Compounds 4i Research Articles

New quinoxaline-oxadiazole hybrids as tubulin inhibitors: Synthesis, cytotoxicity, and molecular dynamics simulations

This study describes the synthesis and biological evaluation of a series of novel quinoxaline-oxadiazole hybrid compounds. These compounds were designed to enhance anticancer activity through the incorporation of specific pharmacophoric groups. Structural characterization using NMR and HRMS spectroscopy confirmed the successful synthesis of the hybrids. Cytotoxicity assays revealed that several compounds exhibited significant activity against various cancer cell lines. Compounds 8a and 8f demonstrated potent activity against A549 cells, while 8a, 8b, and 8c were effective against HaCaT cells. Additionally, compounds 8i and 8a showed activity against HepG2 cells. Molecular docking and dynamics simulations suggested that compounds 8c and 8d bind strongly to the tubulin protein, a target for anticancer drugs. These compounds exhibited binding affinities comparable to known anticancer compounds. The results of this study highlight the potential of quinoxaline-oxadiazole hybrids, especially those with halogen substitutions, as promising candidates for the development of novel anticancer therapeutics.

Phytotoxic and Cytogenetic Assessment of Glycerol Triazole Derivatives in Model Plants and Weeds.

Weed invasion represents a challenge for farmers, who typically manage it with herbicides. However, this approach raises concerns about environmental and human health, as well as increasing resistance in these plants with continued use. Therefore, exploring alternative methods, such as heterocyclic compounds, triazoles, is essential due to their biological and environmental relevance. This study aimed to evaluate the effects of twelve 1,2,3-triazoles on the germination and early development of Lactuca sativa, Bidens pilosa, and Lolium multiflorum, as well as their impact on cell division in the cells of L. sativa. Triazole derivatives 4a, 4b, 4c, 4g, 4h, 4i, 4k, and 4l exhibited phytotoxicity, showing varying levels of inhibition in germination, germination speed index, and root growth. Chlorinated compounds were the most detrimental to lettuce development. B. pilosa was notably affected by compounds 4h, 4i, 4k, and 4l, while L. multiflorum responded most to triazoles 4c and 4l, with effectiveness comparable to that of the herbicide glyphosate. All derivatives, except 4l, exhibited aneugenic mechanisms of action, and 4a, 4b, 4c, 4e, 4f, and 4g showed clastogenic effects. This study demonstrated the potential of triazoles as effective agents against weed growth, with mechanisms that warrant further investigation for agricultural applications.

Unprecedented synthesis of indole-linked tetra-substituted alkenes by catalyst-free domino reaction

Herein, we report a simple, efficient catalyst-free green domino reaction of indole, arylglyoxal, and cyclic 1,3-dicarbonyls such as barbituric acid derivatives/dimedone at 100oC in dimethylformamide medium in open air condition. In this reaction, one C-C and one C=C bonds have been formed in one-pot without using any additive or metal based reagent. Considering the presence of indole, benzoyl and cyclic 1,3-dicarbonyl moieties in the products, it is expected that they will exhibit interesting medicinal properties. All the synthesized products were characterized by recording FTIR, 1H NMR, 13C NMR, and HRMS. Moreover, a single crystal XRD of compound 4i was recorded to confirm the structure of the product. Operational simplicity, gram-scale synthesis, mild reaction conditions, good yields, and wide substrate scope are the salient features of this methodology.

Indole analogs as potential anti-breast cancer agents: Design, synthesis, in-vitro bioevaluation with DFT, molecular docking and ADMET studies

Being a belligerent malignancy, triple-negative breast cancer poses unmet clinical challenges due to lack of targeted therapy, rapid growth rate and metastasis, high heterogeneity, and increased risk of recurrence. Diverse 1-(1H-indol-1-yl)-2-((5-aryl-4H-1,2,4-triazol-3-yl)thio))ethanones have been synthesized in substantial yield (81-87 %) by clubbing 1-(chloroacetyl)indoles with substituted triazoles under refluxing conditions of 4-5 h. The indole integrates demonstrated substantial antitumor efficacy in the MTT assay against the MDA-MB-231 cell line and substituting indole moiety with a halogen (bromo) significantly improves the anti-breast cancer action of the synthesized hybrids compared to the unsubstituted ring. Compound 4i featuring halogen substituent on both the indole and phenyl moieties displayed the highest anticancer action with an IC50 value of 2.121 μM The synthetic variants exhibited a notable binding propensity against the EGFR-TK receptor (PDB ID:1M17). Through in-silico ADMET screening, the pharmacological proclivity of the title compounds has been convicted. The notable bioactivity of the indole hybrids projects them as a potential lead in developing anti-breast cancer medications, especially against TNBC.

Synthesis and Evaluation of Thiazolyl-indole-2-carboxamide Derivatives as Potent Multitarget Anticancer Agents.

Cancer is a complex disease driven by the dysregulation of multiple signaling pathways and cellular processes. The development of compounds capable of exerting multitarget actions against these key pathways involved in cancer progression is a promising therapeutic approach. Here, a series of novel (E/Z)-N-(4-(2-(2-(substituted)hydrazineyl)-2-oxoethyl)thiazol-2-yl)-1H-indole-2-carboxamide derivatives (6a-6z) were designed, synthesized, and evaluated for their biological activity. Compounds 6e, 6i, 6q, 6v, 7a, and 7b exhibited exceptional cytotoxicity against various cancer cell lines, particularly 6i (IC50 = 6.10 ± 0.4 μM against MCF-7 cell lines) and 6v (IC50 = 6.49 ± 0.3 μM against MCF-7 cell lines). These potent compounds inhibited key protein kinases like EGFR, HER2, VEGFR-2, and CDK2, induced cell cycle arrest at the G2/M phase, and promoted apoptosis. Docking studies revealed improved binding affinity of 6i and 6v with target proteins compared to reference drugs. These findings highlight the promising potential of 6i and 6v as multitarget cancer therapeutics deserving further development.

Synthesis, cytotoxic evaluation, and in silico studies of novel benzenesulfonamide-thiazolidinone derivatives against colorectal carcinoma

Thirteen new benzenesulfonamide derivatives containing 4-thiazolidinone were synthesized. Their cytotoxic properties were tested on colorectal carcinoma (HT-29, DLD-1, COLO-205) and normal colon fibroblast (CCD-986Sk) cell lines. Compounds 3l (IC50=114.62 µM), 3a (IC50=25.82 µM), 3k (IC50=30.99 µM), and 3i (IC50=62.94 µM) showed the highest cytotoxicity on HT-29, DLD-1, COLO-205, and CCD-986Sk cell lines, respectively. Compound 3e (IC50=1075.4 µM) exhibited the least cytotoxicity against CCD-986Sk. The apoptosis profile of 5-FU at 5 µM was similar to that of compound 3e at 30 µM. Molecular docking and MD simulations showed stable interactions for compounds 3i and 3e. Molecular docking and MD simulations revealed that compounds 3i and 3e exhibit stable interactions with key cancer-related protein targets, particularly TGFβ2. These interactions suggest their potential as therapeutic agents. The predicted ADME parameters further highlighted compounds 3e and 3i for their favorable lipophilicity, solubility, permeability, and oral absorption profiles, supporting their promise as candidates for future drug development.

Design, synthesis and evaluation of novel LpxC inhibitors containing a hydrazone moiety as Gram-negative antibacterial agents

LpxC inhibitors are new-type antibacterial agents developed in the last twenty years, mainly against Gram-negative bacteria infections. To enable the development of novel LpxC inhibitors with potent antibacterial activities, several series of compounds were designed and synthesized and their antibacterial activities were evaluated against E. coli ATCC25922, P. aeruginosa ATCC27853, P. aeruginosa clinical isolate PAE 22-1, K. pneumoniae ATCC700603, K. pneumoniae clinical isolate KPN+22-1 in vitro. Compound 6i exhibited significant antibacterial activities against above five Gram-negative bacteria except P. aeruginosa ATCC27853. Moreover, compound 6i exhibited moderate liver microsomal stability and a promising pharmacokinetic profile (AUC0-t = 1050 ng h mL−1, oral bioavailability of 13.3 %) in Sprague-Dawley rats, acceptable PPB, low risk of drug-drug interactions and non-cytotoxic activity against hepatic cell. Collectively, compound 6i could be a promising Gram-negative antibacterial agent for further investigation.

Design and synthesis of spiro[pyrrolidine-3,3′-quinoline]-2,2′-dione derivatives as novel antifungal agents targeting chitin synthase

A novel spiro [pyrrolidine-3′,3′-quinoline]-2,2′-dione scaffold was constructed using fragments of quinoline and pyrrolidine. Subsequently, two series of derivatives were designed based on this scaffold. The enzyme inhibition experiments revealed that all designed compounds had moderate to good inhibitory activity against chitin synthase (CHS). The inhibitory effects of compounds 5i, 5j, 8i and 8n were approximately equal to that of control drug polyoxin B (PB, IP = 86.4 ± 2.9 %, IC50 = 0.082 ± 0.013 mM) which is a well-established CHS inhibitor. The results from enzyme kinetic parameters assays proved that these compounds act as non-competitive inhibitors of CHS. The sorbitol protection experiments demonstrated the tested compounds disrupted the synthesis of cell wall, which further verified that the target of these compounds is CHS. The experiments of antimicrobial showed that compounds 5b, 5f, 5i, 5j, 8f, 8i, 8m, 8n and 8o had strong antifungal activity against the four tested pathogenic fungi strains frequently emerging in clinical setting, with MIC values ranging from 4 to 32 μg/mL, which were either superior to or comparable with those of PB or fluconazole. Furthermore, these compounds displayed synergistic or additive effects when combined with fluconazole and these active compounds also showed promising activity against fluconazole-resistant and micafungin-resistant fungi variants. The result of antimicrobial experiments indicated that these compounds had minimal activity to tested bacterial strains. This suggests that they had selective antifungal activity. The results of ADME prediction, in conjunction with the cytotoxicity assay results, indicated that these compounds had favorable pharmacokinetic profiles and low toxicity. In addition, molecular docking studies illustrated that the compound had a strong affinity with the CHS, which was consistent with the results of enzymatic assays. These findings indicated that the designed compounds are non-competitive inhibitors of CHS with good selectivity and broad-spectrum antifungal activity, and possess significant antifungal activity against drug-resistant fungi, suggesting their potential as lead compounds for the development of novel drugs against drug-resistant fungi.

Organocatalytic[3 + 2]Cycloaddition: Synthesis of Quinazoline Containing Sulfonyl 1,2,3‐Triazoles as Potent EGFR Targeting Anti‐Breast Cancer Agents

ABSTRACTA general strategy was developed for the synthesis of new fully decorated 1,2,3‐triazoles (4a–4m and 5a–5g) containing quinazolines from 1‐(4‐nitrophenyl)‐2‐(quinazolin‐8‐ylsulfonyl) ethan‐1‐one and several azides using Ramachary organocatalytic azide‐ketone cycloaddition method. This reaction is reported for the synthesis of fully substituted sulfonyl‐1,2,3‐triazolyl quinazolins at a temperature of 100°C and the yields of the products produced are satisfactory to excellent. In vitro anticancer activity of all these derivatives demonstrated that six compounds, 4d, 4f, 4i, 4j, 5d, and 5e, were effective against two human breast cancer cell lines, MCF‐7 and MDA‐MB‐231. Compounds 4f, 4j, and 5d had more action against both cell lines than Erlotinib. Later, the findings of inhibitory assays of potent compounds 4d, 4f, 4i, 4j, 5d, and 5e against the tyrosine kinase EGFR revealed that compound 5d proved more potent than the reference erlotinib, while 4f and 4j had comparable efficacy. In silico molecular docking studies were also performed on six strong medicines to identify interactions with the EGFR receptor, and the energy estimations were shown to be comparable with the observed IC50 values. Ultimately, using SWISS/ADME and pkCSM, the in silico pharmacokinetic profile of potent compounds 4d, 4f, 4i, 4j, 5d, and 5e was predicted. All of the compounds precisely followed the principles established by Lipinski, Veber, Egan, and Muegge.

Development of new pyrazoles as class I HDAC inhibitors: Synthesis, molecular modeling, and biological characterization in leukemia cells.

Class I histone deacetylases (HDACs) are considered promising targets in current cancer research. To obtain subtype-selective and potent HDAC inhibitors, we used the aminobenzamide scaffold as the zinc-binding group and prepared new derivatives with a pyrazole ring as the linking group. The synthesized compounds were analyzed in vitro using an enzymatic assay against HDAC1, -2, and -3. Compounds 12b, 15b, and 15i were found to be potent HDAC1 inhibitors, also in comparison to the reference compounds entinostat and tacedinaline, with IC50 values of 0.93, 0.22, and 0.68 μM, respectively. The best compounds were measured for their cellular effect and target engagement in acute myeloid leukemia (AML) cells. In addition, we studied the interaction of the compounds with HDAC subtypes using docking and molecular dynamic simulations. In summary, we have developed a new chemotype of HDAC1 inhibitors that can be used for further structure-based optimization.

Synthesis, antimicrobial activity, molecular docking and MD simulation studies, in silico ADME investigations and thermo-acoustic studies of heterocyclic dihydropyrimidine substituted 1,3,4-thiadiazole scaffolds

The connections between the chemical structures and antibacterial properties of different functional groups including organic molecules were examined in this study. we have synthesized a novel series of 1,3,4-thiadiazole hybrids (5a-o) based on 3,4-dihydropyrimidines. After an effective synthesis, the compounds' structure was confirmed by using spectrum techniques like IR, 1H NMR, 13C NMR, and mass spectrometry. Elemental analyses were performed on a Perkin-Elmer 2400 CHN analyzer and the resulting data were within the accepted range (± 0.40) of the calculated values. The in vitro antimicrobial activity of the compounds against a range of bacterial and fungal species. Compound 5i showed potent inhibitory effects against P. aeruginosa with MIC values of 12.5 μg/ml S. aureus and A.niger were positively affected by compound 5k with MIC values of 12.5 μg/ml and 50 μg/ml, respectively. Based on the results, compounds 5a and 5o have moderate activity against C.albicans and E. coli with MIC values of 50 μg/ml and 62.5 μg/ml respectively. Furthermore, molecular docking and molecular dynamics simulations were used to identify the most stable conformation of newly discovered inhibitors. Thermo-acoustical properties of derivatives 5k and 5l in DMSO and DMF solvent have been determined at three different atmospheric pressure temperatures (298.15, 308.15, and 318.15)K. The components of the liquid mixture's molecular interactions have been taken into account to explain these results. The acquired results are interpreted in terms of interactions between solutes and solvents, providing insight into the compounds' potential to form or disrupt structures in DMSO and DMF solutions.

Design, synthesis, bioactivity and action mechanism of N-substituted N'-phenylpicolinohydrazides against phytopathogenic fungi.

N'-phenylpicolinohydrazide has been proven to be a promising lead compound for research and development of novel fungicides for agriculture in our previous study. As our continuing research, in this study, a series of N-substituted derivatives of N'-phenylpicolinohydrazide were synthesized and explored for the inhibition activity on nine phytopathogenic fungi and action mechanism. The results found that eleven of the compounds had excellent antifungal activity with more than 80% inhibition rates at 50 µg/mL on part or most of the fungi, especially A. solani and P. piricola. Compounds 5i, 5j and 5k showed EC50 values of < 8.0 µg/mL against A. solani superior to positive control carbendazim (EC50 = 36.0 µg/mL) while 5p and 5q exhibited the highest activity with EC50 values of 2.72 and 2.80 µg/mL against P. piricola superior to positive control boscalid (EC50>50.0 µg/mL). Furthermore, 5k also showed significant protective effect against A. solani infection on tomatoes in a concentration-dependent manner. Action mechanism research showed that 5k was able to increase the intracellular ROS level, change both MMP and permeability of cell membrane and damage mycelial morphology. Molecular docking studies showed that 5k could bind into ubiquinone-binding region of succinate dehydrogenase by hydrogen bonds, π-cation, π-π stacked, π-alkyl, and alkyl interactions. Additionally, the antibacterial activity was also investigated. Thus, N-substituted derivatives of N'-phenylpicolinohydrazide were emerged as novel and highly promising antifungal molecular skeletons to develop new fungicides for crop protection.

Virtual design and screening of new (+)-catechin derivates N- and/or S-heterocyclic fragment for anti-malarial and anti-SARS-CoV-2 activities by In silico simulation

Hemisynthesis makes it possible to improve the activity or reduce the toxicity of a biocompound by modifying or adding peripheral groups. Catechin present in different plant species was known for its moderate anti-malarial and anti-SARS-CoV-2 activities. The aim of this work was focused on the identification of new compounds with potential anti-SARS-CoV-2 and/or anti-malarial activities, evaluated through In silico simulation. A polyphenol pharmacophore model, based on (+)-catechin (1) was virtually constructed using previously reported inhibitors. N- and/or S-heterocyclic fragments were inserted on the backbone of (+)-catechin and 12 pharmacophore hypotheses were studied. This study targeted 3 proteins biologically responsible for SARS-CoV-2 (PDB ID: 7JYC, 6M0J, and 6HZD) and one protein responsible for malaria (PDB ID: 3SRJ). Molecular docking had shown that the new catechin-aldehyde candidates have good Ligand-Protein affinity in terms of free energy compared to the study reference Narlaprevir and Artesunate for SARS-CoV-2 and malaria respectively. Theoretically, most compounds didn’t show toxicity except compounds 2a, 2i, and 2k, exhibiting hepatotoxic activity. Molecular dynamics was used to prove and assess their binding stability to the target protein for each activity. The 3SRJ-2f and 6HZD-2l structures were selected for anti-malarial and anti-SARS-CoV-2 activity respectively. The 3SRJ-2f and 6HZD-2l complexes showed stable interactions to 100 ns between the inhibitor fragments and the residual amino acids of the protein. To conclude, these novel compounds are probably to become promising lead molecules for the development of effective anti-SARS-CoV-2 and/or anti-malarial of all drugs. Keywords: Catechin, Anti-malarial, Anti-SARS-CoV-2, Docking and Dynamic Molecular, ADMET Analysis.

Design and Synthesis of Isatin-Tagged Isoniazid Conjugates with Cogent Antituberculosis and Radical Quenching Competence: In-vitro and In-silico Evaluations.

In pursuit of potential chemotherapeutic alternates to combat severe tuberculosis infections, novel heterocyclic templates derived from clinically approved anti-TB drug isoniazid and isatin have been synthesized that demonstrate potent inhibitory action against Mycobacterium tuberculosis, and compound 4i with nitrophenyl motif exhibited the highest anti-TB efficacy with a MIC value of 2.54 μM/ml. Notably, the same nitro analog 4i shows the best antioxidant efficacy among all the synthesized compounds with an IC50 value of 37.37 μg/ml, suggesting a synergistic influence of antioxidant proficiency on the anti-TB action. The titled compounds exhibit explicit binding affinity with the InhA receptor. The befitting biochemical reactivity and near-appropriate pharmacokinetic proficiency of the isoniazid conjugates is reflected in the density functional theory (DFT) studies and ADMET screening. The remarkable anti-TB action of the isoniazid cognates with marked radical quenching ability may serve as a base for developing multi-target medications to confront drug-resistant TB pathogens.

Synthesis, cytotoxicity and 99mTc-MIBI tumor cell uptake evaluation of 2-phenylbenzothiazole tagged triazole derivatives.

Aim: The extensive utilization of 2-phenylbenzothiazole due to their wide array of biological activities, particularly in cancer therapy, has caused great attention to explore more potent derivatives.Materials & methods: We report the synthesis of 2-phenylbenzothiazole tagged 1,2,3-triaozle (8) through Cu(I)-catalyzed cycloaddition of alkyne side chain with aryl-substituted azides.Results: The in vitro experiments, using MTT and 99mTc-MIBI cell uptake methods, demonstrated the remarkable anticancer activity of these compounds against A549, SKOV3 and MCF7 cell lines.Conclusion: Compounds 8b, 8f and 8i possessed high cytotoxic activity as compared with doxorubicin. Compound 8g has a similar inhibitory effect on the proliferation of breast cancer cells as doxorubicin. In silico study indicated that compound 8 would be a good lead for the development of new potent anticancer agents.

Synthesis, antibacterial, anti-urease, DFT and molecular docking studies of novel bis-1,3,4-thiadiazoles

A series of 2-substitutedamino-1,3,4-thiadiazoles (4a-4j) were synthesized starting from various isothiocyanate derivatives. The newly synthesized compounds were characterized by 1H NMR, 13C NMR, and elemental analysis. All compounds were tested for antibacterial activity against Proteus vulgaris (ATCC 7829) via the microbroth dilution technique. Among them, compound 4h emerged as the most potent antibacterial agent with MIC value of 4.1 μM. All synthetic compounds were additionally evaluated for their urease inhibitory activity and exhibited good inhibitory potential against urease with IC50 values in the range of 1.732 ± 0.186 - 3.786 ± 0.300 μM as compared to the standard thiourea (IC50 = 11.008 ± 0.932 μM). Compounds 4d, 4h and 4i showed significant inhibitory effects with IC50 values of 1.981 ± 0.265, 1.732 ± 0.186 and 1.937 ± 0.173 μM, respectively. In silico molecular docking study showed the critical interactions of compound 4h with the active site of the urease. According to DFT, compounds 4j and 4d (with low ΔE=4.536 eV and 4.629 eV values, respectively) are more chemically reactive than the other molecules, in which consistent with their inhibitory potentials against the urease enzyme. Molecular Dynamics simulations also were performed to assess the energetic features of the urease in complex with compound 4h. Furthermore, the predicted ADMET characteristics of the compound 4h was calculated using QikProp to gain insights into its pharmacokinetic properties. These newly identified inhibitors of the urease enzyme can serve as leads for further antibacterial drug research and development.

The synthesis of novel unnatural amino acid by intramolecular aza-Michael addition reaction as multitarget enzyme inhibitors.

Synthesis of novel unnatural amino acids (UAAs) from 4-oxo-4-phenylbut-2-enoic acid derivatives with intramolecular aza-Michael addition reaction in the presence of chlorosulfonyl isocyanate (CSI) was reported in soft conditions without any metal catalyst. Acids and base as a catalyst, and solvents effects were investigated for the synthesis of novel UAAs. This novel method provides inexpensive, practicable, and efficient approach to generate UAAs. The use of UAAs has attracted great interest in the development of therapeutic agents and drug discovery to improve their properties. In this context, in addition to the synthesis of new UAAs, their inhibition effects on important metabolic enzymes of acetylcholinesterase (AChE) and carbonic anhydrases I and II (hCA I and II) enzymes were investigated. The compound 2g showed the best inhibition for CA I and AChE enzymes, while compound 2i exhibited the best inhibition profile against CA II isoenzyme. The inhibition values of these compounds were found as 1.85 ± 0.64 for AChE, 0.53 ± 0.07 for hCA I, 0.44 ± 0.15 µM for hCA II, respectively, and they showed a stronger inhibitory property than acetazolamide (standard inhibitor for hCA I and II) and tacrine (standard inhibitor for AChE) molecules. The activity of the studied molecule against different proteins that are hCA I (PDB ID: 2CAB), hCA II (PDB ID: 5AML), and AChE (PDB ID: 1OCE) was examined. Finally, the drug properties of the studied molecule were examined by performing absorption, distribution, metabolism, excretion, and toxicity analysis.

Design and synthesis of Thieno[3, 2-b]pyridinone derivatives exhibiting potent activities against Mycobacterium tuberculosis in vivo by targeting Enoyl-ACP reductase

In this study, a series of novel thieno [3, 2-b]pyridinone derivatives were designed and synthesized using a scaffold hopping strategy. Six compounds showed potent anti-mycobacterial activity (minimum inhibitory concentration (MIC) ≤ 1 μg/mL) against Mycobacterium tuberculosis (Mtb) UAlRa. Compound 6c displayed good activity against Mtb UAlRv (MIC = 0.5–1 μg/mL). Compounds 6c and 6i also showed activity against Mtb UAlRa in macrophages and exhibited low cytotoxicity against LO-2 cells. The selected compounds displayed a narrow antibacterial spectrum, with no activity against representative Gram-positive, Gram-negative bacteria, as well as fungi. Furthermore, compound 6c demonstrated favorable oral pharmacokinetic properties with a T1/2 value of 47.99 h and exhibited good in vivo activity in an acute mouse model of tuberculosis (TB). The target of compound 6c was identified as a NADH-dependent enoyl-acyl carrier protein reductase (InhA) by genome sequencing of spontaneously compound 6c-resistant Mtb mutants, indicating that compound 6c may not require activation and can directly target InhA. In vitro antimicrobial assays against a recombinant M. smegmatis overexpressing the Mtb-InhA, along with InhA inhibition assays, confirmed that InhA is the target of thieno [3, 2-b]pyridinone derivatives. Overall, this study identified thieno [3, 2-b]pyridinone scaffold as a novel chemotype that is promising for the development of anti-TB agents.

Conventional and microwave-assisted synthesis, antimicrobial and antioxidant activity evaluation with in silico studies of carbazole-thiazole-Schiff base hybrids

Conventional and microwave irradiation (MWI) methods were applied to synthesize a series of thirteen carbazole-thiazole-Schiff base hybrids (2a-2m). MWI assisted synthesis was a benign approach to green synthesis on account of its miniscule reaction time and use of solvent. The structures of the synthesized derivatives were confirmed by means of spectral analytical data. All the compounds were evaluated for dual biological potency i.e., antimicrobial and antioxidant activity. The tested analogues had shown some modest antimicrobial activity and compounds 2f and 2i exhibited higher antioxidant activity compared to standard ascorbic acid. Oral bioavailability and adverse effects of the new entities were considered from druglikeness descriptors, having no violation of Lipinski's rule of five and Veber's rule for the synthesized compounds except for 2i, 2l, and 2m. The compounds which exhibited relatively high activity were explored further for molecular docking studies to understand the mode of binding interactions with the receptor protein. Molecular dynamics (MD) simulation was further studied to predict the stability of selective compounds inside the receptors which was well agreed with in vitro results and antioxidant value.

Synthesis, anti-microbial evaluation, and in silico studies of novel quinoline-isoxazole hybrids

A series of novel quinoline-isoxazole hybrids 6a–o has been synthesized via multistep synthetic approach involving hetero Diels-alder reaction strategy. The target compounds were obtained in good yield, using low-cost readily available starting materials using simple reaction conditions. The newly synthesized compounds were confirmed using 1H NMR,13C NMR, and Mass spectroscopic analysis techniques. Further, compounds 6a–o were subjected to in vitro antimicrobial screening against various bacterial and fungal strains, such as Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Salmonella typhi, Aspergillus niger, and Candida albicans. Among these, compounds 6i, 6j, and 6 l were found most active having equally potent compared to standard drug Ampicillin and Gentamycin. Moreover, in silico studies of 6a–o with E. coli DNA gyrase through molecular docking and MD simulations showed excellent binding properties of these derivatives with protein site.