Dyeing of cotton fabric for improved mosquito repellency

Recently, mosquito repellent textile materials are increasingly in demand from consumers as a preventive measure from mosquito-borne diseases like malaria, dengue. Mosquito repellent-treated textile material initially shows good repellency against mosquitoes but upon repeated washing cycles this effect gets washed off considerably. In the present work, 4-Amino-N, N-diethyl–3-methyl benzamide (MD) is synthesized from N, N-diethyl-m-toluamide (DEET) and it is used as base material for synthesis of azo group. This synthesized base MD was then coupled with three different napthols to get dyed cotton fabric using diazotization process. This dyed cotton fabric has imparted mosquito repellent finish in one, single operation of dyeing cum finishing. This approach is based on modification of universally used mosquito repellent and synthesizing an azo group-based dye in the fibre matrix of the cotton fabric. The chemical structures of the MD were characterized using FT-IR and ¹H-NMR spectroscopy. The fastness properties of the dyed cum finished fabric were measured to evaluate the performance of the dyed fabric. Efficacy of mosquito repellency of the dyed cotton fabric was studied using standard methods. The dyed cotton fabric using napthols and MD showed very good and durable mosquito-repellent activity.     

Modified application process on cotton fabric for improved mosquito repellency

As mosquito-borne diseases are increasing continuously throughout the world, mosquito repellent textiles are in demand as a preventive measure for mosquito bites to avoid diseases. In this study, mosquito repellent chemical was prepared by modification of N, N-Diethyl-3-methylbenzamide (DEET) and applied on to cotton textiles. As DEET is a well-known mosquito repellent, it is a main ingredient in this modified DEET (MD). Mosquito repellent textiles were prepared by padding cotton fabrics with MD using a conventional pad-dry-cure method. Mosquito repellent activity was evaluated by cage test method wherein a human arm covered with the treated textiles to Aedes aegypti mosquitoes was exposed. Fabrics treated with MD presented a higher and longer lasting protection from mosquitoes assuring over 90% mosquito repellency for unwashed treated fabrics and between70 and 80% for 10 times washed treated fabrics.     

On-line1H-NMR to facilitate tube preparation in SNIF-NMR analysis

The detection of adulteration of wine by SNIF-NMR (site-specific natural isotopic fractionation-nuclear magnetic resonance) analysis of wine alcohol is a well established and widely used method. Quantitative deuterium ([²H]) NMR spectroscopy of defined distillate/tetramethylurea (TMU) mixtures enables the calculation of the site-specific deuterium/hydrogen ([²H]/H) ratios in the ethanol molecule. TMU with a known [²H]/H ratio serves as the internal standard. The comparison of the [²H]/H ratios of unknown samples with values obtained from authentic samples allows conclusions to be drawn, in terms of the origin of the sugar in the must before fermentation. Up to now, the calculation of [²H]/H ratios has required the exact weighing of both the distillate and the quantity of TMU for the tube preparation, as they affect²H-NMR measurements. The precise quantity of ethanol in the distillates must be determined by Karl-Fischer titration or densitometry. Volatile distillate components are quantified by gas chromatography to ensure a satisfactory purity of the ethanol under study. The quantitative¹H-NMR method described involves determining the TMU/ethanol mass ratios in the tubes prepared for SNIF-NMR measurements. This mass ratio is necessary for the calculation of the [²H]/H ratio. The mass ratios measured using conventional procedures and those determined by on-line¹H-NMR agree 100%. Using this method means that the exact weighing of distillates and TMU for tube preparation and the determination of ethanol content in the distillates are no longer required. At the same time, higher concentrations of volatile components in the distillates, e.g. methanol, can be easily detected.     

多偶氮藏青活性染料的合成及其拼黑色应用

针对活性黑KN-B提升力差以及乌黑度不理想等缺点,以对位酯、H酸与2,2’-二氨基乙二醇二苯醚为原料,合成了多偶氮基藏青色活性染料A。合成优化工艺为:对位酯重氮化过程中,无机酸、NaNO2与对位酯的摩尔比分别为1∶1和1.05∶1、温度0～5℃;酸性偶合时,H酸与对位酯的摩尔比为0.96∶1。将染料A分别与活性染料KN-B、橙DN-EC、红DN-EC进行复配,得到染深性好的黑色拼混染料。与活性黑KN-B相比,其乌黑度明显提高,色牢度相近。     

Using <Superscript>1</Superscript>H and <Superscript>13</Superscript>C NMR techniques and artificial neural networks to detect the adulteration of olive oil with hazelnut oil

The lack of any official analytical method to detect the adulteration of olive oil with a low percentage of hazelnut oil is explained by the similarities in the chemical compositions of both kinds of oils. To counter this problem, an artificial neural network based on ¹H-NMR and ¹³C-NMR data has been developed to detect olive oil adulteration, and the results from this ANN are presented here. A training set consisting of hazelnut oils, pure olive oils, and olive oils blended with 2–20% hazelnut oils was used to design and train a multilayer perceptron with 100% correct classifications. This mathematical model was also validated using an external validation set of blend samples (3–15%) and genuine samples. The detection limit of the model was around 8%.     

Effects of area,year and climatic factors on Barbera wine characteristics studied by the combination of 1H-NMR metabolomics and chemometrics

Barbera is one of the most common red grape in Italy, found in almost every region of the country. The widespread market of the corresponding wine deserves studies on its traceability and authenticity. To this end, the ¹H-NMR database of several wine metabolites was built using spectra recorded in a wine-like matrix containing ethanol and tartaric acid with pH precisely adjusted. The combination of ¹H-NMR metabolomics study and chemometrics (multivariate data analysis) is able to discriminate between samples of such a wine produced in three different areas of Piedmont. The influence of climatic factors on the wine characteristics has also been studied.     

Determination of the overall migration from silicone baking moulds into simulants and food using 1H-NMR techniques

Different silicone baking moulds (37 samples) were characterized with respect to potential migrating substances using ¹H-NMR, RP-HPLC–UV/ELSD and GC techniques. In all cases cyclic organosiloxane oligomers with the formula [Si(CH₃)₂–O] _n were identified (n = 6 … 50). Additionally, linear, partly hydroxyl-terminated organosiloxanes HO–[Si(CH₃)₂–O] _n –H (n = 7 … 20) were found in 13 samples. No substances other than siloxanes could be detected, meaning the migrants mainly consist of organopolysiloxanes. Based on this knowledge, a ¹H-NMR quantification method for siloxanes was established for the analysis of both simulants and foodstuffs. Validation of the ¹H-NMR method gave suitable performance characteristics: limit of detection 8.7 mg kg^–1 oil, coefficient of variation 7.8% (at a level of 1.0 mg kg^–1 food). Migration studies were carried out with simulants (olive oil, isooctane, ethanol (95%), Tenax) as well as preparation of different cakes. From the 1st to 10th experiment, siloxane migration into cakes only slightly decreased, with a significant dependence on fat content. Migration never exceeded a level of 21 mg kg^–1 (3 mg dm^–2) and was, therefore, well below the overall migration limit of 60 mg kg^–1 (10 mg dm^–2). However, migration behaviour into simulants differed completely from these results.     

基于1H-NMR代谢组学法研究辛硫磷诱导鲫鱼代谢变化

目的:规范辛硫磷的使用,保证水产品安全。方法:以淡水鲫鱼为研究对象,选取农业上经常使用的有机磷农药辛硫磷作为外源性环境污染物代表物,采用¹H-NMR代谢组学方法并结合PCA、PLS-DA、OPLS-DA等多元统计学方法研究辛硫磷暴露下鲫鱼体内正常生理代谢的变化,据此推断辛硫磷对鲫鱼的毒性影响及在鲫鱼体内的毒理机制。结果:辛硫磷组与空白组血清样本之间存在显著的差异性代谢产物。与空白组鲫鱼血清相比,辛硫磷组血清中3-羟基丁酸酯、葡萄糖及苯丙氨酸含量显著升高,而谷氨酸、丙氨酸、天冬酰胺、组氨酸等氨基酸,乳酸,不饱和脂肪酸,脂质,甘油磷酸胆碱,磷酸胆碱,胆碱,鸟嘌呤核苷,肌苷含量显著下降(P<0.05)。结论:辛硫磷能够改变鲫鱼体内的能量代谢和氨基酸代谢,干扰鲫鱼体内神经递质的传递以及诱导鲫鱼氧化应激等。同时,这些内源性代谢产物差异性变化可能与辛硫磷在鲫鱼体内发生的Ⅱ相代谢反应有关。     

Evaluation of the effect of carvacrol on the Escherichia coli 555 metabolome by using H-NMR spectroscopy

Cultures of Escherichia coli 555 were grown at four levels of carvacrol (0–2 mM) and the E. coli endo-metabolome was extracted and measured by ¹H NMR spectroscopy. The results show that glucose concentration is going up with concentration of carvacrol and so do formate until the highest concentration is reached, from which point it suddenly decreases. This is interpreted as if the bacteria are increasingly unable to further metabolize glucose and as if the bacteria increasingly shifts with higher levels of carvacrol toward sugar fermentation as carbon source, until the level of carvacrol reaches a level (2.00 mM), where the E. coli must give up. Additionally, the multivariate Principal Component Analysis suggests that the adaptation occurring at sub-lethal doses of carvacrol is different from that occurring at higher doses.     

Symbolic Metabolite Analysis of Pickled Wax Gourd in Eastern China by 1H-NMR Spectroscopy and Multivariate Data

Pickled wax gourd is a traditional fermented vegetable product popular in Zhejiang province, eastern China; however, information on their quality is quite limited. In the present study, we investigated the quality of pickled wax gourd at different processing phases using nuclear magnetic resonance, principal component analysis, and orthogonal partial least squares-discriminant analysis. According to the spectra of ¹H NMR, 36 kinds of metabolites were found at the 20th day of fermentation. Principal component analysis score plot showed that diverse marker metabolites occurred in all designated sampling points (every other 5 days), apart from the samples between the 10th day and 15th day of fermentation. Symbolic metabolites at the first 5 days were L-rhamnose, lactate, fatty acid, arginine, N-acetylglutamate, succinate, phosphorylcholine, glutamate, ornithine, lysine, and β-glucose. Lactate, succinate, glycine, proline, and choline were detected at the following period from the 5th to the 10th day of fermentation. Lactate, succinate, glycine, mannitol, choline, and α-ketoglutaric acid were the main metabolites on the 15th and 20th day. The diversity of metabolites fits with the microbial species structure in different pickling periods. This method was proved to be effective for monitoring the pickling process in real time.     

A study of the evolution of the physicochemical and structural characteristics of olive and sunflower oils after heating at frying temperatures

The evolution of the density, viscosity, oil/water interfacial tension and structure of vegetable oils after heating at frying temperatures was studied to explore the possibility of reusing waste vegetable oils as solid agglomerants for different purposes. Commercial olive and sunflower oils were heated at 150 and 225 °C in the time interval of 1–15 days to achieve a wide range of alteration degrees. Structural changes in the oils were monitored by FT-IR and ¹H NMR. Significant variations occur in the physicochemical and structural characteristics of these oils, which may affect their agglomeration capability, when they were heated at frying temperatures for periods above two days. Under these conditions, the viscosity of the oils increased very quickly, whereas their unsaturation degree decreased noticeably. Decreases in the relative intensities of the NMR spectra signals of the unsaturation-related protons were observed, those corresponding to the diallyl protons occurring much faster. Of the two vegetable oils studied, sunflower oil was found to be more sensitive to thermal treatment, undergoing greater changes in its properties, especially in viscosity, which may show a marked increase.     

Classification of Brazilian vinegars according to their H NMR spectra by pattern recognition analysis

This work describes using ¹H NMR data and pattern recognition analysis to classify vinegars. Vinegar authenticity is linked to raw ingredient source and manufacturing conditions. Application of PCA and HCA methods resulted in the natural clustering of the samples according to the raw material used. Wine vinegars were characterized by a high concentration of ethyl acetate, glycerol, methanol and tartaric acid, while glycerol and ethyl acetate signals were not visible in alcohol/agrin vinegars. Apple vinegars showed to be richer in alanine. The KNN, SIMCA and PLS-DA methods were used to build predictive models for classification of vinegar type wine, apple and alcohol/agrin (27 samples - 22 as training set). The models were tested using an independent set (5 samples), no samples were wrongly classified. Validated models were used to predict the class of 21 commercial samples, which, as expected, were correctly classified. Eight commercial vinegars (honey, orange, pineapple and rice) were discriminated from these samples using PCA method. Honey vinegars did not present ethanol signals and pineapple vinegars presented the largest amount of tartaric acid. Rice and orange vinegars are richer in lactic acid and did not present the methanol signal. Alanine signals were not visible in orange vinegars.     

Ability of methanolic seed extracts of pawpaw (Asiminatriloba) to inhibit n-3 fatty acid oxidation initiated by peroxyl radicals and reactive oxygen,nitrogen, and sulfur

Methanolic extracts from underripe, ripe, and ripe then dried pawpaw seeds (PPSE) were tested for antioxidative effectiveness. Underripe seeds contained more total phenolic compounds than ripe seeds, but ripe seeds showed the highest reducing potential. PPSE samples effectively scavenged DPPH (>86%). PPSE (0–26.8 μM gallic acid) effectively inhibited lipid oxidation biomarkers in 22:6 phosphatidylcholine (PC) liposome suspensions over 7 day’s incubation at room temperature. PPSE inhibited TBARS in 22:6 PC liposome suspensions induced by peroxyl radical generators, free radical generators that produce reactive oxygen, reactive nitrogen, and reactive sulfur species. After 120 min of storage TBARS inhibition by PPSE was in the order of H₂O₂ ? SIN-1 = DSSO = AAPH ? Sulfite > ONOO = MMb > iron/ascorbate. PPSE inhibited lipid oxidation biomarkers in skeletal muscle homogenates induced by iron/ascorbate. The development of value added products from pawpaw seeds may lead to successful commercialisation of this underutilised fruit.     

Study of the suitability of HRMAS NMR for metabolic profiling of tomatoes: Application to tissue differentiation and fruit ripening

The feasibility of HRMAS NMR as an efficient technique for metabolic studies of tomato fruit and tomato tissues is described. A good-taste tomato variety from Almería (Spain) (commercial name Zayno) was chosen for this study. Fruits of three different ripening stages (green, turning and red) were selected, based on their external appearance. NMR data of whole fruits were obtained through ¹H HRMAS NMR spectra of tomato purée. Flesh, peel and seeds from mature red fruits were separately analysed. ¹H HRMAS NMR spectra showed resolutions similar to that of solution ¹H NMR with the advantages of minimal sample manipulation and possibility of analysing polar and non-polar compounds simultaneously. Seeds could be clearly distinguished by visual comparison of the spectra. Tryacylglycerols, in which linoleic (47%) and oleic (28%) acyl chains preponderate, were the major components of seeds. By contrast, signals of fructose, glucose, citric acid, and the amino acids GABA, glutamine and glutamate dominated the spectra of flesh, peel and tomato purée. Principal components analysis, performed on the covariance matrix, revealed a clear separation between peel and flesh. Apart form the presence of the cutin biopolymer, peel showed a specific accumulation of sugar and sugar moieties related to pectin degradation, as well as glycosylated metabolites. Chemometric analysis also allowed the metabolic trajectory from green to red mature stages to be visualised. However, sample heterogeneity in the analysis of the whole fruit proved to be an important issue. The source of such heterogeneity was assigned to the presence of tissues of different hardness in the small amount of sample used. The presence of two clusters of samples at the turning stage indicated that the levels of certain metabolites could diverge significantly in fruits with almost identical appearance.     

Biochemical monitoring of black raspberry (Rubus coreanus Miquel) fruits according to maturation stage by H NMR using multiple solvent systems

Nuclear magnetic resonance (NMR) techniques coupled with multivariate data analysis were used to conduct monitoring of biochemical changes of black raspberry fruits at different stages of maturation and under various extraction and NMR dissolution solvent conditions: extraction with 50% methanol and D₂O as an NMR dissolution solvent, extraction with 50% methanol and 50% methanol-d₄ as an NMR dissolution solvent, and extraction with 100% ethyl acetate and 100% methanol-d₄ as an NMR dissolution solvent. Partial least-squares discriminant analysis reliably distinguished black raspberry fruits according to the maturation stage, whereby the relative levels of various compounds such as amino acids, organic acids, sugars and phenolic compounds were compared using analysis of variance. Sucrose and most of the amino acids, and organic acids decreased, whereas fructose, glucose, and cyanidins increased in relative concentration according to maturation of black raspberry fruits. The total number and kinds of assigned compounds of the three solvent systems were also compared. This research demonstrates that the metabolic profile of black raspberry fruits changes during maturation, and provides objective criteria for determining the stage of black raspberry fruit maturation via a ¹H NMR-based metabolomics technique using multiple solvent systems.     

Classification of olive oils according to geographical origin by using H NMR fingerprinting combined with multivariate analysis

Authentic extravirgin olive oils from 7 different regions (Italy – 3 regions, Greece – 4 regions) have been investigated by ¹H Nuclear Magnetic Resonance (NMR) fingerprinting in combination with multivariate statistical analysis. In order to cover the dominating lipid signals as well as signals from compounds of low abundance in the oil, both a simple one pulse experiment and an experiment with multiple saturation of the lipid signals was applied to each sample. Thus, the dynamic range of concentrations covered by the two experiments was of the order of 100,000 allowing for a more comprehensive NMR assessment of the samples. Monte-Carlo embedded cross-validation was used to demonstrate that a combination of principal component analysis, canonical analysis, and classification via nearest class mean can be used to predict the origin of olive oil samples from ¹H NMR data. Given the rather limited number of samples tested, correct prediction probabilities of 78% were achieved with region specific correct predictions between 53% and 100%.     

Relative molar sensitivities of carnosol and carnosic acid with respect to diphenylamine allow accurate quantification of antioxidants in rosemary extract

We have been developing a high-performance liquid chromatography/photodiode array (HPLC/PDA) employing relative molar sensitivities (RMSs) and adopted it to the accurate quantification of carnosol (CL) and carnosic acid (CA) which are the antioxidants in rosemary extract. The method requires no references of CL or CA and instead uses RMSs with respect to diphenylamine (DPA) whose certified reference material is available from a reagent manufacturer. The molar and response ratios of the analytes to the reference in an artificial mixture of them were determined using ¹H-quantitative nuclear magnetic resonance spectroscopy (¹H-qNMR) and HPLC/PDA at a wavelength of 284 nm under isocratic condition, respectively, and then RMSs were calculated to be 0.111 for CL/DPA and 0.0809 for CA/DPA as averaged values in three HPLC–PDA instruments. The RMS values varied by up to 1.1% as relative standard deviation. To evaluate the performance of HPLC/PDA with the RMSs, the CL and CA contents in rosemary extracts were determined using DPA as a reference. The CL and CA contents were compared with those determined using calibration curves of CL and CA obtained by HPLC measurement of standard solutions prepared from their reagents whose absolute purities were determined using ¹H-qNMR. The differences between the two methods for CL and CA were ≤3% as relative error. This chromatographic method with RMSs allows a simple and reliable quantification when reference of the analyte is unavailable.     

Phytochemical profile of Rosmarinus officinalis and Salvia officinalis extracts and correlation to their antioxidant and anti-proliferative activity

The goal of this study was to monitor the anti-proliferative activity of Rosmarinus officinalis and Salvia officinalis extracts against cancer cells and to correlate this activity with their phytochemical profiles using liquid chromatography/diode array detection/electrospray ion trap tandem mass spectrometry (LC/DAD/ESI-MSⁿ). For the quantitative estimation of triterpenic acids in the crude extracts an NMR based methodology was used and compared with the HPLC measurements, both applied for the first time, for the case of betulinic acid. Both extracts exerted cytotoxic activity through dose-dependent impairment of viability and mitochondrial activity of rat insulinoma m5F (RINm5F) cells. Decrease of RINm5F viability was mediated by nitric oxide (NO)-induced apoptosis. Importantly, these extracts potentiated NO and TNF-α release from macrophages therefore enhancing their cytocidal action. The rosemary extract developed more pronounced antioxidant, cytotoxic and immunomodifying activities, probably due to the presence of betulinic acid and a higher concentration of carnosic acid in its phytochemical profile.     

Study by means of H nuclear magnetic resonance of the oxidation process undergone by edible oils of different natures submitted to microwave action

The oxidation processes of virgin olive, corn and linseed oils, repeatedly submitted to the effect of microwave heating until the temperature reached 190 °C, have been studied by means of ¹H nuclear magnetic resonance. These oxidation processes are very different to those produced at 70 °C with aeration; differences have been found not only in the rate of degradation and in the oxidation mechanisms but also in the nature and proportions of the aldehydes generated. It has also been shown that these oxidative conditions affect the three oils studied in very different ways; virgin olive oil is the least affected by this process and in addition its degradation produces lower proportions of harmful aldehydes.     

Application of light extinction to determine stability of beef emulsions

One of the major concerns in the meat processing industry is the loss of emulsion stability resulting in cooking losses. An optical sensor technology to control the emulsification process would minimize this problem. The normalized light intensity (I_N) as a function of fat/lean ratio (R_FL; 0.075, 0.25, 0.33) and chopping time (CT; 2, 5, 8 min) were measured at three radial distances (2, 2.5, 3 mm) from the light source to calculate the optical density (OD) and the loss of intensity (I_Loss), using a fiber optic spectrometer. ANOVA results were highly significant for I_N, I_Loss. Normalized intensity decreased with increased chopping time as a result of emulsion homogenization, and with increased distance. Chopping time had a positive correlation with fat losses during cooking, which in turn had a negative correlation with I_N and I_Loss. These results suggest that light extinction spectroscopy could provide information about emulsion stability.