Medicinal Chemistry - Volume 20, Issue 7, 2024

Background: Multicomponent reactions are highly useful in synthesizing natural products and bioactive molecules. Out of several MCRs, although utilized widely, some remain neglected in review articles. The Gewald and Groebke-Blackburn-Bienaymé (GBB) reactions are two such reactions. This comprehensive review assimilates applications of Gewald and Groebke-Blackburn- Bienayme reactions in synthesizing novel antimicrobial agents. It presents the antimicrobial properties of the synthesized molecules, providing an overview of their potential druggability. Objective: Developing novel antimicrobial agents is the need of the hour. Toward this objective, the scientific community is developing new methods for constructing novel architectures with potential antimicrobial properties. This review will showcase the usefulness of the Gewald, Strecker, and Groebke-Blackburn-Bienaymé (GBB) reactions in synthesizing antimicrobial molecules. Methods: The articles are searched by using the Sci-finder search tool and summarize the chemistry of their synthesis and antimicrobial evaluation of the molecules. Results: This review focuses on synthesizing antimicrobial molecules using the Gewald, Strecker, and Groebke-Blackburn-Bienaymé (GBB) reactions. The antimicrobial activities of the synthesized molecules are also summarized in tables. Conclusion: This review will briefly overview the application of the Gewald, Strecker, and Groebke- Blackburn-Bienaymé (GBB) reactions in synthesizing novel antimicrobial molecules. It contains several molecules with promising activity against resistant and non-resistant microbial strains. These promising molecules could be studied further to develop novel antibiotics.

Background: Salmonella enterica (S. enterica) serovar Typhimurium, an anaerobic enteric pathogene, could cause human and animal diseases ranging from mild gastroenteritis to whole body serious infections. Objective: The goal of this paper was to synthesize new 6-amido-3-carboxypyridazine derivatives with different lengths of side chains with the aim of getting potent antibacterial agents. Methods: Synthesized compounds were analyzed by analytical techniques, such as ¹H NMR, ¹³C NMR spectra, and mass spectrometry. We designed a series of novel 6-amido-3-carboxypyridazines using FA as the lead compound with the scaffold hopping strategy and their inhibitory activity against the effectors of type III secretion system (T3SS) using SDS-PAGE and western blot analysis for two rounds. Also, the preliminary mechanism of action of this series of compounds on T3SS was performed using real-time qPCR. Results: Nine 6-amido-3-carboxypyridazines was synthesized. The inhibitory activities evaluated showed that compound 2i was the most potent T3SS inhibitor, which demonstrated potent inhibitory activities on the secretion of the T3SS SPI-1 effectors in a dose-dependent manner. The transcription of SPI-1 may be affected by compound 2i through the SicA/InvF regulatory pathway. Conclusion: The novel synthetic 6-amido-3-carboxypyridazines could act as potent leads for the development of novel antibacterial agents.

Background: During the past two decades, many nicotinamide phosphoribosyltransferase (NAMPT) inhibitors were prepared and tested because this enzyme is overexpressed in pancreatic cancer. Although FK866 is a well-known, strong NAMPT inhibitor, it suffers severe drawbacks. Objective: Our work aimed to synthesize efficient NAMPT inhibitors featuring better pharmacokinetic properties than the pyridine-containing FK866. To this aim, the new anticancer agents were based on benzene, pyridazine, or benzothiazole moieties as a cap group instead of the pyridine unit found in FK866 and other NAMPT inhibitors. Methods: The new compounds, prepared exploiting standard heterocycle chemistry and coupling reactions (e.g., formation of amides, ureas, and cyanoguanidines, copper-mediated azide-alkyne cycloaddition), have been fully characterized using NMR and HRMS analyses. Their activity has been evaluated using cytotoxicity and intracellular NAD depletion assays in the human pancreatic cancer cell line MiaPaCa-2. Results: Among the 14 products obtained, compound 28, bearing a pyridazine unit as the cap group and a thiophene moiety as the tail group, showed 6.7 nanomolar inhibition activity in the intracellular NAD depletion assay and 43 nanomolar inhibition in the MiaPaCa-2 cells cytotoxicity assay, comparable to that observed for FK866. Conclusion: The positive results observed for some newly synthesized molecules, particularly those carrying a thiophene unit as a tail group, indicate that they could act as in vivo anti-pancreatic cancer agents.

Introduction: Neuro-inflammation is a complex phenomenon resulting in several disorders. ALOX-5, COX-2, pro-inflammatory enzymes, and amino acid neurotransmitters are tightly correlated to neuro-inflammatory pathologies. Developing drugs that interfere with these targets will offer treatment for various diseases. Objective: Herein, we extend our previous research by synthesizing a series of multitarget hybrids of cinnamic acids with amino acids recognized as neurotransmitters. Methods: The synthesis was based on an In silico study of a library of cinnamic amide hybrids with glycine, γ- aminobutyric, and L - glutamic acids. Drug-likeness and ADMET properties were subjected to In silico analysis. Cinnamic acids were derived from the corresponding aldehydes by Knoevenagel condensation. The synthesis of the amides followed a two-step reaction with 1- hydroxybenzotriazole monohydrate and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride in dry dichloromethane and the corresponding amino acid ester hydrochloride salt in the presence of N,N,-diisopropyl-Nethylamine. Results: The structure of the synthesized compounds was confirmed spectrophotometrically. The new compounds, such as lipoxygenase, cyclooxygenase-2, lipid peroxidation inhibitors, and antiinflammatories, were tested in vitro. The compounds exhibited LOX inhibition with IC⁵⁰ values in the low μM region). Conclusion: Compounds 18a, 23b, and 11c are strong lipid peroxidation inhibitors (99%, 78%, and 92%). Compound 28c inhibits SLOX-1 with IC⁵⁰ =8.5 μM whereas 11a and 22a highly inhibit COX-2 (IC⁵⁰ 6 and 5 μM Hybrids 14c and 17c inhibit both enzymes. Compound 29c showed the highest anti-inflammatory activity (75%). The In silico ADMET properties of 14c and 11a support their drug-likeness.

Background: According to the World Health Organisation, cardiovascular complications have been recognized as the leading course of death between 2000 and 2019. Cardiovascular complications are caused by excess LDL cholesterol in the body or arteries that can build up to form a plaque. There are drugs currently in clinical use called statins that target HMGCoA reductase. However, these drugs result in several side effects. This work investigated using computational approaches to lower cholesterol by investigating green tea extracts as an inhibitors for squalene monooxygenase (the second-rate-controlling step in cholesterol synthesis). Methods: Pharmacophore modeling was done to identify possible pharmacophoric sites based on the pIC50 values. The best hypothesis generated by pharmacophore modeling was further validated by atom-based 3D QSAR, where 70% of the data set was treated as the training set. Prior molecular docking ADMET studies were done to investigate the physiochemical properties of these molecules. Glide docking was performed, followed by molecular dynamics to evaluate the protein conformational changes. Results: Pharmacophore results suggest that the best molecules to interact with the biological target should have at least one hydrogen acceptor (A5), two hydrogen donors (D9 and D10), and two benzene rings (R14 and R15) for green tea polyphenols and theasinensin A. ADMET result shows that all molecules in this class have low oral adsorption. Molecular docking results showed that some green tea polyphenols have good binding affinities, with most of these structures having a docking score of less than -10 kcal/mol. Molecular dynamics further illustrated that the best-docked ligands perfectly stay within the active site over a 100 ns simulation. Conclusion: The results obtained from this study suggest that green tea polyphenols have the potential for inhibition of squalene monooxygenase, except for theasinensin A.

Background: Osteosarcoma (OS) currently demonstrates a rising incidence, ranking as the predominant primary malignant tumor in the adolescent demographic. Notwithstanding this trend, the pharmaceutical landscape lacks therapeutic agents that deliver satisfactory efficacy against OS. Objective: This study aimed to authenticate the outcomes of prior research employing the HM and GEP algorithms, endeavoring to expedite the formulation of efficacious therapeutics for osteosarcoma. Methods: A robust quantitative constitutive relationship model was engineered to prognosticate the IC⁵⁰ values of innovative synthetic compounds, harnessing the power of gene expression programming. A total of 39 natural products underwent optimization via heuristic methodologies within the CODESSA software, resulting in the establishment of a linear model. Subsequent to this phase, a mere quintet of descriptors was curated for the generation of non-linear models through gene expression programming. Results: The squared correlation coefficients and s2 values derived from the heuristics stood at 0.5516 and 0.0195, respectively. Gene expression programming yielded squared correlation coefficients and mean square errors for the training set at 0.78 and 0.0085, respectively. For the test set, these values were determined to be 0.71 and 0.0121, respectively. The s2 of the heuristics for the training set was discerned to be 0.0085. Conclusion: The analytic scrutiny of both algorithms underscores their commendable reliability in forecasting the efficacy of nascent compounds. A juxtaposition based on correlation coefficients elucidates that the GEP algorithm exhibits superior predictive prowess relative to the HM algorithm for novel synthetic compounds.

Introduction: Inflammatory Bowel Disease (IBD) encompasses a group of chronic disorders distinguished by inflammation of the gastrointestinal tract. Among these, Crohn's Disease (CD) stands out as a complex and impactful condition due to challenges for both diagnosis and management, making it a cynosure of research. Methods: In CD, there is the predominance of proinflammatory bacteria, including the Adherentinvasive Escherichia coli (AIEC) with virulence-associated metabolic enzyme Propanediol Dehydratase (pduC), which has been identified as a therapeutic target for the management of CD. Herein, molecular modeling techniques, including molecular docking, Molecular Mechanics with Generalized Born and Surface Area (MMGBSA), drug-likeness, and pharmacokinetics profiling, were utilized to probe the potentials of eighty antibacterial compounds to serve as inhibitors of pduC. Results: The results of this study led to the identification of five compounds with promising potentials; the results of the molecular docking simulation revealed the compounds as possessing better binding affinities for the target compared to the standard drug (sulfasalazine), while Lipinski’s rule of five-based assessment of their drug-likeness properties revealed them as potential oral drugs. MMGBSA free energy calculation and Molecular Dynamics (MD) simulation of the complexes formed a sequel to molecular docking, revealing the compounds as stable binders in the active site of the protein. Conclusion: Ultimately, the results of this study have revealed five compounds to possess the potential to serve as inhibitors of pduC of AIEC. However, experimental studies are still needed to validate the findings of this study.