Efficient Synthesis and Biological Evaluation of a Novel Series of 1,5-Benzodiazepine Derivatives as Potential Antimicrobial Agents

In vitro antibacterial activity of dinuclear thiolato-bridged ruthenium(II)-arene compounds

IMPORTANCE

The in vitro assessment of diruthenium(II)-arene compounds against Escherichia coli, Streptococcus pneumoniae, and Staphylococcus aureus showed a significant antibacterial activity of some compounds against S. pneumoniae, with minimum inhibitory concentration (MIC) values ranging from 1.3 to 2.6 µM, and a medium activity against E. coli, with MIC of 25 µM. The nature of the substituents anchored on the bridging thiols and the compounds molecular weight appear to significantly influence the antibacterial activity. Fluorescence microscopy showed that these ruthenium compounds enter the bacteria and do not accumulate in the cell wall of gram-positive bacteria. These diruthenium(II)-arene compounds exhibit promising activity against S. aureus and S. pneumoniae and deserve to be considered for further studies, especially the compounds bearing larger benzo-fused lactam substituents.

Research progress on antineoplastic, antibacterial, and anti-inflammatory activities of seven-membered heterocyclic derivatives

Abstract:

Seven-membered heterocyclic compounds are important drug scaffolds, because of their unique chemical structures. They widely exist in natural products and show a variety of biological activities. They have commonly been used in central nervous system drugs in the past 30 years. In the past decade, there are many studies on the activities of antitumor, antibacterial, etc. Herein, we summarize the research advances in different kinds of seven-membered heterocyclic compounds containing nitrogen, oxygen, and sulfur heteroatoms with antitumor, antisepsis, and anti-inflammation activities in the past ten years, which is expected to be beneficial to the development and design of novel drugs for the corresponding indications.

Assessment of elementary derivatives of 1,5-benzodiazepine as anticancer agents with synergy potential

Herein, we designed and synthesized 1,5-benzodiazepines as a lead molecule for anticancer activity and as potent synergistic activity with drug Methotrexate. Working under the framework of green chemistry principles, series of 1,5-benzodiazepine derivatives (3a-3a¹) were synthesized using biocatalyst i.e. thiamine hydrochloride under solvent free neat heat conditions. These compounds were screened for in vitro anti cancer activity against couple of cancer cell lines (HeLa and HEPG2) and normal human cell line HEK-293 via MTT assay. The IC₅₀ values for the compounds were in the range 0.067 to 0.35 µM, better than Paclitaxel and compatible with the drug Methotrexate. Compound 3x was found to be influential against both the cell lines with IC₅₀ values of 0.067 ± 0.002 µM against HeLa and 0.087 ± 0.003 µM against HEPG2 cell line, having activity as compatible to the standard drug Methotrexate. Bioinformatic analysis showed that these compounds are good tyrosine kinase inhibitors which was then proved using enzyme inhibition assay. The studies of apoptosis revealed late apoptotic mode of cell death for the compounds against HEPG2 cancer cell line using flow cytometry method. Synergistic studies of compound 3x and drug Methotrexate showed that the combination was highly active against cancer HeLa and HEPG2 cell line with IC50 value 0.046 ± 0.002 µM and 0.057 ± 0.002 µM respectively, which was well supported by apoptosis pathway. Further the compounds proved its scope as DNA intercalating agents, as its molecular docking and DNA binding studies revealed that the compounds would fit well into the DNA strands.

Crystal structure, Hirshfeld surface analysis and inter-action energy calculation of 4-(furan-2-yl)-2-(6-methyl-2,4-dioxo-pyran-3-yl-idene)-2,3,4,5-tetra-hydro-1H-1,5-benzodiazepine

The title compound {systematic name: (S,E)-3-[4-(furan-2-yl)-2,3,4,5-tetra-hydro-1H-benzo[b][1,4]diazepin-2-yl-idene]-6-methyl-2H-pyran-2,4(3H)-dione}, C19H16N2O4, is constructed from a benzodiazepine ring system linked to furan and pendant di-hydro-pyran rings, where the benzene and furan rings are oriented at a dihedral angle of 48.7 (2)°. The pyran ring is modestly non-planar [largest deviation of 0.029 (4) Å from the least-squares plane] while the tetra-hydro-diazepine ring adopts a boat conformation. The rotational orientation of the pendant di-hydro-pyran ring is partially determined by an intra-molecular N-HDiazp⋯ODhydp (Diazp = diazepine and Dhydp = di-hydro-pyran) hydrogen bond. In the crystal, layers of mol-ecules parallel to the bc plane are formed by N-HDiazp⋯ODhydp hydrogen bonds and slipped π-π stacking inter-actions. The layers are connected by additional slipped π-π stacking inter-actions. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (46.8%), H⋯O/O⋯H (23.5%) and H⋯C/C⋯H (15.8%) inter-actions, indicating that van der Waals inter-actions are the dominant forces in the crystal packing. Computational chemistry indicates that in the crystal the N-H⋯O hydrogen-bond energy is 57.5 kJ mol-1.

Efficient Construction of 5H-1,4-Benzodiazepine Derivatives by a Catalyst-Free Direct Aerobic Oxidative Annulation Strategy

A catalyst-free direct aerobic oxidative annulation reaction of 2-aminobenzylic amines and α-hydroxy ketones efficiently afforded versatile 5H-1,4-benzodiazepine derivatives by employing air as economic and green oxidant under mild conditions. Interestingly, solvent was found to be crucial to the reaction, so that by using acetic acid as the best solvent an efficient and practical method could be achieved, requiring no catalysts or additives at all. This method tolerates a wide range of 2-aminobenzylic amines and α-hydroxy ketones and could be scaled up to multigram synthesis and directly applied in one-step synthesis of the pharmaceutically active N-desmethylmedazepam derivatives, revealing the potential of this new method in the synthesis of 5H-1,4-benzodiazepine skeleton-based pharmaceuticals and chemicals.

Benzodiazepines: Drugs with Chemical Skeletons Suitable for the Preparation of Metallacycles with Potential Pharmacological Activity

The synthesis of organometallic compounds with potential pharmacological activity has attracted the attention of many research groups, aiming to take advantage of aspects that the presence of the metal-carbon bond can bring to the design of new pharmaceutical drugs. In this context, we have gathered studies reported in the literature in which psychoactive benzodiazepine drugs were used as ligands in the preparation of organometallic and metal complexes and provide details on some of their biological effects. We also highlight that most commonly known benzodiazepine-based drugs display molecular features that allow the preparation of metallacycles via C-H activation. These organometallic compounds merit further attention regarding their potential biological effects, not only in terms of psychoactive drugs but also in the search for drug replacements, for example, for cancer treatments.

Design, synthesis and neuropharmacological evaluation of new 2,4-disubstituted-1,5-benzodiazepines as CNS active agents

Benzodiazepines (BZDs) represent a class of privilege scaffold in the modern era of medicinal chemistry as CNS active agents and BZD based drugs are used to treat different psychotic disorders. Inspired from the therapeutic potential of BZDs as promising CNS active agents, in the present work three different series of 1,5-benzodiazepines bearing various substitutions at position 2 and 4 of the benzodiazepine core were synthesized by condensing different substituted chalcones with o-phenylenediamine in the presence of piperidine as a base catalyst. Structural characterization of title compounds was done by using various analytical techniques such as IR, NMR, elemental analysis and mass spectral data. All the synthesized compounds (9a-d, 10a-e and 11a-c) were subjected to in vivo neuropharmacological studies to evaluate their CNS depressant and antiepileptic activity. Results of in vivo evaluation data showed that analogue 11b exhibited potent CNS depressant activity which was comparable to the standard drug diazepam. Compounds 10b and 10c displayed significant antiepileptic activity however they were less potent than the standard drug phenobarbitone. Molecular docking studies were performed using MOE software to find the interaction pattern and binding mode at the GABAA receptor (PDB Id: 6HUP). The results of the docking studies were in good agreement with the observed in vivo activity and revealed the satisfactory binding mode of the compounds within the binding site of the protein. The docking scores for the most promising candidates 10c, 11b and Diazepam were found to be -9.18, -9.46 and -9.88, respectively. Further, the compounds showed compliance with the Lipinski's 'rule of five' and exhibited favourable drug-likeness scores. The identified leads can be explored further for the design and development of new BZD based psychotropic agents.

Recent advances in synthesis and medicinal chemistry of benzodiazepines

Benzodiazepines (BZDs) represent a diverse class of bicyclic heterocyclic molecules. In the last few years, benzodiazepines have emerged as potential therapeutic agents. As a result, several mild, efficient and high yielding protocols have been developed that offer access to various functionalized benzodiazepines (BZDs). They are known to possess a wide array of biological activities such as anxiolytic, anticancer, anticonvulsant, antipsychotics, muscle relaxant, anti-tuberculosis, and antimicrobial activities. The fascinating spectrum of biological activities exhibited by BZDs in various fields has prompted the medicinal chemist to design and discover novel benzodiazepine-based analogs as potential therapeutic candidates with the desired biological profile. In this review, an attempt has been made by to summarize (1) Recent advances in the synthetic chemistry of benzodiazepines which enable their synthesis with desired substitution pattern; (2) Medicinal chemistry of BZDs as therapeutic candidates with promising biological profile including insight of mechanistic studies; (3) The correlation of biological data with the structure i.e. structure-activity relationship studies were also included to provide an insight into the rational design of more active agents.

1-Benzyl-3-hydroxy-4-phenyl-2,3,4,5-tetrahydro-1H-1,5-benzodiazepin-2-one

The title compound, C22H20N2O2, forms chains in the [001] direction in the monoclinic crystal, through N—H...O hydrogen bonding. The chains are associatedviaO—H...π(ring) and C—H...π(ring) interactions involving one phenyl ring and the benzene ring of the benzodiazepine as acceptors. For these intermolecular contacts, the H...π separations are close to 2.7 Å.

Trivedi E, Török B, Dembinski R. Regioselective “hydroamination” of alk-3-ynones with non-symmetrical o-phenylenediamines. Synthesis of diversely substituted 3H-1,5-benzodiazepines via (Z)-3-amino-2-alkenones

Reaction of alk-3-yn-1-ones with non-symmetricalo-phenylenediamines provides an effective method with high atom economy for the synthesis of diversely substituted 1,5-benzodiazepines and conjugated enaminones.