A series of four new mixed-ligand copper(II) complexes (1–4) of the type [Cu(L)(diimine)] (ClO₄) [where L is 2-((1H-imidazol-2-yl)methylene)-N-phenylhydrazinecarbothioamide and the diimines are 1,10-phenanthroline (phen, 1), 2,2′-bipyridine (bpy, 2), 4,4′-dimethyl-2,2′-bipyridyl (dmbpy, 3), and 2,2′-dipyridylamine (dpa, 4)] have been successfully synthesized and characterized by various spectral techniques. The K_b values were calculated from electronic absorption spectral titration of these complexes with herring sperm DNA, and these varied in the order phen (1) > dmbpy (3) > bpy (2) > dpa (4). Electrophoresis observations revealed that these complexes (1–4) could efficiently induce single-strand breakage of pUC18 plasmid DNA in the presence of ascorbic acid. These copper complexes underwent a static quenching process with BSA. Moreover, their potential free-radical scavenging and anti-inflammatory properties were also determined using DPPH and protein denaturation techniques. These complexes showed efficient antibacterial activities against Staphylococcus aureus (Gram positive) and Pseudomonas aeruginosa (Gram negative). Furthermore, studies of their in vitro cytotoxicity against AGS cancer cells indicated promising antitumor activity with significant IC₅₀ values.

Brown seaweeds usually contain alginate as a major polymer. The second major sulfated polymer in brown seaweeds is fucoidan, which has huge potential in medicinal applications. In this study, the photosynthetic pigments from Turbinaria decurrens were first extracted using chloroform/methanol in the ratio of 1:1 (v/v), followed by fucoidan extraction with yields of 5.58% (crude) and 1.28% (purified fucoidan) from the dry weight of seaweed, whereas alginate was extracted with a yield of 14.7% DW of seaweed. The isolated fucoidan possessing anticoagulation property was identified and characterized as (1–3)-α-l-fucopyranosyl residues with sulfate groups primarily at the C₄ position and to a lesser extent at the C₂ position, whereas in the case of galactose, at the C₃ and C₆ positions. The AgNPs synthesized using isolated fucoidan exhibit strong anticoagulant activity and possess a good antibacterial property against Gram-negative clinical bacteria. Functional groups such as O–H, C–H, and S═O associated with sugar residues in sulfated fucoidan are involved in the synthesis of the nanoparticles with a spherical shape, size ranging from 10 to 60 nm, and showing polydispersity. From this study, we conclude that fucoidan-coated anionic AgNPs synthesized from T. decurrens have tremendous potential in drug development.

Copper( ii ) complexes with simple and mixed ligands, [Cu(L)(ClO ₄ )] and [Cu(L)(diimine)]ClO ₄ were synthesized and characterized by elemental analysis, UV-vis, FT-IR, electrospray ionization-mass spectrometry (ESI-MS) and electrochemical studies.

In the present study lipopeptide biosurfactant with high emulsification capacity produced by human skin bacterium Paenibacillus thiaminolyticus was purified and subjected to FTIR and NMR spectral analysis which gave evidence of the active characteristics of the surfactant. To augment the antivirulent potential further, the mixer of copper and copper oxide nanoparticles (CuNPs) was synthesized, and characterized by UV–Visible spectroscopy, SEM-EDAX, TEM, and Zeta analysis. Here, we attempted to enhance the antimicrobial and antibiofilm activity with the assistance of encapsulated preparation of lipopeptide and CuNPs in multilamellar liposomes. The proposed mechanism of action of lipopeptide and CuNPs liposomal preparation negatively influences the cell metabolism, secreted virulence such as staphyloxanthin, pyocyanin, and extracellular polysaccharides. The significant decline in the growth of MRSA and P. aeruginosa in both planktonic form and biofilm by lipopeptide and CuNPs treatment were visualized using scanning electron microscopy and High content screening imaging system. In vivo studies revealed that treatment with lipopeptide and CuNPs in multilamellar liposomes extended the lifespan of infected Caenorhabditis elegans by about 75%. Therefore, this study typifies lipopeptide and CuNPs could credibly be a substantial substitute over conventional antibiotics in averting the biofilm associated pathogenesis of MRSA and P. aeruginosa.