Staphylococcus aureus is responsible for numerous instances of superficial, toxin-mediated, and invasive infections. The emergence of methicillin-resistant (MRSA), as well as vancomycin-resistant (VRSA) strains of S. aureus, poses a massive threat to human health. The tenacity of S. aureus to acquire resistance against numerous antibiotics in a very short duration makes the effort towards developing new antibiotics almost futile. S. aureus owes its destructive pathogenicity to the plethora of virulent factors it produces among which a majority of them are moonlighting proteins. Moonlighting proteins are the multifunctional proteins in which a single protein, with different oligomeric conformations, perform multiple independent functions in different cell compartments. Peculiarly, proteins involved in key ancestral functions and metabolic pathways typically exhibit moonlighting functions. Pathogens mainly employ those proteins as virulent factors which exhibit high structural conservation towards their host counterparts. Consequentially, the host immune system counteracts these invading bacterial virulent factors with minimal protective action. Additionally, many moonlighting proteins also play multiple roles in various stages of pathogenicity while augmenting the virulence of the bacterium. This has necessitated elaborative studies to be conducted on moonlighting proteins of S. aureus that can serve as drug targets. This review is a small effort towards understanding the role of various moonlighting proteins in the pathogenicity of S. aureus.

A catalyst‐free, greener and highly efficient method for the synthesis of a series of quinoxaline derivatives involving simple liquid assisted hand‐grinding in a mortar and pestle has been developed. The mechanochemical agitation under LAG was sufficient enough for the smooth condensation of both aromatic and heteromatic 1,2‐diamines with a variety of 1,2‐dicarbonyl compounds to afford the corresponding quinoxalines in high yields. Several of these quinoxaline derivatives inhibit the growth of Mycobacterium smegmatis in moderate to good effect. Simple substitution in the quinoxaline ring was found to be more effective in antibacterial agents than bulky substitution. In particular, pyrido[2,3‐b]pyrazines with an additional N‐atom in the scaffold showed better activity than others. Overall, the key advantages of this method are simplicity of operation, catalyst‐free condition, solvent‐less synthesis, low E‐factor, cleaner reaction profile, devoid of work‐up step, easy purification and shorter reaction times, and the new series of pyrido[2,3‐b]pyrazines are good antibacterial agents against M. smegmatis.

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Two sulfonate functionalized tetraphenylethylene (TPE) derivatives were synthesized and used as probes for the detection and imaging of Gram-positive bacteria (e.g. Staphylococcus aureus).