Determination Of Chemical Constituents Research Articles

Tea authentication and determination of chemical constituents using digital image-based fingerprint signatures and chemometrics.

Tea (Camellia sinensis) fraud has been frequently identified and involves tampering with the labelling of inferior products or without geographical origin certification and even mixing them with superior quality teas to mask an adulteration. Consequently, economic losses and health damage to consumers are observed. Thus, a Chemometrics-assisted Color Histogram-based Analytical System (CACHAS) was employed a simple, cost-effective, reliable, and green analytical tool to screen the quality of teas. Data-Driven Soft Independent Modeling of Class Analogy was used to authenticate their geographical origin and category simultaneously, recognizing correctly all Argentinean and Sri Lankan black teas and Argentinean green teas. For the determination of moisture, total polyphenols, and caffeine, Partial Least Squares obtained satisfactory predictive abilities, with values of root mean squared error of prediction (RMSEP) of 0.50, 0.788, and 0.25mgkg-1, rpred of 0.81, 0.902, and 0.81, and relative error of prediction (REP) of 6.38, 9.031, and 14.58%., respectively. CACHAS proved to be a good alternative tool for environmentally-friendly non-destructive chemical analysis.

Identification and determination of chemical constituents from Yinchen Qingjin granules by ultra high-performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometry.

An ultra high-performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometry method had been used to identify chemical constituents in Yinchen Qingjin Granules. A total of 117 chemical constituents were tentatively identified based on the molecular weight, the mass fragmentation behavior, and the comparison with retention time and accurate mass of reference standards. Meanwhile, an ultra high-performance liquid chromatography coupled with triple quadrupole mass spectrometry method has been developed to evaluate the quality of Yinchen Qingjin Granules through a simultaneous determination of ten components, namely gallic acid, shanzhiside, neochlorogenic acid, chlorogenic acid, caffeic acid, geniposide, liquirition, isoliquirition, glycyrrhizic acid, and rhein. Altogether, content levels of each compound ranged from 0.228 to 8.712mg/g. At the same time, a hydrophilic interaction liquid chromatography combined with UV for the quantification of sarmentosin in Yinchen Qingjin Granules is presented and its content was from 5.608 to 6.200mg/g. The linearity, accuracy, and precision of these two validation methods were satisfactory. The both determination methods were successfully used for the analysis of six batches of Yinchen Qingjin Granules samples made in China and could be as suitable analytical method for quality control.

Determination of Chemical Constituents and Antioxidant Activities of Leaves and Stems from Jatropha cinerea (Ortega) Müll. Arg and Jatropha cordata (Ortega) Müll. Arg.

Jatropha species have been shown to be an important source of secondary metabolites with different biological effects. Jatropha cinerea (Ortega) Müll. Arg and Jatropha cordata (Ortega) Müll. Arg are distributed in the Northwestern region of Mexico, are adapted to extreme weather conditions and are widely used (stems, leaves, and sap) in traditional medicine. The aim of the present study was to carry out the phytochemical characterization and the evaluation of the antioxidant activity in methanolic extracts of stems and leaves from J. cinerea and J. cordata. The compounds present in the extracts of both species were characterized by ESI-IT-MS/MS and quantified by HPLC-DAD. The results showed that the stem extracts of both species are rich in phenolic acids, while the leaf extracts are rich in flavonoids. Some of the main compounds found were gallic acid, gentisic acid, 3,4-Dihydroxybenzoic acid, vitexin, isovitexin, and catechol. Both species showed high concentrations of phenols and total flavonoids and antioxidant activity. J. cordata showed the highest antioxidant capacity and the highest concentration of phenolic compounds. Overall, both Jatropha species are a natural source of antioxidant compounds with potential biotechnological uses.

LC-ESI/MS and GC-MS Methanol Extract Analysis, Phytochemical and Antimicrobial Activity Studies of Centella asiatica

Aims: To determine chemical constituents of the Leaf extracts of Centella asiatica using the LC-MS and GC-MS and their antimicrobial activities.
 Study Design: Structural determination of compounds from the leaf extracts was done using GC-MS and LC-MS analysis. The antimicrobial properties of the extracts were done using disc diffusion method.
 Place and Duration of Study: Pure and Applied Chemistry Department, Masinde Muliro University of Science and Technology, Kenya: Between 2016-2019.
 Methodology: Plant materials of C. asiatica were sequentially extracted separately based on the polarity viz., hexane, ethyl acetate and methanol. Determination of chemical constituents was done using LC-MS and GC-MS analysis and phytochemical screening. The extracts were assayed against Staphylococcus aureus, Klebsiella pneumonia, Escherichia coli and Candida albicans. Standard antimicrobials viz. ampicillin and Nystatin were used as the control. Disc diffusion method was used and zones of inhibition, after respective incubation periods, were used to quantify antibacterial and antifungal activity.
 Results: Phytochemical screening of the hexane, ethyl acetate and methanolic extracts showed that terpenoids, flavonoids, saponins, alkaloids, steroids, amino acids and proteins, reducing sugars and carbohydrates were present. LC-MS and GC-MS analyses of the methanolic extracts identified 22 and 33 compounds, respectively, by use of the national institute of standards and technology (NIST) library. The extracts showed appreciable activity against common microbes tested.
 Conclusion: This study forms the basis for the biological characterization and significance of the compounds identified in the leaf and stem extracts of C. asiatica. These compounds are known to possess antibacterial and antifungal activities that could be established as potential candidates for future drug development. However, these extracts, need to be subjected to further chromatographic procedures to isolate the identified compounds and their bioactivities determined.

Determination of Chemical Constituents of Recycled Consumer Products

Recycled materials are commonly found in various modern consumer products. Although these products are generally regarded as being comparable to those made from non-recycled (virgin) materials, dif...

Characterization and determination of antioxidant components in the leaves of Camellia chrysantha (Hu) Tuyama based on composition–activity relationship approach

Camellia chrysantha (Hu) Tuyama (CCT), an ornamental plant possessing antioxidant activity, has been infused as tea and drank for its health benefits. The antioxidant components in CCT, however, had not been clearly characterized. To quickly identify the antioxidant constituents of CCT, a composition–activity relationship strategy based on ultra high-pressure liquid chromatography coupled with linear ion trap hybrid orbitrap mass spectrometry and orthogonal partial least-squares method has been applied. As a result, 16 variables were found to make significant contributions to the 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity. Six of them were identified as catechin (1), epicatechin (5), vitexin (8), isovitexin (10), quercetin-7-O-β-D-glucopyranoside (12) and kaempferol (16). The strength of 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity was found to be 12 > 1 > 5 > 16 > 8 > 10 by validation test. Meanwhile, a liquid chromatography-electrospray ionization-mass spectrometry method was established for quantitative determination of six marker compounds in CCT samples from different preparations. The validation of the method, including linearity, sensitivity (limitation of detection and limitation of quantification), repeatability, precision, stability, and recoveries, was carried out and demonstrated to meet the requirements of quantitative analysis. This is the first report on the comprehensive characterization and determination of chemical constituents in CCT by ultra high-pressure liquid chromatography coupled with linear ion trap hybrid orbitrap mass spectrometry. The results indicate that the composition–activity relationship approach may be a useful method for the discovery of active constituents in natural plants and the quality control of medicinal herbs.

Assessment of inhibitory potential of Pothos scandens L. on ovalbumin-induced airway hyperresponsiveness in balb/c mice

Pothos scandens L. was used in Indian traditional medicine as an antiasthmatic drug. The ethanolic and aqueous extracts were prepared with aerial parts of P. scandens (PSE & PSA). ESI MS/MS of PSE ethanolic extract was carried out for the determination of chemical constituents. CP1 is isolated from the PSE, structurally confirmed with NMR and LCMS/MS. PSE, PSA and CP1 are evaluated against ovalbumin (OVA) induced airway hyperresponsiveness (AHR) in balb/c mice. The test drugs are administered p.o. prior to challenge with aerosolized 2.5% w/v OVA. Total and differential leucocyte count, nitrite (NO2), nitrate (NO3), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-13 (IL-13) are estimated in bronchoalveolar lavage fluid (BALF). Similarly, myeloperoxidase (MPO), malonaldehyde (MDA) and total lung protein (TLP) are estimated in the lungs. The results reveal a significant increase in total and differential leucocyte count, NO2, NO3, TNF-α, IL-6, and IL-13 in OVA induced AHR. However, these parameters are significantly decreased in PSE and PSA tested doses (PSE 100 & 200mg/kg). While, treatment with CP1 is less effective at 5 & 10mg/kg doses. Similar observations obtain for MPO and MDA in lungs. However, the mean value indicated that the PSE at 200mg/kg showed a significant restoration in all the parameters. Pro-inflammatory mediators are known to be responsible for AHR. Histopathology revealed justifies the effectiveness. The present investigations suggest PSE are interesting molecules for further research for asthma, with an approach through pro-inflammatory inhibitory pathway. P. scandens is a potential herbal medicine for allergy induced asthma.

Nature and Performance of Tropical Wood Natural Fiber Cementitious Composites

AbstractTwelve commercially available tropical wood natural fiber species and their cementitious composites were thoroughly studied for possible production of natural fiber cementitious composites (NFCCs) through (1) the determination of chemical constituents of the fiber species, (2) determination of compatibility of natural fiber cement and correlation of the compatibility with chemical constituents, and (3) examination of the mechanical property of NFCC and its correlation with the compatibility and chemical constituents of wood natural fibers. The results showed that (1) the chemical constituents of the 12 tropical wood fibrous materials varied considerably from one another, with cellulose content ranging between 40 and 57%, lignin ranging between 21 and 34%, and solubility ranging between 2.40 and 29.06% depending on the type of solutions, (2) pH values were below 7 for all natural fibers tested (pH of 3.36–6.22), and the acid-to-base ratio (ABR) values were no greater than 1, indicating that the bas...

Near-infrared evaluation of wet mink diets

Near-infrared spectroscopy (NIRS) is a relatively new technology in the determination of chemical constituents in compound (complete) feeds. The current paper reports on the application of NIRS to the measurement of dry matter (DM), crude protein (CP) and crude fat (CF) in wet diets for mink and the development of a calibration to predict these chemical constituents. In total, 287 typical wet mink feeds were collected from commercial mink ranches located on the south shore of Nova Scotia, Canada, to provide a large representative sample population. After population structuring, using CENTER and SELECT software (ISI) during calibration development, there were 73 samples remaining in the calibration. All feeds were analyzed by standard reference methods (primary) and then scanned (secondary) with a scanning monochromator NIR, model 5000 (NIRSystems Inc.), to develop a global calibration to predict DM, CP and CF. The “best fit” treatment for the calibration was a modified partial least squares analysis with a standard normal variate (SNV) correction for scatter, a derivative math treatment of 1, 4, 4, 1 to remove particle size interference while scanning segments 1108–2492 skipping every 8 nm for prediction of DM, CP and CF. Standard error of calibration (SEC, g kg −1), proportion of explained variance (RSQ), and standard error of cross-validation (SECV, g kg −1) for DM, CP, and CF were; 11.9, 0.92 and 14.3; 11.3, 0.96 and 17.5; and 20.0, 0.92 and 22.5. Two external validation sets were used to evaluate the accuracy of the calibration with standard error of prediction (SEP), ranging from 12.7 to 19.5 g kg −1. Based on the results of the data reported the use of NIRS technology in the nutritional evaluation of complete wet diets for mink is feasible. The most promising future use for this NIRS application is as on-line quality control in a central feed kitchen.

Separation and determination of chemical constituents in the volatile oil of three traditional Chinese crude drugs

The parts of Jilin ginseng growing on the ground, Radix aucklandiae and the citrus tangerina peels were extracted with ether, and yellow volatile oil 0.31 wt.%, 2.1 wt.% and 1.6 wt.% were obtained respectively. Their chemical constituents were separated and determined by gas chromatography and interfaced with mass spectrometry in an electron impact mode.

Development and evaluation of a regression equation of prediction for fat-free soft tissue in heterogenous populations of cattle.

Regression equations to predict kilograms of fat-free soft tissue (the sum of water and protein from chemical analyses) were developed from data collected on 526 steers and heifers. Straightbred animals representing Angus, Braunvieh, Charolais, Gelbvieh, Hereford, Limousin, Pinzgauer, Red Poll, and Simmental breeds of cattle contributed to the data set. Cattle ranged in slaughter weight and age from approximately 350 to 575 kg and from 13 to 23 mo, respectively. Diets (100% ground alfalfa, 67% ground alfalfa and 33% ground corn or 33% ground alfalfa and 67% ground corn) were cross-classified with breed and sex. Estimative traits included in the equation were warm carcass weight, fat depth at the 12th rib, and body impedance. Carcass soft-tissue samples were taken for determination of chemical constituents. The prediction equation accounted for 94% of the variation in fat-free soft tissue of the carcass. Adjusting for breed-sex-diet contemporary groups increased the R2 value by 2% units. The prediction model was evaluated using data collected on 65 steers sired by Charolais or by Hereford bulls at the Ft Keogh Livestock and Range Research Laboratory (Miles City, MT). Postweaning feeding strategies and slaughter ages varied among these animals. Carcass weight, back fat depth, and resistive impedance measures were recorded. Carcass soft-tissue samples were taken for determination of chemical constituents. Values of estimator variables recorded at Ft. Keogh were used in the regression equation to predict fat-free soft tissue for each animal. The values for kilogram of fat-free soft tissue determined from chemical analysis were regressed on predicted fat-free soft tissue. the results indicate that fat-free soft tissue of carcasses can be accurately predicted using estimative traits that do not diminish carcass value.

Evidence for the Formation of Glucose (Not Sucrose) in the Metabolism of Germinating Sunflower Seeds

The application of carbon-13 nuclear magnetic resonance to studies of intact seeds has provided a technique for direct observation and determination of chemical constituents in living matter. A reexamination of products formed during the germination of sunflower, castor bean, and peanut seeds revealed that for the latter two sucrose is the main product from metabolism of germinating seeds, as expected. In the case of sunflower seeds, however, precise assignment of absorptions of individual carbon atoms reveals the presence of glucose and not sucrose, as was assumed from classical studies on mechanisms of germinating seed metabolism (this discrepancy is probably due to processes that occur during the extraction and labeling required for tracer studies)

Metabolism of Pyridine Coenzymes in Microorganisms

NADP was enzymatically synthesized from NAD and p-nitrophenyl phosphate or nucleoside monophosphate with the enzyme preparation of Proteus mirabilis (IFO 3849). In this phosphotransferring reaction, ATP did not serve as phosphoryl donor.In addition to NADP, an unidentified substance (Compound I) showing fluorescence with methyl ethyl ketone and having no coenzyme activity to glutamic dehydrogenase was synthesized. The yield of NADP was usually below 30 per cent of Compound I.NADP was isolated from the reaction mixture and its coenzyme activity to some dehydrogenases was demonstrated.A new derivative of NAD (Compound I) synthesized from NAD and p-nitrophenyl phosphate by the enzyme preparation of Proteus mirabilis (IFO 3849), was isolated from the reaction mixture.After degradation of this compound with snake venom nucleotide pyrophosphatase, Compound III was obtained. 5′-NMN was phosphorylated to Compound IV by the same enzyme preparation of P. mirabilis. By the determination of chemical constituents and ...