Stabilized cationic dipeptide capped gold/silver nanohybrids: Towards enhanced antibacterial and antifungal efficacy
摘要:
The nanoparticles of silver/gold and cationic peptides have been recognized as potent antimicrobials for long, but their combined effect has so far not been explored. The present study reports the green synthesis of short cationic dipeptide stabilized AuNPs/AgNPs based nanohybrid materials. It thoroughly investigates the effect of conjugation of short cationic peptides on the antimicrobial properties of metallic nanoparticles. In the context of the antimicrobial evaluation of synthesized nanoconjugates, it was observed that peptide capped AgNPs exhibited higher antimicrobial activity as compared to peptide capped AuNPs as well as native peptides and unconjugated metallic nanoparticles. Specifically, L-His-L-Arg-OMe capped AgNPs exhibited MIC of 0.50, 0.37 and 0.25 mu M against E.coli, S. aureus and S. typhimurium respectively and MIC of 0.80 and 10.00 mu M against C. albicans and C. glabrata respectively. These results indicate that synthetic dipeptides render AgNPs as better antimicrobial agents in comparison to the native AgNPs and positively charged dipeptides. In addition, the time kill profile of cationic peptide (L-His-L-Arg-OMe) capped AgNPs was found to be even better than the known antibiotics. The cytotoxic behavior of all synthesized nanoconjugates of cationic peptides was studied and was found to be within acceptable limits. The present study opens a completely new class of antimicrobials for combating a wide range of bacterial and fungal pathogens. Another interesting and crucial finding was that dipeptide capped AgNPs displayed maximum antimicrobial activity with observed approximate 2-10 fold reduction in nano formulation dosage against tested microbes. (C) 2017 Elsevier B.V. All rights reserved.
Microwave-assisted solution phase peptide synthesis in neat water
作者:Amit Mahindra、Karthik Nooney、Shrikant Uraon、Krishna K. Sharma、Rahul Jain
DOI:10.1039/c3ra43040e
日期:——
An environmentally benign protocol for solution phase peptide synthesis has been developed in neat water using TBTU/HOBt/DIEA as a coupling combination under microwave irradiation. Key features of this procedure are the replacement of commonly used toxic organic solvents like DMF and NMP, the use of lower amounts of reactants, compatibility with both N-α-Boc- and N-α-Fmoc-protected amino acids and all commonly used side-chain protective groups, short reaction time, and racemization-free synthesis in high yield and purity.
Stabilized cationic dipeptide capped gold/silver nanohybrids: Towards enhanced antibacterial and antifungal efficacy
作者:Manish Bajaj、Satish K. Pandey、Tamanna Nain、Surinder K. Brar、Prabhjot Singh、Shivakanksha Singh、Nishima Wangoo、Rohit K. Sharma
DOI:10.1016/j.colsurfb.2017.07.009
日期:2017.10
The nanoparticles of silver/gold and cationic peptides have been recognized as potent antimicrobials for long, but their combined effect has so far not been explored. The present study reports the green synthesis of short cationic dipeptide stabilized AuNPs/AgNPs based nanohybrid materials. It thoroughly investigates the effect of conjugation of short cationic peptides on the antimicrobial properties of metallic nanoparticles. In the context of the antimicrobial evaluation of synthesized nanoconjugates, it was observed that peptide capped AgNPs exhibited higher antimicrobial activity as compared to peptide capped AuNPs as well as native peptides and unconjugated metallic nanoparticles. Specifically, L-His-L-Arg-OMe capped AgNPs exhibited MIC of 0.50, 0.37 and 0.25 mu M against E.coli, S. aureus and S. typhimurium respectively and MIC of 0.80 and 10.00 mu M against C. albicans and C. glabrata respectively. These results indicate that synthetic dipeptides render AgNPs as better antimicrobial agents in comparison to the native AgNPs and positively charged dipeptides. In addition, the time kill profile of cationic peptide (L-His-L-Arg-OMe) capped AgNPs was found to be even better than the known antibiotics. The cytotoxic behavior of all synthesized nanoconjugates of cationic peptides was studied and was found to be within acceptable limits. The present study opens a completely new class of antimicrobials for combating a wide range of bacterial and fungal pathogens. Another interesting and crucial finding was that dipeptide capped AgNPs displayed maximum antimicrobial activity with observed approximate 2-10 fold reduction in nano formulation dosage against tested microbes. (C) 2017 Elsevier B.V. All rights reserved.
Synthetic studies on novel benzimidazolopeptides with antimicrobial, cytotoxic and anthelmintic potential
作者:Rajiv Dahiya、Devender Pathak
DOI:10.1016/j.ejmech.2006.11.015
日期:2007.6
presence of cupric chloride. The coupling of compounds 5-8 with different amino acid ester hydrochlorides/dipeptide/tripeptide/tetrapeptide methylesters afforded novel benzimidazolopeptide derivatives 5a-f, 6a-h, 7a-g and 8a-g. The structures of all newly synthesized compounds were established on the basis of analytical, IR, (1)H NMR, (13)C NMR and mass spectral data. Selected peptideester derivatives were