Aza-Michael promoted glycoconjugation of PETIM dendrimers and selectivity in mycobacterial growth inhibitions. Issue 7 (3rd February 2023)

• Record Type: Journal Article
• Authors: Sarkar, Biswajit; Mahapa, Avisek; Dey, Kalyan; Manhas, Rakshit; Chatterji, Dipankar; Jayaraman, Narayanaswamy
• Is Part Of: RSC advances. Volume 13:Issue 7(2023)
• Page Start: 4669
• Page End: 4677
• Publication Date: 2023-02-03
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d2ra08196b
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Glycoconjugation of primary amine-terminated PETIM dendrimer generations 1 to 3 is conducted using a sugar vinyl sulfoxide as aza-Michael acceptor in aq. MeOH. The native and glycoconjugate dendrimers show selective mycobacterial growth inhibition. Abstract : The benign nature of aza-Michael addition reaction in aqueous solutions is demonstrated herein to conduct a direct glycoconjugation of amine-terminated poly(ether imine) (PETIM) dendrimers. Zero to three generations of dendrimers, possessing up to 16 amine functionalities at their peripheries, undergo aza-Michael reaction with unsaturated sugar vinyl sulfoxide in aq. MeOH solutions and afford the corresponding dendrimers modified with multiple glycosyl moieties at the periphery. First order kinetics of the glycoconjugation is monitored at varying temperatures and the rate constants are observed to be 60–508 s −1, for zero and first generation dendrimers. The antibacterial effects of amine-terminated dendrimers and the corresponding glycoconjugates are studied across Gram-positive, Gram-negative and acid-fast bacteria. Among the species, M. smegmatis and M. tuberculosis showed the greatest growth inhibition effect at micromolar concentrations, for the native amine-terminated and the corresponding glycoconjugated dendrimers. Quantitative assays are performed to adjudge the inhibition efficacies of dendrimers and the glycoconjugates. Selectivity to inhibit M. smegmatis and M. tuberculosis growth, and minimal effects on other bacterial species by dendrimers and glycoconjugates are emphasized.