茚酮氨基甲酸酯衍生物的设计合成及其对乙酰胆碱酯酶抑制活性的研究

目的设计合成茚酮氨基甲酸酯衍生物并进行乙酰胆碱酯酶(AChE)抑制活性测试。方法以羟基苯丙酸为起始原料,经分子内Friedel-Crafts酰化、羟基的氨基甲酸酯化和羟醛缩合3步反应合成目标物;采用Ellman法,以拉多替吉(ladostigil)为阳性对照,测试目标化合物对AChE的抑制活性。结果合成了8个未见文献报道的新化合物,其结构和纯度均经1H-NMR、MS谱测定。结论目标化合物对AChE均表现出一定的抑制活性,可作为先导化合物做进一步的改造和修饰。     

Design, synthesis and evaluation of novel 2-(aminoalkyl)-isoindoline-1,3-dione derivatives as dual-binding site acetylcholinesterase inhibitors

A new series of 2-(diethylaminoalkyl)-isoindoline-1,3-dione derivatives intended as dual binding site cholinesterase inhibitors were designed using molecular modeling and evaluated as inhibitors of acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), and the formation of the β-amyloid (Aβ) plaques. For AChE inhibitory activity, the spectrophotometric method of Ellman and the electrophoretically mediated microanalysis assay were used, giving good results. Most of the synthesized compounds had AChE inhibitory activity with IC(50) values ranging from IC(50) = 0.9 to 19.5 μM and weak Aβ anti-aggregation inhibitory activity. These results support the outcome of docking studies which tested compounds targeting both the catalytic active site (CAS) and the peripheral anionic site (PAS) of AChE. The most promising selective AChE inhibitors are compounds 10 (IC(50) = 1.2 μM) and 11 (IC(50) = 1.1 μM), with 6-7 methylene chains, which also inhibit Aβ fibril formation.     

Design and synthesis of new templates derived from pyrrolopyrimidine as selective multidrug-resistance-associated protein inhibitors in multidrug resistance

In our continued effort to identify selective MRP1 modulators, we have developed two novel templates, 3 and 4, through rational drug design by identifying the key pharmacophore interaction at the 7-position of the pyrrolopyrimidine template 1. Further synthesis and SAR work on these novel templates gave a number of potent MRP1 modulators with great selectivity against Pgp. Additional studies to reduce the CYP3A4 inhibition are also reported. Several compounds of these classes were subjected to in vivo xenograft studies and in vivo efficacies were demonstrated.     

Flavonoids as acetylcholinesterase inhibitors

Flavonoids are new promising potential natural compounds for treating Alzheimer's disease (AD). Actually most promising drugs for symptomatic treatment of AD are acetylcholinesterase inhibitors (AChEI). Flavonoids with AChE inhibitory activity and due to their well known antioxidant activity could be new multipotent drugs for AD treatment. This work focuses on natural and synthetic flavonoids inhibitors of the enzyme acetylcholinesterase (AChE). Over, all this review refers to 128 flavonoids, which are classified in chemical structure, and summarizes 64 references.     

Aminopyridazines as acetylcholinesterase inhibitors

Following the discovery of the weak, competitive and reversible acetylcholinesterase (AChE)-inhibiting activity of minaprine (3c) (IC50 = 85 microM on homogenized rat striatum AChE), a series of 3-amino-6-phenylpyridazines was synthesized and tested for inhibition of AChE. A classical structure-activity relationship exploration suggested that, in comparison to minaprine, the critical elements for high AChE inhibition are as follows: (i) presence of a central pyridazine ring, (ii) necessity of a lipophilic cationic head, (iii) change from a 2- to a 4-5-carbon units distance between the pyridazine ring and the cationic head. Among all the derivatives investigated, 3-[2-(1-benzylpiperidin-4-yl)ethylamino]-6-phenylpyridazine (3y), which shows an IC50 of 0.12 microM on purified AChE (electric eel), was found to be one of the most potent anti-AChE inhibitors, representing a 5000-fold increase in potency compared to minaprine.1     

Design and synthesis of novel FKBP inhibitors.

Small molecule FKBP inhibitors were prepared with inhibitory activity ranging from micromolar to nanomolar. The design of these inhibitors derives from a structural analysis of the substrates for FKBP and cyclophilin. As a consequence of this analysis two key observations were made, namely: (1) amino ketone moieties are suitable as FKBP recognition elements at the P1-P1' site and (2) the P3'-P4' site will accept a trans-olefin as a suitable mimetic of a peptide moiety. The preparation of these non-peptide inhibitors is readily accomplished by a protocol which includes the synthesis of chiral propargylic amines and their subsequent conversion into vinyl zirconium reagents.     

Design and synthesis of novel inhibitors of prohormone convertases

Prohormone convertase-1 (PC1) and furin are subtilisin-like endopeptidases involved in the biosynthesis of peptide hormones. Five decapeptides representing the junction between the pro-region and the catalytic region of PC1 were prepared. The core sequence corresponded to D-Tyr-Arg-Ser-Lys-Arg-Xaa-Val-Gln-Lys-Asp where D-Tyr replaces the native Glu residue and Xaa, representing the P1′ position, corresponds to L-Ser, L-Leu or the unnatural amino acids, D-Ser, β-Ala, γ-Abu, β-Cha or γ-Hyp. Another analog incorporating an Orn residue in place of the Arg at the P1 site was also prepared. These peptides, synthesized by solid-phase Fmoc chemistry, were fully characterized by FAB-MS, ¹H-NMR and amino acid composition. Except for Orn, γ-Hyp, L/D-Ser and L-Leu containing analogs, the others were found to be moderate to potent competitive inhibitors of hPCl activity in the following order: γ-Abu>β-Cha>β-Ala, with K_i values ranging from 1 to 8.6 μM. Both L-Ser and L-Leu analogs were correctly cleaved at the acyl carbon COOH-terminal to the Lys-Arg pair by human PCl, whereas β-Cha, γ-Abu, β-Ala and D-Ser analogs proved to be very poor substrates. The Orn and γ-Hyp derivatives were not cleaved by the enzyme at all. The three analogs containing β-Cha, γ-Abu and β-Ala also proved to be potent inhibitors of the human furin activity in the following order: β-Ala>β-Cha> γ-Abu, with K₁ ranging from 0.8 to 2.2μM. Two more peptides, modified at the P1 position by addition of a semicarbazone (SC) moiety, were also synthesized by liquid-phase chemistry. These peptides, Arg-Ser-Lys-argininal-SC and Arg-Lys-Lys-argininal-SC, also proved to be potent competitive inhibitors of hPCl and exhibited K_i values 3.6 and 2.3 μM, respectively.     

Design and synthesis of a novel series of pyranonaphthoquinones as topoisomerase II catalytic inhibitors

On the basis of previous pharmacophore modeling studies of naphthoquinones derivatives, we have designed and synthesized a new set of pyranonaphthoquinones. These compounds were obtained through a direct and highly efficient approach based on an intramolecular domino Knoevenagel hetero Diels-Alder reaction from lawsone (2-hydroxynaphthoquinone) and a variety of aldehydes containing an alkene. The synthesized pyranonaphthoquinones were evaluated against the alpha isoform of human topoisomerase II (hTopoIIalpha). Among the 11 derivatives studied, we found that six of them act as catalytic inhibitors of the enzyme in vitro. These six derivatives strongly preclude the enzyme from decatenating or relaxing suitable substrates. Finally, we correlate their active/inactive status with docking studies of these novel compounds into the ATPase domain of hTopoIIalpha.     

Discovery and synthesis of hydronaphthoquinones as novel proteasome inhibitors

Screening efforts led to the identification of PI-8182 (1), an inhibitor of the chymotrypsin-like (CT-L) activity of the proteasome. Compound 1 contains a hydronaphthoquinone pharmacophore with a thioglycolic acid side chain at position 2 and thiophene sulfonamide at position 4. An efficient synthetic route to the hydronaphthoquinone sulfonamide scaffold was developed, and compound 1 was synthesized in-house to confirm the structure and activity (IC(50) = 3.0 ± 1.6 μM [n = 25]). Novel hydronaphthoquinone derivatives of 1 were designed, synthesized, and evaluated as proteasome inhibitors. The structure-activity relationship (SAR) guided synthesis of more than 170 derivatives revealed that the thioglycolic acid side chain is required and the carboxylic acid group of this side chain is critical to the CT-L inhibitory activity of compound 1. Furthermore, replacement of the carboxylic acid with carboxylic acid isosteres such as tetrazole or triazole greatly improves potency. Compounds with a thio-tetrazole or thio-triazole side chain in position 2, where the thiophene was replaced by hydrophobic aryl moieties, were the most active compounds with up to 20-fold greater CT-L inhibition than compound 1 (compounds 15e, 15f, 15h, 15j, IC(50) values around 200 nM, and compound 29, IC(50) = 150 nM). The synthetic iterations described here not only led to improving potency in vitro but also resulted in the identification of compounds that are more active such as 39 (IC(50) = 0.44 to 1.01 μM) than 1 (IC(50) = 3.54 to 7.22 μM) at inhibiting the proteasome CT-L activity in intact breast cancer cells. Treatment with 39 also resulted in the accumulation of ubiquitinated cellular proteins and inhibition of tumor cell proliferation of breast cancer cells. The hit 1 and its analogue 39 inhibited proteasome CT-L activity irreversibly.     

Bispyridinium cyclophanes: novel templates for human choline kinase inhibitors

The synthesis and biological activities of four novel bispyridinium cyclophanes as choline kinase (ChoK) inhibitors are presented. Their synthetic methodology has been optimized according to dilution, temperature, and reaction time and provides pure bispyridinium cyclophanes in high yields very easily. One of these cyclophanes (6, 4,8-diaza-3(1,4),9(4,1)-dipyridina-1(1,4),6(1,3)-dibenzenacyclodecaphan-3(1),9(1)-bis(ilium) dibromide) has an IC(50(ChoK)) of 0.3 microM and is the most potent human ChoK inhibitor described to date.     

Design and synthesis of novel indole beta-diketo acid derivatives as HIV-1 integrase inhibitors

Diketo acids such as S-1360 (1A) and L-731,988 (2) are potent and selective inhibitors of HIV-1 integrase (IN). A plethora of diketo acid-containing compounds have been claimed in patent literature without disclosing much biological activities and synthetic details (reviewed in Neamati, N. Exp. Opin. Ther. Pat. 2002, 12, 709-724). To establish a coherent structure-activity relationship among the substituted indole nucleus bearing a beta-diketo acid moiety, a series of substituted indole-beta-diketo acids (4a-f and 5a-e) were synthesized. All compounds tested showed anti-IN activity at low micromolar concentrations with varied selectivity against the strand transfer process. Three compounds, the indole-3-beta-diketo acids 5a and 5c, and the parent ester 9c, have shown an antiviral activity in cell-based assays. We further confirmed a keto-enolic structure in the 2,3-position of the diketo acid moiety of a representative compound (4c) using NMR and X-ray crystallographic analysis. Using this structure as a lead for all of our computational studies, we found that the title compounds extensively interact with the essential amino acids on the active site of IN.     

新型环丙烷类B-Raf激酶抑制剂的设计合成及抗肿瘤活性研究

目的设计合成一系列环丙烷类B-Raf激酶抑制剂并测定其对人肝癌Hep G2细胞增殖的影响。方法以索拉非尼(sorafenib)为先导化合物,通过结构优化设计新型环丙烷类B-Raf激酶抑制剂,并以对羟基苯甲醛为起始原料经过苄基保护、缩合、酯化、环丙化、水解、酰胺化、脱苄、亲核取代等反应合成目标化合物。以索拉非尼为阳性对照物,采用MTT法测定目标化合物对人肝癌HepG2细胞增殖的影响。结果与结论合成了16个未见文献报道的新化合物,其结构经核磁共振氢谱鉴定。初步的体外活性评价结果表明,其中9个化合物表现出良好的肿瘤细胞抑制活性,优于阳性对照药索拉非尼,具有进一步研究的价值。     

Design and synthesis of novel N-hydroxy-dihydronaphthyridinones as potent and orally bioavailable HIV-1 integrase inhibitors

HIV-1 integrase (IN) is one of three enzymes encoded by the HIV genome and is essential for viral replication, and HIV-1 IN inhibitors have emerged as a new promising class of therapeutics. Recently, we reported the synthesis of orally bioavailable azaindole hydroxamic acids that were potent inhibitors of the HIV-1 IN enzyme. Here we disclose the design and synthesis of novel tricyclic N-hydroxy-dihydronaphthyridinones as potent, orally bioavailable HIV-1 integrase inhibitors displaying excellent ligand and lipophilic efficiencies.     

Design and synthesis of novel 1,4-benzodiazepine derivatives and their biological evaluation as cholinesterase inhibitors

A new series of 1,4-benzodiazepine-2,5-dione structurally related to cyclopenin has been synthesized. The new compounds were assayed in vivo and in vitro for their ability to inhibit acetylcholinesterase enzyme and were found to have potent reversible anticholinesterase activity when tested in vitro for isolated frog rectus abdominis and guinea pig ileum in addition to increasing brain cholinesterase level in rats when percentage inhibition were tested in vivo, moreover compounds 5a, 5b, 5c and 5g were the most active. LD(50) was performed for these derivatives and they displayed high safety margin.     

9,10-Dihydroergotalkaloids as inhibitors of acetylcholinesterase

A kinetic analysis of the interaction of 9,10-dihydroergotalkaloids with electrophorus electricus acetylcholinesterase [E.3.1.1.7] and acetylthiocholine as substrate shows a mixed type of inhibition of this enzyme. The inhibitor constants Ki were found to be for 9,10-dihydroergokryptine 198 mumol, 9,10-dihydroergotamine 144 mumol, 9,10-dihydroergocristine 117 mumol. A more potent inhibitor is ergotamine with the inhibitor constant Ki = 15 mumol and a mixed type of inhibition.     

Design, synthesis, and biological evaluation of novel carbohydrate-based sulfamates as carbonic anhydrase inhibitors

Carbonic anhydrases (CAs) IX and XII are enzymes with newly validated potential for the development of personalized, first-in-class cancer chemotherapies. Here we present the design and synthesis of novel carbohydrate-based CA inhibitors, several of which were very efficient inhibitors (K(i)<10 nM) with good selectivity for cancer-associated CA isozymes over off-target CA isozymes. All inhibitors comprised a carbohydrate core with one hydroxyl group derivatized as a sulfamate. Five different carbohydrates were chosen to present a selection of molecular shapes with subtle stereochemical differences to the CA enzymes active site. Variable modifications of the remaining sugar hydroxyl groups were incorporated to provide an incremental coverage of chemical property parameters that are associated with biopharmaceutical performance. All sulfamate inhibitors displayed ligand efficiencies that are consistent with those reported for good drug lead candidates.     

含噻唑环的新型二肽基肽酶IV抑制剂的设计合成及其降血糖作用

目的 合成一类新型的以噻唑环为母体的二肽基肽酶IV (DPP-IV)抑制剂,并测试它们在治疗糖尿病方面的活性。方法 通过Hantzsch噻唑合成反应制备各种2-氨基噻唑,用氯乙酰氯和三乙胺进行氯乙酰化,乙酰化产物经芳基甲胺处理得到相应的仲胺,仲胺在干燥的乙醚中用氯化氢乙醚溶液处理即可得到目标化合物。利用小鼠体内葡萄糖耐受量法测定目标化合物在治疗糖尿病方面的活性。结果 合成了20个结构新颖的化合物,其结构经过¹H-NMR、 ¹³C-NMR、和ESI-MS谱确证。结论 活性测试结果显示,有3个化合物具有明显的降血糖作用,其中化合物6l的活性与阳性对照药格列齐特和格列喹酮相当,另外两化合物6d、6n的 降血糖作用比阳性对照药强,显示出在治疗糖尿病方面的价值。     

4-苯基-2-氨基嘧啶类化合物的设计合成及其抗肿瘤活性

目的设计合成一系列4-苯基-2-氨基嘧啶类新型化合物,并测定其对前列腺癌细胞(PC-3)的生长抑制活性。方法以硝基苯乙酮为起始原料,通过嘧啶环合、酰胺缩合、硝基还原、氨基保护及脱保护反应合成目标化合物。采用MTT法测试化合物对前列腺癌PC-3细胞的生长抑制活性;采用均相时间分辨荧光法测定化合物对激酶AKT1的抑制活性。结果与结论合成了9个未见文献报道的4-苯基-2-氨基嘧啶类化合物,其结构经1H-NMR、MS谱确证。化合物9a-1、9a-3、9b-1(5μmol·L-1)对激酶AKT1的抑制率大于60%。     

Recent developments in the synthesis of acetylcholinesterase inhibitors

The acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activities of a series of pyrano[2,3-b]quinolines (2, 3), [1,8]naphthyridines (5, 6), 4-amino-2,3-diaryl-5,6,7,8-tetrahydrofuro[2,3-b]quinolines (11-13)/ 4-amino-6,7,8,9-tetrahydro-2,3-diphenyl-5H-cyclohepta[e]furo[2,3-b]pyridine (14), 4-amino-5,6,7,8-tetrahydro-2,3-diphenylthieno[2,3-b]quinoline (15)/ 4-amino-6,7,8,9-tetrahydro-2,3-diphenyl-5H-cyclohepta[e]thieno[2,3-b]pyridine (16) are described. These compounds are tacrine analogues that have been prepared from readily available polyfunctionalized ethyl [6-amino-5-cyano-4H-pyran]-3-carboxylates (9, 10), ethyl [6-amino-5-cyanopyridine]-3-carboxylates (7, 8), 2-amino-3-cyano-4,5-diarylfurans (17-19) and 2-amino-3-cyano-4,5-diphenylthiophene (20) via Friedl?nder condensation with selected ketones. These compounds are competitive and, in a few cases, non-competitive inhibitors for AChE, the most potent being compound (14), though three-fold less active than tacrine. The BuChE inhibitory activity is only significant in compounds 11 and 14, ten-fold less active than tacrine. Furthermore, the products 12 and 13 are selective and moderate AChE inhibitors.