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The epidermal growth factor receptor (EGFR) plays a crucial role in regulating cellular growth and survival, and its dysregulation is implicated in various cancers, making it a prime target for cancer therapy. Natural compounds known as catechins have garnered attention as promising anticancer agents. These compounds exert their anticancer effects through diverse mechanisms, primarily by inhibiting receptor tyrosine kinases (RTKs), a protein family that includes the notable member EGFR. Catechins, characterized by two chiral centers and stereoisomerism, demonstrate variations in chemical and physical properties due to differences in the spatial orientation of atoms. Although previous studies have explored the membrane fluidity effects and transport across cellular membranes, the stereo-selectivity of catechins concerning EGFR kinase inhibition remains unexplored. In this study, we investigated the stereo-selectivity of catechins in inhibiting EGFR kinase, both in its wild-type and in the prevalent L858R mutant. Computational analyses indicated that all stereoisomers, including the extensively studied catechin (-)-EGCG, effectively bound within the ATPbinding site, potentially inhibiting EGFR kinase activity. Notably, gallated catechins emerged as superior EGFR inhibitors to their non-gallated counterparts, revealing intriguing binding trends. The top four stereoisomers exhibiting high dock scores and binding energies with wild-type EGFR comprise (-)-CG (-)-GCG (+)-CG, and (-)-EGCG. To assess dynamic behavior and stability, molecular dynamics simulations over 100 ns were conducted for the top-ranked catechin (-)-CG and the widely investigated catechin (-)-EGCG with EGFR kinase. This study enhances our understanding of how the stereoisomeric nature of a drug influences inhibitory potential, providing insights that could guide the selection of specific stereoisomers for improved efficacy inexisting drugs. [ABSTRACT FROM AUTHOR]

A set of novel N-methylspiropyrrolidine hybrids have been synthesized regio selectively employing 1,3-dipolar cycloaddition reaction of substituted chalcones with azomethine ylides (work up in situ from isatin and sarcosine). The spiropyrrolidines structures were studied using FT-IR, 1H and 13C NMR spectroscopic data, and was finally confirmed by X-ray diffraction study. Hirshfeld surface analysis was correlated with X-ray diffraction and described different intermolecular contacts. Good antibacterial activity was reported against gram-positive and gram-negative bacterial strains of Bacillus subtillis, Enterococcus faecalis, E. coli, and Pseudomonas aeruginosa. Initially, antibacterial activity of compounds was confirmed by the zone of inhibition. Most of the compounds have shown MIC and MBC in the range between 50-200 µg∕mL against both types of bacteria. Further, for mechanism of action, the tested compounds were checked for the inhibition of an established bacterial drug target, DNA gyrase using in silico approaches. [ABSTRACT FROM AUTHOR]

Organotin compounds (OTCs) are a commercially important group of organometallic compounds of tin used globally as polyvinyl chloride stabilizers and marine antifouling biocides. Worldwide use of OTCs has resulted in their ubiquitous presence in ecosystems across all the continents. OTCs have metabolic and endocrine disrupting effects in marine and terrestrial organisms. Thus, harmful OTCs (tributyltin) have been banned by the International Convention on the Control of Harmful Antifouling Systems since 2008. However, continued manufacturing by non-member countries poses a substantial risk for animal and human health. In this study, structural binding of common commercial OTCs, tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), triphenyltin (TPT), diphenyltin (DPT), monophenyltin (MPT), and azocyclotin (ACT) against sex-steroid nuclear receptors, androgen receptor (AR), and estrogen receptors (ERα, ERβ) was performed using molecular docking and MD simulation. TBT, DBT, DPT, and MPT bound deep within the binding sites of AR, ERα, and Erβ, showing good dock score, binding energy and dissociation constants that were comparable to bound native ligands, testosterone and estradiol. The stability of docking complex was shown by MD simulation of organotin/receptor complex with RMSD, RMSF, Rg, and SASA plots showing stable interaction, low deviation, and compactness of the complex. A high commonality (50–100%) of interacting residues of ERα and ERβ for the docked ligands and bound native ligand (estradiol) indicated that the organotin compounds bound in the same binding site of the receptor as the native ligand. The results suggested that organotins may interfere with the natural steroid/receptor binding and perturb steroid signaling. [ABSTRACT FROM AUTHOR]

The 1,3-dipolar cycloaddition reaction of the chalcones with azomethine ylide (generated by isatin and sarcosine) has been constructed to functionalize novel spiropyrrolidines. The synthesized compounds (4a–d) structures were characterized by modern spectroscopic techniques and further corroborated a compound 4a by single crystal X-ray study. The in vitro antibacterial activity of novel spiropyrrolidines was evaluated against the Gram-positive and Gram-negative bacterial strains Bacillus subtillis, Enterococcus faecalis and Escherichia coli, Pseudomonas aeruginosa, respectively. Among them, compound 4c was found the most potent antibacterial agent. The minimum inhibitory concentration (MIC) observed was 75 and 125 µg/mL against all targeted Gram-positive and negative strains respectively. Furthermore, the compounds were also explored for their inhibitory potential against a known therapeutic target and an essential bacterial enzyme, DNA gyrase using computational methods. [ABSTRACT FROM AUTHOR]