Inhibitory Activity of Chitin, (2-Acetamido-2-Deoxy-Hexopyranose) against Penicillin-Binding Proteins of Staphylococcus aureus

Abstract

Antibacterial compounds from aquatic sources have the potential to contribute significantly to the treatment of the ever-increasing drug-resistant infectious diseases. The chitin 2-acetamido-2-deoxy-hexopyranose from the freshwater prawn Caridina gracilirostris showed antibacterial activity against Staphylococcus aureus. Two different types of chitin films, (1) chitin and starch, and (2) chitin, starch, and ascorbic acid were tested against S. aureus using in silico molecular docking. The inhibitory action of 2-acetamido-2-deoxy-hexopyranose was recorded against the penicillin-binding protein (PBP2a) of S. aureus. The chitin films exhibited their potential as an effective antibacterial agent through binding energy and ligand efficiency. Further, the inhibitory constant also indicated the potent antibacterial nature of the chitin films. The hydrogen bond interaction of chitin with PBP2a was with serine 49 and threonine 413, at 2.2 Å and 3.4 Å, respectively. The druggability of 2-acetamido-2-deoxy-hexopyranose showed good oral bioavailability, and pharmacokinetics properties were within a normal range. The chitin did not undergo any metabolism and appeared to be of a nontoxic nature. The 2-acetamido-2-deoxy-hexopyranose could be suggested as a novel drug against S. aureus.