Synthesis, characterization, and evaluation of fluoride removal capacity of calcium-impregnated Euphorbia neriifolia carbon (Ca-Enc).

Fluoride ions must be removed from drinking water in order to prevent fluorosis. Many conventional techniques have been examined for the defluoridation of water all over the world. As far as fluoride ions are concerned, adsorption is the most promising method for the removal of them from aqueous environments. In the present study, we aim to find out how well Euphorbia neriifolia plants can remove fluoride from water using activated and carbonized adsorbents. The Euphorbia neriifolia plant stem was pulverized, dried, and activated using calcium ions extracted from used eggshells collected nearby. The synthesized adsorbent material before and after adsorption of fluoride ions was systematically characterized using FTIR, XRD, SEM with EDAX, TGA, and zero-point charge. The defluoridation capacity of the as-prepared adsorbent material was investigated using batch adsorption studies. Various influencing factors such as contact time, solution pH, initial fluoride concentration, mass of the adsorbent, temperature, and co-existing ions were systematically investigated towards the removal of fluoride ion on prepared adsorbent material. This study was conducted to identify the optimal conditions of prepared adsorbent for the maximum removal of fluoride ions from aqueous solution. A groundwater sample with fluoride content of more than 1.5 ppm was taken and studied in this present work. A basic quality indicator of the synthesized material was examined, and its ability to remove fluoride was determined. The findings provide insight into the selective elimination of fluoride ions from aqueous environment.

Iodine catalyzed synthesis of imidazo[1,2-a]pyrazine and imidazo[1,2-a]pyridine derivatives and their anticancer activity.

An efficient iodine-catalyzed method for synthesizing imidazo[1,2-a]pyrazines and imidazo[1,2-a]pyridines via one-pot three-component condensations has been reported. The product, generated in situ by the reaction between an aryl aldehyde and 2-aminopyridine or 2-aminopyrazine, undergoes [4 + 1] cycloaddition with tert-butyl isocyanide, affording the corresponding imidazopyrazine and imidazopyridine derivatives in good yields. The photophysical properties of these new fluorescent derivatives are also presented. The anti-cancer activities of the synthesized compounds (10a-m) and (12a-l) were evaluated against four cancer cells (Hep-2, HepG2, MCF-7, A375) and the normal Vero cell. Significant anti-cancer activities were observed and compared with the standard drug Doxorubicin. In vitro experimental results revealed that compound 12b is a promising lead with IC50 values of 11 µM, 13 µM, 11 µM, 11 µM, and 91 µM against Hep-2, HepG2, MCF-7, A375, and Vero, respectively.

Design, synthesis, and characterization of non-hemolytic antimicrobial peptides related to human cathelicidin LL-37.

We designed and synthesised the N-terminally labeled cationic and hydrophobic peptides, i.e., FFKKSKEKIGKEFKKIVQKI (P1) and FRRSRERIGREFRRIVQRI (P2) related to the human cathelicidin LL-37 peptide. The integrity and molecular weight of the peptides were confirmed by mass spectrometry. The purity and homogeneity of peptides P1 and P2 were determined by comparing LCMS or analytical HPLC chromatograms. The circular dichroism spectroscopy reveals the conformational transitions upon interaction with membranes. Predictably, peptides P1 and P2 showed a random coil structure in the buffer and formed α-helix secondary structure in TFE and SDS micelles. This assessment was further confirmed by 2D NMR spectroscopic methods. The analytical HPLC binding assay measurements revealed that peptides P1 and P2 display preferential interactions with the anionic lipid bilayer (POPC:POPG) moderately than zwitterionic (POPC). The efficacies of the peptides were tested against Gram-positive and Gram-negative bacteria. It is imperative to note here that the arginine-rich P2 exerted higher activity against all the test organisms as compared with that shown by the lysine-rich peptide P1. To test the toxicity of these peptides, a hemolytic assay was performed. P1 and P2 showed very little to no toxicity for a hemolytic assay, which is significant for P1 and P2 to be used as potential therapeutic agents in practical applications. Both peptides P1 and P2 were non-hemolytic and appeared to be more promising as they demonstrated wide-spectrum antimicrobial activity.

Design and synthesis of novel N-terminal peptides of integrin and aminopeptidase are new finding for anticancer activity.

The short peptides, containing the amino acid sequence asparagine-glycine-arginine (NGR) and arginine-glycine-aspartic acid (RGD), possess the strong binding ability to N (APN/CD13) aminopeptidase receptor and integrin proteins involved in antitumor properties are overexpressed. A novel short N-terminal modified hexapeptides P1 and P2 was designed and synthesized using the Fmoc-chemistry solid phase peptide synthesis protocol. Notably, the cytotoxicity of the MTT assay demonstrated the viability of normal and cancer cells up to lower peptide concentrations. Interestingly, both peptides show good anticancer activities against the four cancer cells and normal cells namely, Hep-2, HepG2, MCF-7, A375, and Vero and compared with standard drugs, doxorubicin and paclitaxel. Additionally, in silico studies were applied to predict the binding sites and binding orientation of the peptides for potential anticancer targets. Steady-state fluorescence measurements showed that peptide P1 exhibits preferential interactions with POPC/POPG anionic bilayers rather than the zwitterionic POPC lipid bilayers and peptide P2, did not show any preferential interaction with lipids bilayers. But impressively, peptide P2 shows anticancer activity due to the NGR/RGD motif. Circular dichroism studies demonstrated that the peptide's secondary structure changes only minimally upon binding to the anionic lipid bilayers.