Bacterial infections are regarded as one of the leading causes of fatal morbidity and death in patients infected with diseases. The ability of microorganisms, particularly methicillin-resistant Staphylococcus aureus (MRSA), to develop resistance to current drugs has evoked the need for a continuous search for new drugs with better efficacies. Hence, a series of non-PAINS associated pyrrolylated-chalcones (1–15) were synthesized and evaluated for their potency against MRSA. The hydroxyl-containing compounds (8, 9, and 10) showed the most significant anti-MRSA efficiency, with the MIC and MBC values ranging from 0.08 to 0.70 mg/mL and 0.16 to 1.88 mg/mL, respectively. The time-kill curve and SEM analyses exhibited bacterial cell death within four hours after exposure to 9, suggesting its bactericidal properties. Furthermore, the docking simulation between 9 and penicillin-binding protein 2a (PBP2a, PDB ID: 6Q9N) suggests a relatively similar bonding interaction to the standard drug with a binding affinity score of −7.0 kcal/mol. Moreover, the zebrafish model showed no toxic effects in the normal embryonic development, blood vessel formation, and apoptosis when exposed to up to 40 µM of compound 9. The overall results suggest that the pyrrolylated-chalcones may be considered as a potential inhibitor in the design of new anti-MRSA agents.

High-quality single crystals of the title compound, 2C13H11NO2·H2O, were grown and a structural analysis was performed. The asymmetric unit comprises one molecule of 3-(3-hydroxyphenyl)-1-(1H-pyrrol-2-yl)prop-2-en-1-one (3HPPP), which was recently discovered to be a promising anti-MRSA candidate, and a half-molecule of water. The compound crystallizes in the monoclinic space group P2/c. The crystal structure features intermolecular pyrrole-N—H...O (water), carbonyl/keto-C—O...H—O-phenol and phenol-C—O...H (water) hydrogen bonds, which help to consolidate the crystal packing. A Hirshfeld surface analysis for the components in the asymmetric unit showed that H...H (40.9%) and H...C/C...H (32.4%) contacts make the largest contributions to the intermolecular interactions of 3HPPP. Considering the presence of water, in its vicinity H...O/O...H and H...C/C...H are the most significant contacts, contributing 48.7 and 29.8%, respectively.