Synthesis and Antimicrobial Activity of Glycosylated 2-Aryl‑5‑amidinobenzimidazoles

A series of new glycosylated 2-aryl-5-amidinobenzimidazoles derived from four different carbohydrates (D-glucose, D-galactose, N-acetyl-D-glucosamine and lactose) were synthesized by the condensation of the appropriate 4-formyl-3-methoxyphenyl glycoside with 4-amidino- or 4-N-isopropylamidino-ortho-phenylenediamine hydrochloride. All the compounds were properly characterized by high resolution mass spectrometry, uni- and bidimensional 1H and 13C nuclear magnetic resonance and then were evaluated for their antibacterial and antifungal potential. Considering the antifungal potential of them, two derivatives were active against Candida parapsilosis at 96.4 µmol L-1 and another was active against this same strain at 83.5 µmol L-1. In addition, one benzamidine showed activity against Candida glabrata at 97 µmol L-1. Considering the antibacterial potential of these compounds, six of them showed better activity against three different stains: three of them with IC50 of 96.4, 97 and 83.5 μmol L-1 against Gram-positive Micrococcus luteus, the other two with IC50 96.5 and 96.4 μmol L-1 against Gram-positive Enterococcus faecalis and one against Gram-negative Escherichia coli at 90.5 µmol L-1. These findings suggest this structural pattern can be employed for design of more potent agents for discovery of new antimicrobial drug candidates.