Purification, structural elucidation and anticancer activity of a compound extracted from Aspergillus fumigatus strain MF-1.

The fungus is a great source of secondary metabolites which may possess various biological activities for the treatment of human diseases and disorders. The present study aimed to identify the secondary metabolites from Aspergillus fumigatus strain MF-1 using analytical techniques (chromatographic and spectroscopic). The instruments includes 1H-NMR, 13C-NMR, DEPT, COSY, HMQC, FTIR and UV-Vis spectrophotometer were employed to study the extracted compound and the produced compound is 2,5-dioxocyclopentylamino-7-oxohepta-1,3,5-trienyl-2,5-dihydroxy-3-chlorophenyl-2,4,6-trimethyldeca-2,4-dienamide. Furthermore, the four fractions were tested over HeLa cell lines for their cytotoxicity performance and found that fraction 4 exhibited potent cytotoxic effect with IC50 value of 74.38 ± 0.31 µg/mL on HeLa cell lines than other fractions.

Hazardous heavy metals in the pristine lacustrine systems of Antarctica: Insights from PMF model and ERA techniques.

A comprehensive study was presented on the ecological risk, distribution, and quantitative source apportionment of heavy metals in the selected lacustrine systems of Schirmacher Hills using various environmental indices and methods. A total of 25 sediment samples from 16 lakes were collected around scientific research stations and analyzed for metals. Geochemical approaches and ecological risk assessment methods were implemented to characterize and evaluate the contamination level and associated risk in the lacustrine systems. Moreover, statistical techniques and a positive matrix factorization (PMF) model were indorsed to understand metals' association and apportion their probable sources. Results revealed that most of the heavy metals (mean concentration in ppm) such as Al (77,504.09), Cd (1.36), Co (29.52), Cr (102.75), Cu (65.19), Fe (57,632.87), Mn (679.05), Ni (49.13), Pb (10.11), and Zn (253.78) are originated from natural weathering of source rocks (78.53%) followed by human-induced actions/ station activities coupled with atmospheric deposition (21.47%). Environmental risk assessment (ERA) techniques suggest that the lakes in the study area are under minimal to moderate enrichment/ contamination category and experienced minimal to adverse biological effects where metal toxicity risk is minimal.

Photocatalytic degradation of polyethylene plastics by NiAl2O4 spinels-synthesis and characterization.

Over past twenty years, daily usage of Microplastics (MPs) and their pollution are gradually increasing. Especially, the polyethylene bags were used for food storage. So their productivity as well discarding after use are rapidly growing and shown their great impact on the environment. Hence, there is need to control the plastics from environment decomposition. For that, we have attempted that preparation of NiAl2O4 Spinels by two different methods such as co-precipitation and hydrothermal. The synthesized spinels were thoroughly studied by some instrumental techniques like X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM-EDX), Fourier transform infrared (FT-IR), and ultraviolet (UV-Vis) spectrophotometer). The photocatalytic experiment was adopted for the degradation of commercially available polyethylene bags using prepared spinels. The obtained results from FTIR after degradation process confirmed that the polyethylene sheet was degraded in 5 h with the help of prepared spinels and the weight loss is 12.5% obtained using hydrothermally prepared spinels. This study shows new path to develop more functional materials for the degradation of MPs.

Fabrication of multifunctional TANI/Cu2O/Ag nanocomposite for environmental abatement.

During past decade, the ternary nanocomposite is ubiquitous in nanotechnology. Herein, a simple fabrication of cuprous oxide (Cu2O) and silver (Ag) nanoparticles into Tetraaniline (TANI) matrix by in situ-polymerization approach to attain Tetramer-Metal Oxide-Metal (TANI/Cu2O/Ag, shortly TCA) ternary composite was reported firstly. The synthesized materials were further characterized by a series of instrumental techniques to understand its structure, morphology and thermal properties. This nanocomposite showed promising applications in wastewater treatment by the testing of photocatalytic activity over the pararosaniline hydrochloride (PRA) dye degradation under visible light radiations, removal of Cadmium ion (Cd2+) by adsorption, corrosion resistance and antibacterial activity against both gram positive and gram negative bacterial strains. The obtained results of TCA compared with the pure TANI and binary nanocomposite (TANI/Cu2O) declared that the TCA composite is excellent material to solve the environmental issues due to lesser bandgap energy, visible light respond, high absorptivity, and long-life excitation.

Facile simultaneous synthesis of tetraaniline nanostructures/silver nanoparticles as heterogeneous catalyst for the efficient catalytic reduction of 4-nitrophenol to 4-aminophenol.

Nanocomposites of tetraaniline (TAN) nanostructures/silver nanoparticles (Ag NPs) were synthesized by an interfacial polymerization method using N-phenyl-1, 4-phenylenediamine (NPPD), AgNO3 and ammonium persulphate (APS) as monomer, oxidizing agent in immiscible solvent toluene-water respectively. The structure and morphology of the as-prepared TAN and Ag NPs were investigated by UV-visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and thermogravimetry (TG). The results of FTIR spectroscopy confirmed the formation of TAN and Ag NPs and those of XRD showed the presence of the face centred cubic (fcc) phase of Ag NPs. The FESEM and TEM images gave direct evidence that Ag NPs stabilized with the TAN nanostructures. TGA indicated the enhanced thermal stability of the nanocomposites (NCs). The catalytic activity of TAN/Ag NCs was investigated for the model reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of excess sodium borohydride.

Hydrogeochemistry of the deglaciated lacustrine systems in Antarctica: Potential impact of marine aerosols and rock-water interactions.

The deglaciated lacustrine systems in Grovnes, Larsemann Hills, East Antarctica was assessed for its solute dynamics and hydrogeochemical interactions. These pristine high latitude lacustrine systems serve as a natural laboratory to understand the interaction between hydrosphere, lithosphere and atmosphere thus providing valuable insights on the functioning of major biogeochemical cycles. A total of 14 fresh water lakes were identified and the water samples were analysed for its physico-chemical characteristics. The abundance of anions and cations in the lake water samples were in the following order of Cl- > HCO3- > SO42- > NO3- and Na+ > Mg2+ > Ca2+ > K+ respectively. Moreover, the lakes exhibit slightly alkaline condition due to dissolution of alkaline earth metals and atmospheric fallout. Na+-Cl--HCO3- and Na+-Cl- are the commonly noticed water type in the study area and higher concentration of Na+-Cl- were due to the effect of sea spray through marine aerosols. Reverse ion exchange is noticed in most of the lakes due to saline influence. Three major mechanisms such as rock dominance, precipitation/snow and evaporation/sea spray controls the lake water geochemistry in the study area. Silicate weathering and evaporite dissolution also contribute ionic load to the lake water. Significant positive correlations (p < .01) among major ions reveal sources from bedrock weathering along with marine aerosols. Trace element chemistry shows that rock-water interaction is the primary source for dissolved metals in the lake water followed by long range atmospheric transport in the form of aeolian dust. Mineral groups such as evaporites, sulphates, carbonates, metal oxides and hydroxides are responsible for the dissolution of metal complexes in the lake water. Furthermore, lakes falling within a micro basin have shown higher Na+-Cl- content which is due to the catchment effect where snow enriched with sea spray melts during the austral summer feeding these lakes.