Synthesis and Characterization of Multicolor Luminescent and Thermally Stable Thioureas and Polythioamides.

Two new polythioamides were prepared through the polycondensation reaction between thiourea monomers and terephthaloyl dichloride, while the thiourea monomers were synthesized by the interaction of aromatic (4,4'-diaminophenylsulfone) or alicyclic (1,2-cyclohexanediamine) diamine with ammonium thiocyanate. The elemental composition of polythioamides was confirmed through CHN microanalysis. The structure and properties of thiourea monomers and polythioamides were determined through proton NMR, UV-Vis, FT-IR spectroscopy, fluorescence, TGA/DTA and SEM. The polythioamides indicated high thermal stabilities which were assessed from their Tmax (temperature indicating highest rate of weight loss) values (670 °C and 346 °C) observed in their DTG graphs. The thioureas and polythioamides were fluorescent and showed multicolor (violet, green, yellow, orange and red) emissions at different excitation wavelengths. All the synthesized compounds were also tested for their antifungal and antibacterial functions and showed antibacterial activity against Salmonella typhi, Bacillus subtilis and Staphylococcus aureus, and antifungal activity against Candida albicans.

Comparative zinc tolerance and phytoremediation potential of four biofuel plant species.

Soil pollution has become a serious environmental problem worldwide due to rapid industrialization and urbanization. Zinc (Zn) contamination has raised concerns about potential effects on plants and human health. This study was conducted to assess the capability of four biofuel plants: Abelmoschus esculentus, Avena sativa, Guizotia abyssinica, and Glycine max to remediate and restore Zn contaminated soil. Selected plants were grown in soil exposed to different Zn treatments (50, 100, 200, 300, 400, 600, 800 and 1000 mg Zn kg-1) for 12 weeks. Soil without spike taken as control. Zn induced toxicity significantly (p < 0.05) reduced seed germination and inhibited plant growth and leaf chlorophyll content. The investigated plants can tolerate a soil content of 800 mg Zn kg-1 with the exception of A. sativa, which was most tolerant to high Zn concentrations (1000 mg Zn kg-1) for all growth criteria. Moreover, increasing Zn content in soil resulted in a significant (p < 0.05) increase in Zn accumulation in various tissues of the four biofuel plants. According to phytoremediation efficiency, the four biofuel plants studied were arranged as follows: A. sativa (5.05%) > A. esculentus (4.15%) > G. max (2.31%) > G. abyssinica (1.17%). This study concluded that all tested biofuel plants species, especially A. sativa exhibited high Zn concentrations in roots and shoots, high Zn uptake capability, high tolerance, and high biomass at 50-800 mg Zn kg-1 treatments. Consequently, these biofuel plants are excellent candidates for phytoremediation in Zn contaminated soils.

Heavy metal contamination of soil poses a serious threat to the environment. Physical and chemical remediation methods are commonly used to remediate metal contaminated sites. It is not commercially viable, except that it is harmful and causes soil degradation. Alternatively, biological remediation techniques are cheap and environmentally friendly. Different plant species have been found to differ in their ability to accumulate metals under contaminated soil. Therefore, the present study provides a unique opportunity to study the metal accumulation potential of four biofuel plants (Abelmoschus esculentus, Avena sativa, Guizotia abyssinica and Glycine max) under zinc metal spiked soils. These plants are able to grow rapidly by developing a strong root system, high biomass production, and high tolerance to metal toxicity that helps them survive in contaminated soil environments. The investigated biofuel plant can be used to decontaminate contaminated sites and serves as a source of commercially valuable products that extract metals from biomass through combustion.

Silver Nanoparticles with Sodium Dodecyl Sulfate as a Colorimetric Probe for the Detection of Dithiocarbamate Pesticides in Environmental Samples.

A rapid and simple colorimetric approach has been developed for sensing dithiocarbamate pesticides (ziram, zineb and maneb) in environmental samples using sodium dodecyl sulfate capped silver nanoparticles (SDS-AgNPs). They were characterized by a UV-vis spectrophotometer, FT-IR, SEM and EDX. Dithiocarbamates on interactions with SDS-AgNPs induce the aggregation of NPs, leading to a color change from yellow to greyish or dark brownish, depending on the concentration of pesticides added. A shift in the wavelength was observed from 400 to 570 nm with the broad band. The absorption ratio, 570/400 nm, was found to be linearly related to the concentration of pesticides in the range of 195.7 - 733.9 ng/mL for ziram, 17.6 - 66.2 ng/mL for zineb and 16.9 - 63.6 ng/mL for maneb with the detection limits of 149.3, 4.0 and 9.1 ng/mL for ziram, zineb and maneb, respectively. The method was successfully applied for the determination of DTCs in environmental samples (tap water, tomato, mango beverage) with percentage recoveries of 94.8 - 108.4% for ziram, 93.7 - 105.4% for zineb and 93.2 - 107.6% for maneb. The procedure was repeatable with inter-day RSD (n = 5) within 3.4, 4.8, 7.6% and intra-day RSD (n = 5) within 1.2, 1.7 and 1.8% for the ziram, zineb and maneb respectively.

Evaluation of chromium phyto-toxicity, phyto-tolerance, and phyto-accumulation using biofuel plants for effective phytoremediation.

Contamination of chromium signifies one of the major threats to soil system. Phytoremediation is a promising technique to reclaim metal-contaminated soil using plants which are capable to tolerate and accumulate heavy metals within in their tissues. The experiment reported in this article was carried out with six biofuel plant species, Cyamopsis tetragonoloba, Glycine max, Avena sativa, Abelmoschus esculentus, Sesamum indicum and Guizotia abyssinica, were subjected to eight Cr concentrations (0.5, 2.5, 5, 10, 25, 50, 75 and 100 mg kg-1 soil) to investigate Cr toxicity, tolerance and accumulation. After 12 weeks of experiment, Cr phytotoxicity on morphological and biochemical parameters were evaluated. For six plant species, seed germination and most of growth parameters were significantly (p < 0.05) reduced under high Cr stress. Chlorophyll contents were also decreased with increased Cr concentrations. Accumulation of Cr was higher in roots than shoot in all studied plants. Significant Cr accumulation was in the order of C. tetragonoloba > A. sativa > A. esculentus > S. indicum > G. max > G. abyssinica. Bioconcentration factor, bioaccumulation coefficient, translocation factor and phytoremdiation ratio suggested that C. tetragonoloba, A. sativa and A. esculentus being more tolerant; having higher Cr accumulation and could be a high efficient plants for reclamation of Cr-contaminated soils.

New Fluorescent, Thermally Stable and Film Forming Polyimines Containing Naphthyl Rings.

Three new aliphatic-aromatic polymers having naphthyl rings were prepared by the polycondenstion of dialdehydes or diketone monomers with 1,5-naphthalenediamine or 1,4-phenylenediamine. The monomers were prepared by the reaction of aromatic aldehyde or ketone with 1,6-dibromohexane. The molecular mass of the monomers was confirmed through E.I mass spectroscopy. The structures of monomers and polymers were characterized by 1HNMR, FT-IR, UV-Vis Spectroscopy, SEM and TG/DTA. Fluorescence emissions of monomers and polymers were recorded and their quantum yields were calculated, all the compounds showed fluorescence property and indicated violet, blue-green, orange and red light emissions. The quantum yields of the polymers were obtained within the range of 0.04 to 24.3%. The semicrystalline and amorphous nature of the polymers was analyzed through powdered X-ray diffraction. Antimicrobial activities of the polymers were examined against different bacterial and fungal species. Thin film forming ability of the synthesized polymers was evaluated by making their blends with PVC (poly vinyl chloride) in different w/w% ratios.

Water quality assessment of Ramser site, Indus Delta, Sindh, Pakistan.

Seven representative sampling stations were selected from Indus Delta comprising of (1) Keti Bander, (2) Darya Peer, (3) Kharo Chanr, (4) Jati, (5) Shah Bander, (6) Nariri Dhand and (7) Left Bank Outfall Drain (LBOD) near Rupa Mari. The sampling scheme was repeated seven times during 2014-2015 for 1 year. The samples were analysed for temperature, conductivity, pH, hardness, chloride, alkalinity, dissolved oxygen, biological oxygen demand, chemical oxygen demand, sulphate, orthophosphate-P, nitrite-N, nitrate-N, Na, K, Fe, Ni, Cr, Co, Cd, Zn, Cu, Pb and As. The analysis was carried out using standard analytical procedures. A number of parameters crossed the WHO permissible limits and water quality guidelines for aquatic life and indicated pollution within coastal region. Coefficient of correlation (r) among physicochemical parameters and metal ions were examined and a number of parameters did not correlate positively and did not indicate natural origin and may indicate their presence due to human activity. The samples were examined for cluster analysis, and principal component analysis. The samples also indicated the presence of Presumptive Coliform, Faecal coliform and E. coli.

Rapid diagnostic method of tobacco products in saliva by fourier transform infrared spectroscopy (FTIR).

The present study was designed to explore the easy and fast method diagnosis of tobacco products in saliva of tobacco users (TU) by FTIR. Sixty four male tobacco users (TU) with mean age range 15.3 to 30.7 years were randomly selected for collection of saliva samples before and after tobacco use (smoking, chewing and dipping tobacco). Twenty were the smoking tobacco users (STU), 24 were chewing tobacco users (CTU) and 20 were dipping tobacco users (DTU). CTU were the users of Mainpuri (n=10) and users of PEN, FIT, 2100 (n=14). Forty eight saliva samples of age and gender matched healthy individuals with negative personal or family history of any addiction were also collected for comparison which served as controls. All were analyzed for their salivary flow rate, salivary pH and salivary diagnostic bands by FTIR. Significantly increased SFR (p<0.05) and salivary pH were found in after chewing tobacco as compared to before its chewing. The comparison between after tobacco use and controls we found decreased SFR and salivary pH for STU. Significant decreased SFR and increased salivary pH were found before or after use of dipping tobacco as compared to controls. Sharp bands at 735-745 cm-1 were found and may be used as salivary diagnostic bands for STU, 945-949 cm-1 for DTU and 900-915 cm-1 for CTU as well as DTU. In conclusion, the salivary diagnostic bands were found at 735-745 cm-1, 900-915 cm-1 and 945-949 cm-1 for TU by easy and fast method using FTIR.

Synthesis, Characterization and Biological Studies of New Linear Thermally Stable Schiff Base Polymers with Flexible Spacers.

Five new linear Schiff base polymers having azomethine structures, ether linkages and extended aliphatic chain lengths with flexible spacers were synthesized by polycondensation of dialdehyde (monomer) with aliphatic and aromatic diamines. The formation yields of monomer and polymers were obtained within 75-92%. The polymers with flexible spacers of n-hexane were somewhat soluble in acetone, chloroform, THF, DMF and DMSO on heating. The monomer and polymers were characterized by melting point, elemental microanalysis, FT-IR, (1)HNMR, UV-Vis spectroscopy, thermogravimetry (TG), differential thermal analysis (DTA), fluorescence emission, scanning electron microscopy (SEM) and viscosities and thermodynamic parameters measurements of their dilute solutions. The studies supported formation of the monomer and polymers and on the basis of these studies their structures have been assigned. The synthesized polymers were tested for their antibacterial and antifungal activities.

Improved Gas Chromatographic Determination of Guanidino Compounds Using Isovaleroylacetone and Ethyl Chloroformate as Derivatizing Reagents.

An improved GC method in terms of sensitivity and decrease in the analysis time has been developed for the analysis of eight guanidino compounds: guanidine (G), methylguanidine (MG), creatinine (CTN), guanidinoacetic acid (GAA), guanidinobutyric acid (GBA), guanidinopropionic acid (GPA), argenine (Arg), and guanidinosuccinic acid (GSA), using isovaleroylacetone (IVA) and ethyl chloroformate (ECF) as derivatizing reagents. The separation was obtained from column HP-5 (30 m × 0.32 mm i.d.) with film thickness of 0.25 µm within 11 min. The linear calibrations were obtained with 0.5 to 50 µg/mL with coefficient of determination (R(2)) within 0.9969 - 0.9998. Limits of detections (LODs) were within 5 - 140 ng/mL. The derivatization, separation and determination was repeatable (n = 6) with relative standard deviation (RSD) within 1.2 - 3.1%. The guanidino compounds were determined in deproteinized serum of healthy volunteers and uremic patients within below LOD to 8.8 µg/mL and below LOD to 43.99 µg/mL with RSD within 1.4 - 3.6%. The recovery of guanidino compounds calculated by standard addition from serum was within 96.1 - 98.9%, with RSD 1.4 - 3.6%.