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The organic transformations in water are considered a safe, non-toxic, economical, and eco-friendly alternative. A new series of amphiphile, N -acyl- N -(pyridin-2-ylmethyl)glycine (PyNAG) with variable hydrophobicity was successfully synthesized from glycine. The self-assembly properties were characterized by critical micellar concentration (CMC), aggregation number (N agg), and diameter (D H). The PyNAG with N - stearoyl moiety showed lower CMC, higher N agg , and larger D H compared to PyNAG with N - lauryl moiety. Molecular dynamics simulation reveals that the micelle structure is compact and non-bonded energy contribution arises from electrostatic, and van der Walls forces contribute to perfect packing and micelle formation. The ability of the PyNAG micelles to execute important organic transformations in water was demonstrated through synthesizing chromenoquinoline via the Povarov reaction. Micelles with varying diameters were used to conduct the Povarov reaction in order to better understand the functions of the hydrophobicity core of the micellar environment in organic reactions. The results reveal that the Povarov reaction produces a good yield in N -stearoyl- N -(pyridin-2-ylmethyl)glycine (PyN18G) micelles, better than organic solvent and commercial surfactant. Moreover, a linear correlation between the yield and the hydrophobicity of the PyNAG was observed. The findings demonstrate that the micellar interior significantly affects the reactivity of the substrate, which should be taken into consideration while creating new media for metal-catalyzed green synthesis. [Display omitted] • Reported micelle formation from pyridine tethered N-acyl glycine. • Electrostatic and van der Walls forces contributes for micelle packing. • Micelles serves as a medium for Povarov reaction on water. • Micelle hydrophobicity play significant role in chromenoquinoline synthesis. [ABSTRACT FROM AUTHOR]

The rising threat to antibiotic armamentarium demand innovative methods to use standard antibiotics against multidrug-resistant (MDR) pathogens. Herein, we demonstrated phytolectin-cationic lipid complex have the ability to renew the ciprofloxacin (CIP) activity against MDR uropathogenic Escherichia coli (R4UPEC). The minimum inhibitory concentrations (MIC) obtained for CIP against R4UPEC studied were very high (MIC = 1000 µM) which may not be suitable for clinical testing. Strikingly, CIP in combination with Butea monosperma seed lectin (BMSL) and cationic lipid, 2-((N-(2-hydroxyethyl)palmitamido)methyl)− 1-methylpyridin-1-ium iodide (cN16E) showed 64-fold lower MIC (15.63 µM). Checkerboard assay revealed that the BMSL-cN16E (BcN16E) complex and CIP work synergistically against R4UPEC. The complex, BcN16E-CIP exerts antimicrobial activity through outer membrane permeabilization, inner membrane disruption, proton motive force dissipation and enhancing the generation of reactive oxygen species. The therapeutic efficacy evaluated in a zebrafish, intramuscular infection model using R4UPEC, the BcN16E-CIP reduce the bacterial load and decrease neutrophil infiltration in muscles and low down the liver cell necrosis. The results demonstrate significantly lower MIC for CIP when complex with BcN16E and showed exceptional in vivo efficacy against infectious MDR bacteria. [Display omitted] • Phytolectin-lipid conjugates enhance ciprofloxacin activity. • Antimicrobial mechanism attributed to modulation in outer and inner membrane. • The conjugate inhibits the efflux pumps. • Treatment with conjugate rescue the multidrug-resistant infected zebrafish. [ABSTRACT FROM AUTHOR]

Functionalizing the nanoparticles to target the bacteria surface is an effective approach to curb drug resistance pathogens. The present study describes the synthesis of N-myristoyltaurine capped silver nanoparticles (AgNPs) and functionalization of AgNPs with jacalin (JAgNPs), a lectin from the seeds of Artocarpus integrifolia. JAgNPs has fourfold lower minimum inhibitory concentration than AgNPs and kills the S. aureus in less than 30 min through inducing oxidative stress and membrane damage. JAgNPs (31.25 µM) was found to have excellent biofilm inhibitory activity at lower concentration than AgNPs (62.5 µM). This was judged by crystal violet assay, light microscopy imaging and confocal laser scanning microscopy (CLSM) method. CLSM analysis reveals that JAgNPs is highly effective as compared to AgNPs in reducing the bio-volume and average biofilm thickness to 18.3 ± 2.5 µm3/µm2 and 14.0 ± 2.6 µm, respectively. Scanning electron microscopy (SEM) study reveals that JAgNPs prevents the colony formation and inhibited exopolysaccharide synthesis, thereby reducing the formation of biofilm. At minimum biofilm inhibitory concentrations, SEM and double staining technique using CLSM provides evidence that cells are intact and live, suggesting that NPs exhibit true biofilm activity. The findings indicate that jacalin functionalization may offer a unique way to use nanosilver at lower concentrations for treating infection associated with S. aureus biofilm. [Display omitted] • Jacalin functionalized AgNPs kills S. aureus in less than 30 min. • NPs exert antibacterial activity through inducing oxidative stress and membrane damage. • Jacalin-AgNPs exhibit antibiofilm activity at 0.5X MIC. • NPs inhibits exopolysaccharide biosynthesis. [ABSTRACT FROM AUTHOR]