Smritilekha Bera

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Amphiphilic lysine-ligated neomycin B building blocks were prepared by reductive amination of a protected C5″-modified neomycin B-based aldehyde and side chain-unprotected lysine or lysine-containing peptides. It was demonstrated that a suitably protected lysine-ligated neomycin B conjugate (NeoK) serves as a building block for peptide synthesis, enabling(More)
Eight N-acetylglucosamine-1-phosphate and N-acetylgalactosamine-1-phosphate analogs have been synthesized chemically and were tested for their recognition by the GlmU uridyltransferase enzyme. Among these, only substrates that have an amide linkage to the C-2 nitrogen were transferred by GlmU to afford their corresponding uridine diphosphate(UDP)-sugar(More)
Aminoglycoside antibiotics and cationic detergents constitute two classes of clinically important drugs and antiseptics. Their bacteriological and clinical efficacy, however, has decreased recently due to antibiotic resistance. We have synthesized aminoglycoside-lipid conjugates in which the aminoglycoside neomycin forms the cationic headgroup of a(More)
Triazole linked heparosan and chondroitin disaccharide and tetrasaccharide building blocks were synthesized in a stereoselective manner by applying a very efficient copper catalyzed azide-alkyne cycloaddition (CuAAC) reaction of appropriately substituted azido-glucuronic acid and propargyluted N-acetyl glucosamine and N-acetyl galactosamine derivative,(More)
OBJECTIVES Neomycin B exhibits poor antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, while kanamycin A shows weak activity against MRSA, methicillin-resistant Staphylococcus epidermidis (MRSE) and P. aeruginosa. The main purpose of this work was to study whether lipid conjugation of guanidinylated(More)
The solid- and solution-phase synthesis of amphiphilic aminoglycoside-peptide triazole conjugates (APTCs) accessed by copper(I)-catalyzed 1,3-dipolar cycloaddition reaction between a hydrophobic and ultrashort peptide-based alkyne and a neomycin B- or kanamycin A-derived azide is presented. Antibacterial evaluation demonstrates that the antibacterial(More)
Cationic amphiphiles containing multiple positively charged amino functions define a structurally diverse class of antibacterials with broad-spectrum activity and different modes of action. Oligocationic amphiphiles have been used as antibiotics to treat infections and as antiseptics and disinfectants for decades with little or no occurrence of resistance.(More)
Investigating the effect of lipid hydrophobicity on the activity of amphiphilic neomycin B conjugates, six polycationic amphiphiles (PAs) were created. Four of the new compounds incorporated either palmitic or arachidic di-lipid lysine tails, while two had single fluorinated undecanoic acid tails. The basicity of half of the compounds was increased through(More)
The use of ultrasound has emerged as one of the most useful alternative energy sources for the synthesis of carbohydrate-derived biologically and pharmaceutically potential compounds. Spectacular advances have been made in the field of sonication-assisted organic reactions, which are known for producing superior yields, enhanced reactivity of the reactant,(More)
Amphiphilic aminoglycoside antimicrobials are an emerging class of new antibacterial agents with novel modes of action. Previous studies have shown that amphiphilic neomycin-B and kanamycin-A analogs restore potent antibacterial activity against Gram-positive neomycin-B- and kanamycin-A-resistant organisms. In this paper, we investigated the antibacterial(More)