Molecular docking and in vitro antibacterial activity of chiral phthalimide on ESBL producing gram negative bacteria.

Antibiotic resistance is tricky enemy that challenges our healthcare system. It is a stealthy, adaptive and ever evolving opponent, which can take years to develop but can spread like wildfire. In this study, derivatives of chiral phthalimides were developed with this aim to control the growth of resistant strains of Klebsiella pneumonia, Escherichia coli and Pseudomonas aeruginosa by targeting their resistance causing proteins and explore their binding interaction focal points through computational docking. Total 8 novel chiral phthalimides were synthesized and its antibiogram analysis was done on Muller-Hinton Agar by disc diffusion method. Cytotoxicity studies were made to check efficacy of tested compounds on human RBCs and monitor release of hemoglobin absorbance at 540nm. By using in silico molecular approach, crystal structure of target protein was retrieved from Protein Data Bank and docked through Autodock vina and PyRx. The obtained results revealed that seven out of eight compounds have active inhibitory effects against virulent strains. Minimum Inhibitory Concentration (MIC) was measured for most potent compounds i.e., 2-(1,3-dioxoisoindolin-2-yl)-3-(4-hydroxyphenyl) propanoic acid (compound 7) and 3-(1,3-dioxoisoindolin-2-yl) propanoic acid (compound 8). Docking studies displayed a report of highest affinity binding points i.e., amino acids LYS315, ALA318, TYR150, THR262, HIS314 and ARG148 for compound 7 while ALA 318, LYS 315, ARG14 and ILE291 for compound 8.

Novel chiral phthalimides: Antimicrobial evaluation and docking study against Acinetobacter baumannii's OmpA protein.

Antibiotics have been a vital component in the fight against microbial diseases for over 75 years, saving countless lives. However, the global rise of multi-drug-resistance (MDR) bacterial infections is pushing us closer to a post-antibiotic era where common infections may once again become lethal. To combat MDR Acinetobacter baumannii, we investigated chiral phthalimides and used molecular docking to identify potential targets. Outer membrane protein A (OmpA) is crucial for A. baumannii resistant to antibiotics, making it a pathogen of great concern due to its high mortality rate and limited treatment options. In this study, we evaluated three distinct compounds against the OmpA protein: FIA (2-(1,3-dioxoindolin-2yl)-3-phenylpropanoic acid), FIC (2-(1,3-dioxoindolin-2yl)-4-(methylthio) butanoic acid), and FII (3-(1,3-dioxoindolin-2yl)-3-phenylpropanoic acid). Molecular docking results showed that these three compounds exhibited strong interactions with the OmpA protein. Molecular dynamics (MD) simulation analysis further confirmed the stability and binding efficacy of these compounds with OmpA. Their antimicrobial activities were assessed using the agar well diffusion method, revealing that FIA had an optimal zone of inhibition of 24 mm. Additionally, the minimum inhibitory concentrations (MIC) of these compounds were determined, demonstrating their bactericidal properties against A. baumannii, with MICs of 11 µg/µL for FIA, 46 µg/µL for FIC, and 375 µg/µL for FII. In vitro cytotoxicity data indicated that none of the three compounds were hemolytic when exposed to human red blood cells. This finding is particularly significant as it highlights the superior efficacy of FIA against A. baumannii compared to the other compounds. With thorough pharmacokinetic validations, these chiral phthalimides are promising alternative therapeutic options for treating infections caused by A. baumannii, offering new hope in the face of rising antibiotic resistance.

Chiral phthalimides against penicillin-binding protein 2a of methicillin-resistant Staphylococcus aureus: molecular docking and in vitro analysis.

Staphylococcus aureus (S. aureus) is a commensal bacterium and an opportunistic pathogen causing a wide variety of infections ranging from localized skin and soft tissue infections to life-threatening severe bacteremia, osteomyelitis, endocarditis, atopic dermatitis, prosthetic joint infection, staphylococcal food poisoning, medical device-related infections, and pneumonia. It is attributed to an acquired resistant gene, mecA, encoding penicillin-binding protein 2a (PBP2a). PBP2a is an essential protein responsible for the resistivity of methicillin-resistant S. aureus (MRSA) to various beta-lactam antibiotics. The antimicrobial treatment alternatives for MRSA are increasingly limited. Therefore, developing alternative therapeutic options for its treatment is the need of the day. Phthalimides and their N-substituted derivatives are of biological importance as they possess extensive biological and pharmaceutical properties and can serve as an excellent therapeutic option for MRSA. This study uses three chiral phthalimides (FIA, FIB, and FIC) to check their in silico and in vitro inhibitory effects. Molecular docking of these chiral phthalimides against PBP2a of MRSA was performed initially. After promising results, these novel compounds were screened through the agar-well diffusion method and micro-broth dilution assay to investigate their in vitro inhibitory activities with FIB being the strongest anti-staphylococcal agent yielding a 21 mm zone of inhibition and a minimum inhibitory concentration (MIC) of 0.022 ug, respectively. The zones of inhibition obtained through the in vitro activity showed that these chiral phthalimides possess substantial anti-MRSA activities and have the potential to be considered as alternative chemotherapeutics to treat the infections caused by MRSA after the confirmation of their cytotoxic and pharmacokinetic studies.