Cryptocarya species are mainly distributed in Africa, Asia, Australia and South America, widely used in traditional medicines for the treatment of skin infections and diarrhea. The present investigation reports on the extraction by hydrodistillation and the chemical composition of three Cryptocarya species (Cryptocarya impressa, Cryptocarya infectoria, and Cryptocarya rugulosa) essential oils from Malaysia. The chemical composition of these essential oils was fully characterized by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). A total of 51 components were identified in C. impressa, C. infectoria, and C. rugulosa essential oils representing 91.6, 91.4, and 83.0% of the total oil, respectively. The high percentages of α-cadinol (40.7%) and 1,10-di-epi-cubenol (13.4%) were found in C. impressa oil. β-Caryophyllene (25.4%) and bicyclogermacrene (15.2%) were predominate in C. infectoria oil. While in C. rugulosa oil, bicyclogermacrene (15.6%), δ-cadinene (13.8%), and α-copaene (12.3%) were predominate. To the best of our knowledge, there is no report on the essential oil composition of these three species.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Polygonum minus is a plant rich with bioactive components that contribute to food, pharmaceutical, and perfume industries. However, high moisture content in fresh plants will allow
microbial activity that leads to the degradation of plant quality. This can be prevented by
drying the fresh plants to preserve the characteristics of their bioactive components. The
present work was conducted to determine the effect of different drying methods such as
air-drying, oven-drying (40 and 60°C), and freeze-drying on essential oil (EO) yield and
chemical compounds of P. minus roots. For comparison purposes, all samples were extracted
by maceration with n-hexane at room temperature. Then, the samples were analysed and
identified by using gas chromatography-mass spectrometry (GC-MS). The highest EO yield
extract was obtained from freeze-drying (4.15 ± 0.5), followed by air-drying (3.79 ± 0.19). EO
yield from oven-drying at 40 and 60°C was 3.4 ± 0.14 and 0.86 ± 0.04, respectively. Results
showed that by increasing the drying temperature, the EO yield would decrease and cause a
loss of major chemical compounds in the P. minus root. Air-drying was found to be the best
method in preserving the presence of important chemical compound in P. minus roots such as
β-caryophyllene (1.43%), pentadecane (4.34%), hexadecanoic acid (3.91%) and oleic acid
(3.97%).
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Gas chromatography mass spectrometry (GC-MS) and headspace gas chromatography mass spectrometry (HS/GC-MS) were used to study metabolites produced by Lactococcus lactis subsp. cremoris MG1363 grown at a temperature of 30 °C with and without agitation at 150 rpm, and at 37 °C without agitation. It was observed that L. lactis produced more organic acids under agitation. Primary alcohols, aldehydes, ketones and polyols were identified as the corresponding trimethylsilyl (TMS) derivatives, whereas amino acids and organic acids, including fatty acids, were detected through methyl chloroformate derivatization. HS analysis indicated that branched-chain methyl aldehydes, including 2-methylbutanal, 3-methylbutanal, and 2-methylpropanal are degdradation products of isoleucine, leucine or valine. Multivariate analysis (MVA) using partial least squares discriminant analysis (PLS-DA) revealed the major differences between treatments were due to changes of amino acids and fermentation products.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Lactococcus lactis subsp. cremoris MG1363 is an important starter culture for dairy fermentation. During industrial fermentations, L. lactis is constantly exposed to stresses that affect the growth and performance of the bacterium. Although the response of L. lactis to several stresses has been described, the adaptation mechanisms at the level of in vivo fluxes have seldom been described. To gain insights into cellular metabolism, 13C metabolic flux analysis and gas chromatography mass spectrometry (GC-MS) were used to measure the flux ratios of active pathways in the central metabolism of L. lactis when subjected to three conditions varying in temperature (30°C, 37°C) and agitation (with and without agitation at 150 rpm). Collectively, the concentrations of proteinogenic amino acids (PAAs) and free fatty acids (FAAs) were compared, and Pearson correlation analysis (r) was calculated to measure the pairwise relationship between PAAs. Branched chain and aromatic amino acids, threonine, serine, lysine and histidine were correlated strongly, suggesting changes in flux regulation in glycolysis, the pentose phosphate (PP) pathway, malic enzyme and anaplerotic reaction catalysed by pyruvate carboxylase (pycA). Flux ratio analysis revealed that glucose was mainly converted by glycolysis, highlighting the stability of L. lactis' central carbon metabolism despite different conditions. Higher flux ratios through oxaloacetate (OAA) from pyruvate (PYR) reaction in all conditions suggested the activation of pyruvate carboxylate (pycA) in L. lactis, in response to acid stress during exponential phase. Subsequently, more significant flux ratio differences were seen through the oxidative and non-oxidative pentose phosphate (PP) pathways, malic enzyme, and serine and C1 metabolism, suggesting NADPH requirements in response to environmental stimuli. These reactions could play an important role in optimization strategies for metabolic engineering in L. lactis. Overall, the integration of systematic analysis of amino acids and flux ratio analysis provides a systems-level understanding of how L. lactis regulates central metabolism under various conditions.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
In this study, the photocatalytic degradation of toxic pollutant (2-chlorophenol) in the presence of ZnO nanoparticles (ZnO NPs) was investigated under solar radiation. The three main factors, namely pH of solution, solar intensity and calcination temperature, were selected in order to examine their effects on the efficiency of the degradation process. The response surface methodology (RSM) technique based on D-optimal design was applied to optimise the process. ANOVA analysis showed that solar intensity and calcination temperature were the two significant factors for degradation efficiency. The optimum conditions in the model were solar intensity at 19.8 W/m(2), calcination temperature at 404 °C and pH of 6.0. The maximum degradation efficiency was predicted to be 90.5% which was in good agreement with the actual experimental value of 93.5%. The fit of the D-optimal design correlated very well with the experimental results with higher values of R (2) and R (2)adj correlation coefficients of 0.9847 and 0.9676, respectively. The intermediate mechanism behaviour of the 2-chlorophenol degradation process was determined by gas chromatography-mass spectrometry (GC-MS). The results confirmed that 2-chlorophenol was converted to acetic acid, a non-toxic compound.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Over the last decade, metabolomics has continued to grow rapidly and is considered a dynamic technology in envisaging and elucidating complex phenotypes in systems biology area. The advantage of metabolomics compared to other omics technologies such as transcriptomics and proteomics is that these later omics only consider the intermediate steps in the central dogma pathway (mRNA and protein expression). Meanwhile, metabolomics reveals the downstream products of gene and expression of proteins. The most frequently used tools are nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). Some of the common MS-based analyses are gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). These high-throughput instruments play an extremely crucial role in discovery metabolomics to generate data needed for further analysis. In this chapter, the concept of metabolomics in the context of systems biology is discussed and provides examples of its application in human disease studies, plant responses towards stress and abiotic resistance and also microbial metabolomics for biotechnology applications. Lastly, a few case studies of metabolomics analysis are also presented, for example, investigation of an aromatic herbal plant, Persicaria minor metabolome and microbial metabolomics for metabolic engineering applications.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
The essential oil in leaves of Polygonum minus Huds., a local aromatic plant, were identified by a pipeline of gas chromatography (GC) techniques coupled with mass-spectrometry (MS), flame ionization detector (FID) and two dimensional gas chromatography time of flight mass spectrometry (GC x GC-TOF MS). A total of 48 compounds with a good match and high probability values were identified using this technique. Meanwhile, 42 compounds were successfully identified in this study using GC-MS, a significantly larger number than in previous studies. GC-FID was used in determining the retention indices of chemical components in P. minus essential oil. The result also showed the efficiency and reliability were greatly improved when chemometric methods and retention indices were used in identification and quantification of chemical components in plant essential oil.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry/instrumentation; Gas Chromatography-Mass Spectrometry/methods*
The enzyme 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase is the key enzyme of the mevalonate pathway that produces cholesterol. Inhibition of HMG-CoA reductase reduces cholesterol biosynthesis in the liver. Synthetic drugs, statins, are commonly used for the treatment of hypercholesterolemia. Due to the side effects of statins, natural HMG-CoA reductase inhibitors of plant origin are needed. In this study, 25 medicinal plant methanol extracts were screened for anti-HMG-CoA reductase activity. Basella alba leaf extract showed the highest inhibitory effect at about 74%. Thus, B. alba was examined in order to investigate its phytochemical components. Gas chromatography with tandem mass spectrometry and reversed phase high-performance liquid chromatography analysis revealed the presence of phenol 2,6-bis(1,1-dimethylethyl), 1-heptatriacotanol, oleic acid, eicosyl ester, naringin, apigenin, luteolin, ascorbic acid, and α-tocopherol, which have been reported to possess antihypercholesterolemic effects. Further investigation of in vivo models should be performed in order to confirm its potential as an alternative treatment for hypercholesterolemia and related cardiovascular diseases.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Plant resins, and particularly dammars from the Dipterocarpaceae family, were widely used in the past, notably as part of caulking material. The organic composition of resins, already complicated, is not always preserved over time and can be considerably affected by ageing. Hence, their occurrence in archaeological items leads to the necessity to identify them taxonomically with precision. Resinous organic materials collected near and/or on wrecks discovered in South China Sea, supposed to contain dammar resins because of their geographical excavation context, were investigated by gas chromatography-mass spectrometry (GC-MS), together with freshly collected dammars, to establish taxonomic and alteration parameters allowing to identify dammar even in very altered samples or in mixtures together with other organic materials. This study specially focuses on three samples collected within or close to the M1J wreck, a Portuguese wreck lost in the Straight of Malacca during the 16th century. Our analyses establish that all three are made of dammar, two of them in association with pitch and bitumen. In addition, biodegradation biomarkers were detected in all these three samples, indicating that they were submitted to microbial degradation processes during their ageing.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
The aim of the present study was to extract and characterize bioactive components from separate body organs of Holothuria leucospilota. Preliminary qualitative assessment of the crude extracts was positive for phenols, terpenoids, carbohydrates, flavonoids, saponins, glycosides, cardiac glycosides, steroids, phlobatannins, and tannins in all body organs evaluated. Phenolics were the most abundant group of bioactives accounting for approximately 80%. The extraction solvent mixtures that yielded most compounds evaluated were methanol/acetone (3:1, v:v) and methanol/distilled water (3:1, v:v). In other analyses, GC-MS data revealed diverse metabolic and biologically active compounds, where those in high concentrations included 2-Pentanone, 4-hydroxy-4-methyl- among the ketones; phenol- 2,4-bis(1,1-dimethylethyl)-, a phenol group; and 2-Chlorooctane, a hydrocarbon. Among FA and their methyl/ethyl esters, n-hexadecanoic acid, 5,8,11,14-eicosatetraenoic acid ethyl ester (arachidonic acid), and 5,8,11,14,17-eicosapentaenoic acid methyl ester (EPA) were among the most abundant FAMEs accounting for approximately 50% of the subgroups measured. Data from GC-FID analysis revealed methyl laurate (C12:0), methyl myristate (C14:0), methyl palmitate (C16:0), and methyl stearate (18:0) methyl esters as the most abundant saturated FA, whereas cis-9-oleic methyl ester (C18:1) and methyl linoleate (C18:2) were found as the major monounsaturated FA and PUFA FAMEs, respectively, in the body wall of the species. Taken together, the extraction and characterization of different categories of metabolically and biologically active compounds in various organ extracts of H. leucospilota suggest that the species is potentially a rich source of cholesterol-lowering, antioxidant, antimicrobial, and anticancer agents. These substances are known to benefit human health and assist in disease prevention. These findings justify the use of sea cucumbers in traditional folklore medication and the current interest and attention focused on the species to mine for bioactives in new drugs research.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
A novel nitrogen-sulphur macrocyclic Schiff base, 4,11,20,27-tetrathioxo3,12,19,28-tetrathia-5,6,9,10,21,22,25,26-octaazatricyclo[28.2.2.214,17]hexatriaconta 1(33),6,8,14(36),15,17(35),22,24,30(34),31-decaene-2,13,18,29-tetraone (TGSB) derived from terephthaloyl-bis-dithiocarbazate (TDTC) and glyoxal (ethane-1,2-dione) is synthesised via condensation. Metal complexes are formed by reacting the Schiff base with various metal salts such as Ru(III), Mo(V), Cd(II), Zn(II) and Cu(II). The complexes are expected to have a general formula of M2L or M3L with a square planar or square pyramidal geometry. These compounds were characterised by various physicochemical and spectroscopic techniques. From the data, it is concluded that the azomethine nitrogen atom and the thiolate sulphur atom from the ligand are bonded to the metal ion. In the IR spectra of the complexes, the presence of the C=N band in the region of 1600 cm-1 indicates the successful formation of the Schiff base. The structures of the Schiff base and metal complexes are confirmed via FT-IR, GC-MS and NMR spectroscopic analysis. The magnetic susceptibility measurements, electronic spectral data and molar conductivity analysis support the desired geometry of the complexes. The Schiff base and its metal complexes are evaluated for their biological activities against the invasive human bladder carcinoma cell line (EJ-28) and the minimuminvasive human bladder carcinoma cell line (RT-112). The RuTGSB and CdTGSB complexes showed selective activity against RT-112.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Recently, the abuse of ketum, an indigenous psychoactive plant, has received a lot of attention in Malaysia. To help national law enforcement agencies control its abuse, the laboratory of the Forensic Division has developed a procedure for its positive identification. Botanical identification may not be practical or conclusive, owing to the wide range of ketum materials available on the market, including dry macerated leaves, powdered leaves and drinks. In order to confirm that a substance is, in fact, ketum or that a preparation is derived from ketum, gas chromatography-mass spectrometry is used to definitively identify the presence of the psychoactive principle mnitragynine.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry/methods
A method has been developed for the determination of trace levels of alpha-endosulfan, beta-endosulfan, endosulfan sulfate, and endosulfan diol in rat plasma and tissue samples. Endosulfan and its metabolites in the plasma samples were extracted with solid-phase extraction Chromabond-end-capped C18 cartridges and analyzed by a Shimadzu QP-5050A gas chromatograph-mass spectrometer (GCMS) with quadrupole detector in selected-ion-monitoring mode. The analysis of endosulfan and its metabolites in liver and kidney samples involved solvent extraction, Florisil solid-phase-extraction cleanup, and quantitation by GCMS. Recovery experiments for the plasma and tissue samples were conducted over concentration ranges of 10-100 ng mL(-1) and 100-1000 ng mL(-1), respectively. The method was applied to the analysis of trace levels of endosulfan and its metabolites in plasma and tissue samples collected from an animal study. Trace levels of alpha-endosulfan and beta-endosulfan in the ranges of undetectable to 3.11 microg g(-1) and undetectable to 1.19 microg g(-1), respectively, were detected in the kidney samples, whereas trace levels of endosulfan sulfate in the range of 0.02-0.22 microg g(-1) were detected in the liver samples of rats. Neither endosulfan nor its metabolites was detected in any of the plasma samples.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
The abuse of phenylbutazone among rheumatoid arthritis patients has recently become a subject of interest. Unscrupulous manufacturers take advantage of the miraculous analgesic property of phenylbutazone and deliberately add this toxic drug in their preparations without declaring its presence on the label. In a recent survey, many such illicit preparations were seized from Chinese medical halls in Johor and sent to the Department of Chemistry, Johor Bahru for analysis. Here a Gas Chromatograph Mass Selective Detector (GC-MSD) method was developed for the determination of phenylbutazone in illicit traditional preparations.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry/methods*
Volatile compounds in the peel of calamansi (Citrus microcarpa) from Malaysia, the Philippines and Vietnam were extracted with dichloromethane and hexane, and then analysed by gas chromatography-mass spectroscopy/flame ionisation detector. Seventy-nine compounds representing >98% of the volatiles were identified. Across the three geographical sources, a relatively small proportion of potent oxygenated compounds was significantly different, exemplified by the highest amount of methyl N-methylanthranilate in Malaysian calamansi peel. Principal component analysis and canonical discriminant analysis were applied to interpret the complex volatile compounds in the calamansi peel extracts, and to verify the discrimination among the different origins. In addition, four common hydroxycinnamic acids (caffeic, p-coumaric, ferulic and sinapic acids) were determined in the methanolic extracts of calamansi peel using ultra-fast liquid chromatography coupled to photodiode array detector. The Philippines calamansi peel contained the highest amount of total phenolic acids. In addition, p-Coumaric acid was the dominant free phenolic acids, whereas ferulic acid was the main bound phenolic acid.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Calamansi juices from three countries (Malaysia, the Philippines and Vietnam) were characterised through measuring volatiles, physicochemical properties and non-volatiles (sugars, organic acids and phenolic acids). The volatile components of manually squeezed calamansi juices were extracted using dichloromethane and headspace solid-phase microextraction, and then analysed using gas chromatography-mass spectrometry/flame ionisation detector, respectively. A total of 60 volatile compounds were identified. The results indicated that the Vietnam calamansi juice contained the highest amount of volatiles. Two principal components obtained from principal component analysis (PCA) represented 89.65% of the cumulative total variations of the volatiles. Among the non-volatile components, these three calamansi juices could be, to some extent, differentiated according to fructose and glucose concentrations. Hence, this study of calamansi juices could lead to a better understanding of calamansi fruits.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Stability indicating assay describes a technique which is used to analyse the stability of drug substance or active pharmaceutical ingredient (API) in bulk drug and pharmaceutical products. Stability indicating assay must be properly validated as per ICH guidelines. The important components in a stability indicating assay include sensitivity, specificity, accuracy, reliability, reproducibility and robustness. A validated assay is able to measure the concentration changes of drug substance/API with time and make reliable estimation of the quantity of the degradation impurities. The drug substance is separated and resolved from the impurities. Pros and cons of HPLC, GC, HPTLC, CE and SFC were discussed and reviewed. Stability indicating assay may consist of the combination of chromatographic separation and spectroscopic detection techniques. Hyphenated system could demonstrate parallel quantitative and qualitative analysis of drug substances and impurities. Examples are HPLC-DAD, HPLC-FL, GC-MS, LC-MS and LC-NMR. The analytes in the samples are separated in the chromatography while the impurities are chemically characterised by the spectroscopy in the system. In this review, various chromatographic methods which had been employed as stability indicating assays for drug substance and pharmaceutical formulation were systematically reviewed, and the application of hyphenated techniques in impurities characterisation and identification were also discussed with supporting literatures.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
The preservation of active constituents in Cassia alata through the removal of moisture is crucial in producing a final product with high antioxidant activity. This study aims to determine the influences of various drying methods and drying conditions on the antioxidant activity, volatiles and phytosterols content of C. alata. The drying methods used were convective drying (CD) at 40 °C, 50 °C and 60 °C; freeze drying; vacuum microwave drying (VMD) at 6, 9 and 12 W/g; and two-stage convective pre-drying followed by vacuum microwave finish drying (CPD-VMFD) at 50 °C and 9 W/g. The drying kinetics of C. alata are best described by the thin-layer model (modified Page model). The highest antioxidant activity, TPC and volatile concentration were achieved with CD at 40 °C. GC-MS analysis identified the presence of 51 volatiles, which were mostly present in all samples but with quantitative variation. The dominant volatiles in fresh C. alata are 2-hexenal (60.28 mg 100 g-1 db), 1-hexanol (18.70 mg 100 g-1 db) and salicylic acid (15.05 mg 100 g-1 db). The concentration of phytosterols in fresh sample was 3647.48 mg 100 g-1 db, and the major phytosterols present in fresh and dried samples were β-sitosterol (1162.24 mg 100 g-1 db). CPD-VMFD was effective in ensuring the preservation of higher phytosterol content in comparison with CD at 50 °C. The final recommendation of a suitable drying method to dehydrate C. alata leaves is CD at 40 °C.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Nasopharyngeal carcinoma (NPC) is a malignancy that occurs in the epithelium of the nasopharynx. The standard treatment of NPC patients with locoregionally advanced stages is problematic and is often associated with toxicities. Therefore, it is essential to screen for naturally occurring compounds with strong apoptosis-inducing activity and minimal toxicity. This study investigated the effects of the standardized methanol extract of Cinnamomum burmannii Blume stem bark and its main constituent, trans-cinnamaldehyde (TCA), on human NPC cell lines. The content of TCA in C. burmannii methanol extract was standardized to be 13.61% w/w by means of gas chromatography-mass spectrometry (GC-MS). NPC cell proliferation was clearly inhibited within 24 h of treatment, with TCA exhibiting greater activity than the methanol extract. TCA was more active against NPC cells compared with cisplatin. There was a pronounced downregulation of the proliferation markers, Ki67 and proliferating cell nuclear antigen (PCNA) in the TCA-treated cells; while morphological observation indicated the induction of apoptosis. Caspase activation and prominent DNA damage, which are markers of apoptosis induction were detected. TCA demonstrated the ability to scavenge nitric oxide. The simultaneous combination of TCA and cisplatin produced synergistic anti-proliferative effects. Collectively, these data indicate the potential use of TCA for the treatment of NPC.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry
Dicofol, an extensively used organochlorine pesticide and a recommended Stockholm convention persistent organic pollutant (POP) candidate is well known for its endocrine disruptive properties. The sonochemical degradation of Dicofol in aqueous media has been investigated using a 20-kHz probe type sonicator with power inputs from 150 to 450 W. The degradation rate was determined as a function of concentration of Dicofol, solution pH, bulk phase temperature, ultrasonic power density and H2O2 addition. At optimum operating conditions, the pseudo-first-order degradation rate constant (k) was determined to be 0.032 min-1 and the extent of degradation was found to be 86% within 60 min of ultrasound treatment. High performance liquid chromatography (HPLC) and Gas chromatography coupled with mass spectroscopy (GC-MS) analysis indicated the presence of degraded products. The obtained results of Dicofol degradation and control experiments in the presence of H2O2 and radical scavenger test suggest thermal decomposition along with radical attack at bubble-vapor interface to be the dominant degradation pathway. Sonochemical treatment is effective and promising for successful removal of harmful pesticides such as Dicofol and superior removal efficiency for other POPs is expected in the near future with the successful implementation of ultrasound-based wastewater treatment.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry