Coupling of carboxymethyl starch with 2-carboxyethyl acrylate: A new sorbent for the wastewater remediation of methylene blue.

Textile and printing industries play a vital role in the economy of any country. But the effluents of these industries, which contain toxic Methylene Blue (MB) dye when mixed with fresh water, make it unfit for human health and aquatic life. For the removal of MB, different adsorbents were used, but they were expensive, non-biodegradable or less effective. In this research, novel carboxymethyl starch grafted poly 2-carboxyethyl acrylate (CM-St-g-P2CEtA) was synthesized by reacting carboxymethyl starch with 2-carboxyethyl acrylate. The reaction followed a free radical polymerization mechanism. The structure and properties of CM-St-g-P2CEtA were investigated by advanced analytical techniques. The CM-St-g-P2CEtA was employed for the remediation of Methylene Blue (MB) dye from wastewater. The removal percentage (%R) of MB was checked under different parameters, like different pH levels, different initial concentrations of dye, different adsorbent doses, and different contact times. The results obtained during the experiment were subjected to different adsorption and kinetic models. In the kinetic investigation, the experimental results were best represented by the pseudo-second-order kinetic model due to its high R2 value of 0.999. Similarly, with a regression coefficient (R2) value of 0.947, the Langmuir adsorption isotherm was best represented by the experimental results. The Langmuir adsorption model showed that MB dye was adsorbed on the surface of CM-St-g-P2CEtA in a monolayer pattern. The pseudo 2nd order kinetic model suggested that the adsorption process favored chemisorption mechanism. The CM-St-g-P2CEtA showed maximum percentage removal efficiency (%R) of 99.3% for MB dye.

Microwave Irradiation Assists the Synthesis of a Novel Series of bis-Arm s-Triazine Oxy-Schiff Base and Oxybenzylidene Barbiturate Derivatives.

A novel series of s-triazines incorporating 4-hydroxybenzaldehyde and 4-hydroxy-3-methoxybenzaldehyde was prepared and fully characterized. The reaction was carried out via stepwise nucleophilic aromatic substitution of chlorine atoms in cyanuric chloride. The first chlorine was substituted by different amines (morpholine, piperidine, or diethylamine) to afford 2,4-dichloro-6-substituted-1,3,5-triazine. The second and third chlorines were substituted by benzaldehyde derivatives in the presence of Na2CO3 as a HCl scavenger to afford the target products: s-triazine oxyaldehyde derivatives (dipodal). The dipodal derivatives were reacted with acid hydrazide, hydralazine, barbituric, or thiobarbituric acid derivatives using conventional heating or microwave irradiation to afford the di-arm s-triazine oxy-Schiff base and oxybenzylidene barbiturate derivatives in good yields. Microwave irradiation done in less solvent afforded the target product in less reaction time with good yield and purity. These types of derivatives might have special interest in coordination and medicinal chemistry.

Antibacterial, Antioxidant Activity of Ethanolic Plant Extracts of Some Convolvulus Species and Their DART-ToF-MS Profiling.

Convolvulus austroaegyptiacus Abdallah & Sa'ad (CA) and Convolvulus pilosellifolius Desr. (CP) are commonly used in the Saudi Arabia folk medicine. They are potent in treating the ulcers and skin diseases. The lack of information about their biological activities led us to investigate the possible biological activities by determination of antibacterial and antioxidant activities of total ethanolic extracts and various fractions. Total flavonoid contents of the plants were determined by colorimetric method while total phenols were determined by using Folin-Ciocalteu method. In vitro antibacterial activity was studied against E. coli, P. aeruginosa, and B. subtilis, and the total antioxidant capacity was evaluated by radical scavenging method. IC50 were found to be 21.81, 17.62, and 3.31 µg/mL for CA, CP, and vitamin C, respectively, while the lowest MIC value of 0.25 mg/mL was recorded with CP extract against B. subtilis. Around 21 compounds are tentatively elucidated from both plants using rapid, simple, and high-resolution analytical technique for chemical profiling of natural compounds by direct analysis in real-time of flight-mass spectrometry, of which 17 were not isolated or reported previously.

Structural elucidation and physicochemical properties of mononuclear Uranyl(VI) complexes incorporating dianionic units.

Two derivatives of organouranyl mononuclear complexes [UO2(L)THF] (1) and [UO2(L)Alc] (2), where L = (2,2'-(1E,1'E)-(2,2-dimethylpropane-1,3-dyl)bis(azanylylidene, THF = Tetrahydrofuran, Alc = Alcohol), have been prepared. These complexes have been determined by elemental analyses, single crystal X-ray crystallography and various spectroscopic studies. Moreover, the structure of these complexes have also been studied by DFT and time dependent DFT measurements showing that both the complexes have distorted pentagonal bipyramidal environment around uranyl ion. TD-DFT results indicate that the complex 1 displays an intense band at 458.7 nm which is mainly associated to the uranyl centered LMCT, where complex 2 shows a band at 461.8 nm that have significant LMCT character. The bonding has been further analyzed by EDA and NBO. The photocatalytic activity of complexes 1 and 2 for the degradation of rhodamine-B (RhB) and methylene blue (MB) under the irradiation of 500W Xe lamp has been explored, and found more efficient in presence of complex 1 than complex 2 for both dyes. In addition, dye adsorption and photoluminescence properties have also been discussed for both complexes.

Functionalized nanoparticles based solid-phase membrane micro-tip extraction and high-performance liquid chromatography analyses of vitamin B complex in human plasma.

Iron nanoparticles were prepared by a green method following functionalization using 1-butyl-3-methylimidazolium bromide. 1-Butyl-3-methylimidazole iron nanoparticles were characterized using FTIR spectroscopy, energy dispersive X-ray fluorescence, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The nanoparticles were used in solid-phase membrane micro-tip extraction to separate vitamin B complex from plasma before high-performance liquid chromatography. The optimum conditions obtained were sorbent (15 mg), agitation time (30 min), pH (9.0), desorbing solvent [water (5 mL) + methanol (5 mL) + sodium hydroxide (0.1 N) + acetic acid (d = 1.05 kg/L, pH 5.5), desorbing volume (10 mL) and desorption time (30 min). The percentage recoveries of all the eight vitamin B complex were from 60 to 83%. A high-performance liquid chromatography method was developed using a PhE column (250 × 4.6 mm, 5.0 µm) and water/acetonitrile (95:5, v/v; pH 4.0 with 0.1% formic acid) mobile phase. The flow rate was 1.0 mL/min with detection at 270 and 210 nm. The values of the capacity, separation and resolution factor were 0.57-39.47, 1.12-6.00 and 1.84-26.26, respectively. The developed sample preparation and chromatographic methods were fast, selective, inexpensive, economic and reproducible. The developed method can be applied for analyzing these drugs in biological and environmental matrices.

sym-Trisubstituted 1,3,5-Triazine Derivatives as Promising Organic Corrosion Inhibitors for Steel in Acidic Solution.

Triazine derivatives, namely, 2,4,6-tris(quinolin-8-yloxy)-1,3,5-triazine (T3Q), N²,N4,N6-tris(pyridin-2-ylmethyl)-1,3,5-triazine-2,4,6-triamine (T3AMPy) and 2,2',2''-[(1,3,5-triazine-2,4,6-triyl)tris(azanediyl)] tris(ethan-1-ol) (T3EA) were synthesized and their inhibition of steel corrosion in hydrochloric acid solution was investigated using electrochemical techniques. The corrosion protection of the prepared compounds increased with increasing concentration and reached up to 98% at 250 ppm. The adsorption of T3Q, T3AMPy, and T3EA on the steel surface was in accordance with the Langmuir adsorption isotherm. The electrochemical results revealed that T3Q, T3AMPy and T3EA act as excellent organic inhibitors and can labeled as mixed type inhibitors. The efficiencies of the tested compounds were affected by the nature of the side chain present in the triazine ring, where T3EA gave the least inhibition while T3Q and T3AMPy gave higher and almost the same inhibition effects. The inhibition efficiencies obtained from the different electrochemical techniques were in good agreement.

Enantiomeric resolution of multiple chiral centres racemates by capillary electrophoresis.

Enantiomeric resolution of multichiral centre racemates is an important area as some multichiral centre racemates are of great medicinal importance. However, enantioseparation of such types of racemates is a challenging task. Amongst many analytical techniques, capillary electrophoresis is a powerful technique and may be used to resolve such racemates. Only few papers are available describing enantiomeric resolution of such racemates. Therefore, efforts have been made to describe the enantiomeric resolution of multichiral centre racemates by capillary electrophoresis. This article discusses the importance of multichiral racemates, the need for capillary electrophoresis in enantiomeric resolution and chiral resolution of multichiral centre racemates using various chiral selectors. Further, attempts have been made to discuss the future challenges and prospects of enantiomeric resolution of multichiral racemates. The various chiral selectors used for the purpose are chiral crown ether, cyclodextrins, polysaccharides, macrocyclic glycopeptide antibiotics and ligand exchange.

Heterocyclic Scaffolds: Centrality in Anticancer Drug Development.

Cancer has been cursed for human beings for long time. Millions people lost their lives due to cancer. Despite of the several anticancer drugs available, cancer cannot be cured; especially at the late stages without showing any side effect. Heterocyclic compounds exhibit exciting medicinal properties including anticancer. Some market selling heterocyclic anticancer drugs include 5-flourouracil, methortrexate, doxorubicin, daunorubicin, etc. Besides, some natural products such as vinblastine and vincristine are also used as anticancer drugs. Overall, heterocyclic moeities have always been core parts in the expansion of anticancer drugs. This article describes the importance of heterocyclic nuclei in the development of anticancer drugs. Besides, the attempts have been made to discuss both naturally occurring and synthetic heterocyclic compounds as anticancer agents. In addition, some market selling anticancer heterocyclic compounds have been described. Moreover, the efforts have been made to discuss the mechanisms of actions and recent advances in heterocyclic compounds as anticancer agents. The current challenges and future prospectives of heterocyclic compounds have also been discussed. Finally, the suggestions for syntheses of effective, selective, fast and human friendly anticancer agents are discussed into the different sections.

High Quality CdS Thin Film Growth by Avoiding Anomalies in Chemical Bath Deposition for Large Area Thin Film Solar Cell Application.

Many high efficiency thin-film solar cells incorporate a thin layer of CdS in the device structure to form a heterojunction. Chemical bath deposition (CBD) is the most preferred method of deposition especially for large area thin film solar cells. This study explored the effects of ammonium sulfate on the CdS film produced by CBD using cadmium sulfate as the cadmium source. The concentration of ammonium sulfate was varied from 0 M up to 0.006 M. The resulting optical, structural and surface morphological properties of the films were characterized. Results have shown that the films obtained at higher concentrations of ammonium sulfate were smoother and the occurrence of pinholes was also reduced. Agglomeration of CdS particles that is usually present in films deposited using cadmium sulfate as a precursor was also noticeably reduced. It was also observed that the rate of deposition also increased, resulting in a thicker film for identical deposition time and temperature. The average thickness of the films produced ranged from 60 nm to 180 nm.

Enantio-separation of drugs with multiple chiral centers by chromatography and capillary electrophoresis.

Some drugs with more than one chiral center are of high medicinal values. However, the chiral resolution of such types of racemate is a challenging task for scientists. The evolution of efficient chiral selectors is a hope for the future. Some papers have described such types of chiral resolution. The different techniques used for the purpose are HPLC, micellar electrokinetic chromatography, supercritical fluid chromatography, capillary electrochromatography and capillary electrophoresis. Owing to these facts, it was necessary to review the enantiomeric resolution of racemic drugs having more than one chiral center. The present article describes the chiral resolution of labetalol, formoterol, nadolol, indenolol, nebivolol and diltiazem using above cited techniques. In addition, attempts have been made to discuss the chiral recognition mechanism and future perspectives.

Advances in chiral separations of small peptides by capillary electrophoresis and chromatography.

Many chemical and biological processes are controlled by the stereochemistry of small polypeptides (di-, tri-, tetra-, penta-, hexapeptides, etc). The biological importance of peptide stereoisomers is of great value. Therefore, the chiral resolution of peptides is an important issue in biological and medicinal sciences and drug industries. The chiral resolutions of peptide racemates have been discussed with the use of capillary electrophoresis and chromatographic techniques. The various chiral selectors used were polysaccharides, cyclodextrins, Pirkle types, macrocyclic antibiotics, crown ethers, imprinted polymers, etc. The stereochemistry of dipeptides is also discussed. Besides, efforts are made to explain the chiral recognition mechanisms, which will be helpful in understanding existing and developing new stereoselective analyses. Future perspectives of enantiomeric resolution are also predicted. Finally, the review concludes with the demand of enantiomeric resolution of all naturally occurring and synthetic peptides.

Biotransformation of dianabol with the filamentous fungi and ß-glucuronidase inhibitory activity of resulting metabolites.

Biotransformation of the anabolic steroid dianabol (1) by suspended-cell cultures of the filamentous fungi Cunninghamella elegans and Macrophomina phaseolina was studied. Incubation of 1 with C. elegans yielded five hydroxylated metabolites 2-6, while M. phaseolina transformed compound 1 into polar metabolites 7-11. These metabolites were identified as 6ß,17ß-dihydroxy-17α-methylandrost-1,4-dien-3-one (2), 15α,17ß-dihydroxy-17α-methylandrost-1,4-dien-3-one (3), 11α,17ß-dihydroxy-17α-methylandrost-1,4-dien-3-one (4), 6ß,12ß,17ß-trihydroxy-17α-methylandrost-1,4-dien-3-one (5), 6ß,15α,17ß-trihydroxy-17α-methylandrost-1,4-dien-3-one (6), 17ß-hydroxy-17α-methylandrost-1,4-dien-3,6-dione (7), 7ß,17ß,-dihydroxy-17α-methylandrost-1,4-dien-3-one (8), 15ß,17ß-dihydroxy-17α-methylandrost-1,4-dien-3-one (9), 17ß-hydroxy-17α-methylandrost-1,4-dien-3,11-dione (10), and 11ß,17ß-dihydroxy-17α-methylandrost-1,4-dien-3-one (11). Metabolite 3 was also transformed chemically into diketone 12 and oximes 13, and 14. Compounds 6 and 12-14 were identified as new derivatives of dianabol (1). The structures of all transformed products were deduced on the basis of spectral analyses. Compounds 1-14 were evaluated for ß-glucuronidase enzyme inhibitory activity. Compounds 7, 13, and 14 showed a strong inhibition of ß-glucuronidase enzyme, with IC50 values between 49.0 and 84.9 µM.

Cyclo-hexyl-ammonium nitrate.

In the title salt, C6H14N(+)·NO3 (-), the cyclo-hexyl ring adopts a chair conformation. The ammonium group occupies an equatorial position and the crystal struture is stabilized by inter-molecular N-H⋯O hydrogen-bonding inter-actions, resulting in a three-dimensional network.

Facile method for the synthesis of silver nanoparticles using 3-hydrazino-isatin derivatives in aqueous methanol and their antibacterial activity.

INTRODUCTION: A new method for preparation of silver nanoparticles (AgNPs) based on using hydrazino-isatin derivatives in an aqueous methanol reaction medium is reported here. AgNPs were prepared using silver nitrate solubilized in a water core as the source of silver ions and 3-hydrazino-isatin derivatives (3-hydrazino-isatin [IsH] and 1-benzyl-3-hydrazino-isatin [BIsH]) solubilized in methanol core as a reducing agent. The proposed method is effective, rapid, and convenient. X-ray diffraction (XRD), energy dispersive X-ray analysis, scanning electron microscope (SEM) and transmission electron microscopy (TEM) were used for characterization of the AgNPs. The TEM micrographs confirmed that the nanopowders consist of well-dispersed agglomerates of grains with a narrow size distribution of 18-21 nm and 17-20 nm. The AgNPs, as well as BIsH, showed high antimicrobial and bactericidal activity against the Gram-positive Bacillus subtilis and Gram-negative Micrococcus luteus and Proteus vulgaris, as well as antifungal activities against Saccharomyces cerevisiae. On the other hand, they were not effective against the Gram-negative Escherichia coli. PURPOSE: A simple, effective, rapid, and convenient chemical reduction method for the synthesis of AgNPs in an aqueous methanol reaction medium using hydrazino-isatin derivatives and studying their antibacterial effect. RESULTS: IsH and BIsH are remarkably powerful reductants for Ag+ ions in an aqueous methanol medium, which could be considered as a simple chemical reduction method for formation of AgNPs. The AgNP formation depends on the solubility of the hydrazino-isatin derivatives. BIsH gave more AgNPs than IsH, as observed from XRD. The formation of AgNPs is attributed to the adsorption of hydrazine derivatives and/or interparticle interaction on the surface of AgNP through electrostatic interactions between the lone pair electrons of the hydrazino group (C=N-NH2) and the positive surface of AgNPs. AgNPs and BIsH showed high antimicrobial and bacterial activity. CONCLUSION: In summary, it is shown that IsH and BIsH are remarkably powerful reductants for Ag+ ions in an aqueous methanol medium. BIsH gave more AgNPs than IsH, as observed from XRD due to better solubility of the BIsH than IsH in aqueous-methanol. The formation of AgNPs is attributed to the adsorption of hydrazine derivatives and/or interparticle interaction on the surface of AgNPs through electrostatic interactions between the lone pair electrons of the hydrazino group (C=N-NH2) and the positive surface of AgNPs. The AgNps as well as BIsH ligand showed high antimicrobial and bactericidal activity.

Advances in enantiomeric resolution on monolithic chiral stationary phases in liquid chromatography and electrochromatography.

During the last decade, chiral monolithic stationary phases have been prepared and used for rapid enantioseparations in CEC and HPLC. Various chiral selectors are used to prepare these CSPs. The preparation, properties, and applications of these CSPs are discussed in this paper. Attempts have been made to describe optimization strategies and the chiral recognition mechanisms. A comparison of chiral separations in CEC and HPLC is described. Efforts have also been made to predict the future perspectives and challenges of chiral monolithic stationary phases. The most effective chiral selectors include polysaccharides, cyclodextrins, and macrocyclic glycopeptide antibiotics. These chiral phases produced acceptable analytical enantiomeric separation of a variety of racemates. However, the development of these CSPs for preparative-scale separations is needed.

Enantiomeric separation and simulation studies of pheniramine, oxybutynin, cetirizine, and brinzolamide chiral drugs on amylose-based columns.

Solid phase extraction (SPE)-chiral separation of the important drugs pheniramine, oxybutynin, cetirizine, and brinzolamide was achieved on the C18 cartridge and AmyCoat (150 x 46 mm) and Chiralpak AD (25 cm x 0.46 cm id) chiral columns in human plasma. Pheniramine, oxybutynin, cetirizine, and brinzolamide were resolved using n-hexane-2-PrOH-DEA (85:15:0.1, v/v), n-hexane-2-PrOH-DEA (80:20:0.1, v/v), n-hexane-2-PrOH-DEA (70:30:0.2, v/v), and n-hexane-2-propanol (90:10, v/v) as mobile phases. The separation was carried out at 25 ± 1 ºC temperature with detection at 225 nm for cetirizine and oxybutynin and 220 nm for pheniramine and brinzolamide. The flow rates of the mobile phases were 0.5 mL min(-1). The retention factors of pheniramine, oxybutynin, cetirizine and brinzolamide were 3.25 and 4.34, 4.76 and 5.64, 6.10 and 6.60, and 1.64 and 2.01, respectively. The separation factors of these drugs were 1.33, 1.18, 1.09 and 1.20 while their resolutions factors were 1.09, 1.45, 1.63 and 1.25, and 1.15, respectively. The absolute configurations of the eluted enantiomers of the reported drugs were determined by simulation studies. It was observed that the order of enantiomers elution of the reported drugs was S-pheniramine > R-pheniramine; R-oxybutynin > S-oxybutynin; S-cetirizine > R-cetirizine; and S-brinzolamide > R-brinzolamide. The mechanism of separation was also determined at the supramolecular level by considering interactions and modeling results. The reported SPE-chiral high-performance liquid chromatography (HPLC) methods are suitable for the enantiomeric analyses of these drugs in any biological sample. In addition, simulation studies may be used to determine the absolute configuration of the first and second eluted enantiomers.

Seasonal concentrations of lead in outdoor and indoor dust and blood of children in Riyadh, Saudi Arabia.

Because detrimental effects of exposure to lead (Pb) on human health have been observed, we previously investigated concentrations of Pb in water supplies and blood of adult residents of Riyadh, Saudi Arabia. The objectives of the present study were to: (1) examine seasonal rates of deposition of Pb in dust in several areas of Riyadh city, (2) measure concentrations of Pb in both outdoor and indoor dust, (3) compare concentrations of Pb in dust in Riyadh with those reported for other cities, and (4) quantify Pb in blood of children living in Riyadh. Mean, monthly deposition of PB in outdoor dust was 4.7 × 10(1) ± 3.6 tons km(-2), with a mean Pb concentration of 2.4 × 10(2) ± 4.4 × 10(1) µg/g. Mean, monthly deposition of Pb in indoor dust was 2.7 ± 0.70 tons km(-2), with a mean concentration of 2.9 × 10(1) ± 1.5 × 10(1) µg Pb/g. There was a significant (P < 0.01) correlation between concentrations of Pb in outdoor and indoor dust. There was no correlation between concentrations of Pb in indoor dust and that in blood of children of Riyadh, whereas there was a weakly significant (P < 0.05) correlation between concentrations of Pb in outdoor dust and that in blood of children. The mean (±SD) concentration of Pb in blood of children in Riyadh was 5.2 ± 1.7, with a range of 1.7-1.6 × 10(1) µg/dl. Concentrations of Pb in blood of 17.8 % of children in Riyadh were greater than 10 µg/dl, which is the CDC's level of concern.

Removal of arsenic species from water by batch and column operations on bagasse fly ash.

Bagasse fly ash (BFA, a sugar industrial waste) was used as low-cost adsorbent for the uptake of arsenate and arsenite species from water. The optimum conditions for the removal of both species of arsenic were as follows: pH 7.0, concentration 50.0 µg/L, contact time 50.0 min, adsorbent dose 3.0 g/L, and temperature 20.0 °C, with 95.0 and 89.5 % removal of arsenate and arsenite, respectively. The Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich adsorption isotherms were used to analyze the results. The results of these models indicated single-layer uniform adsorption on heterogeneous surface. Thermodynamic parameters, i.e., ΔG°, ΔH°, and ΔS°, were also calculated. At 20.0 to 30.0 °C, the values of ΔG° lie in the range of -4,722.75 to -4,878.82 and -4,308.80 to -4,451.73 while the values of ΔH° and ΔS° were -149.90 and -121.07, and 15.61 and 14.29 for arsenate and arsenite, respectively, indicating that adsorption is spontaneous and exothermic. Pseudo-first-order kinetics was followed. In column experiments, the adsorption decreased as the flow rate increased with the maximum removal of 98.9 and 95.6 % for arsenate and arsenite, respectively. The bed depth service time and Yoon and Nelson models were used to analyze the experimental data. The adsorption capacity (N o) of BFA on column was 3.65 and 2.98 mg/cm(3) for arsenate and arsenite, respectively. The developed system for the removal of arsenate and arsenite species is economic, rapid, and capable of working under natural conditions. It may be used for the removal of arsenic species from any contaminated water resources.

Identification of wild collected mosquito vectors of diseases using gas chromatography-mass spectrometry in Jazan Province, Saudi Arabia.

Thirty-three species of mosquitoes have been reported from the Kingdom of Saudi Arabia. Several of these mosquitoes, Anopheles gambiae Giles s.l., Anopheles stephensi Liston, Culex pipiens Linnaeus, Culex quinquefasciatus Say, Culex tritaeniorhynchus Giles, Stegomyia aegypti (Linnaeus) and Aedimorphus vexans arabiensis (Patton) are known vectors of human and animal diseases. In this study, the cuticular hydrocarbon profiles of eight mosquito species using gas chromatography-mass spectrometry were analyzed. Wild collected fourth-instar larvae were reared, and single, newly emerged, unfed adult females were used for the analysis. A total of 146-160 peaks were detected from the cuticular extracts by gas chromatography. Repeated analysis of variance (ANOVA) and Tukey HSD Post Hoc test was used to test for quantitative differences in relative hydrocarbon quantity. In addition, a linear regression model was applied using Enter method to determine the diagnostic peaks for the eight mosquito specimens. The ANOVA test indicated that relative peaks were significant (P < 0.05) when selected pairs of peaks were compared. Also, seven compounds showed qualitative differences among the five mosquito vectors tested. The classes of constituents present were n-alkanes, monomethylalkanes, dimethylalkanes, trimethylalkanes, alkenes, branched aromatic hydrocarbons, aldehydes and esters. These compounds have a carbon chain length ranging from 8 to 18 carbons. The most abundant compound in all adult mosquito specimens was n-hexylacrylate [retention time (RT) 6.73 min], which was not detected in Cx. pipiens. In Cx. pipiens, the most abundant peak was benzaldehyde (RT 2.98 min). Gas chromatography-mass spectrometry is a suitable method to identify adult mosquitoes, especially from focal areas of public health concern such as Jazan Province, Saudi Arabia. This method allows a wide range of adult collected material to be identified with high accuracy.

Improvement of mercuric chloride-induced testis injuries and sperm quality deteriorations by Spirulina platensis in rats.

The present study was undertaken to investigate the protective effect of the filamentous cyanobacterium Spirulina platensis (S. platensis) on mercury (II) chloride (HgCl(2))-induced oxidative damages and histopathological alterations in the testis of Wistar albino rats. The animals were divided into four equal groups, i) control, ii) HgCl(2), iii) S. platensis and iv) combination of HgCl(2)+S. platensis. Oxidative stress, induced by a single dose of HgCl(2) (5 mg/kg, bw; subcutaneously, s.c.), substantially decreased (P<0.01) the activity level of testicular key enzymatic antioxidant biomarkers (superoxide dismutase, SOD; catalase, CAT and glutathione peroxidase, GPx), oxidative stress makers (blood hydroperoxide; testicular reduced glutathione, GSH and malondialdehyde, MDA), and testicular mercury levels. Moreover, HgCl(2) administration resulted in a significant (P<0.01) increase in the number of sperms with abnormal morphology and decrease in epididymal sperm count, motility, plasma testosterone level and testicular cholesterol. Furthermore, HgCl(2) exposure induced histopathological changes to the testis including morphological alterations of the seminiferous tubules, and degeneration and dissociation of spermatogenic cells. Notably, oral pretreatment of animals with Spirulina (300 mg/kg, bw) lowered the extent of the observed HgCl(2)-mediated toxicity, whereby significantly reducing the resulting lipid peroxidation products, mercury accumulation in the testis, histopathological changes of the testes and spermatozoal abnormalities. In parallel, the pretreatment with Spirulina also completely reverted the observed Hg-Cl(2)-induced inhibition in enzymatic activities of antioxidant biomarkers (SOD, CAT and GPx) back to control levels. The pretreatment of rats with S. platensis significantly recovered the observed HgCl(2)-mediated decrease in the weight of accessory sex organs. Taken together, our findings clearly highlight the role of S. platensis as a protective modulator of HgCl(2)-induced testicular injuries and suggest some therapeutic potential in mammals. Further investigation of therapeutic strategies employing Spirulina against heavy metals toxicity in humans is therefore warranted.