Potentially toxic elements contamination and its removal by aquatic weeds in the riverine system: A comparative approach.

Thamirabarani river acquires large untreated sewage effluents from the Tirunelveli and Thoothukudi districts of South Tamil Nadu. This study examined the concentration of trace elements in water, sediment, and phytoaccumulation potential of aquatic weeds viz., A. cristata, E. crassipes, S. natans, and P. stratiotes, growing along Srivaikundam dam of Thamirabarani river. The Pb, As, Hg, Cd, and Ni concentrations in water were slightly higher than the US Food and Drug Administration (USFDA) drinking water guidelines; however, their accumulation in sediment was below WHO's sediment quality guideline. This study concludes that the phytoaccumulation factor (PAF) and translocation factor (TF) was >1 in E. crassipes and A. cristata, representing them as hyperaccumulators, suitable for phytoremediation in polluted localities. E. crassipes, A. cristata, and S. natans accumulated (100-500 fold) higher trace elements concentrations than that present in the water. Also, the concentrations of trace elements found in the aquatic weeds were below the recommended levels for the critical plant range (CRP). These selected aquatic weeds are more suitable for plant hybridization to be modified as superbug plants.

Design, Synthesis and In Vitro Mechanistic Investigation of Novel Hexacyclic Cage-Like Hybrid Heterocycles.

Novel hexacyclic cage-like hybrid heterocycles have been synthesized in excellent yields employing a relatively less explored non-stabilized azomethine ylides derived from acenaphthenequinone and tyrosine with functionalized dipolarophiles using [3 + 2] cycloaddition strategy. The synthesized hexacyclic cage-like hybrid heterocycles were characterized by spectroscopic analysis. Following the physical characterization, these cage-like hybrid heterocycles were tested for their biological activity by means of different cancer (A549 and Jurkat cells) and non-cancer (BRL-3A and PCS-130) in vitro cell culture systems. The results of the study under tested concentrations (up to 100 µM) indicated that these compounds are not affecting any viability to the cell growth of non-cancer cells, while providing significant anticancer activity against both of the cancer cells. Further analysis of in-depth mechanistic study for the cell death indicated that these compounds are exhibiting late apoptosis or early necrosis pathway to the cells where it is operated by the induction of caspases.