A microwave promoted solvent-free approach to steroidal quinolines and their in vitro evaluation for antimicrobial activities

Expanding Diversity of Fused Steroid-Quinoline Hybrids by Sequential Amination/Annulation/Aromatization Reactions

Viable alternative approaches to a variety of ring A and ring D-fused steroid-quinoline hybrids, along with ring A, D-fused, and/or ring A-fused, side chain-substituted steroid-bis-quinolines were explored by means of sequential amination/annulation/aromatization reactions of suitable ketosteroids with 2-acyl-substituted anilines. Key factors directing the chemoselective behavior of polyfunctionalized substrates were investigated. Remarkably, the use of TMSOTf as an alternative promoter/catalyst enabled the direct synthesis of the desired hybrids, avoiding the protection/deprotection steps of the conventional procedures when the starting substrates contained labile functional groups.

An insight into sustainable and green chemistry approaches for the synthesis of quinoline derivatives as anticancer agents

Quinolones, a key class of heterocyclics, are gaining popularity among organic and medicinal chemists due to their promising properties. Quinoline, with its broad spectrum of action, plays a primordial role in chemotherapy for cancer. Drugs include lenvatinib and its structural derivatives carbozantinib and bosutinib, and tipifarnib are the popular anticancer agents. Owing to the importance of quinoline, there are several classical methods for the synthesis such as, such as Gould-Jacobs, Conrad-Limpach, Camps cyclization, Skraup, Doebnervon Miller, Combes, Friedlander, Pfitzinger, and Niementowski synthesis. These methods are well-commended for developing an infinite variety of quinoline analogues. However, these procedures are associated with several drawbacks such as long reaction times, use of hazardous chemicals or stoichiometric proportions, difficulty of working up conditions, high temperatures, organic solvents, and the presence of numerous steps, all of which have an impact on the environment and the economy. As a result, researchers are working hard to develop green quinoline compounds in the hopes of making groundbreaking discoveries in the realm of cancer. In this review, we have highlighted significant research on quinoline-based compounds and their structure-activity relationship (SAR). Furthermore, because of the significant economic and environmental health and safety (EHS) concerns, more research is being dedicated to the green synthesis of quinolone derivatives. The current review offers recent advances in quinoline derivatives as anticancer agents for green synthesis using microwave, ultrasound, and one-pot synthesis. We believe that our findings will provide useful insight and inspire more green research on this framework to produce powerful and selective quinoline derivatives.

Synthesis and biological activities of bicyclic pyridines integrated steroid hybrid

Reports on structural modification of heterosteroids through various reactions, and developed synthetic routes have considerably increased over the last decade. The present review encompasses the applicable approaches dealing with the utility of reactive moieties in various steroids for the synthesis of fused bicyclic pyridines, and binary bicyclic pyridines all over the years. The different sections include the synthesis of steroids-fused, and binary quinolines, pyridopyrimidines, imidazopyridines, spirocyclic imidazopyridines, pyrazolopyridines, thienopyridines, pyridinyl-thiazoles, and tetrazolopyridine hybrids, as well as, the diverse biological applications of these heterocyclic steroids. The researchers' interest was principally focused on investigating the flexibility of synthetic strategies for various derivatives of natural steroids and building proposals based on heterocyclic steroids for drug discovery, biological assessments, and synthetic applications.

Microwave-assisted synthesis of novel steroidal heterocyclic analogs as potent inhibitors of RANKL-induced osteoclastogenesis

Osteoporosis is a significant public health issue in our aging population. It is an excessive bone resorption condition brought on by osteoclastogenesis, which makes bones more brittle. In the present work, a series of novel heterosteroidal derivatives have been synthesized using the microwave technique and were evaluated as antiosteoclastogenic agents. The structures of the newly synthesized compounds have been confirmed using analytical and spectral data. The antiosteoclastogenic activity of the newly synthesized compounds was estimated in vitro against osteoclast-differentiated cells from the RAW 264.7 cell line. The pregnenolone dimer 10, the pyridinotestosterone derivative 2, and the phenylnicotinonitrile pregnenolone derivative 8a attained the most promising antiosteoclastogenic activity displaying IC50 (the half maximal inhibitory concentration) values of 5.45 ± 5.30, 11.88 ± 2.09, and 13.40 ± 3.00 µM, respectively, in comparison with dimethyl itaconate (IC50  = 17.76 ± 3.20 µM) and alendronate (IC50  = 4.48 ± 1.89 µM) as reference compounds. Finally, an in silico ADME (Absorption, Distribution, Metabolism, and Excretion) study was conducted to evaluate the synthesized compounds' pharmacokinetic and drug-likeness properties. The results manifested that almost all the investigated compounds' properties were compatible with the specified optimal range, which indicates their reassuring pharmacokinetic properties.

Synthesis, biological activities, and future perspectives of steroidal monocyclic pyridines

Steroidal pyridines are a class of compounds that have been the subject of extensive research in recent years due to their potential biological activities. The introduction of a pyridine ring into the steroid skeleton can significantly alter the chemical and biological properties of the compound, making it more potent and/or selective for a particular target. Different synthetic methods have been developed for the preparation of steroidal pyridines. This review provides an overview of the synthesis, biological activities, and future perspectives of steroidal monocyclic dihydropyridines, tetrahydropyridines, and pyridines from 2005 to the present. The different synthetic methods that have been developed for the preparation of these steroids are discussed, as well as the proposed mechanisms and the biological activities that have been reported. Finally, the potential of steroidal monocyclic pyridines for the development of new drugs is discussed. This review is intended to provide a comprehensive overview of the field of steroidal monocyclic pyridines for researchers and scientists who are interested in this area of research. It is also hoped that this review will stimulate further research into the synthesis and biological activities of steroidal pyridines to develop new and improved drugs for the treatment of diseases.

Application of Quinoline Ring in Structural Modification of Natural Products

Natural compounds are rich in pharmacological properties that are a hot topic in pharmaceutical research. The quinoline ring plays important roles in many biological processes in heterocycles. Many pharmacological compounds, including saquinavir and chloroquine, have been marketed as quinoline molecules with good anti-viral and anti-parasitic properties. Therefore, in this review, we summarize the medicinal chemistry of quinoline-modified natural product quinoline derivatives that were developed by several research teams in the past 10 years and find that these compounds have inhibitory effects on bacteria, viruses, parasites, inflammation, cancer, Alzheimer's disease, and others.

Synthesis of Nitrogen-Containing Heterocyclic Scaffolds through Sequential Reactions of Aminoalkynes with Carbonyls

Sequential reactions of aminoalkynes represent a powerful tool to easily assembly biologically important polyfunctionalized nitrogen heterocyclic scaffolds. Metal catalysis often plays a key role in terms of selectivity, efficiency, atom economy, and green chemistry of these sequential approaches. This review examines the existing literature on the applications of reactions of aminoalkynes with carbonyls, which are emerging for their synthetic potential. Aspects concerning the features of the starting reagents, the catalytic systems, alternative reaction conditions, pathways and possible intermediates are provided.

Secosteroid-quinoline hybrids as new anticancer agents

An elegant approach to unknown secosteroid-quinoline hybrids is disclosed. A series of 13,17-secoestra-1,3,5(10)-trien-17-oic acid [N'-(iso)quinolylmethylene]hydrazides was prepared and these novel type of secosteroids was screened for antiproliferative activity against estrogen-responsive human breast cancer cell line MCF-7. Most of the synthesized compounds showed a cytotoxic effect superior to that of reference drug cisplatin; the lead compound exhibits the highest activity with the IC₅₀ value of about 0.8 μM and is 7 times more active than cisplatin. A high selectivity index was observed for the hit 13,17-secoestra-1,3,5(10)-trien-17-oic acid [N'-quinolylmethylene]hydrazides 2a and 2c. Compounds 2a and 2c evaluated in luciferase reporter assays exhibited high antiestrogenic potency which was superior to that of tamoxifen. These hit compounds were characterized by high activity against MCF-7 cells that retained towards multidrug-resistant NCI/ADR-RES cells.

Spectroscopic profiling, DFT computations, molecular docking and molecular dynamic simulation of biologically active 5-isoquinolinesulfonic acid

The title compound 5-isoquinolinesulfonic acid (5IQSA) is characterized using the FT-IR, FT-Raman, NMR and UV-Vis spectra. The optimized molecular geometry, vibrational assignments, infrared intensities and Raman scattering are precisely calculated using Density Functional Theory (DFT) with the B3LYP/6-311++G(d,p) basis set. The ¹H and ¹³C NMR chemical shifts are computed and compared with the experimental data. The TD-DFT/M062X/6-311++G(d,p) method is used to compute UV-Vis for different solvents, and the results are compared to UV-Vis spectra obtained experimentally. The HOMO-LUMO band gap energy is calculated for various solvents and compared to the band gap of UV-Vis spectra. Molecular dynamics simulations are used to investigate the biomolecular stability. Non-Linear Optical (NLO) behaviour has been illustrated using hyperpolarizability calculations. Topological studies such as Reduced Gradient Density (RDG), Electron Localization Function (ELF) and Localized Orbital Locator (LOL) are performed. The Molecular Electrostatic Potential (MEP), Natural Bond Orbital (NBO) analysis, Fukui functions and thermodynamic properties were analysed. To explore the biological behaviour of the examined compound, molecular docking was performed to evaluate the hydrogen bond distance and binding energies with (2XA4) kinase inhibitor protein.Communicated by Ramaswamy H. Sarma.

Trifluoromethylated Quinolone-Hydantoin Hybrids: Synthesis and Antibacterial Evaluation

A series of new trifluoromethyl-substituted quinolones and hydantoin hybrids has been synthesized and evaluated against Gram-positive bacterium (Staphylococcus aureus MTCC 96) and Gram-negative bacteria (Pseudomonas aeruginosa MTCC 441, Klebsiella pneumonia MTCC 109, and Escherichia coli MTCC 442). Compound  19c, having the 6-propene group on the quinolone ring, showed similar activity to a standard drug (chloramphenicol) by exhibiting MIC values of 50 µg/mL against S. aureus and P. aeruginosa. Physicochemical properties of compound 19c were also determined, which were in line with Lipinski’s rule of five, suggesting the suitability of compound 19c in biological systems. Various types of binding interactions of 19c within the active site of DNA gyrase of S. aureus were also streamlined by molecular docking studies, suggesting its capability to block the catalytic process of the DNA gyrase, which could be the possible reason for its antibacterial potential.

Recent advances on synthesis and biological activities of C-17 aza-heterocycle derived steroids

Steroids modification for improving their biological activities is one of the most efficient and fruitful methods to develop novel medicines. Steroids with aza-heterocycles attaching to the C-17 owing various biological activities have received great attentions and some of the compounds are developed successfully as drugs. In this review, the research of the syntheses and biological activities of steroids bearing various aza-heterocycles published in the last 8 years is assembled, and some important structure-activity relationships (SARs) of active compounds are presented. According to the analysis of the literatures and our experiences in this field, the potential of aza-heterocyclic steroids as medicinal drugs is proposed.

[4+2] Cycloaddition reactions with aza-o-QMs of fulvenes: Construction of tetrahydroquinoline derivatives

An efficient [4+2] cycloaddition reaction of fulvenes with the in situ generated aza-o-quinone methides from N-(o-chloromethyl)aryl sulfonamides with the assistance base has been developed to afford a series of tetrahydroquinoline derivatives. The reaction tolerates a wide range of aza-o-quinone methides and fulvenes bearing four to seven-membered rings to afford the corresponding tetrahydroquinolines in moderate to good yields. Based on the literature analysis, a plausible mechanism for this [4+2] cycloaddition was proposed.

Synthesis, antibacterial, anti-oxidant and molecular docking studies of imidazoquinolines

Quinoline and imidazole derivatives have been playing a significant role in functional bioactivities and were potentially used as antibacterial, antifungal, anticancer, and anti-inflammatory drugs. Owing to the limitation of drug resistance, herein we synthesized thio-, chloro-, and hydroxyl-functionalized various imidazoquinolines by molecular hybridization approach. All the imidazoquinoline derivatives were examined for their antibacterial activity against selected bacterial pathogens by the agar well diffusion method. In addition, the anti-oxidant efficacy of imidazoquinolines was also tested using ferric reducing antioxidant power (FRAP). Among them, electron-withdrawing (-Cl) substituent containing imidazoquinoline 5f showed higher antibacterial and anti-oxidant activities than other imidazoquinolines and reached the effectiveness of the standard. In addition, compounds 4f, 5e, and 3f showed moderate antibacterial activity and other derivatives displayed weak activity against various pathogens. Molecular docking studies were also performed on selected imidazoquinoline derivatives (3f, 4f, and 5f), which showed high docking score and strong binding energy values. These results revealed that thio-imidazoquinoline could assist as a prototype for the designing of multidrug-resistant antibiotics against various microbial organisms.

UV Properties and Loading into Liposomes of Quinoline Derivatives

The scientific relevance of quinolines is strictly linked to the fine-tuning of their features by functionalizing the heterocyclic core. Consequently, the compounds of this class are very versatile and can be used as possible drugs for a lot of medical applications. In this work, the inclusion of eight synthetic quinoline derivatives in liposomes formulated with different lipids was investigated in terms of the encapsulation efficiency and to highlight the effect on the liposome size distribution and thermotropic behavior. Excellent encapsulation was accomplished with all the quinoline/phospholipid combinations. Differences in the interactions at the molecular level, dependent on the quinoline molecular scaffolds and lipid structure, were observed, which could significantly bias the interaction with the drug and its release in pharmaceutical applications. Experiments in combination with computational studies demonstrated that the UV absorption of quinolines with expanded conjugation could be affected by the environment polarity. This was probably due to a solvent-dependent ability of these quinolines to stack into aggregates, which could also occur upon inclusion into the lipid bilayer.

Recent investigations into synthesis and pharmacological activities of phenoxy acetamide and its derivatives (chalcone, indole and quinoline) as possible therapeutic candidates

Medicinal chemistry can rightfully be regarded as a cornerstone in the public health of our modern society that combines chemistry and pharmacology with the aim of designing and developing new pharmaceutical compounds. For this purpose, many chemical techniques as well as new computational chemistry applications are used to study the utilization of drugs and their biological effects. In the biological interface, medicinal chemistry constitutes a group of interdisciplinary sciences, as well as controlling its organic, physical and computational pillars. Therefore, medicinal chemists working to design an integrated and developing system that portends an era of novel and safe tailored drugs either by synthesizing new pharmaceuticals or to improving the processes by which existing pharmaceuticals are made. It includes researching the effects of synthetic, semi-synthetic and natural biologically active substances based on molecular interactions in terms of molecular structure with triggered functional groups or the specific physicochemical properties. The present work focuses on the literature survey of chemical diversity of phenoxy acetamide and its derivatives (Chalcone, Indole and Quinoline) in the molecular framework in order to get complete information regarding pharmacologically interesting compounds of widely different composition. From a biological and industrial point of view, this literature review may provide an opportunity for the chemists to design new derivatives of phenoxy acetamide and its derivatives that proved to be the successful agent in view of safety and efficacy to enhance life quality.

Microwave-assisted One-pot Synthesis of 2-Substituted Quinolines by Using Palladium Nanoparticles as a Catalyst developed from Green Alga Botryococcus braunii

Background:

Quinoline is a type of N-based organic heterocyclic biologically active compound. Quinolines have grasped the interest of scientists because of their wide scope of applications. Several methods have been developed for the synthesis of quinoline and its derivatives. In this study, a new, efficient, simple, one-pot synthesis of the substituted quinolines was developed by using palladium nanoparticles as a catalyst.

Methods:

Catalyst synthesized by algal extract of green alga Botryococcus braunii and palladium acetate solution, and characterized by different instrumental techniques like FTIR, SEM, and XRD. The synthesized palladium nanoparticles explored for the catalytic activity in the synthesis of quinoline derivatives by the use of 2-aminobenzyl alcohol in toluene with acetyl derivatives followed by the addition of potassium hydroxide. The formation of the product was confirmed by 1HNMR, 13C NMR, and electron ionization mass spectra.

Results:

The formation of palladium nanoparticles characterized by visual observation means the color change from light pale yellow to dark brown indicates the reduction of palladium ions into palladium nanoparticles. Synthesized palladium nanoparticles characterized by FTIR spectrum of the algal extract of green algae B. braunii for the presence of proteins, lipids, carbohydrates, carotenoids, vitamins and other secondary metabolites in algal extract, which function as active components for bioreduction. The morphology of the catalyst was confirmed by SEM and X-ray diffraction measurements for shape, crystalline nature and size. The synthesized palladium nanoparticles explored for the catalytic activity in the synthesis of quinoline derivatives by use of 2-aminobenzyl alcohol in toluene and added acetyl derivatives followed by the addition of potassium hydroxide. In order to establish the optimum heating method, a comparative study between conventional and microwave heating method was carried out in the presence of palladium nanoparticles as a catalyst.

Conclusion:

This protocol provides a convenient and practical procedure for the preparation of quinoline derivatives from 2-aminobenzyl alcohol, acetyl derivatives, potassium hydroxide and palladium nanoparticles as a catalyst. This protocol will be helpful in synthesizing other quinoline derivatives and several organic heterocycles which are used in different fields such as biological, industrial, pharmaceutical, chemical, medical, etc.

Study on the interactions between B-norcholesteryl benzimidazole compounds with ct-DNA

The study of molecule-DNA interaction is very important for designing an improved therapeutic agent. In previous studies, we synthesized some B-norcholesteryl benzimidazole compounds, and the tests on cancer cells showed that these compounds had good in vitro anti-cancer activities. In order to further investigate mechanism of their actions, three different B-norcholesteryl benzimidazole compounds were selected and interaction of these compounds with the calf thymus DNA (ct-DNA) was monitored by using various methods including UV-Vis and fluorescence spectroscopic techniques, viscosity measurement, and circular dichroism (CD). The results proved a hypochromic effect accompanied with a slight red-shift due to the interaction of the molecules with ct-DNA. According to the UV-Vis and fluorescence spectra, the mentioned compounds were bound to DNA, preferentially through partial intercalation into the DNA helix. Moreover, the ethidium bromide (EB) and Hoechst 33258 competitive binding experiments were also used to confirm the interaction mode of the compounds with ct-DNA. In the Hoechst 33258 displacement experiment, no significant change in the fluorescence intensity was observed. Additional assays such as iodide quenching, viscosity, and CD spectroscopy further confirmed that intercalation should be the major binding mode of the selected compounds with DNA. The cytotoxicity of these three compounds was also evaluated by MTT method, and the results confirmed that binding ability of these compounds to DNA was consistent with their cytotoxicity behavior. The experimental results indicated a higher binding affinity for compound 3 compared to the other compounds. This research provided a better understanding on the molecular mechanism of the interaction between B-norcholesteryl benzimidazole compounds and tumor cells, and offered a beneficial perspective to the designation of novel B-norsteroidal anticancer compounds.

Design, synthesis and biological evaluation of novel 5α, 8α-endoperoxide steroidal derivatives with hybrid side chain as anticancer agents

A series of novel 5α, 8α-endoperoxide steroidal hybrid derivatives containing isatin or indole substituents on the C-17 side chain were synthesized and characterized. The preliminary anti-proliferative activity of the compounds against HepG2, MCF-7, HT-29 and HeLa cell lines were investigated. Compounds 7g and 7l displayed significant anti-proliferative activity in vitro against HepG2 and Hela cells, with IC₅₀ values lower than 8 μM. Furthermore, the biological functions of 7g were examined by flow cytometry and colony analysis. The results showed that 7g could induce HepG2 cell apoptosis, inhibited cell cycle progression, and colony growth. The studies indicated that structural modification at C-17 position could be a promising launch point for design steroidal anticancer agents.

Rh(iii)-catalyzed alkynylation: synthesis of functionalized quinolines from aminohydrazones

Rhodium-catalyzed, chemo- and regioselective synthesis of functionalized quinolines using 2-aminohydrazones and terminal alkynes has been described.

Green recipes to quinoline: A review

The quinoline core possesses a vast number of biological activities such as anticancer, antimalarial, antimicrobial, antifungal, antitubercular and antileishmanial. The conventional classical synthetic methods require the use of expensive and harsh conditions such as high temperature. Currently the scientific communities are searching new methodology to eliminate the use of chemicals, solvents and catalysts, which are hazardous to human health as well as to environment. This review provides a concise overview of new dimensions of green chemistry approaches in designing quinoline scaffold that would encourage the researchers towards green chemistry as well as future application of these greener, non-toxic, environment friendly methods in designing quinoline scaffold.

Palladium-Catalyzed Regioselective Alkoxylation via C-H Bond Activation in the Dihydrobenzo[c]acridine Series

5,6-Dihydrobenzo[c]acridine belongs to the large aza-polycyclic compound family. Such molecules are not fully planar due to the presence of a partially hydrogenated ring. This paper describes the first Pd-catalyzed alkoxylation via C-H bond activation of variously substituted 5,6-dihydrobenzo[c]acridines. We determined suitable conditions to promote the selective formation of C-O bonds using 10% Pd(OAc)2, PhI(OAc)2 (2 eq.) and MeOH as the best combination of oxidant and solvent, respectively. Under these conditions, 5,6-dihydrobenzo[c]acridines bearing substituents at both rings A and D were successfully functionalized, giving access to polysubstitutited acridine motifs.

Synthesis and biological evaluation of novel steroidal 5α,8α-epidioxyandrost-6-ene-3β-ol-17-(O-phenylacetamide)oxime derivatives as potential anticancer agents

Inspired by the significant anti-cancer activity of our previously screened natural ergosterol peroxide (EP, 1), we synthesized and characterized a series of novel 5α,8α-epidioxyandrost-3β-ol-17-(O-phenylacetamide)oxime derivatives (9a-o). The anti-proliferative activity of the synthesized compounds against human hepatocellular carcinoma cells (HepG2, Sk-Hep1) and human breast cancer cells (MCF-7, MDA-MB231) were investigated. Compounds 9d, 9f, 9h, 9j and 9m displayed good anti-proliferative activity (most IC₅₀<20μM) in vitro. Furthermore, fluorescence imaging showed that the designed coumarin-9d conjugate (12) localized mainly in mitochondria, leading to enhanced anticancer activities over the parent structure.

Synthesis of 5α,8α-Ergosterol Peroxide 3-Carbamate Derivatives and a Fluorescent Mitochondria-Targeting Conjugate for Enhanced Anticancer Activities

Inspired by the significant anticancer activity of our previously screened natural ergosterol peroxide (1), we synthesized and characterized a series of novel ergosterol peroxide 3-carbamate derivatives. The antiproliferative activities of the synthesized compounds against human hepatocellular carcinoma cells (HepG2, SK-Hep1) and human breast cancer cells (MCF-7, MDA-MB231) were investigated. 5α,8α-Epidioxyergosta-3-yl-(piperazine-1)carbamate (3 d) and 5α,8α-epidioxyergosta-3-yl-(piperidin-4-methylamine)carbamate (3 f) and their hydrochloride salts exhibited significant in vitro antiproliferative activities against the tested tumor cell lines, with IC₅₀ values ranging from 0.85 to 4.62 μm. Furthermore, fluorescent imaging showed that the designed coumarin-3 d conjugate (5) localized mainly in mitochondria, leading to enhanced anticancer activities over the parent structure 1. As a whole, it appeared that substituent changes at the C3 position could serve as a promising launch point for further design of this type of steroidal anticancer agent.

Heterogeneous catalytic synthesis of quinoline compounds from aniline and C1–C4 alcohols over zeolite-based catalysts

The synthesis of quinolines from aniline and a C₁–C₄ alcohol was conducted under gas-phase reaction conditions over a series of zeolite-based catalysts.

Microwave-assisted one-pot synthesis of steroid–quinoline hybrids and an evaluation of their antiproliferative activities on gynecological cancer cell lines

Steroidal and nonsteroidal ring-fused quinolines were efficiently synthesized under microwave conditions and their antiproliferative activities were investigated.

Regioselective synthesis, antimicrobial evaluation and theoretical studies of 2-styryl quinolines

2-Styryl quinolines (9a-l) have been synthesized regioselectively from 2-methyl-quinoline by using NaOAc in water acetic acid binary solvents and evaluated for their antibacterial activity against both Gram-positive and Gram-negative strains. Among these, the compounds 12 and 8 were found to be active against both bacterial strains. Compounds 9b, 9f, 9g, 9i, 9j and 9k were the most active among the series exhibiting MIC values ranging between 1.9 and 31.2 μg ml(-1) against different bacterial strains. Compounds 9j and 9k were found to be as potent as the standard drug ciprofloxacin against Micrococcus luteus, Klebsiella planticola and Staphylococcus aureus. In addition, the compounds showed bactericidal activity; compound 9j was found to be better than ciprofloxacin, with an MBC value of 0.9 μg ml(-1) against both M. luteus and K. planticola. The compounds also inhibited biofilm formation, and compound 9j was found to be equipotent to erythromycin against M. luteus and S. aureus MLS16. Further, theoretical studies such as those on druggable properties and PMI plot have been carried out.

One-Pot Synthesis, Spectroscopic and Physicochemical Studies of Quinoline Based Blue Emitting Donor-Acceptor Chromophores with Their Biological Application

Blue emitting cyano substituted isoquinoline dyes were synthesized by one-pot multicomponent reactions (MCRs) of aldehydes, malononitrile, 6-methoxy-1,2,3,4-tetrahydro-naphthalin-1-one and ammonium acetate. Results obtained from spectroscopic (FT-IR, (1)H-NMR, (13)C-NMR, EI-MS) and elemental analysis of synthesized compounds was in good agreement with their chemical structures. UV-vis and fluorescence spectroscopy measurements proved that all compounds are good absorbent and fluorescent. Fluorescence polarity study demonstrated that these compounds were sensitive to the polarity of the microenvironment provided by different solvents. In addition, spectroscopic and physicochemical parameters, including electronic absorption, excitation coefficient, stokes shift, oscillator strength, transition dipole moment and fluorescence quantum yield were investigated in order to explore the analytical potential of synthesized compounds. The anti-bacterial activity of these compounds were first studied in vitro by the disk diffusion assay against two Gram-positive and two Gram-negative bacteria then the minimum inhibitory concentration (MIC) was determined with the reference of standard drug chloramphenicol. The results displayed that compound 3 was better inhibitors of both types of the bacteria (Gram-positive and Gram-negative) than chloramphenicol. Graphical Abstract ᅟ.

A Straightforward Approach toward Multifunctionalized Pyridazines via Imination/Electrocyclization

A facile synthesis of functionalized 3-carbamide pyridazines starting from readily available chlorovinyl aldehydes and oxamic acid thiohydrazides via cascade imination/electrocyclization is reported. In the presence of p-toluenesulfuric acid, various ketones have been efficiently incorporated into the pyridazine derivatives through a two-step sequence involving a Vilsmeier-Haack reaction and imination. The synthetic value of this method has been demonstrated by efficient synthesis of steroidal pyridazines.

Evaluation of antimicrobial activity of glycinate and carbonate derivatives of cholesterol: Synthesis and characterization

A series of glycinate and carbonate derivatives of cholesterol (4a–t) were synthesized, characterized and assessed for their in vitro antimicrobial activity. Our results revealed that the compounds exerted inhibitory activities against gram-negative bacteria and fungi.

Synthesis, characterization and antitumor activities of some steroidal derivatives with side chain of 17-hydrazone aromatic heterocycle

Here a series of dehydroepiandrosterone-17-hydrazone and estrone-17-hydrazone derivatives possessing various aromatic heterocycle structures in 17-side chain of their steroidal nucleus were synthesized and their structures were evaluated. The antiproliferative activity of synthesized compounds against some cancer cells was investigated. The results have demonstrated that some dehydroepiandrosterone-17-hydrazone derivatives show distinct antiproliferative activity against some cancer cells through inducing cancer cell apoptosis, and compound 8 with a quinoline structure in 17-side chain displays excellent antiproliferative activity in vitro against SGC 7901 cancer cell (human gastric carcinoma) with an IC50 value of 1 μM. In addition, estrone-17-hydrazone derivatives having a key feature of indole group in the structure showed a special obvious cytotoxicity against HeLa cells, but almost inactive against other cells. The information obtained from the studies is valuable for the design of novel steroidal chemotherapeutic drugs.

Synthesis and characterization of steroidal heterocyclic compounds, DNA condensation and molecular docking studies and their in vitro anticancer and acetylcholinesterase inhibition activities

A facile and efficient approach for the synthesis of steroidal heterocyclic compounds (4–12) has been performed. Furthermore, these newly synthesized compounds were evaluated for their various biological activities.

An efficient route for annulation of pyrimidines to steroids and non-steroids via a base catalyzed one-pot three component reaction

A facile strategy for the synthesis of steroidal A- and D-ring fused pyrimidines has been accomplished in high yields via a one-pot reaction of steroidal ketones, aromatic aldehydes and amidine derivatives in presence of potassium tert-butoxide in refluxing ethanol. The generality of the reaction was also extended to non-steroidal ketones.

Synthesis of steroidal and nonsteroidal vicinal heterocyclic alcohols, N-(1-cycloalkenyl)heterocycles and their antibacterial studies

A solvent free steroidal and nonsteroidal epoxide ring opening reaction by nitrogen containing heterocycles under microwave irradiation is described. Some of the epoxide ring opening compounds were converted to their corresponding N-(1-cycloalkenyl)heterocycles via an acid catalyzed dehydration reaction. The antimicrobial activities of the epoxide ring opening compounds and N-(1-cycloalkenyl)heterocyclic compounds were tested by agar diffusion assay. Compounds 6, 9-12, 24 and 27 showed moderate inhibition against the growth of pathogenic bacteria Escherichia coli, Pseudomonas syringae, Bacillus subtilis, Proteus vulgaris and Staphylococcus aureus.