Compounds 4n Research Articles

Semi-Preparation and X-ray Single-Crystal Structures of Sophocarpine-Based Isoxazoline Derivatives and Their Pesticidal Effects and Toxicology Study.

Recently, research and development of novel pesticides from natural plant products have received much attention. To accelerate the application of sophocarpine as the agrochemical candidate, a series of novel sophocarpine-based isoxazoline derivatives were prepared by the 1,3-dipolar [2 + 3] cycloaddition reaction of sophocarpine with different chloroximes. Their structures were well characterized by high-resolution mass spectra, infrared spectra, and proton/carbon-13 nuclear magnetic resonance spectra. Eight steric configurations of compounds 5a, 5e', 5f, 5g, 5h, 5i, 5r, and 5u' were further determined by X-ray single-crystallography. Against Aphis citricola Van der Goot, compounds 5n (LD50: 0.032 μg/nymph) and 5o (LD50: 0.024 μg/nymph) exhibited greater than 3.7- and 4.9-fold potent aphicidal activity compared to sophocarpine (LD50: 0.118 μg/nymph). Against Tetranychus cinnabarinus Boisduval, derivative 5g displayed the most promising acaricidal activity with the LC50 value of 0.247 mg/mL, which was 14.2-fold that of sophocarpine. Compounds 5d and 5g also exhibited good control efficacy against T. cinnabarinus. Scanning electron microscopy images indicated that compound 5g can destroy the mite cuticle layer. These results will provide the foundation for the structural modification and use of sophocarpine derivatives as agrochemicals in the future.

Tandem Synthesis of Piriqualone and Analogues Using Deep Eutectic Solvents: Photophysical and Theoretical Insights

This study presents a sustainable chemical approach for the tandem synthesis of Piriqualone a sedative and anxiolytic drug and its analogues using a green protocol. The research investigates the ability of deep eutectic solvents (DESs) to act as catalysts as well as solvent in a tandem reaction involving metal‐free dehydrogenation and sp3 C‐H bond functionalization, leading to the formation of styryl‐heterocyclic compounds (7a‐p). These styryl derivatives were thoroughly characterized through spectral analysis and photophysical property evaluation. The relationship between chemical structure and AIE properties was particularly examined for compound 7n. Additionally, the experimental findings were corroborated by density functional theory (DFT) calculations. The structures of compounds 7j, 7p and 7fa were further validated through single crystal X‐ray diffraction (XRD) analysis.

Synthesis and antifungal activities of small molecule arylthiazolamine derivatives.

Developing new fungicides to compensate for the deficiencies of existing fungicides resistance in phytopathogenic fungi is a research hotspot in the field of pesticides. Aiming to discover novel template small molecules with excellent antifungal activity, thirty-eight arylthiazolamine derivatives were synthesized through bromination, cyclization, halogenation, and acylation reactions. The synthesized compounds were screened for antifungal activity against ten typical fungal pathogens, and some halogenated arylthiazolamines and amides exhibited excellent broad-spectrum antifungal activity, especially compounds 4m (3.96-47.76μg/mL), 5k (0.10-7.70μg/mL) and 5n (2.08-11.21μg/mL). Among them, compound 5k provided comparable protection and curative effects to chloroticonil and boscalid against B. dothidea and V. mali infection in apple and apple tree branches, respectively, and it could exert antifungal effects by inhibiting the differentiation of mycelium spores, spore germination, and bud tube growth. This study provides high-efficiency and inexpensive candidate compounds for managing of diseases caused by plant pathogenic fungi.

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.

Design, synthesis, and in silico insights of novel N’-(2-oxoindolin-3-ylidene)piperidine-4-carbohydrazide derivatives as VEGFR-2 inhibitors

Vascular endothelial growth factor (VEGF) is a crucial key factor in breast tumorigenesis. VEGF plays an important role in angiogenesis, tumor proliferation, and metastasis. Herein, we report the design and synthesis of twenty-one novel piperidine/oxindole derivatives as potential VEGFR-2 inhibitors. The designed compound library aimed to occupy the binding site of VEGFR-2 in a similar binding pattern to that of the reference VEGFR-2 inhibitor Sorafenib. The synthesized compounds were biologically evaluated for their cytotoxic effects against two breast cancer cell lines (MCF-7 and MDA-MB-468). Compounds 12e and 6n were the most potent cytotoxic derivatives against the former and the latter cell lines, showing IC50 values of 8.00 and 0.60 µM, respectively. Furthermore, all the synthesized compounds were evaluated for their inhibitory activities towards VEGFR-2, with compound 12e showing the most potent activity with an IC50 value of 45.9 nM, surpassing the reference standard Sorafenib (IC50 = 48.6 nM). Additionally, compound 6n emerged as the top performer when tested with the other most promising compounds for their cytotoxic effects on HUVEC (IC50 = 28.77 nM). The designed library of compounds was subjected to molecular docking and molecular dynamic simulations, which revealed key binding interactions within the VEGFR-2 active site, including hydrogen bonding with Cys919, Glu885, and Asp1046 residues. Moreover, in silico predictions of physicochemical and pharmacokinetic properties for the target compounds indicated favorable drug-like characteristics.

Development and Evaluation of Bis-benzothiazoles as a New Class of Benzothiazoles Targeting DprE1 as Antitubercular Agents.

Benzothiazole-bearing compounds have emerged as potential noncovalent DprE1 (decaprenylphosphoryl-β-d-ribose-2'-epimerase) inhibitors active against Mycobacterium tuberculosis. Based on structure-based virtual screening (PDB ID: 4KW5), a focused library of thirty-one skeletally diverse benzothiazole amides was prepared, and the compounds were assessed for their antitubercular activity against M.tb H37Ra. Most potent compounds 3b and 3n were further evaluated against the M.tb H37Rv strain by the microdilution assay method. Among the compounds evaluated, bis-benzothiazole amide 3n emerged as a hit molecule and demonstrated promising antitubercular activity with minimum inhibitory concentration (MIC) values of 0.45 μg/mL and 8.0 μg/mL against H37Ra and H37Rv, respectively. Based on the preliminary hit molecule (3n), a focused library of 12 more bis-benzothiazole amide derivatives was further prepared by varying the substituents on either side to obtain new leads and generate a structure-activity relationship (SAR). Among these compounds, 6a, 6c, and 6d demonstrated remarkable antitubercular activity with MIC values of 0.5 μg/mL against H37Ra and 1.0, 2.0, and 8.0 μg/mL against H37Rv, respectively. The most active compound, 6a, also displayed significant efficacy against four drug-resistant tuberculosis strains. Compound 6a was assessed for in vitro cytotoxicity against the HepG2 cell line, and it displayed insignificant cytotoxicity. Furthermore, time-kill kinetic studies demonstrated time- and dose-dependent bactericidal activity of this compound. The GFP release assay revealed that compound 6a targets the inhibition of a cell wall component. SNPs in dprE-1 gene assessment revealed that compound 6a binds to tyrosine at position 314 of DprE1 and replaces it with histidine, causing resistance similar to that of standard TCA1. In silico docking studies further suggest that the strong noncovalent interactions of these compounds may lead to the development of potent noncovalent DprE1 inhibitors.

Green One-Pot Synthesis of Thiazole Scaffolds Catalyzed by Reusable NiFe2O4 Nanoparticles: In Silico Binding Affinity and In Vitro Anticancer Activity Studies.

A facile, green, one-pot multicomponent synthesis strategy was employed to fabricate novel thiazole scaffolds incorporating phthalazine, pyridazine, and pyrido-pyridazine derivatives (4a-4o). This synthetic route entailed the reaction of an α-halo carbonyl compound (1) with thiosemicarbazide (2) and various anhydrides (3a-3o), utilizing NiFe2O4 nanoparticles as a reusable catalyst in an ethanol:water (1:1) solvent system. The cytotoxicity of the synthesized compounds was meticulously assessed against three cancer cell lines, A375, HeLa, and MCF-7, employing IC50 values (μM) as the benchmark, and compared to the reference drug erlotinib. Compound 4n displayed remarkable efficacy against A375 (0.87 ± 0.31 μM), HeLa (1.38 ± 1.24 μM), and MCF-7 (1.13 ± 0.96 μM) cell lines, significantly surpassing erlotinib's IC50 values. Additionally, compounds 4k, 4l, 4m, and 4o demonstrated notable cytotoxicity across all tested cell lines, indicating their potential as effective anticancer agents. In silico docking studies against Hsp82 and Hsp90 proteins indicated that ligands 4k, 4m, 4c, 4j, 4o, and 4l had superior binding affinities compared to erlotinib. ADME analysis showed that compounds 4n, 4j, 4l, 4m, and 4o had favorable pharmacokinetic profiles, including nontoxicity, high human intestinal absorption, and low CYP inhibitory promiscuity. Structure-activity relationship analysis revealed that cyano and benzylidene substitutions significantly enhanced anticancer activity. Overall, the synthesized compounds, particularly 4n, demonstrated high efficacy, favorable binding interactions, and promising pharmacokinetic profiles, making them strong candidates for further development as anticancer agents.

Synthesis, anticancer, α-glucosidase inhibition, molecular docking and dynamics studies of hydrazone-Schiff bases bearing polyhydroquinoline scaffold: In vitro and in silico approaches

A series of hydrazone-Schiff base derivatives of polyhydroquinoline (PHQ) nucleus have been synthesized, structurally deduced by NMR (13C- and 1H-) and HR-ESI-MS spectroscopic methods and finally subjected for anti-cancer and α-glucosidase inhibitory activities. The MTT assay's results exposed that these eight compounds (2j, 2u, 2t, 2w, 2s, 2r, 2x, and 2d) presented notable activity against breast cancer MDA-MB-231 cells having IC50 in the range of 11.4 ± 0.2 to 15.1 ± 0.4 µM, while the remaining fourteen compounds displayed significant to good anti-breast cancer activity. In case of α-glucosidase inhibition, eight compounds (2n, 2j, 2e, 2o, 2w, 2q, 2v, and 2l) exhibited superior inhibition against α-glucosidase enzyme with IC50 values ranging from 8.72 ± 0.14 to 16.16 ± 0.17 µM, compare with the standard acarbose. Additionally, the remaining eighteen derivatives showed significant to least inhibitory activity. The in silico docking, and molecular dynamic displayed the minimal divergence in MM-PBSA values for 2n, 2j, 2e, and 2o which suggests a strong and stable interaction with the protein's amino acid backbone. Pharmacokinetic profiles and anti-glucosidase ability suggested them as potential drug candidates for further studies.

SAR Study of 4,8-Disubstituted Pyrimido[5,4-d]pyrimidines Exhibiting Antitrypanosomal and Antileishmanial Activity.

A set of new derivatives of 4,8-disubstituted pyrimido[5,4-d]pyrimidines were efficiently synthesized and in vitro evaluated against Trypanosoma brucei and Leishmania infantum promastigotes and intramacrophage amastigotes. The in vitro cytotoxicity was determined using the THP-1 cell line, and early in vitro ADME-Tox was carried out using in vitro assays for cytotoxicity (A549 and HEK293 cell lines) and CYP3A4 and hERG cardiotoxicity liabilities. All the new compounds were active against T. brucei (0.11 μM ≤ IC50 ≤ 8.72 μM; 1 ≤ selectivity index (SI) ≤ 877), but only eight were active against L. infantum promastigotes (0.20 μM ≤ IC50 ≤ 14.88 μM; 1 ≤ SI < 502) with three also active against L. infantum intramacrophage amastigotes (3.00 μM ≤ IC50 ≤ 8.51 μM). Compounds 4a, 4c, and 4n were identified as the hit compounds to further develop as antitrypanosomal and antileishmanial agents.

3-Benzylaminomethyl Lithocholic Acid Derivatives Exhibited Potent and Selective Uncompetitive Inhibitory Activity Against Protein Tyrosine Phosphatase 1B (PTP1B).

Protein tyrosine phosphatase 1B (PTP1B) is a promising drug target for treating type 2 diabetes (T2DM) and obesity. As a result, developing new therapies that target PTP1B is an attractive strategy for treating these diseases. Herein, we detail the synthesis of 15 lithocholic acid (LA) derivatives, each containing different benzylaminomethyl groups attached to the C3 position of the steroid skeleton. The derivatives were assessed against two forms of PTP1B enzyme (hPTP1B1-400 and hPTP1B1-285), and the most potent compounds were then tested against T-cell protein tyrosine phosphatase (TCPTP) to determine their selectivity. The results showed that compounds 6m and 6n were more potent than the reference compounds (ursolic acid, chlorogenic acid, suramin, and TCS401). Additionally, both compounds exhibited greater potency over hPTP1B1-400. Furthermore, enzyme kinetic studies on hPTP1B1-400 revealed that these two lithocholic acid derivatives have an uncompetitive inhibition against hPTP1B1-400 with K i values of 2.5 and 3.4 μM, respectively. Interestingly, these compounds were around 75-fold more selective for PTP1B over TCPTP. Finally, docking studies and molecular dynamics simulations (MDS) were conducted to determine how these compounds interact with PTP1B. The docking studies revealed hydrophobic and H-bond interactions with amino acid residues in the unstructured region. MDS showed that these interactions persisted throughout the 200 ns simulation, indicating the crucial role of the unstructured zone in the biological activity and inhibition of PTP1B.

Synthesis of Novel Benazepril-Derived Trizole Compounds Assisted by Ultrasound: In Vitro and In Silico Analysis for Potential Anticancer Properties.

Benazepril-based novel trizole derivatives are being explored as potential anticancer agents, designed with an N-substituted 1,2,3-triazole moiety linked to Benazepril's N-1 position via a methylene bridge. An ultrasound irradiated CuAAC method was used to prepare all these compounds and evaluated their anti-proliferative activities against cancer and drug-resistant cell lines. While some of these compounds demonstrated anti-proliferative activity towards leukemic cancer cell line K562, two of them displayed complete inhibitory activity. Interestingly, the compounds 5n and 5o showed potent activity against imatinib-resistant cell lines suggesting their promise to overcome cancer drug resistance. Furthermore, molecular docking analysis revealed that compounds 5n and 5o have higher predicted sensitivity towards ACE protein when compared to benazepril and lisinopril indicating their value as potential drug lead molecules. This research introduces a distinctive approach by employing ultrasound to facilitate CuAAC reactions in medicinal chemistry.

Docking and Simulation Studies on Novel Analogues of 3,4,5-Trihydroxy Benzoic Acid as HSP90Alpha Inhibitors

Abstract: HSP90 assists as a crucial molecular chaperone that responds to environmental stressors and helps in the survival of cells in microorganisms. This protein is integral to the stress response, aiding in the stabilization of various proteins essential for microbial survival. Consequently, the ability of a number of tissues to adjust to endogenous stress depends critically on appropriate chaperone activity. Modulators of chaperone activity, however, have emerged as a novel and developing area of drug discovery due to the association between changed chaperone function and the development of numerous illnesses. Inhibition of HSP90alpha can disrupt proper protein folding, thus impairing growth and virulence in fungi. In this work, we selected novel leads of gallic acid derivatives with the help of OSIRIS Property Explorer and DruLiTo software. Selected leads were subjected to ADME-T studies for further screening. Docking and molecular simulation studies on selected compounds were performed using Schrodinger v21 and GROMACS software to predict the bioactivity of novel leads of 3,4,5 trihydroxy benzoic acid for suppression of the HSP90alpha enzyme. Compounds 4N, 18N, 15N, and 14N showed good docking scores of -6.5, -6.4, -5.91, and -5.98, respectively, which was comparable to standard ciprofloxacin. Compound 4N and compound 14N demonstrated notable binding interactions and were selected for further investigation through molecular dynamics studies with HSP90alpha (PDB ID: 1YC1). RMSD, H BOND, and RMSF analysis confirmed the stable binding of compounds 4N and 14 N with the HSP90 enzyme. The RMSF plot showed less than 0.35 nm fluctuation for the HSP90alpha enzyme in complex with different ligands. It can be concluded that ligand binding can cause stability to the conformation of the protein. Compounds 4N and 14N are considered to be the best theoretical lead, which can further be studied experimentally as HSP90 alpha inhibitors for antimicrobial activity. other: Ongoing research aims to uncover more insights into the specific mechanisms of action, optimize structural features for enhanced efficacy, and explore potential synergies with existing antimicrobial agents. As a result, these derivatives hold promise as candidates for the development of novel antimicrobial agents with a broad spectrum of activity against bacteria and fungi

Design, synthesis, biological evaluation, and molecular modeling simulations of new phthalazine-1,4-dione derivatives as anti-Alzheimer's agents.

The development of targeted phthalazine-1,4-dione acetylcholinesterase (AChE) inhibitors for treating Alzheimer's disease involved the synthesis of 32 compounds via a multistage process. Various analytical techniques confirmed the compounds' identities. Thirteen compounds were found to inhibit AChE by more than 50% without affecting butyrylcholinesterase (BChE). Among these, three compounds, 8m, 8n, and 8p, exhibited extraordinary activity similar to donepezil, a reference AChE inhibitor. During enzyme kinetic studies, compound 8n, displaying the highest AChE inhibitory activity, underwent evaluation at three concentrations (2 × IC50, IC50, and IC50/2). Lineweaver-Burk plots indicated mixed inhibition activity for compound 8n against AChE, suggesting a combination of competitive and noncompetitive characteristics. Additionally, effective derivatives 8m, 8n, and 8p exhibited high blood-brain barrier (BBB) permeability in in vitro parallel artificial membrane permeability assay tests. Molecular docking studies revealed that these compounds bind to the enzyme's active site residues in a position similar to donepezil. Molecular dynamic simulations confirmed the stability of the protein-ligand system, and the chemical reactivity characteristics of the compounds were investigated using density functional theory. The compounds' wide energy gaps suggest stability and therapeutic potential. This research represents a significant step toward finding a potential cure for Alzheimer's disease. However, further research and testing are required to determine the compounds' safety and efficacy. The unique structure of phthalazine derivatives makes them suitable for various biological activities, and these compounds show promise for developing effective drugs for treating Alzheimer's disease. Overall, the development of these targeted compounds is a crucial advancement in the search for an effective treatment for Alzheimer's disease.

Synthesis of β-Amino Carbonyl 6-(Aminomethyl)- and 6-(Hydroxymethyl)pyrazolopyrimidines for DPP-4 Inhibition Study.

Type-2 diabetes is a chronic progressive metabolic disease resulting in severe vascular complications and mortality risk. Recently, DPP-4 inhibitors had been conceived as a favorable class of agents for the treatment of type 2 diabetes due to the minimal side effects. Sitagliptin is the first medicine approved for the DPP-4 inhibitor. Its structure involved three fragments: 2,4,5-triflorophenyl fragment pharmacophore, enantiomerically β-amino carbonyl linker, and tetrahydrotriazolopyridine. Herein, we are drawn to the possibility of substituting tetrahydrotriazolopyridine motif present in Sitagliptin with a series of new fused pyrazolopyrimidine bicyclic fragment to investigate potency and safety. Two series of fused 6-(aminomethyl)pyrazolopyrimidine and 6-(hydroxymethyl) pyrazolopyrimidine derivatives containing β-amino ester or amide as linkers were successfully designed for the new DPP-4 inhibitors. Most fused 6-methylpyrazolopyrimidines were evaluated against DPP-4 inhibition and selectivity capacity. Based on research study, β-amino carbonyl fused 6-(hydroxymethyl)pyrazolopyrimidine possesses the significant DPP-4 inhibition (IC50 ≤ 59.8 nM) and presents similar with Sitagliptin (IC50 = 28 nM). Particularly, they had satisfactory selectivity over DPP-8 and DPP-9, except for QPP. β-Amino esters and amides fused 6-(hydroxymethyl)pyrazolopyrimidine were developed as the new DPP-4 inhibitors. Those compounds with a methyl group or hydrogen in N-1 position and methyl substituted group in C-3 of pyrazolopyrimidine moiety showed better potent DPP-4 inhibition (IC50 = 21.4-59.8 nM). Furthermore, they had satisfactory selectivity over DPP-8 and DPP-9 Finally, the docking results revealed that compound 9n was stabilized at DPP-4 active site and would be a potential lead drug.

Discovery of Novel (+)-Nootkatone-Based Amine Derivatives as Potential Insecticide Candidates.

To discover novel natural product-based insecticides, a series of (+)-nootkatone-based amine derivatives 3a-t were prepared and evaluated for their insecticidal activities against Mythimna separata Walker, Myzus persicae Sulzer, and Plutella xylostella Linnaeus. Insecticidal assays showed that most of the title (+)-nootkatone derivatives exhibited stronger insecticidal activities against three insect pests than the precursor (+)-nootkatone after the introduction of amine groups on the parent (+)-nootkatone. Compounds 3a, 3d, 3h, 3m, 3n, 3p, and 3r displayed more promising growth inhibitory (GI) effect against M. separata than the commercially available botanical insecticide toosendanin. Compound 3o exhibited the most potent aphicidal activity with an LD50 value of 0.011 μg/larvae, which was 2.09-fold higher than the positive control rotenone. Additionally, compounds 3g and 3n showed more promising larvicidal activity against P. xylostella with LC50 values of 260 and 230 mg/L, respectively, superior to that of rotenone (460 mg/L). Moreover, derivatives 3g and 3n exhibited better control efficacy toward P. xylostella than rotenone under greenhouse conditions. Preliminary mechanistic studies revealed that derivative 3n could inhibit the activity of glutathione S-transferase (GST) in P. xylostella and thus exerted larvicidal activity, and molecular docking further demonstrated that 3n could interact well with some amino acid residues of GST. Finally, the toxicity assay suggested that derivatives 3g and 3n were relatively less toxic to nontarget organisms. These findings will provide insights into the development of (+)-nootkatone derivatives as green pesticides.

Development of chromone-thiazolidine-2,4-dione Knoevenagel conjugates as apoptosis inducing agents

Overexpression of Bcl-2 protein is a predominant hallmark of disturbed apoptotic pathway in most of the cancers. Herein, chromone-linked thiazolidinediones were designed and synthesized to target Bcl-2 for regulating anti-apoptotic proteins. The study on in vitro cancer cell lines revealed the presence of compounds 8a, 8k, 8l, and 8n, which were found to have good to moderate anti-proliferative activity (with an IC50 concentration less than 10 µM). Among them, 8l depicted the highest cytotoxicity on the A549 cell line with an IC50 of 6.1 ± 0.02 µM. Aberrantly, the compounds displayed less toxicity towards human embryonic kidney HEK cells underlining its selectivity. The DCFDA study revealed a gradual increase in the ROS generation of 8l, followed by its quantification by flow analysis. Similarly, the studies including DAPI, AO/EtBr and Annexin-V binding clearly elucidated the DNA damage, membrane integrity prospects, and insights for early and late apoptotic phases. Markedly, the Bcl-2-FITC anti-body study revealed that compound 8l reduced the expression of anti-apoptotic proteins by 79.1 % compared to the control at 9 µM concentration. In addition, the molecular docking study provided the impending scope of these hybrids, showing promising interaction with the Mcl-1 target (member of the Bcl-2 family) with comparable binding affinities.

Novel quinazoline sulfonamide-based scaffolds modulate methicillin-resistant Staphylococcus aureus (MRSA) pneumonia in immunodeficient irradiated model: Regulatory role of TGF-β

A library of new quinazoline pharmacophores bearing benzenesulfonamide moiety was designed and synthesized. Compounds 3a–n were screened for their in vitro antimicrobial activity against eight multidrug-resistant clinical isolates. Compounds 3d and 3n exhibited prominent antibacterial activity, specifically against MRSA. After exhibiting relative in vitro and in vivo safety, compound 3n was selected to assess its anti-inflammatory activity displaying promising COX-2 inhibitory activity compared to Ibuprofen. In vivo experimental MRSA pneumonia model was conducted on immunodeficient (irradiated) mice to reveal the antimicrobial and anti-inflammatory responses of compound 3n compared to azithromycin (AZ). Treatment with compound 3n (10 and 20 mg/kg) as well as AZ resulted in a significant decrease in bacterial counts in lung tissues, suppression of serum C-reactive protein (CRP), lung interleukin-6 (IL-6), myeloperoxidase activity (MPO) and transforming growth factor-β (TGF-β). Compound 3n showed a non-significant deviation of lung TGF-β1 from normal values which in turn controlled the lung inflammatory status and impacted the histopathological results. Molecular docking of 3n showed promising interactions inside the active sites of TGF-β and COX-2. Our findings present a new dual-target quinazoline benzenesulfonamide derivative 3n, which possesses significant potential for treating MRSA-induced pneumonia in an immunocompromised state.

Structure-Based Drug Design of ADRA2A Antagonists Derived from Yohimbine.

Yohimbine, a natural indole alkaloid and a nonselective adrenoceptor antagonist, possesses potential benefits in treating inflammatory disorders and sepsis. Nevertheless, its broader clinical use faces challenges due to its low receptor selectivity. A structure-activity relationship study of novel yohimbine analogues identified amino esters of yohimbic acid as potent and selective ADRA2A antagonists. Specifically, amino ester 4n, in comparison to yohimbine, showed a 6-fold higher ADRA1A/ADRA2A selectivity index (SI > 556 for 4n) and a 25-fold higher ADRA2B/ADRA2A selectivity index. Compound 4n also demonstrated high plasma and microsomal stability, moderate-to-low membrane permeability determining its limited ability to cross the blood-brain barrier, and negligible toxicity on nontumor normal human dermal fibroblasts. Compound 4n represents an important complementary pharmacological tool to study the involvement of adrenoceptor subtypes in pathophysiologic conditions such as inflammation and sepsis and a novel candidate for further preclinical development to treat ADRA2A-mediated pathologies.

Enzymatic synthesis of pyridine heterocyclic compounds and their thermal stability

An efficient method was discovered for catalyzing the esterification under air using Novozym 435 to obtain pyridine esters. The following conditions were found to be optimal: 60 mg of Novozyme 435, 5.0 mL of n-hexane, a molar ratio of 2:1 for nicotinic acids (0.4 mmol) to alcohols (0.2 mmol), 0.25 g of molecular sieve 3A, a revolution speed of 150 rpm, a reaction temperature of 50 °C, and reaction time of 48 h. Under nine cycles of Novozym 435, the 80 % yield was consistently obtained. Optimum conditions were used to synthesize 23 pyridine esters, including five novel compounds. Among them, gas chromatography-mass spectrometry-olfactometry (GC-MS-O) showed phenethyl nicotinate (3g), (E)-hex-4-en-1-yl nicotinate (3m), and octyl nicotinate (3n) possessed strong aromas. Thermogravimetric analysis (TG) revealed that the compounds 3g, 3m and 3n exhibited stability at the specified temperature. This finding provides theoretical support for adding pyridine esters fragrance to high-temperature processed food.

Synthesis, antifungal evaluation, two-dimensional quantitative structure-activity relationship and molecular docking studies of isoxazole derivatives as potential fungicides.

Sheath blight and bakanae disease, prominent among emerging rice ailments, exert a profound impact on rice productivity, causing severe impediments to crop yield. Excessive use of older fungicides may lead to the development of resistance in the pathogen. Indeed, a pressing and immediate need exists for novel, low-toxicity and highly selective fungicides that can effectively combat resistant fungal strains. A series of 20 isoxazole derivatives were synthesized using alkoxy/halo acetophenones and N,N-dimethylformamidedimethylacetal. These compounds were characterized by various spectroscopic techniques, namely 1H nuclear magnetic resonance (NMR), 13C NMR and liquid chromatography-high-resolution mass spectrometry, and were evaluated for their fungicidal activity against Rhizoctonia solani and Fusarium fujikuroi. Compound 5n (5-(2-chlorophenyl) isoxazole) exhibited highest activity (effective dose for 50% inhibition [ED50] = 4.43 μg mL-1) against R. solani, while 5p (5-(2,4-dichloro-2-hydroxylphenyl) isoxazole) exhibited highest activity (ED50 = 6.7 μg mL-1) against F. fujikuroi. Two-dimensional quantitative structural-activity relationship (QSAR) analysis, particularly multiple linear regression (MLR) (Model 1), highlighted chi6chain and DistTopo as the key descriptors influencing fungicidal activity. Molecular docking studies revealed the potential of these isoxazole derivatives as novel fungicides targeting sterol 14α-demethylase enzyme, suggesting their importance as crucial intermediates for the development of novel and effective fungicides. All test compounds were effective in inhibiting both fungi, according to the QSAR model, with various descriptors, such as structural, molecular shape analysis, electronic and thermodynamic, playing an important role. Molecular docking studies confirmed that these compounds can potentially replace commercially available fungicides and help control fungal pathogens in rice crops effectively. © 2024 Society of Chemical Industry.