Main Chemical Groups Research Articles

Seasonal variation in colleter exudates in Myrcia splendens (Myrtaceae)

Colleters are secretory structures that play a role in protecting meristems from dehydration. Little attention has been given to the effect of seasonal variation on colleter exudates. Therefore, this study aimed to characterise the main chemical groups found in colleter exudates as well as to correlate the chemical nature of the secretion with seasonal variation. We used Myrcia splendens as a model to understand seasonal variation in colleter exudates. For that, meristems and shoot apices of M. splendens were collected and subjected to standard anatomical techniques. In M. splendens, colleters arise from protodermal cells and are similar to trichomes. Mature colleters are conic and composed of a short stalk and a long secretory head. Histochemical analyses found that colleter exudates differed according to the seasonality. Composition of the secretions was more diverse in the dry season than in the wet season. During the dry season, colleters secreted five different compounds (i.e. total polysaccharides, mucilage–pectins, total proteins, total lipids and phenolic compounds), whereas in the wet season, only three compounds were found (i.e. total proteins, total lipids and phenolic compounds). Our study extends what was known in earlier works, demonstrating changes in colleter exudates due to environmental seasonality.

Effects of temperature on the chemical composition of tars produced from the gasification of coconut and palm kernel shells using downdraft fixed-bed reactor

Tar is derived from the gasification of cellulose and hemicellulose-rich coconut shell (CS) and lignin rich-palm kernel shell (PKS) using a downdraft fixed-bed reactor at 700 °C–900 °C. The tar yields and higher heating values from both biomass decrease with the increase in temperature, but high tar yields and higher heating values are obtained from PKS. Fourier transform infrared showed a similar pattern between the wavenumbers of 1500 cm−1 and 4000 cm−1, thereby indicating that the main chemical groups in CS and PKS tars are similar. The ultraviolet–visible spectroscopy shows that the aromatic content of tars increases with the increase in temperature, and CS tars show higher fluorescence intensity than PKS tars at >800 °C. Proton nuclear magnetic resonance shows that the tars from CS and PKS exhibit highly aromatic and phenolic protons, respectively. Gas chromatography–mass spectrometry results reveal that the total relative content of compounds in PKS tars is slightly higher than that in CS tars, and phenol group is the most abundant compound at all temperatures. Overall, the formation of aromatics and light PAHs are higher with CS tars, but PKS tars are more stable for the formation of heterocyclic and heavy PAHs.

Chemical composition of table olive wastewater and its relationship with the bio-fortifying capacity of tomato (Solanum lycopersicum L.) plants

Recently, the potential use as fertilizer of some wastewaters from table olive factories has been reported but the cause of this activity has not been disclosed up to now. In this study, a huge number of table olive waste solutions were analyzed from three consecutive seasons. Sugars, phenolic and mineral compounds were the main chemical groups identified. The individual effect of these components was tested on the growth of tomato plants and the quality of their fruits. Two factorial designs were assayed (24 and 23), in which the individual groups of chemical substances were sugars, minerals (nitrogen, potassium and phosphor), simple and polymeric phenols. Also, fresh wash water from Spanish-style green table olive processing was tested. The main conclusion was that no one individual group caused the fertilizer activity but a synergetic action of all of them was efficient and the fresh waste solution tested was the most effective.

Polyamide 6.6 thin films with distinct ratios of the main chemical groups: Influence in the primary neuronal cell culture

Neuronal cell cultures have been instrumental to the advance of our knowledge in a wide range of areas. One of the limitations of this model is the lack of stability, over time, of the substrate materials that are used in neuronal cell cultures. In this work, sputtering was used to permanently modify glass coverslips with a polyamide 6.6 thin film, using different discharge gases. Differences in the chemical composition of the films, resulting from the conditions used in deposition, were correlated with the surface properties. After characterization by SEM, TEM, AFM, XPS, zeta-potential, wettability and evaluation of the mechanical properties, some surfaces were selected for in vitro testing in the development of cultured cerebrocortical neurons. The results showed that the chemical composition and surface charge are particularly affected by the variation of the deposition parameters, although wettability, for example, did not present significant variations. In vitro tests revealed that the surfaces with higher NH 2 /COOH ratio allowed the adhesion and differentiation of neurons, with a morphology similar to that obtained after plating of the cells on poly- d -lysine-coated glass. This work opens new perspectives for the permanent modification of materials towards multifunctional neural compatible surfaces and open new areas for bioengineering applications. • Polyamide 6.6 thin films for permanent modification of glass surface for neurons adhesion • The surface of the deposited material can be preconditioned during deposition. • The tuning of surface properties potentially ensures more stable materials for cell attachment. • Polyamide permanent modified glass present similar results to the standard PDL-glass.

LC‐DAD‐ESI‐MS/MS and GC‐MS profiling of phenolic and aroma compounds of high oleic sunflower oil during deep‐fat frying

Sunflower oils obtained after frying potatoes for different times (1, 5, and 10) and non-fried oils were analyzed. In total, 43 aroma substances were identified by GC-MS analyses and aldehydes were detected as the main chemical group. The concentration of aldehydes increased with the frying process and among them, (E,E)-2,4-decadienal, (E)-2-heptenal, and hexanal were found to be the major aroma compounds. High performance liquid chromatography with diode array detector, coupled with mass in tandem mode, were employed for quantitative and qualitative analysis of phenolic compounds. Rutin was the major phenolic compound in sunflower oils followed by chlorogenic acid, and they constituted the largest proportion of the total phenolic content in all oil samples. The concentration of phenolic compounds of sunflower oil revealed essential changes during several thermal processes and underwent degradation during heating. Only about 2% of its initial content presented after 10 frying process. Practical applications The present study explores the effects of the deep-fat frying process on aroma and phenolic compositions of sunflower oil. The cooking technique plays a significant role in the expanding global food industry. The findings of the research could be helpful for standardizing and preserving the taste, aroma, and nutritional value of the used oils and foods. Additionally, for the researchers, this study would give insight for identification and qualification phenolic and aroma compounds of sunflower oil.

Contribution of the multivariate analysis and origin for groundwater quality of mixed aquifer in the Msila plain (Algeria)

The change of climate and intensive exploitation of groundwater resources in the plain of M'sila has influenced the hydrochemical functioning of the complex aquifer. This resulted in a decrease in the piezometric level of groundwater. The multivariate statistical techniques were used to determine the main factors and regrouping parameters/wells and to understand the origin of groundwater chemistry. Multivariate analysis (principal component analysis and cluster analysis) was performed to identify a common source for sampling data of a semi-arid aquifer. Physicochemical analyses were conducted on the waters of 17 wells. The chemical water classification shows the dominance of a chlorinated calcium and magnesium sulphate type facies, which has a very remarkable tendency towards the salinisation. Cluster analysis based on major parameters contents defined four main chemical water groups with increased water-rock interaction. Some parameters presented the highest concentrations of the total of dissolved salts provoking a poor quality of water.

Review of Effluents and Health Effects of Cooking and the Performance of Kitchen Ventilation

ABSTRACT Cooking effluents are one of the most important sources of pollution in the indoor and outdoor environment. Exposure to cooking oil fumes (COFs) can increase the risk of many diseases. A healthy indoor environment and an energy-efficient ventilation system in kitchens are urgently demanded. This review is concerned with the current knowledge of the physical and chemical compositions of aerosols generated from typical cooking processes as reported in the literature. It is focused on the effects of cooking fuel, cooking oil, cooking temperature, cooking method, cooking style and other factors on the characteristics of cooking particles. The improvement measures in kitchen ventilation, supply air strategy and evaluation index for the kitchen environmental protection are also reviewed. It was found that the cooking process emits high concentrations of particulate matter (PM), and inhalable particles account for a high proportion, which may cause serious harm to human body. Coupled with various factors affecting the particle concentrations and particle size distribution, as well as the main chemical components groups used to characterize the cooking particles, include PAHs, fatty acids, dicarboxylic acids, n-alkanes, sterols, monosaccharide anhydrides, metals and ions. Using an appropriate ventilation system and some auxiliary measures can effectively reduce cooking oil fumes pollution.

Antioxidant flavonoids from Alhagi maurorum with hepatoprotective effect

Background: Alhagi maurorum, commonly used in folk medicine, has been reported to have several biological activities. Objective: We have studied the antioxidant chemical components from A. maurorum to determine their in vitro antiproliferative and hepatoprotective activities. Materials and Methods: The alcoholic extract of A. maurorum root was subjected to a successive solvent fractionation and various chromatographic techniques guided by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay to isolate their antioxidant active compounds. The structures of the isolated compounds were identified through the extensive use of nuclear magnetic resonance and mass spectroscopy coupled with correlation to known compounds. The antioxidant and cytotoxic activities of the isolated compounds were quantified using DPPH and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assays, respectively. The hepatoprotective activity of each extract and the total flavonoid fraction were assessed quantitatively on carbon tetrachloride (CCl4)-induced hepatotoxicity in rats. Results: Fourteen flavonoids, including four aglycones (1–4) and ten glycosides (5–14), were isolated. The flavonoid glycosides (6–14) are being reported for the first time to our knowledge. The free aglycones, those of the flavonol type, exhibited strong antioxidant and antiproliferative activities. The flavonoid glycosides exhibited weak cytotoxic activity against the hepatocellular carcinoma cell line. The total flavonoid fraction showed the strongest hepatoprotective activity against CCl4-induced hepatotoxicity. Conclusion: A total of 14 flavonoids were identified from A. maurorum; nine of them were isolated for the first time. Flavonoids were the main chemical group identified from the A. maurorum root extracts, and they are responsible for the hepatoprotective activity. The findings set up a scientific explanation for the folkloric administration of A. maurorum in the treatment of hepatic disorders.

Electrochemical synthesis of polypyrrole films doped with iodine by luminescent discharge plasma

ABSTRACTThis work presents a study about synthesis of polypyrrole films electrochemically doped with iodine by luminescent discharge plasma in aqueous sodium sulfate solution, and its structural, morphological and electrical characterization. The synthesis is carried out at atmospheric pressure with square pulse from -1.06 to 1.16 V for 120 minutes. Doping times of the films are 10, 30 and 50 minutes. The films have thicknesses of 6, 12.7, 20.32 and 25.4 μm, and linear growth trend according to the time exposure of their synthesis. The main chemical groups exhibited in the films are C-H, N-H and CH2I, which are characteristics of film doped with Iodine. The electrical conductivity calculated of polypyrrole films is in the range 10-5-10-3 S/cm, and its activation energy is between 0.052 and 1.77 eV.

Characterization of aroma and aroma‐active composition of Gaziantep cheese by solvent‐assisted flavor evaporation (SAFE) and aroma extract dilution analysis (AEDA)

The present study explores the effect of milk sources on aroma and aroma-active composition of Gaziantep cheeses. A total of 30 aroma compounds were extracted using solvent-assisted flavor evaporation (SAFE) method and identified using GC-MS analysis. Acids were determined as the main aromatic chemical group of the cheese samples followed by the ketones and alcohols. Between the samples, main difference detected in the mean value of compounds, the sheep cheese was significantly higher than goat cheese. Among the compounds, acetoin was the main aroma compounds and followed by the hexanoic and butanoic acids. With regard to the aroma-active compounds, in total 10 compounds were sensed using aroma extract dilution analysis and GC-MS-Olfactometry. Acetoin was the major aroma-active. Additionally, terpenes were differences determining chemical group. Thus, lavandulol and linalool oxide were the aroma-active terpene compounds identified only in goat cheese sample with 32 and 16 FD factors. Practical applications The flavor of cheese highly effect consumer acceptance and preference. Thus, the improvements of applications for flavor control and manipulation in cheeses have become progressively significant. The findings of the research could be helpful for standardizing and preserving the taste, aroma of the cheese in industry. Additionally, for the researchers, this study would give insight for identification and qualification aroma and aroma-active compounds of Gaziantep cheese for the first time.

Characterization of bioactive and volatile profiles of thyme (Thymus vulgaris L.) teas as affected by infusion times

The influence of different infusion times on phenolic, volatile, antioxidant, and colour properties of thyme (Thymus vulgaris L.) teas was investigated in the present study. The thyme teas were prepared using freshly boiled water at infusion times of 0, 2, and 5 min. The effect of infusion time on phenolics, volatiles, and antioxidant properties was clearly observed. Among the phenolic compounds identified in the samples by LC–MS–MS, luteolin-diglucuronide-glucuronide and protocatechuic acid-hexoside were identified for the first time ever in thyme teas, with the most dominant phenolic compound in all samples subsequently being luteolin-diglucuronide-glucuronide. A significant correlation between the phenolic compounds and antioxidant properties demonstrates that phenolic compounds affected the antioxidant potential of the thyme tea infusions. A total of 27 volatile compounds were identified and quantified in the samples. The main chemical group of the volatile compounds in the thyme teas was terpenes and represented almost 90% of the total volatiles in thyme teas. Among the terpenes, thymol (61.74–78.82%), p-cymene (8.92–17.90%) and carvacrol (4.41–5.62%) being the most abundant volatiles in all the teas. Results obtained by sensory evaluation indicate that taste panelists preferred thyme tea prepared at a 0-min infusion time.

Acaricidal activity of extracts from different structures of Piper tuberculatum against larvae and adults of Rhipicephalus microplus

ABSTRACT The strategies to control the cattle tick, Rhipicephalus microplus are based mainly on the use of synthetic pesticides. However, the emergence, establishment, and development of resistance of ticks is rendering the main chemical groups ineffective. Finding new molecules to effectively control infestations by R. microplus is necessary to maintain the productivity of cattle herds, particularly of taurine breeds established in equatorial and tropical regions of the world. Ethanol extracts from the leaves, stems, and fruits of Piper tuberculatum were evaluated in bioassays at concentrations of 50, 25, 12.50, 6.25, 3.12 and 1.56 mg mL-1. The concentrations lethal to 50% of the individuals (LC50) of tick larvae after 24 hours of exposure were 3.62, 3.99 and 5.30 mg mL-1 for fruit, stem and leaf extracts, respectively. Against the engorged females, the highest efficacy rates were obtained at the concentration of 50 mg mL-1, corresponding to 71.57%, 68.38% and 37.03% of the fruit, leaf and stem extracts, respectively. The main effect of the ethanol extracts was on the egg hatching rate of ticks, with a reduction of 55.63% for the fruit and leaf extracts, and 20.82% for the stem extract. The results show that P. tuberculatum is a promising source of molecules for use as active ingredients in pesticide formulations for R. microplus control.

In Vitro Cytotoxic and Anti-inflammatory Activities of Tanacetum argenteum (Lam.) Willd. subsp. argenteum Extract.

The objective of this study was to examine the anti-inflammatory and cytotoxic potential of n-hexane, ethyl acetate, and methanolic extracts of Tanacetum argenteum subsp. argenteum. Tanacetum L. is the third largest genus of Asteraceae family and is represented by 60 taxa in Turkish flora. Sesquiterpene lactones and pyrethrins are the main chemical groups of the genus. T. argenteum subsp. argenteum is an endemic taxa that is distributed in the Central and South Anatolia. In vitro anti-inflammatory activity was assayed using iNOS and NF-κB inhibition tests on RAW264.7 and HeLa cells. The cytotoxic activities were tested against ten cell lines using MTT assays. As a result, the n-hexane extract was found more active than the positive control parthenolide in iNOS test (IC50: 0.627±0.16 μg/mL) and cytotoxic experiments against PC3 and MPANC-96 cell lines (IC50: 2.85±0.51 μg/mL and 5.35±1.24 μg/mL, respectively).

Effect of an Iron Compound Added to Diesel Fuels in Both Soot Reduction Capacity and Soot Oxidation Reactivity

This study evaluates the effect of an iron precursor incorporation (50 ppm and 1500 ppm by weight) into a commercial diesel and a laboratory-prepared diesel surrogate, not only in the in situ soot reduction capacity, but also, in the physicochemical characteristics and reactivity of this carbonaceous material towards oxidation. The in situ soot reduction capacity measurements and the Fe-containing soot sample collection for after-treatment tests were performed in a drop-tube like reactor placed inside of a vertically tubular furnace operated at 900 °C. The results indicate that as the iron content in fuel increases, the in situ soot reduction capacity increases up to 50% for commercial diesel and 42% for the diesel surrogate. However, although the soot particles collected on filters did not show significantly changes in the main chemical groups due to the fuel additive incorporation, the graphitization degree among samples differ, being structurally more ordered the soot particles from pure fuels than tho...

Analysis of adsorption processes of dissolved organic matter (DOM) on ferrihydrite using surrogate organic compounds

Ferrihydrite (Fh) has been recently used in water treatment for removing dissolved organic matter (DOM), but its governing interactions with low-molecular weight DOM are largely unknown. This study aimed to elucidate the influence of chemical structure of DOM on the interactions between functional groups of DOM and Fh using various surrogates representing DOM in natural waters. We tested four surrogate compounds: L-glutamic acid, resorcinol, L-serine, and tannic acid, which represent the main chemical groups of carboxylic and hydroxyl groups; and the Suwannee River NOM (SRNOM) that represents the composition of DOM in natural aquatic systems. Batch adsorption experiments revealed that the DOM adsorption onto Fh was significantly influenced by the steric arrangements of -COOH and -OH functional groups. Both L-serine with α-carboxyl group and resorcinol with hydroxyl groups in meta-position were marginally removed by Fh, indicating that the adsorption of DOM on Fh was determined by their chemical structures and the relative positions of carboxylate and hydroxyl groups. The adsorption of L-glutamic acid was controlled by the pH-dependent ligand exchange of γ-carboxyl groups, which was similar to the SRNOM adsorption. In contrast, adsorption of tannic acid was not affected by pH, which can be explained by a two-step adsorption, namely, ligand exchange followed by multi-layer adsorption to the partitioning phase. The results of kinetic experiments demonstrated that adsorption of DOM by Fh was significant and rapid. The kinetic adsorption data can be expressed by the pseudo-second-order equation, indicating that the adsorption step might be the rate-limiting step.

Volatile and key odourant compounds of Turkish Berberis crataegina fruit using GC-MS-Olfactometry

This research was conducted to identify the aroma and aroma-active compounds of Berberis crataegina for the first time. Volatile profile of B. crataegina was obtained using the purge and trap extraction method with dichloromethane. Gas chromatography was coupled to mass spectrometry (GC–MS) allowed the quantitative and qualitative detection of 22 compounds in the sample. Aldehydes were the main chemical group in the sample and followed by aromatic alcohols and lactone. Aroma extract dilution analysis was implemented for the specification of key odourants of B. crataegina. In total, eight key odourants were detected in the extract of the sample, using GC–MS–Olfactometry and aldehydes were the leading chemical group. The key odourants, found to be contributing to the overall aroma in B. crataegina, were nonanal (FD = 1024; green, flowery), hexanal (FD = 512; green) and linalool (FD = 256; flowery, rose) because of high FD factors.

Equilibrium Isotherm, Kinetic Modeling, Optimization, and Characterization Studies of Cadmium Adsorption by Surface-Engineered Escherichia coli

Background:Amongst the methods that remove heavy metals from environment, biosorption approaches have received increased attention because of their environmentally friendly and cost-effective feature, as well as their superior performances.Methods:In the present study, we investigated the ability of a surface-engineered Escherichia coli, carrying the cyanobacterial metallothionein on the cell surface, in the removal of Ca (II) from solution under different experimental conditions. The biosorption process was optimized using central composite design. In parallel, the kinetics of metal biosorption was studied, and the rate constants of different kinetic models were calculated.Results:Cadmium biosorption is followed by the second-order kinetics. Freundlich and Langmuir equations were used to analyze sorption data; characteristic parameters were determined for each adsorption isotherm. The biosorption process was optimized using the central composite design. The optimal cadmium sorption capacity (284.69 nmol/mg biomass) was obtained at 40°C (pH 8) and a biomass dosage of 10 mg. The influence of two elutants, EDTA and CaCl2, was also assessed on metal recovery. Approximately, 68.58% and 56.54% of the adsorbed cadmium were removed by EDTA and CaCl2 during desorption, respectively. The Fourier transform infrared spectrophotometer (FTIR) analysis indicated that carboxyl, amino, phosphoryl, thiol, and hydroxyl are the main chemical groups involved in the cadmium bioadsorption process.Conclusion:Results from this study implied that chemical adsorption on the heterogeneous surface of E. coli E and optimization of adsorption parameters provides a highly efficient bioadsorbent.

Composition, proteolysis, and volatile profile of Strachitunt cheese

Strachitunt, a blue-veined Italian cheese, received the Protected Designation of Origin (PDO) label in 2014. Its unique technological feature is represented by the dual-curd method of production. Strachitunt is produced from raw bovine milk with or without the inoculation of natural starter cultures of lactic acid bacteria, and the addition of secondary cultures of mold spores is not permitted by the product specification. Physico-chemical properties, proteolysis, and volatile profile of Strachitunt were investigated in 10 cheese samples (ripened for 75 d) made throughout spring 2015 and provided by the main cheese maker. Overall, composition parameters showed a large variability among samples. Cheese was characterized by an acid paste (pH 5.46) and a lower extent of proteolysis compared with other blue-veined varieties. The main chemical groups of volatile organic compounds were alcohols and esters, whereas ketones represented only a minor component. The erratic adventitious contamination by mold spores of the cheese milk, the unique dual-curd method of cheese-making, and the large time variability between the piercing time and the end of ripening could be highlighted as the main causes of both the distinctive analytical fingerprint and the scarce standardization of this blue-veined cheese.

Chemical Composition and Antimicrobial Activity of Leaf, Ripe and Unripe Peel of Bitter Orange (Citrus aurantium) Essential Oils

A B S T R A C T Background and Objectives: The chemical composition and antimicrobial activity of bitter orange (Citrus aurantium) leaf, ripe and unripe peel essential oils, cultivated in southwest of Iran, were investigated. Materials and Methods: The analysis of chemical composition of hydro-distilled essential oils was carried out by GC-MS. The disc diffusion and broth micro-dilution were used to assay the antimicrobial effect of achieved essential oils. Results: According to the GC-MS analysis, 34, 39 and 21 components were determined in the leaf, ripe and unripe peel, respectively. The results revealed that the main components of all essential oils were linalool and limonene. The oxygenated monoterpene and hydrocarbonated monoterpene were the main chemical groups of leaf and peel essential oils, respectively. Although all of the examined essential oils had antimicrobial potential, the leaf and unripe peel essential oils with MIC of 4.67 mg/ml were the most effective against the bacteria and yeast species, respectively, and the ripe peel essential oil was the weakest one. The growth of Saccharomyces cerevisiae was controlled in the treated orange juices. The antifungal activity of essential oils was increased by rising up in their concentration and decreased by passing time. Unripe and ripe essential oils showed the strongest and weakest anti yeast potential, respectively. Conclusions: The essential oils of leaves and ripe and unripe peels of bitter orange could be used as natural preservatives in food industry.

Contemplation on new drug approvals by U.S. FDA, 2011-2015

Background: The U.S Food and Drugs Administration (FDA) is the world's leading drug regulatory authority. There are reports of more product pipelines in oncology therapy area. The objective of this study was to see the overall trends of new drug approvals by the U.S. FDA in last 5 years and find the therapeutic areas with higher new drug approvals. Methods: New drug approvals data obtained from publicly available databases of the U.S. FDA from 2011 through 2015. For the drug products identified, the drugs were classified into fourteen main Anatomical Therapeutic Chemical (ATC) groups, single or combination products, New Drug Application (NDA) chemical types, review classification and approval date. Results: There were 182 new drugs approved from 2011 through 2015 by the U.S. FDA with a mean of 36.4 approvals per year. Out of these 182 new drug approvals, 149 (81.87%) approvals were for new molecular entity (NME) and 33 (18.13%) for biologics license application (BLA). There were more number of new drug approvals in antineoplastic and immunomodulating agents (L) ATC group (n=66; 36.26% of total new drug approvals). Conclusions: For new drugs approved between 2011 and 2015, the U.S. FDA was first to approve majority of new drugs. There was upward trend of new drug approvals in antineoplastic therapeutic area.