Good Inhibitory Activity Research Articles

Exploration of 1,3,5-trisubstituted pyrazoline derivatives as human carbonic anhydrase inhibitors: Synthesis, biological evaluation and in silico studies

The human carbonic anhydrase (hCA) IX and XII isoforms are overexpressed in hypoxic conditions, contributing to cancer. Lack of isoform selectivity has been one of the main challenges associated with the existing drugs targeting hCAs. Hence, the development of alternative approaches, such as tail approach to develop more selective hCA IX and XII inhibitors is need of the hour. In the present work, we designed and synthesized 24 new 1,3.5-trisubstituted-pyrazoline derivatives with diverse substitutions. The synthesized analogs were evaluated for their hCA inhibitory activities against hCA I, II, IX, and XII isoforms. Among the tested compounds, derivative 8 displayed good inhibitory activity against hCA IX (Ki = 331 nM) and XII (Ki = 96.7 nM). In addition, 9a-g also exhibited some inhibitory activities against hCA IX and XII, with Kis ranging from 574 to 799 nM and 137–369 nM, respectively. Molecular modelling studies of compound 8 displayed metal coordination with zinc ion and hydrophobic, hydrophilic interactions with adjacent amino acid residues, and maintained stable interactions throughout 100 ns. In addition, ADMET studies demonstrated that compound 8 obeyed the Lipinski's rule of five and was found to be druggable and non-toxic. Hence, compound 8 was identified as potential lead for further development.

Identification of new structure of indol-3-acetyl-arylsulfonohydrazide as potent α-glucosidase and α-amylase inhibitors and molecular docking

Herein this work, indole analogs (1-16) were synthesized by treating 2-(1H-indol-3-yl)acetohydrazide with various aryl sulfonyl chloride in pyridine as solvent and screened for α-amylase and α-glucosidase inhibitory activity under positive control of standard drug acarbose (IC50 = 12.80 ± 0.10 μM /12.90 ± 0.10 μM. All analogs of the series appeared with excellent to good inhibitory activity as compared to standard drug. The inhibitory activity range for α-amylase is 0.70 ± 0.01 μM to 19.40 ± 0.40 μM, while for α-glucosidase inhibitory activity is 1.20 ± 0.10 μM to 20.40 ± 0.40 μM respectively. Most of the analogs appeared with excellent inhibitory activity, and some analogs like 5, 6, 7, 8, 9, 10,13 and 14 for both enzymes displayed many folds better inhibitory activity than standard drug acarbose. The influences of substituents on inhibitory activity were superficially resonated via structure activity relationship. Docking studies were established to confirm the binding interaction between analogs and active sites of enzymes.

Design, Synthesis, Biological Evaluation and Molecular Docking Studies of New Thiazolidinone Derivatives as NNRTIs and SARS-CoV-2 Main Protease Inhibitors.

HIV-1 remains a major health problem worldwide since the virus has developed drug-resistant strains, so, the need for novel agents is urgent. The protein reverse transcriptase plays fundamental role in the viruses' replication cycle. FDA approved Delavirdine bearing a sulfonamide moiety, while thiazolidinone has demonstrated significant anti-HIV activity as a core heterocycle or derivative of substituted heterocycles. In this study, thirty new thiazolidinone derivatives (series A, B and C) bearing sulfonamide group were designed, synthesized and evaluated for their HIV-1 RT inhibition activity predicted by computer program PASS taking into account the best features of available NNRTIs as well as against SARS-COV-2 main protease. Seven compounds showed good anti-HIV inhibitory activity, with two of them, C1 and C2 being better (IC50 0.18 μΜ & 0.12 μΜ respectively) than the reference drug nevirapine (IC50 0.31 μΜ). The evaluation of molecules to inhibit the main protease revealed that 6 of the synthesized compounds exhibited excellent to moderate activity with two of them (B4 and B10) having better IC50 values (0.15 & 0.19 μΜ respectively) than the reference inhibitor GC376 (IC50 0.439 μΜ). The docking studies is coincides with experimental results, showing good binding mode to both enzymes.

Biotransformation of Glaucic Acid Isolated from the Root of Lindera glauca by the Endophytic Fungi Penicillium Chrysogenum SHJ-07.

Glaucic acid isolated from the root of Lindera glauca, was investigated by the biotransformation methods via the endophytic fungi, resulting in the production of five new glausesquiterpenes A-E (1-5), along with a known analogue 6. Their structures were elucidated based on spectroscopic methods and electronic circular dichroism (ECD) calculations. In the bioassays, glausesquiterpene A (1) showed good inhibitory activity of NO production in LPS-activated RAW 264.7 macrophages with an IC50 value of 20.1 μM than positive control (Indomethacin, IC50 24.1 μM). Further in vitro studies demonstrated that glausesquiterpene A significantly suppressed the protein expression of iNOS and COX-2 at the concentration of 25.0 μM.

Synthesis of novel indazole derivatives as inhibitors of diabetics II along with molecular docking and simulation study

In the light of the pharmacological significance of the indazole and 1, 3, 4-thiadiazole scaffold, hybrid analogs of indazole and 1, 3, 4-thiadiazole (1–14) were synthesized, identified using HREI-MS, 1H, and 13CNMR, and their capability for inhibition of α-amylase and α-glucosidase enzymes was evaluated. Generally, most of the synthesized derivatives of the series exhibited good inhibition activity in comparison to the reference drug acarbose with IC50 value of 10.30 ± 0.20 for α-amylase, and 9.80 ± 0.20 for α-glucosidase. Amongst the synthesized derivatives, fluoro substituted analog 10 appeared to be the most potent inhibitor having IC50 value of 9.90 ± 0.30 for α-amylase and 9.20 ± 0.30 for α-glucosidase. A structure activity relationship (SAR) for the series was established based on electronic effects and the positions of various groups on the phenyl ring. To comprehend the chemicals' binding interactions, molecular docking along with simulation study were also carried out. Compound 10 was ranked top in the series based on docking score and interactions with receptors. Compound 10 establish more H-bond contacts with the active site's residue of alpha-amylase and α-glucosidase as compared to all other compounds. Furthermore, 10 was found to be highly stable throughout 50 ns MD simulation. As compared to the control drug, 10 revealed high stability with both α-amylase and α-glucosidase enzymes during molecular dynamics simulation.

Therapeutic Importance of Extracts from Leaf and Bark of <i>Gymnacranthera farquhariana</i>

Background: Gymnacranthera farquhariana (Hook. f. and Thomson) Warb. is one of the endangered tree taxon of the Western Ghats, a biodiversity hot-spot in peninsular India. Very few reports are available on biological applications of the bark, leaf and seed of this plant. Aim: The present work deals with the screening of methanol and aqueous extracts of G. farquhariana from leaf and bark for therapeutic importance. Methods: Anti-bacterial activities of extracts were carried out using two bacterial strains viz., Pseudomonas aeruginosa and Staphylococcus aureus through the agar well diffusion method. The antifungal activities by poison bait method using Aspergillus niger, Colletotrichum gloeosporioides and Fusarium solani. Each experimental parameter was conducted in triplicate. Results: The results showed that G. farquhariana bark and leaf extracts exhibited promising activities against bacteria. Antifungal activity also showed good inhibition activity. The extracts showed a good anti-diabetic potential in α-amylase inhibitory assay. Bark aqueous extract showed 54.79% inhibition for α- amylase inhibition assay at 250μL. The extract also showed good anti-inflammatory potential in the Bovine Serum Albumin (BSA) denaturation assay. Bark aqueous extract showed 83.9% inhibition for BSA denaturation assay at 100 μL. Conclusion: Both leaf and bark extracts of the plant showed good antioxidant, anti-diabetic and antimicrobial activity. This is the first such in vitro report concerning G. farquhariana plant parts.

Synthesis, biological evaluation, molecular docking and dynamic simulation of novel benzofuran derivatives as potential agents against Alzheimer's disease

We have synthesized novel benzofuran derivatives (1–20), characterized through different spectroscopic techniques such as 1HNMR, 13CNMR, HREI-MS and screened against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) enzymes. All derivatives showed inhibitory activities having IC50 values ranging from 0.70 ± 0.01 to 28.10 ± 0.50 µM (against AChE), while 0.80 ± 0.01 to 31.20 ± 0.60 µM (against BuChE) as compared to the standard drug Donepezil (IC50 = 2.16 ± 0.12 and 4.50 ± 0.10 µM, respectively). Except derivative 5, all other derivatives of the series showed good inhibitory activity against both acetylcholinesterase and butyrylcholinesterase, but some analogues like 2, 4, 7, 14, 15, and 16 displayed many folds better inhibitory activity than the standard drug donepezil. The influences of substituents on inhibitory activity were superficially resonated via the structure-activity relationship. We established molecular docking and MD simulation studies to confirm the binding interaction between potent derivatives and active sites of enzymes.

Discovery of dual-targeted molecules based on Olaparib and Rigosertib for triple-negative breast cancer with wild-type BRCA

PARP inhibitors (PARPis) demonstrate significant potential efficacy in the clinical treatment of BRCA-mutated triple-negative breast cancer (TNBC). However, a majority of patients with TNBC do not possess BRCA mutations, and therefore cannot benefit from PARPis. Previous studies on multi-targeted molecules derived from PARPis or disruptors of RAF-RAF pathway have offered an alternative approach to develop novel anti-TNBC agents. Hence, to broaden the application of PARP inhibitors for TNBC patients with wild-type BRCA, a series of dual-targeted molecules were constructed via integrating the key pharmacophores of Olaparib (Ola) and Rigosertib into a single entity. Subsequent studies exhibited that the resulting compounds 13a–14c obtained potential anti-proliferative activity against BRCA-defected or wild-type TNBC cells. Among them, an optimal compound 13b showed good inhibitory activity toward PARP-1, displayed approximately 34-fold higher inhibitory activity than that of Ola in MDA-MB-231 cells, and exerted multi-functional mechanisms to induce apoptosis. Moreover, 13b displayed superior antitumor efficacy (TGI, 61.3 %) than the single administration of Ola (TGI, 38.5 %), 11b (TGI, 51.8 %) or even their combined administration (TGI, 56.7 %), but did not show significant systematic toxicity. These findings suggest that 13b may serve as a potential candidate for BRCA wild-type TNBC.

Xanthine oxidase inhibitors: Virtual screening and mechanism of inhibition studies

Xanthine oxidase (XO), which plays a key role in purine metabolism, is an important target enzyme for the prevention and treatment of hyperuricemia. Inhibitory activity against XO is a common criterion for the screening of compounds with potential anti-hyperuricemic activity. In this study, 22 XO inhibitors were used to construct a 3D-QSAR pharmacophore model. Subsequently, molecular docking and in vitro activity evaluations were used to identify strong XO inhibitors from a list of 2000 natural compounds. The interaction mechanisms of these compounds with XO were analyzed based on inhibition kinetics and multi-spectral analyses. The pharmacophore model was composed of three hydrogen bond receptors and a hydrophobic center. The screened compounds — Diosmetin, Fisetin, and Genistein — all showed good XO inhibitory activity, with IC50 values of 1.86 ± 0.11 μM, 5.83 ± 0.08 μM, and 7.56 ± 0.10 μM, respectively. Kinetic analysis, fluorescence quenching assays, and molecular docking experiments showed that Diosmetin, Fisetin, and Genistein docked near the same active site of XO, mainly affecting the microenvironment of tryptophan residues. These molecules showed static binding to XO via hydrogen bonds, hydrophobic interactions, and van der Waals forces. Diosmetin and Genistein were competitive inhibitors, whereas Fisetin was a mixed inhibitor. Infrared spectroscopy showed that Diosmetin, Fisetin, and Genistein increased the α-helix content of XO from 7.4 % to 16.6 %, 21.4 %, and 11.2 %, respectively, thereby enhancing its stability. In summary, the pharmacophore model constructed in this study was accurate. The flavonoids Diosmetin, Fisetin, and Genistein effectively inhibited the activity of XO, and the amino acid residues LEU257, ILE353, and VAL259 played a key role in the interaction between the flavonoids and XO. These findings are of great significance for the screening and development of new XO inhibitors.

Hybrid Analogues of Hydrazone and Phthalimide: Design, Synthesis, In vivo, In vitro, and In silico Evaluation as Analgesic Agents.

Based on the anti-inflammatory and analgesic activity of hydrazone and phthalimide, a new series of hybrid hydrazone and phthalimide pharmacophores was prepared and evaluated as analgesic agents. The designed ligands were synthesized by reaction of the appropriate aldehydes and 2- aminophthalimide. Analgesic, cyclooxygenase inhibitory, and cytostatic activity of prepared compounds were measured. All the tested ligands demonstrated significant analgesic activity. Moreover, compounds 3i and 3h were the most potent ligands in the formalin and writhing tests, respectively. Compounds 3g, 3j, and 3l were the most COX-2 selective ligands and ligand 3e was the most potent COX inhibitor with a 0.79 of COX-2 selectivity ratio. The presence of electron-withdrawing moieties with hydrogen bonding ability at the meta position was found to affect the selectivity efficiently, in which compounds 3g, 3l, and 3k showed high COX-2 selectivity, and compound 3k was the most potent one. The cytostatic activity of selected ligands demonstrated that compounds 3e, 3f, 3h, 3k, and 3m showed good analgesic and COX inhibitory activity and were less toxic than the reference drug. High therapeutic index of these ligands is one of the valuable advantages of these compounds.

Novel Benzothiazole Derivatives: Synthesis, Anticancer Activity, Density Function Theory (DFT) Study, and ADMET Prediction

Benzothiazole is an amazing small molecule involved in many applications in industrial and pharmaceutical industries to prepare many candidate compounds as effective drugs. In this study, we presented some derivatives of this compound that were prepared easily and quickly with the help of microwaves to minimize time, energy, and finances. The compounds’ cytotoxicity against the two cell lines SK-GT-4 and AMGM5 was examined. The cytotoxic effect of each compound at different concentrations was measured using the MTT assay. Compounds exhibited no potent cytotoxic effects toward the SK-GT-4 cell line. Compounds B1 and B2 had a high IC50 value and good growth inhibition activity against the AMGM5 cell line. According to in silico absorption, distribution, metabolism, and excretion analysis (ADME) prediction studies, the compounds B1, B2, and B3 met Lipinski and were drug-like in most physicochemical parameters. Despite some violations, generally favorable pharmacokinetic properties. It is also assumed that it can potentially become a drug candidate in the future. Various electronic parameters were examined using DFT/WB97XD/6-31++G(d,p), and studies were conducted to support the experimental findings. To estimate the binding modes of compounds B1 and B5, we also performed in silico molecular docking studies.

Novel Piperidone Hydrazine Carbodithioate Derivative: Synthesis, In Silico Drug-Likeness Analysis and Anticancer Properties

An efficient synthesis of a novel compound of hydrazine carbodithioate derivative of piperidone, (E)-methyl-2-(3-methyl-2,6-diphenylpiperidin-4-ylidene)hydrazinecarbodithioate (1), was performed using methyl dithiocarbazinate and 3-methyl-2,6-diphenylpiperidin-4-one as the starting materials. The reaction was carried out in an acidic medium using methanol as a solvent. The novel compound was characterized by FTIR, Mass, and NMR spectral techniques. The hydrazine carbodithioate derivative (1) was then tested for its anticancer activity against the liver cancer cell line, Hep G2, using the MTT assay. The IC50 values of the newly synthesized compound were found to be 34.33 ± 0.79 µM (24 hours) and 27.64 ± 1.42 µM (48 hours). The in vitro antitumor studies demonstrated that the novel compound (1) exhibited good inhibitory activity against the Hep G2 cancer cells. Furthermore, in silico properties such as lipophilicity, water solubility, pharmacokinetic properties, drug likeness, and medicinal chemistry were analyzed using the SwissADME tool.

Uncovering the Potential ofO-Prenylated 3-aryl-benzopyran Derivatives as Osteogenic and Cancer Cell Growth Inhibitory Agents.

Naturally, O-prenylation of 3-aryl-benzopyrans enhances the biological activities of these compounds. In this study, substituted O-prenylated 3-aryl-benzopyrans (21a-c, 22a-c, 23a-c, 24a-c 25a-c, 27 and 28) were synthesized and evaluated for osteogenic and cancer cell growth inhibitory potentials using cell-based in-vitro models. Amongst the target compounds, 21a, 22b, 23c, and 24c showed good osteogenic activity at 1 pM concentration, whereas 26 and 27 showed osteogenic activity at 100pM and 10nM, respectively. Compounds 21a, 22b, and 23c showed good cancer cell growth inhibitory activity against breast cancer cells (MCF-7 and MBA-231). Amongst active compounds, 27 presented the best anticancer activity against MDAMB-231 cells with selectivity towards non-cancerous cells [IC50 3.76 µM with SI 13.3]. The in-silico study of compounds showed their structural complementarities with the LBD of estrogen receptors and compliance with dragability parameters.

Discovery and optimization of 4-(imidazo[1,2-a]pyrimidin-3-yl)thiazol-2-amine derivatives as novel phosphodiesterase 4 inhibitors.

Phosphodiesterases (PDEs) are important intracellular enzymes that hydrolyze the second messengers cAMP and/or cGMP. Now several studies have shown that PDE4 received particular attention due to which it represents the most prominent cAMP-metabolizing enzyme involved in many diseases. In this study, we performed prescreening of our internal compound library and discovered the compound (PTC-209) with moderate PDE4 inhibitory activity (IC50 of 4.78 ± 0.08μM). And a series of 4-(imidazo[1,2-a]pyrimidin-3-yl)thiazol-2-amine derivatives as novel PDE4 inhibitors starting from PTC-209 were successfully designed and synthesized using a structure-based discovery strategy. L19, the most potent inhibitor, exhibited good inhibitory activity (IC50 of 0.48 ± 0.02μM) and remarkable metabolic stability in rat liver microsomes. Our study presents an example of discovery novel PDE4 inhibitors, which would be helpful for design and optimization of novel inhibitors in future.

From Hit to Lead: Discovery of First-In-Class Furanone Glycoside D228 Derived from Chimonanthus salicifolius for the Treatment of Inflammatory Bowel Disease.

TNFα and related inflammatory factor antibody drugs have been orchestrated for the treatment of inflammatory bowel disease (IBD). However, antibody drugs elicited inevitable disadvantages and small molecule drugs are in an urgent need. Herein, we described the discovery, design, synthesis, and SAR studies from furanone glycoside compound Phoenicein (hit) isolated from Chimonanthus salicifolius to D228 (lead). Remarkably, D228 exhibited good inhibitory activity on B and T lymphocyte and excellent anti-IBD efficacy in vivo. Mechanistically, D228 alleviated the inflammation response by downregulating the MyD88/TRAF6/p38 signaling. Importantly, the relationship of D228, Phoenicein, and their aglycone 7a was deduced: D228 could be considered as a prodrug and metabolized to intermediate Phoenicein. In turn, Phoenicein released their shared active aglycone 7a. Additionally, D228 demonstrated good and balanced profiles of safety and efficacy both in vitro and in vivo. These results suggested that D228 could be used as an ideal lead and potentially utilized for IBD chemotherapy.

Novel quinoline-4-carboxamide derivatives potentiates apoptosis by targeting PDK1 to overcome chemo-resistance in colorectal cancer: Theoretical and experimental results

A series of novel N,2-diphenyl-6-(aryl/heteroaryl)quinoline-4-carboxamide derivatives were designed and synthesized using the Suzuki coupling reaction and evaluated them for their anticancer activity. These compounds were screened for anti-colon cancer activity through in-silico studies by molecular docking and molecular dynamics studies. Furthermore, the density functional theory was used to determine the molecule's electrical properties. The molecular electrostatic potential map is used to evaluate the charge distribution on the molecule surface. Unveiling that the compound 7a (binding energy of −10.2 kcal/mol) has good inhibition activity compared to other synthesized compounds (7b-7j) as well as the standard drug Gefitinib. The stability of the compound 7a with the 1OKY protein was confirmed through molecular dynamics simulation studies, indicating potential anti-colon cancer activity against phosphoinositide dependent protein kinase-1 (PDK1). The in-silico ADMET pharmacokinetic properties indicate adherence to Lipinski's rule of five for favorable safety profiles and the compound falls within the optimal range for physicochemical and pharmacokinetic properties, which is comparable to that of the standard medication drug Gefitinib. The synthesized library of compounds was further evaluated for their in-vitro anticancer potency against colon, pancreatic and breast cancer cells. The results demonstrated that the compounds effectively suppressed the proliferative potential of the screened cells in a concentration-dependent manner, as revealed by MTT assay. The anticancer potential of these molecules was further evaluated by acridine orange/PI, and Hoechst/PI which demonstrates the potential of molecules to induce apoptosis in cancer cells. Further investigations and optimization of these derivatives could lead to the development of effective anticancer strategies.

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.

Natural flavonoids as promising lactate dehydrogenase A inhibitors: Comprehensive in vitro and in silico analysis.

The inhibitory potential of 17 flavonoids on lactate dehydrogenase A (LDHA), a key enzyme in the downstream process of aerobic glycolysis in cancer cells, is investigated. Fisetin exhibited excellent inhibitory activity (IC50 = 0.066 µM). Quercetin 3-β-D-glucoside, quercetin 3-galactoside, luteolin, neoeriocitrin, and luteolin 7-O-β-D-glucoside showed good inhibitory activity (IC50 = 1.397-15.730 µM). Biochanin A, baicalein, quercetin, scutellarein-7-glucuronide, diosmetin, baicalein 7-O-β-D-glucuronide, and apigenin 7-apioglucoside demonstrated moderate inhibitory activity (IC50 = 33.007-86.643 µM). Eriodictyol, quercetin 7-O-β-D-glucoside, apigenin 7-O-β-D-glucoside, and epicatechin were inactive. The Lineweaver-Burk plot showed that fisetin competitively inhibits NADH binding (Ki = 0.024 µM). Ki values for other compounds were calculated using the Cheng-Prusoff equation (Ki = 0.2799-2.1661 µM). The study revealed that the inhibitory effect of flavonoids varies with the number and position of OH groups and bound sugars. Molecular docking analyses indicated that flavonoids exhibited strong interactions with the NADH binding site of LDHA through hydrophobic interactions and hydrogen bonds. Molecular dynamic simulations tested the stability of the fisetin-LDHA complex over 100 ns and showed fisetin's high binding affinity to LDHA, maintaining strong hydrogen bonds. The binding energy of fisetin with LDHA was -33.928 kcal/mol, indicating its effectiveness as an LDHA inhibitor. Consequently, flavonoids identified as strong inhibitors could be potential cancer treatment sources through LDHA inhibition.

New Arene and/or Heteroarene‐Linked 1,3,4‐Oxadiazoles: Synthesis of Potential Methicillin‐Resistant Staphylococcus aureus and Vancomycin‐Resistant Enterococcus Inhibitors

AbstractBacterial infections, particularly those associated with methicillin‐resistant Staphylococcus aureus (MRSA) and vancomycin‐resistant Enterococcus (VRE), threaten public health and economies, with rising antibiotic resistance resulting in more deaths yearly. In this study, we investigated the bacterial inhibitory activity of some new 1,3,4‐oxadiazoles prepared, in good yields, using a two‐step tandem protocol. Therefore, the appropriate N‐benzoylhydrazones were prepared first, then, without isolation, underwent oxidative‐cyclization in the presence of chloramine trihydrate. More 4‐acyloxyphenyl‐linked 1,3,4‐oxadiazoles were prepared by the pyridine‐mediated acylation of 2‐(4‐hydroxyphenyl)‐1,3,4‐oxadiazoles with the appropriate acyl chlorides. Some new products demonstrated good activity, particularly against S. aureus and Enterococcus faecalis strains. The 4‐(5‐(furan‐2‐yl)‐1,3,4‐oxadiazol‐2‐yl)phenyl acetate showed comparable antibacterial activity to ciprofloxacin, with MIC/MBC values up to 3.6/7.2 µM against the previous strains. Moreover, it demonstrated good inhibitory activity against different MRSA and VRE strains when compared to linezolid. It had MIC/MBC values of 7.2/14.4 and 14.4/57.8 µM against MRSA and VRE strains, respectively.

Discovery of Novel Nonpeptidic and Noncovalent Small Molecule 3CLpro Inhibitors as anti-SARS-CoV-2 Drug Candidate.

SARS-CoV-2 has still been threatening global public health with its emerging variants. Our previous work reported lead compound JZD-07 that displayed good 3CLpro inhibitory activity. Here, an in-depth structural optimization for JZD-07 was launched to obtain more desirable drug candidates for the therapy of SARS-CoV-2 infection, in which 54 novel derivatives were designed and synthesized by a structure-based drug design strategy. Among them, 24 compounds show significantly enhanced 3CLpro inhibitory potencies with IC50 values less than 100 nM, and 11 compounds dose-dependently inhibit the replication of the SARS-CoV-2 delta variant. In particular, compound 49 has the most desirable antiviral activity with EC50 of 0.272 ± 0.013 μM against the delta variant, which was more than 20 times stronger than JZD-07. Oral administration of 49 could significantly reduce the lung viral copies of mice, exhibiting a more favorable therapeutic potential. Overall, this investigation presents a promising drug candidate for further development to treat SARS-CoV-2 infection.