This is the first report on characterization of DHN melanin produced by a novel strain of A. bridgeri and may find potential application as a natural antioxidant in the cosmetic and pharmaceutical industries.

Mixture of fatty acids obtained from coconut, palm kernel, palm, jatropha, karanja, Sterculia foetida, and high oleic sunflower oils were used for the preparation of sodium N-acyl isoleucines (NaNAIle) via Schotten-Baumann reaction except castor oil which was prepared in thermal condensation in good yields. The products were characterized by chromatographic and spectral techniques. Surface active properties such as surface tension, wetting, foaming characteristics, emulsion stability, calcium tolerance, and micellization properties were evaluated for all the synthesized products. The results showed that all the products exhibited superior surface active properties like critical micelle concentration (CMC) and emulsion stability when compared to the commercial surfactant, sodium lauryl sulphate (SLS). The NaNAIle also exhibited promising cytotoxicity against human cancer cell lines except 3 and 5. 5, 6, and 8 showed antimicrobial activity against Gram-positive and Gram-negative bacteria. 1, 2, 7, and 8 exhibited good antioxidant properties.

A series of six new ferrocene-carbohydrate conjugates was prepared from pentose and hexose sugar derivatives. These include the ferrocenecarbaldehyde acetal 2, four ferrocenyltriazoles 4a-d derived from furanose sugar and the ferrocenyltriazole 4e derived from a pyranose sugar. The compounds were characterised by spectroscopic means and the structures of the new conjugates 2 and 4a were determined by means of X-ray crystallography. A UV/Vis study of these compounds performed in aqueous solutions under physiological conditions confirmed their stability. The CD spectral analysis shows the effect of the nature of substituents of the carbohydrate moieties. The electrochemical studies conducted in a buffer solution display one-electron reversible oxidation processes for these compounds. These results indicate that the compounds are suitable for conducting bio-[a]

Microbial infections due to biofilm formation on medical implants are serious complications arising after surgery which can be prevented by using antimicrobial coatings on biomaterial surfaces. We developed a simple, rapid and green chemistry approach for synthesis of silver glyconanoparticles (AgNPs) using Kocuran, an exopolysaccharide produced by Kocuria rosea strain BS-1. Kocuran-capped AgNPs exhibited a characteristic surface plasmon resonance (SPR) peak around 435 nm. They were mono-dispersed, spherical with an average particle size of 12 nm. XRD and SAED studies suggested that AgNPs were crystalline in nature. AgNPs had a zeta potential of -33.9 mV and were anionic charged. They showed colloidal stability at different pH (6 to 10), temperatures (30 °C to 100 °C), in NaCl, NaNO3 and BSA solutions. Kocuran-capped AgNPs exhibited effective antimicrobial activity against Staphylococcus aureus and Escherichia coli and cell death was mainly due to hydroxyl radical induction and depletion of NADH. They also inhibited the biofilm development by S. aureus and E. coli and confocal scanning laser microscopic images revealed the damage of intact cell architecture. In vitro evaluation of Kocuran-capped silver glyconanoparticles on human gingival fibroblasts demonstrated good cell proliferation as compared to commercial AgNPs suggesting that they are biocompatible and non-toxic in nature. This is a first report on Kocuran-functionalized AgNPs exhibiting potential antibacterial and antiadhesive properties for use as antimicrobial coatings against bacterial adhesion and biofilm formation on silicone urethral catheters.