Indoline derivatives I: synthesis and factor Xa (FXa) inhibitory activities

A series of bisamidine derivatives each having a ring structure in the center of the molecule was synthesized and their Factor Xa (FXa) inhibitory activities were evaluated. Among them, some indoline derivatives showed potent inhibitory activities in vitro. In particular, (R)-18a having an (R)-configuration at the 2-position of the indoline ring exhibited the most potent FXa inhibitory activity in vitro, more potent than DX-9065a. Furthermore, (R)-18a exhibited more potent anticoagulant activity than DX-9065a. We also succeeded in obtaining an X-ray crystal structure of FXa bound with (R)-18a.     

Synthesis and biological evaluation of substituted indazolyl amide derivatives as S-adenosyl-L-homocysteine hydrolase inhibitors

A series of novel amide derivatives bearing an indazole moiety were synthesized and evaluated for their in vitro S-adenosyl-L-homocysteine hydrolase (SAHase) inhibitory activity. Among these compounds, 8b, 8m, 8r and 8w showed better or similar inhibitory effects compared to the positive control aristeromycin. These results provide a novel lead for the discovery of more potent non-adenosine analogs as SAHase inhibitors.     

de novo design and synthesis of N-benzylanilines as new candidates for VEGFR tyrosine kinase inhibitors

N-Benzylanilines were designed and synthesized as vascular endothelial growth factor (VEGF)-2 inhibitors using de novo drug design systems based on the X-ray structure of VEGFR-2 kinase domain. Among compounds synthesized, compound showed the most potent inhibitory activity toward VEGFR-2 (KDR) tyrosine kinase and its IC(50) value was 0.57 microM.     

Structure-activity relationships of new N-acylanthranilic acid derivatives as plasminogen activator inhibitor-1 inhibitors

Novel anthranilic acid derivatives having substituted N-acyl side chains were designed and synthesized for evaluation as plasminogen activator inhibitor-1 (PAI-1) inhibitors. Compounds with a 4-diphenylmethyl-1-piperazinyl moiety on the acyl side chains in general exhibited potent in vitro PAI-1 inhibitory activity and good pharmacokinetic profiles after oral administration in rats. Compound 16f (TM5275) was identified as a promising candidate for further pharmacological evaluation.     

酰胺类KARI酶抑制剂的设计、合成和生物活性

以分子对接法进行MDL/ACD三维数据库搜寻所得到的大量结构信息为指导, 从中选取部分酰胺类小分子进行化学合成和结构表征. 生物活性测试结果表明, 设计合成的8个酰胺类化合物在200 μg/mL浓度下对水稻KARI酶具有不同程度的抑制活性, 化合物1和6的抑制率可达到57.4%和48.1%. 部分化合物在100 μg/mL浓度下对双子叶植物油菜的胚根和单子叶植物稗草的茎叶的抑制活性较为显著, 化合物1和6对油菜胚根生长抑制率分别为52.0%和72.6%, 其与KARI酶体外(in vitro)抑制活性具有一定的相关性. 这些酰胺类化合物可作为KARI酶抑制剂为后续分子设计提供借鉴.     

Design,Synthesis, and Evaluation of Dihydropyranopyrazole Derivatives as Novel PDE2 Inhibitors for the Treatment of Alzheimer’s Disease

Phosphodiesterase 2 (PDE2) has been regarded as a novel target for the treatment of Alzheimer’s disease (AD). In this study, we obtained (R)-LZ77 as a hit compound with moderate PDE2 inhibitory activity (IC₅₀ = 261.3 nM) using a high-throughput virtual screening method based on molecular dynamics. Then, we designed and synthesized 28 dihydropyranopyrazole derivatives as PDE2 inhibitors. Among them, compound (+)-11h was the most potent PDE2 inhibitor, with an IC₅₀ value of 41.5 nM. The molecular docking of PDE2-(+)-11h reveals that the 4-(trifluoromethyl)benzyl)oxyl side chain of the compound enters the H-pocket and forms strong hydrophobic interactions with L770/L809/F862, which improves inhibitory activity. The above results may provide insight for further structural optimization of highly potent PDE2 inhibitors and may lay the foundation for their use in the treatment of AD.     

Synthesis and anti-influenza evaluation of polyvalent sialidase inhibitors bearing 4-guanidino-Neu5Ac2en derivatives

Polyvalent sialidase inhibitors bearing 4-guanidino-Neu5Ac2en derivatives on a poly-L-glutamine backbone are described. Aiming for a longer retention time of 4-guanidino-Neu5Ac2en (zanamivir) in bronchi and lungs, we focused on supermolecules bearing 4-guanidino-Neu5Ac2en derivatives bound at their C-7 position through noncleavable alkyl ether linkages. We first found that alkylation of the 7-hydroxyl group of sialic acid derivative 8 proceeded smoothly, and produced 7-O-alkyl-4-guanidino-Neu5Ac2en derivatives 13, which exhibited equipotent inhibitory activity against not only influenza A virus sialidase but also influenza A virus in the cell culture. Next, we synthesized poly-L-glutamine bearing 7-O-alkyl-4-guanidino-Neu5Ac2en derivatives linked by amide bonds, 26, which showed enhanced antiviral activity against influenza A virus and more potent efficacy in vivo relative to a monomeric sialidase inhibitor.     

Synthesis and biological evaluation of novel 1, 2, 3-benzotriazin-4-one derivatives as leukotriene A4 hydrolase aminopeptidase inhibitors

A series of novel 1,2,3-benzotriazin-4-one derivatives were designed,synthesized and their inhibitory activities against leulcotriene A_4 hydrolase aminopeptidase in vitro were evaluated.Many compounds showed moderate to good activities at the concentration of 10 μmol/L.Among them,compound Ⅳ-16 exhibited the highest inhibitory activity up to 80.6% with an IC_(50) of 1.30 ± 0.20 μmol/L The compound Ⅳ-16 was also tested the proliferation inhibitory activities in THP1 human AML cell line and its binding model with LTA_4H enzyme by molecular docking was studied.It indicated that 1,2,3-benzotriazin-4-one was a promising scaffold for further study.The relationship between structure and inhibitory activity was also preliminarily discussed.     

Synthesis,Biological Evaluation,and In Silico Studies of New Acetylcholinesterase Inhibitors Based on Quinoxaline Scaffold

A quinoxaline scaffold exhibits various bioactivities in pharmacotherapeutic interests. In this research, twelve quinoxaline derivatives were synthesized and evaluated as new acetylcholinesterase inhibitors. We found all compounds showed potent inhibitory activity against acetylcholinesterase (AChE) with IC₅₀ values of 0.077 to 50.080 µM, along with promising predicted drug-likeness and blood–brain barrier (BBB) permeation. In addition, potent butyrylcholinesterase (BChE) inhibitory activity with IC₅₀ values of 14.91 to 60.95 µM was observed in some compounds. Enzyme kinetic study revealed the most potent compound (6c) as a mixed-type AChE inhibitor. No cytotoxicity from the quinoxaline derivatives was noticed in the human neuroblastoma cell line (SHSY5Y). In silico study suggested the compounds preferred the peripheral anionic site (PAS) to the catalytic anionic site (CAS), which was different from AChE inhibitors (tacrine and galanthamine). We had proposed the molecular design guided for quinoxaline derivatives targeting the PAS site. Therefore, the quinoxaline derivatives could offer the lead for the newly developed candidate as potential acetylcholinesterase inhibitors.     

槲皮素-3-O-丙基衍生物的合成及生物活性研究

槲皮素是具有丰富生物活性的黄酮类化合物,药理活性显著。本文以槲皮素为先导物,选择性对C环3位羟基进行修饰,以廉价的芦丁为原料,经苄基保护、Williamson成醚反应,再经Pd/C催化加氢脱苄基得到28个未见文献报道的槲皮素-3-O-丙基衍生物,其结构经¹H NMR、¹³C NMR、ESI-MS进行确证。采用MTT法考察了所合成化合物对人食管鳞癌（EC109）、人胃癌（HGC27）、人乳腺癌（MCF-7）、小鼠黑色素瘤（B16-F10）的增殖抑制作用。结果显示,通过化学方法对槲皮素结构进行修饰后,其体外抗肿瘤活性增强。其中,化合物F3(IC₅₀=5.23±0.37μmol/L)、F5(IC₅₀=2.63±0.09μmol/L)对小鼠黑色素瘤（B16-F10）抑制作用比5-氟尿嘧啶(IC₅₀=14.38±0.27μmol/L)好,值得进一步研究。     

Synthesis and Evaluation of PDE5 Inhibitory Activity of Novel Pyrido[2＇,1＇：5,1]pyrazolo[4,3-d]pyrimidin-4-one Derivatives

Novel pyridopyrazolopyrimidinone derivatives were designed and synthesized as potential PDE5 inhibitors. The target compounds demonstrated significant inhibitory activity against human platelet PDE5, but less potent than sildenafil.     

A novel class of inhibitors for human and rat steroid 5alpha-reductases: synthesis and biological evaluation of indoline and aniline derivatives. III

While searching for novel nonsteroidal inhibitors of human and rat prostatic 5alpha-reductases, we found a new series of indoline and aniline derivatives that showed potent inhibitory activities for both enzymes. Among them, 3-chloro-4-?[1-(4-phenoxybenzyl)indolin-5-yl]oxylbenzoic acid (2e, YM-36117) showed a more potent inhibitory activity for the human enzyme than ONO-3805 with an IC50 value of 5.3 nM and a reduced rat prostatic dihydrotestosterone (DHT) concentration by oral administration. The synthesis and the structure-activity relationships of these indoline and aniline derivatives are presented.     

Syntheses of (4,1-benzoxazepine-3-ylidene)acetic acid derivatives and their inhibition of squalene synthase

The (3,5-trans)-7-chloro-5-(2-chlorophenyl)-2-oxo-1,2,3,5-tetrahydro-4,1-benzoxazepine-3-acetic acid derivatives 1 have been previously identified as potent squalene synthase inhibitors. A series of (4,1-benzoxazepin-3-ylidene)acetic acid derivatives were synthesized and evaluated for their inhibition of rat and human squalene synthase, and the (E)-isomers were found to exhibit potent inhibitory activity, with the same potency as 4,1-benzoxazepine-3-acetic acid derivatives. In contrast the (Z)-isomers did not exhibit significant inhibitory activity, and the active conformation of the 4,1-benzoxazepine-3-acetic acid derivatives was deduced from the folded conformation of the (E)-isomers.     

Synthesis,Biological Evaluation and Molecular Docking of Novel Phenylpyrimidine Derivatives as Potential Anticancer Agents

Based on our previous researches, a novel phenylpyrimidine pharmacophore model was proposed and fifteen derivatives were synthesized and characterized by means of spectroscopy methods. The inhibitory effects of them were screened against HeLa cell line by virtue of MTT assay in vitro. The results indicate some of the phenylpyrimidine derivatives exhibit potent biological activities. Among them, compounds 6g and 6h exhibit the best activity at half maximal inhibitory concentrations of 1.5 and 2.8 μmol/L, respectively. These compounds also exhibit good activities against HepG2 cell line and MCF-7 cell line. FLT-3 kinase was screened as the most potent molecular target. Computational docking between compound 6g and FLT-3 was carried out to interpret the binding mode. The results show phenylpyrimidine derivatives have effective antitumor activities, which provides a base for further research of them as antitumor agents.     

Novel and versatile methodology for synthesis of β-aryl-β-mercapto ketone derivatives as potential urease inhibitors

The objective was to obtain new scaffold of compounds possessing anti-urease activity. For this new and simple method for the synthesis of β-aryl-β-mercapto ketone derivatives based on Michael addition of thiophenol to chalcones in an ionic liquid as a solvent was improved. The products were obtained in good to moderate yields with high purity and characterized by spectral and elemental analyses. The activities of synthesized compounds were investigated as new inhibitors of jack bean urease. Among 22 synthesized compounds, all of them have shown inhibitory effect in micromolar range, and the most potent one has IC₅₀ = 6 μM compared to hydroxyurea IC₅₀ = 100 μM as a reference inhibitor. A docking study was performed using Autodock 4.2 in parallel to in vitro experiments to illustrate the corresponded binding affinities as well as binding site, and involved residues in interaction. These computational results complimented the experimental inhibition activity and enabled us to report a potent urease inhibitors based on β-aryl-β-mercapto ketone scaffold.     

Design,Synthesis, and Biological Evaluation of Novel Pyrazole,Oxazole, and Pyridine Derivatives as Potential Anticancer Agents Using Mixed Chalcone

New pyrazole, oxazole, and pyridine derivatives bearing naphthalene and furan moieties have been prepared by condensing 3‐(furan‐2‐yl)‐1‐(naphthalen‐2‐yl)prop‐2‐en‐1‐one 1 with different nitrogen and carbon nucleophiles such as hydrazine, hydroxylamine, cyclohexanone, cyclopentanone, ethyl cyanoacetate, and malononitrile, respectively. Cyclization of chalcone 1 with malononitrile in refluxing ethanol and ammonium acetate gave the corresponding dihydropyridine, which was condensed with different carbon electrophilic reagents such as ethyl cyanoacetate, ethyl acetoacetate, formamide, and acetic anhydride to yield the pyridine derivatives 13 – 16 . Elemental and spectroscopic evidences characterized all the newly synthesized compounds. All of the newly synthesized compounds were tested in vitro for their anti‐proliferative activities against HePG‐2 and MCF‐7 cell lines. Compounds 11 , 8 , and 15 displayed promising growth inhibitory effect toward the two cell lines compared with the standard drug doxorubicin.     

N-substituted hydroxyureas as urease inhibitors

In order to seek a urease inhibitor more potent than hydroxyurea (1), its alkyl- or phenyl-substituted derivatives were synthesized and evaluated for their effect on the jack bean urease. Of 16 compounds tested, m-methyl- (10) and m-methoxy-phenyl substituted hydroxyurea (13) showed the most potent inhibitory activities against the enzyme.     

Angiotensin-converting enzyme inhibitors: synthesis and biological activity of N-substituted tripeptide inhibitors

A new series of highly potent angiotensin-converting enzyme (ACE) inhibitors, 1-(N2-substituted L-lysyl-gamma-D-glutamyl)octahydro-1H-indole-2-carboxylic acids, was synthesized; various acyl groups were introduced at the alpha-amino group of the N-terminal P1 Lys. The effect of the N2-acyl groups on in vitro inhibitory activity and oral antihypertensive effect was examined. All of the synthesized N-acyl tripeptides were found to have in vitro inhibitory activity at an approximately nanomolar level, and showed antihypertensive potency in renal hypertensive rats at a dose of 10 mg/kg, when administered orally. Among them, compounds 7e, g and 9f, i, m showed potent and long-lasting antihypertensive effects compared with enalapril (2a). Their structure-activity relationships are also discussed.