solvent Extraction and Gas Chromatography-Mass Spectrometry Method

In the current study, the volatile nitrosamines (N-nitrosodimethylamine, N-nitrosomethylethylamine, N-nitrosodiethylamine, N-nitrosopyrrolidine, N-nitrosodi-n-propylamine, N-nitrosopiperidine, N-nitrosodi-n-butylamine, N-nitrosodiphenylamine) were detected in 28 selected Chinese meat products. An ultrasonic solvent extraction and gas chromatography mass spectometry analysis using a HP-5MS capillary column probed to be the best method. The concentration of eight volatile nitrosamines showed a good linear relationship and the linear correlation coefficient was above 0.999. The limit of detection of the instrument (IDL) and limit of quantification of the instrument (IQL) was 1.134–9.894 μg/L and 3.779–32.980 μg/L, respectively. The limit of detection of the method (MDL) and limit of quantification of the method (MQL) was 0.057–0.495 μg/kg and 0.189–1.649 μg/kg, respectively. The recovery of the method was 82.575–108.364%. The volatile nitrosamines contents were detected by the current method in 28 selected Chinese meat products. The results showed that the N-nitrosamine levels of Chinese sausages and emulsion sausages were generally higher than that of cooked sausages, and the contents in sausage with garlic flavor were obviously low. The major volatile nitrosamines found in our samples were N-nitrosomethylethylamine, N-nitrosopyrrolidine, N-nitrosodi-n-butylamine, and N-nitrosodiphenylamine.

Study on Eupatorium triplinerve Vahl from South India, A Rich Source for Thymohydroquinone dimethylether and its Antimicrobial Activity

The seasonal variations, composition and the antimicrobial activity of essential oils from the stem and leaves of Eupatorium triplinerve Vahl were analyzed by gas chromatography-mass spectometry (GC-MS), the components of the essential oils were identified by comparing their mass spectra fragmentation patterns, RI and by the comparison with the literature data. The oil content ranged from 0.25-0.40 %, with comparable in two different seasons. The essential oil obtained from the leaves and the stem was characterized by a very high content of thymohydroquinone dimethylether, i.e. 80.3-86.9 % of the total oil (higher percentage in stem) when compared with the reported values in India (20-40 %). Other oil constituents occurring in much lower amounts were β-caryophyllene (4-6 %), β-eudesmene (6-10 %). The antimicrobial activities of the volatile oil and thymohydroquinone dimethylether were evaluated against four bacterial and four fungal strains using disc diffusion assay method. The stem and leaf essential oils found to have significant antimicrobial effect compared to that of thymohydroquinone dimethylether. Hence the antimicrobial effect of the volatile oil could be attributed to its minor components. The E. triplinerve can be recommended for a new chemotype from south India due to the dominant occurrence of thymohydroquinone dimethylether.

Chemical composition and bioactivity of the essential oil of Artemisia anomala from China

The composition and the bioactivity of the essential oil of Artemisia anomala, a traditional medicinal herb in China, were investigated. The composition of the essential oil was analyzed by gas chromatography–mass spectometry (GC–MS), and a total of 39 components representing 98.1% in this plant were identified. The main constituents were camphor (18.3%), 1, 8-cineole (17.3%), β-caryophyllene oxide (12.7%), and borneol (9.5%). The antimicrobial activities of the oil were separately evaluated against six micro-organisms, Bacillus cereus (CMCCB 63301), Micrococcus flavus (ATCC 14698), Escherichia coli (ATCC 11775), Pseudomonas aeruginosa (ATCC 10145), Staphylococcus epidermidis (ATCC 12228), and a clinical-isolated strain Staphylococcus aureus. The results showed that the oil possessed inhibitory activity against B. cereus, M. flavus, E. coli, S. epidermidis, and S. aureus, among which the best inhibition was observed against B. cereus with a MIC of 0.313 μL/mL. The antiproliferative activities of the oil were assessed against four human tumor cell lines, A459 (human lung adenocarcinoma), BRO (human melanoma), MCF7 (human breast cancer), and PC3 (human prostate). The oil showed the ability to inhibit proliferation of human cancer cells. And the MCF7 cell line was the most sensitive to the oil with an IC50 of 0.09.