Synthesis of anticancer β-lactams: mechanism of action

Design, Synthesis, Characterization, and Analysis of Antimicrobial Property of Novel Benzophenone Fused Azetidinone Derivatives through In Vitro and In Silico Approach

A sequence of novel 2-(4-benzoyl-2-methyl-phenoxy)-N-(3-chloro-2-oxo-4-phenyl-azetidin-1-yl)-acetamide analogues 9(a−n) were synthesized by multistep synthesis. The newly synthesized compounds were well characterized, and their antimicrobial activities were carried out by disc diffusion and broth dilution methods. Further, all the novel series of compounds (9a−n), were tested against a variety of bacterial and fungal strains in comparison to Ketoconazole, Chloramphenicol, and Amoxicillin as standard drugs, respectively. Compounds 9a, 9e, and 9g as a lead molecule demonstrated a good inhibition against tested strains. Further, molecular docking studies have been performed for the potent compounds to check the three-dimensional geometrical view of the ligand binding to the targeted proteins.

Isocyanide-Based Multicomponent Reactions in Water: Advanced Green Tools for the Synthesis of Heterocyclic Compounds

Reaction rate acceleration using green methods is an intriguing area of research for chemists. In this regard, water as a "green solvent" plays a crucial role in the acceleration of some organic transformations and reveals exclusive selectivity and reactivity in comparison with conventional organic solvents. In particular, multicomponent reactions (MCRs) as sustainable tools lead to the rapid generation of small-molecule libraries in water and aqueous media due to the prominent role of the hydrophobic effect. MCRs, as diversity-oriented synthesis (DOS) methods, have great efficiency with simple operations, atom, pot, and step economy synthesis, and mechanistic beauty. Among diverse classes of MCRs, isocyanide-based multicomponent reactions (I-MCRs), as sustainable and versatile reactions, have gained considerable attention in the synthesis of diverse heterocycle rings, especially in drug design because of the peculiar nature of isocyanide as a particular active reactant. I-MCRs that are performed in water are mild, environmentally friendly, and easily controlled, and have a reduced number of workup, purification, and extraction steps, which fit well with the advantages of "green" chemistry. Performing these powerful organic transformations in water and aqueous media is accompanied by acceleration owing to negative activation volumes, which originate from connecting several reactants together to generate a single product. It should be noted that the combination of MCR strategy and aqueous phase reaction is of growing interest for the development of sustainable synthetic techniques in organic conversions. However, an exclusive account focusing on the recent progress in eco-friendly I-MCRs for the construction of heterocycles in water and aqueous media is particularly lacking. This review highlights the progress of various kinds of I-MCRs in water and aqueous media as benign methods for the efficient construction of vital heterocyclic scaffolds, with a critical discussion of the subject in the period 2000-2021. We hope that this themed collection will be of interest and beneficial for organic and pharmaceutical chemists and will inspire more reaction development in this fascinating field.

Conceptual design and cost-efficient environmentally Benign synthesis of beta-lactams

Stereoselective preparation of diverse trans and cis β-lactams following different experimental conditions are executed. A variety of circumstances are critically analyzed. It has been found that the stereochemistry of the products depends on a number of parameters including the conditions of the procedures, composition of the Schiff bases and acid chlorides or equivalents, method of addition of the reactants, temperature of the process and nature of the media. Using some of the compounds and methods as described herein, a number of useful chemical transformations for the preparation of heterocycles are achieved. These methods include indium-catalyzed glycosylation of amino β-lactams, preparation of pyrrole-substituted β-lactams, cycloaddition with sterically congested Schiff bases towards β-lactams, Michael reaction for the preparation of polycyclic oxazepenes and synthesis of two chiral isomers of the thienamycin side chain. Most of the products are obtained stereospecifically and in optically active forms. Many reactions described here are catalytic and therefore, these are environmentally friendly.

A Novel Baker’s Yeast-Mediated Microwave-Induced Reduction of Racemic 3-Keto-2-Azetidinones: Facile Entry to Optically Active Hydroxy β-Lactam Derivatives

Objective:

Microwave technology, together with enzymatic catalysis is a nature-friendly chemical synthesis method with low wastage of solvent and good yield of the products.

Methods:

Enzymes from various microorganisms can be used in the biochemical processes of a wide range of compounds assisted by microwave irradiation

Results:

In this work, the microwave-induced reaction of α-keto β-lactams by Baker's yeast in organic solvent was conducted to afford optically active cis and trans-α-hydroxy-β-lactams for the first time.

Conclusion:

These hydroxy compounds are the precursors of numerous natural products of medicinal significances.

Design, Synthesis, Anti-microbial and Molecular Docking Studies of Novel 5-Pyrazyl-2-Sulfanyl-1, 3, 4-Oxadiazole Derivatives

BACKGROUND

Chemical modification of Oxadiazole may lead to a potent therapeutic agent. A series of novel 5-pyrazyl-2-sulfanyl-1, 3, 4-oxadiazole derivatives (5ag) have been synthesised utilising pyrazinoic acid as a precursor. The new oxadiazole compounds were docked against potential targets and evaluated for antibacterial and antitubercular activity.

METHODS

The 5-pyrazyl-2-substituted sulfanyl-1, 3,4-oxadiazole derivatives (5a-g) were synthesized from the crucial intermediate 2-sulfanyl-5-pyrazyl-1, 3,4-oxadiazole (4), which was prepared by treating the 2-pyrazyl hydrazide with CS2 and pyridine. IR, ¹HNMR, ¹³C, MS and elemental analyses were used to confirm the chemical structures.

RESULTS

Antimicrobial activity was determined for each synthesized compound. Additionally, compounds were evaluated for antitubercular activity against the Mycobacterium Tuberculosis H37Rv strain. Compounds 5c, 5g, and 5a had a favourable antibacterial profile, while 5c and 5g (MIC = 25 g/ml) demonstrated potential antitubercular activity when compared to the other produced compounds. Molecular docking experiments using V-Life Science MDS 4.6 supplemented the biological data.

CONCLUSION

Each compound has been tested for antibacterial and antitubercular action against a variety of microorganism strains and exhibits considerable activity. Additionally, molecular docking analysis confirmed the experimental results by describing improved interaction patterns.

Recent Advances in β-lactam Derivatives as Potential Anticancer Agents

Cancer, accounts for around 10 million deaths annually, is the second leading cause of death globally. The continuous emergency of drug-resistant cancers and the low specificity of anticancer agents are the main challenges in the control and eradication of cancers, so it is imperative to develop novel anticancer agents. Immense efforts have been made in developing new lead compounds and novel chemotherapeutic strategies for the treatment of various forms of cancers in recent years. β-Lactam derivatives constitute versatile and attractive scaffolds for the drug discovery since these kinds of compounds possess a variety of pharmacological properties, and some of them exhibited promising potency against both drug-sensitive and drug-resistant cancer cell lines. Thus, β-lactam moiety is a useful template for the development of novel anticancer agents. This review will provide an overview of β-lactam derivatives with the potential therapeutic application for the treatment of cancers covering articles published between 2000 and 2020. The mechanisms of action, the critical aspects of design and structureactivity relationships are also discussed.

Stereochemical preference toward oncotarget: Design, synthesis and in vitro anticancer evaluation of diastereomeric β-lactams

PURPOSE

In the battle against cancer discovery of new and novel chemotherapeutic agent demands extreme obligation. Development of anticancer compounds with higher potency and reduced side-effects is timely and challenging.

EXPERIMENTAL DESIGN

A small series of fourteen diastereomeric β-lactams (seven pairs) were synthesized through multi-step process exploring [2+2] ketene-imine cycloaddition as the key step. Comparative stereochemical preferences were studied through computational docking and validated by in vitro evaluation. β-tubulin was considered as possible molecular target and in vitro anticancer evaluation was conducted against SiHa, B16F10, K562 and Chang cell lines. Caspase-3 activation assay and hematoxylin/eosin staining of the cells were also accomplished.

RESULTS

Better docking scores of the cis- over the trans-β-lactams indicated favorable β-lactam-β-tubulin interactions in cis-geometry. In vitro (IC50) evaluation confirmed better anticancer activity of the cis-diastereoisomers. Apoptosis-induced cell death was supported by caspase-3 activation study. A cis-β-lactam [(±)-Cis-3-amino-1-phenyl-4-(p-tolyl) azetidin-2-one, 6C] was found to be more active (in vitro) than the marketed natural drug colchicine against SiHa and B16F10 (six times higher potency) cell lines. Reduced toxicity (compared to colchicine) in Chang cells confirmed better site-selectivity (accordingly less side-effects) of 6C than colchicine. Aside from 6C, most of the reported molecules demonstrated good to strong in vitro anticancer activity against SiHa and B16F10 cancer cell lines.

CONCLUSIONS

Stereochemical preferences of the cis-β-lactams over their trans-counterparts, toward the molecular target β-tubulin, was confirmed by docking studies and in vitro anticancer evaluation. Apoptosis was identified as the cause of cell death. The lead 6C exhibited higher potency and selectivity than the marketed drug colchicine both in silico as well as in vitro.

Biological Evaluation in Vitro and in Silico of Azetidin-2-one Derivatives as Potential Anticancer Agents

Potential anticancer activity of 16 azetidin-2-one derivatives was evaluated showing that compound 6 [N-(p-methoxy-phenyl)-2-(p-methyl-phenyl)-3-phenoxy-azetidin-2-one] presented cytotoxic activity in SiHa cells and B16F10 cells. The caspase-3 assay in B16F10 cells displayed that azetidin-2-one derivatives induce apoptosis. Microarray and molecular analysis showed that compound 6 was involved on specific gene overexpression of cytoskeleton regulation and apoptosis due to the inhibition of some cell cycle genes. From the 16 derivatives, compound 6 showed the highest selectivity to neoplastic cells, it was an inducer of apoptosis, and according to an in silico analysis of chemical interactions with colchicine binding site of human α/β-tubulin, the mechanism of action could be a molecular interaction involving the amino acids outlining such binding site.

Novel Pyrazolo[3,4-b]pyridine Derivatives: Synthesis, Characterization, Antimicrobial and Antiproliferative Profile

Three novel series of pyridine derivatives, namely Schiff's bases, 4-thiazolidinones and azetidin-2-ones bearing pyrazolo[3,4-b]pyridine moiety, have been synthesized. The chemical structures of the synthesized compounds were characterized. The compounds were tested for their antimicrobial activity using the agar well diffusion and broth macrodilution methods. The compounds were also evaluated for their antiproliferative activity using the sulforhodamine B (SRB) assay. The majority of the tested compounds exhibited slight to high antimicrobial activity against the test microorganisms with minimum inhibitory concentrations (MICs) of 0.12-62.5 µg/mL when compared to that of 3 standard antimicrobial agents (Ampicillin, 0.007-0.03 µg/mL; Gentamicin; 0.015-0.24 µg/mL; and Amphotericin B, 0.03-0.98 µg/mL). Compound (7b) was found to be nearly as active as the standard antimicrobial drug Amphotericin B against Fusarium oxysporum fungal strain with MIC of 0.98 µg/mL. Some of the test compounds showed remarkable cytotoxic activities against Hep G2 (hepatocellular carcinoma) cells (IC50=0.0158-71.3 µM) in comparison to the standard anticancer drug doxorubicin (IC50=0.008 µM). Among the compounds tested, (5), (6a), (6b), (7b), and (10) exhibited antiproliferative potency (IC50=0.0001-0.0211 µM) that was found to be better than that of doxorubicin (IC50=0.099 µM) against MCF7 (breast adenocarcinoma) cells. In particular, (7b) displayed the highest significant antiproliferative efficacy against both Hep G2 and MCF7 cell lines showing IC50 values of 0.0158 µM and 0.0001 µM, respectively. Our findings suggest that the synthesized compounds may be promising candidates as novel antimicrobial and antiproliferative agents.

Bismuth nitrate-induced novel nitration of estradiol: an entry to new anticancer agents

Direct nitration of estradiol was carried out using metal nitrates on solid surfaces under mild condition, and a combination of bismuth nitrate pentahydrate impregnated KSF clay was found to be the best reagent to synthesize 2- and 4-nitroestradiol effectively. Furthermore, various basic side chains were introduced, through O-linker at C-3, to these nitroestradiols. The ability of these derivatives to cause cytotoxicity in Estrogen Receptor (ER)-positive and ER-negative breast cancer cell lines, as well as cancer cell lines of other origins, was examined. Qualitative structure activity relationship (SAR) has also been studied. We found that a basic side chain containing either a piperidine or morpholine ring, when conjugated to 2-nitroestradiol, was particularly effective at causing cytotoxicity in each of the cancer cell lines examined. Surprisingly, this effective cytotoxicity was even seen in ER-negative breast cancer cells.

Asymmetric synthesis and evaluation of α-quaternary chiral lactam derivatives as novel anticancer agents

Asymmetric synthesis of α-quaternary chiral lactam derivatives as novel anticancer agents and evaluation of their cytotoxic potentials and spectrums are reported. Among the developed lactam derivatives, the most active new compounds (S)-4m and (S)-4n synthesized via asymmetric phase-transfer catalytic alkylation in very high optical yields (98 % ee) show promising in vitro anticancer activities with low micromolar IC50 values against colon, uterus, lung, and breast human cancer cells.

Biological activity of 3-chloro-azetidin-2-one derivatives having interesting antiproliferative activity on human breast cancer cell lines

Resveratrol (3,4',5 tri-hydroxystilbene), a natural plant polyphenol, has gained interest as a non-toxic agent capable of inducing tumor cell death in a variety of cancer types. However, therapeutic application of these beneficial effects remains very limited due to its short biological half-life, labile properties, rapid metabolism and elimination. Different studies were undertaken to obtain synthetic analogs of resveratrol with major bioavailability and anticancer activity. We have synthesized a series 3-chloro-azetidin-2-one derivatives, in which an azetidinone nucleus connects two aromatic rings. Aim of the present study was to investigate the effects of these new 3-chloro-azetidin-2-one resveratrol derivatives on human breast cancer cell lines proliferation. Our results indicate that some azetidin-based resveratrol derivatives may become new potent alternative tools for the treatment of human breast cancer.

An expeditious iodine-catalyzed synthesis of 3-pyrrole-substituted 2-azetidinones

2-Azetidinones and pyrroles are two highly important classes of molecules in organic and medicinal chemistry. A green and practical method for the synthesis of 3-pyrrole-substituted 2-azetidinones using catalytic amounts of molecular iodine under microwave irradiation has been developed. Following this method, a series of 3-pyrrole- substituted 2-azetidinones have been synthesized with a variety of substituents at N-1 and at C-4. The procedure is equally effective for mono- as well as polyaromatic groups at the N-1 position of the 2-azetidinone ring. The C-4 substituent has no influence either on the yield or the rate of the reaction. Optically pure 3-pyrrole-substituted 2-azetidinones have also been synthesized following this methodology. No deprotection/rearrangement has been identified in this process, even with highly acid sensitive group-containing substrates. A plausible mechanistic pathway has also been suggested based on the evidence obtained from ¹H-NMR spectroscopy. The extreme rapidity with excellent reaction yields is believed to be the result of a synergistic effect of the Lewis acid catalyst (molecular iodine) and microwave irradiation.

Microwave-assisted polystyrene sulfonate-catalyzed synthesis of novel pyrroles

Background

Pyrroles are widely distributed in nature and important biologically active molecules. The reaction of amines with 2,5-dimethoxytetrahydrofuran is a promising pathway for the synthesis of pharmacologically active pyrroles under microwave irradiation.

Results

Microwave-induced polystyrenesulfonate-catalyzed synthesis of pyrroles from amines and 2,5-diemthoxytetrahydrofuran has been accomplished with excellent yield. This method produces pyrroles with polyaromatic amines.

Conclusion

The present procedure for the synthesis of N-aromatic substituted pyrroles will find useful application in the area of pharmacologically active molecules.

Polystyrenesulfonate-catalyzed synthesis of novel pyrroles through Paal-Knorr reaction

BACKGROUND

The classical Paal-Knorr reaction is one of the simplest and most economical methods for the synthesis of biologically important and pharmacologically useful pyrrole derivatives.

RESULTS

Polystyrenesulfonate-catalyzed simple synthesis of substituted pyrroles following Paal-Knorr reaction has been accomplished with an excellent yield in aqueous solution. This method also produces pyrroles with multicyclic polyaromatic amines.

CONCLUSIONS

The present procedure for the synthesis of N-polyaromatic substituted pyrroles will find application in the synthesis of potent biologically active molecules.

A microwave-assisted bismuth nitrate-catalyzed unique route toward 1,4-dihydropyridines

The classical Hantzsch reaction is one of the simplest and most economical methods for the synthesis of biologically important and pharmacologically useful 1,4-dihydropyridine derivatives. Bismuth nitrate pentahydrate under microwave irradiation is proven to act as a very efficient catalyst for a one-pot, three-component synthesis of 1,4-dihydropyridines in excellent yields from diverse amines/ammonium acetate, aldehydes and 1,3-dicarbonyl compounds within 1–3 min under solvent-free conditions. The present environmentally benign procedure for the synthesis of 1,4-dihydropyridines is suitable for library synthesis and it will find application in the synthesis of potent biologically active molecules. The excellent yield and extreme rapidity of the method is due to a concurrent effect of the catalyst and microwave irradiation.

A truly green synthesis of α-aminonitriles via Strecker reaction

Background

The classical Strecker reaction is one of the simplest and most economical methods for the synthesis of racemic α-aminonitriles (precursor of α-amino acids) and pharmacologically useful compounds.

Results

Indium powder in water is shown to act as a very efficient catalyst for one-pot, three-component synthesis of α-aminonitriles from diverse amines, aldehydes and TMSCN. This general rapid method is applicable to a wide range of amines and aldehydes and produces products in excellent yield.

Conclusions

The present one-pot, three-component environmentally benign procedure for the synthesis of α-aminonitriles will find application in the synthesis of complex biologically active molecules.

Polycyclic aromatic compounds as anticancer agents: Evaluation of synthesis and in vitro cytotoxicity

Polycyclic aromatic hydrocarbons (PAHs) are considered to be significant environmental carcinogens. Additionally, various planar ring systems are capable of intercalating with DNA, leading to a number of drugs that possess chemotherapeutic activity. In this study, three new polyaromatic compounds with a side chain were synthesized, and spectroscopic as well as elemental analyses were performed. The addition of the long chains to either chrysene or pyrene caused a red-shift in the spectral emission when compared to the corresponding polycyclic aromatic hydrocarbons itself. Furthermore, the cytotoxicity of the three novel polyaromatic compounds was evaluated in vitro in a panel of cultured mammalian cell lines. The pyrenyl ether demonstrated better cytotoxicity compared to cisplatin against colon (HT-29) as well as cervical (HeLa) cancer cell lines. In conclusion, three new compounds were synthesized and investigated in this study. This novel method is likely to play a role in other areas of research.