具有四氢苯并[4,5]咪唑并[1,2-a]吡嗪骨架凝血酶抑制剂的设计合成及生物活性研究

以具有四氢苯并[4,5]咪唑并[1,2-a]吡嗪新骨架的凝血酶抑制剂1为先导化合物,设计合成了14个氨基甲酸酯衍生物(2a~6a,2b~6b和7~10).同时,在化合物1结构的基础上,引入具有抗血栓活性的川芎醇(HTMP),设计合成了新型结构的化合物11.目标化合物的结构均经1H NMR,13C NMR和HRMS确证.生物活性测试结果显示,所有目标化合物对凝血酶诱导的血小板聚集均有一定的抑制活性,其中化合物4b的抑制活性[IC50=(0.11±0.08)μmol/L]强于对照药达比加群酯[IC50=(0.60±0.05)μmol/L].在体内抗血栓活性测试中,化合物4b能以剂量依赖的方式减少大鼠静脉血栓的形成.化合物11对凝血酶诱导的血小板聚集的抑制活性较弱,但其抑制大鼠静脉血栓形成的作用与达比加群酯相当,这可能是由于化合物11在体内水解为川芎醇和化合物1,两者协同产生抗血栓作用所致.     

Design and synthesis of sulfur based inhibitors of matrix metalloproteinase-1

Fibroblast collagenase (MMP-1), a member of the matrix metalloproteinases family, is believed to be a pathogenesis of arthritis, by cleaving triple-helical type II collagen in cartilage. From the similarity of the active site zinc binding mode with hydroxamate, we designed and synthesized alpha-mercaptocarbonyl possessing compounds (3-5), which incorporated various peptide sequences as enzyme recognition sites. The P4-P1 peptide incorporating compound (3) exhibited as potent inhibition as the hydroxamate (1) and the carboxylate (2) type inhibitors, with an IC50 of 10(-6) M order against MMP-1. But the inhibitor (3) related compounds (6-8) displayed decreased or no inhibitory potencies. These results suggest that the existence of both the carbonyl and thiol groups might be critical for the inhibition, and the distance between the two functional groups is important for inhibitory potency. For Pn' peptide incorporating compounds (4a-k), except for 4h and 4k, all compounds showed IC50 values under sub-nanomolar. Among them, for potent inhibition, Leu was better than Phe and Val as the P1' amino acid, and the P2' position amino acid was necessary, and preferentially Phe. Insertion of the Pn peptide into 4d or 4k, giving compounds 5a-c, did not increase the activities of 4d and 4k. Substitution of the mercapto group with other functional groups lost the activity of compound 4a. The stereochemical preference at the thiol-attached position was also determined by preparation of both isomers of 4a. It was found that the S configuration compound (36b) is approximately 100 times more potent than the corresponding R-isomer (36a).     

Discovery of Novel Boron-Containing N-Substituted Oseltamivir Derivatives as Anti-Influenza A Virus Agents for Overcoming N1-H274Y Oseltamivir-Resistant

To address drug resistance to influenza virus neuraminidase inhibitors (NAIs), a series of novel boron-containing N-substituted oseltamivir derivatives were designed and synthesized to target the 150-cavity of neuraminidase (NA). In NA inhibitory assays, it was found that most of the new compounds exhibited moderate inhibitory potency against the wild-type NAs. Among them, compound 2c bearing 4-(3-boronic acid benzyloxy)benzyl group displayed weaker or slightly improved activities against group-1 NAs (H1N1, H5N1, H5N8 and H5N1-H274Y) compared to that of oseltamivir carboxylate (OSC). Encouragingly, 2c showed 4.6 times greater activity than OSC toward H5N1-H274Y NA. Moreover, 2c exerted equivalent or more potent antiviral activities than OSC against H1N1, H5N1 and H5N8. Additionally, 2c demonstrated low cytotoxicity in vitro and no acute toxicity at the dose of 1000 mg/kg in mice. Molecular docking of 2c was employed to provide a possible explanation for the improved anti-H274Y NA activity, which may be due to the formation of key additional hydrogen bonds with surrounding amino acid residues, such as Arg152, Gln136 and Val149. Taken together, 2c appeared to be a promising lead compound for further optimization.     

A mechanism-based 3D-QSAR approach for classification and prediction of acetylcholinesterase inhibitory potency of organophosphate and carbamate analogs

Organophosphate (OP) and carbamate esters can inhibit acetylcholinesterase (AChE) by binding covalently to a serine residue in the enzyme active site, and their inhibitory potency depends largely on affinity for the enzyme and the reactivity of the ester. Despite this understanding, there has been no mechanism-based in silico approach for classification and prediction of the inhibitory potency of ether OPs or carbamates. This prompted us to develop a three dimensional prediction framework for OPs, carbamates, and their analogs. Inhibitory structures of a compound that can form the covalent bond were identified through analysis of docked conformations of the compound and its metabolites. Inhibitory potencies of the selected structures were then predicted using a previously developed three dimensional quantitative structure-active relationship. This approach was validated with a large number of structurally diverse OP and carbamate compounds encompassing widely used insecticides and structural analogs including OP flame retardants and thio- and dithiocarbamate pesticides. The modeling revealed that: (1) in addition to classical OP metabolic activation, the toxicity of carbamate compounds can be dependent on biotransformation, (2) OP and carbamate analogs such as OP flame retardants and thiocarbamate herbicides can act as AChEI, (3) hydrogen bonds at the oxyanion hole is critical for AChE inhibition through the covalent bond, and (4) π–π interaction with Trp86 is necessary for strong inhibition of AChE. Our combined computation approach provided detailed understanding of the mechanism of action of OP and carbamate compounds and may be useful for screening a diversity of chemical structures for AChE inhibitory potency.     

Synthesis of a non-hydrolyzable estrone sulfate analogue bearing the difluoromethanesulfonamide group and its evaluation as a steroid sulfatase inhibitor

Steroid sulfatase (STS) catalyzes the hydrolyis of steroidal sulfates such as estrone sulfate (ES1) and is considered to be an attractive target in the treatment of steroid dependent cancers. A non-hydrolyzable estrone sulfate (ES1) analogue bearing an alpha,alpha-difluorosulfonamide moiety at the 3-position on the A-ring, compound , was synthesized. Key to the success of this synthesis was the first use of the allyl group as a sulfonamide protecting group. The pK(a) of this ES1 mimic in 0.1 M bis-tris propane, 10% DMSO was determined to be 8.05 using 19F NMR. Compound is a reversible inhibitor with a K(i) similar to that of its sulfonate analogue at pH 7.0. It is more potent than its non-fluorinated sulfonamide analogue and, its inhibitory potency increases with increasing pH, a trend opposite to that of other STS inhibitors. Possible reasons for this are presented.     

Synthesis of novel pyrido[3′,2′:4,5]thieno[3,2‐d]pyrimidines,pyrido[3″,2″:4′,5′]thieno[3′,2′:4,5]pyrimido[l,6‐a]benzimidazoles and related fused systems

3‐Amino‐4‐aryl‐5‐ethoxycarbonyl‐6‐methylthieno[2,3‐b]pyridine‐2‐carboxamides 3a‐c were prepared from ethyl 4‐aryl‐3‐cyano‐6‐methyl‐2‐thioxo‐1,2‐dihydropyridine‐5‐carbonylates 1a‐c and reacted with some carbonyl compounds to give tetrahydropyridothienopyrimidine derivatives 6a‐c, 7a‐c and 8a‐c , respectively. Treatment of compound 3c with chloroacetyl chloride led to the formation of a next key compound, ethyl 2‐chloromethyl‐4‐oxo‐3,4‐dihydropyrido[3′,2′:4,5]thieno[3,2‐d]pyrimidine‐8‐carboxylate 9 . Also, 3‐amino‐2‐benzimidazolylthieno[2,3‐b]pyridine‐5‐carboxylate 5 and 2‐(3′‐aminothieno [2,3‐b]pyridin‐2′‐yl)‐4‐oxo‐3,4‐dihydropyrido[3′,2′:4,5]thieno[3,2‐d]pyrimidine‐8‐carboxylate 17 were prepared from 1c. The compounds 5, 9 and 17 were used as good synthons for other pyridothienopyrimidines and pyridothienopyrimidobenzimidazoles as well as for related fused polyheterocyclic systems.     

Synthesis of Certain Fused Thienopyrimidines of Biological Interest

4‐(4‐Acetylphenylamino)cycloocteno[4,5]thieno[2,3‐d]pyrimidine ( 4 ) was prepared and condensed with certain aldehydes, phenylhydrazine, malononitrile to obtain 5a‐d , 6 and 7 , respectively. 4‐Hydrazino & 4‐substituted amino derivatives of 2‐arylcycloocteno[4,5]thienopyrimidines 10a‐c & 11a‐i were synthesized. Cyclization of the hydrazino compounds 10a‐c with orthoalkanoate esters or the arylidene derivatives 12a‐c with bromine in acetic acid afforded the fused triazolo system 13a‐i . Reaction of the hydrazino compound 10c with acetic anhydride gave 15 while the reaction of 10b,c with acid chlorides gave 16a‐d . Furthermore, the tetrazolothienopyrimidines 17a‐c were synthesized. Some of the newly synthesized compounds were tested for their antimicrobial activity.     

Unexpected formation of an azetidine-carborane derivative by dehydration of N-(1,12-dicarba-closo-dodecaboran-1-yl)formamide. The first X-ray structure of a 2,3-bis(imino)azetidine

Efforts to dehydrate (1,12-dicarba-closo-dodecaboran(12)-1-yl)formamide (a = 6.685(2) A, b = 12.877(4) A, c = 12.547(4) A, alpha = gamma = 90 degrees, beta = 90.724(11) degrees, V = 1080.8(6) A(3), Z = 4) resulted in the formation of a series of unexpected products. Addition of the Burgess reagent to the formamide, for example, led to the isolation of the corresponding methyl carbamate (a = 11.529(8) A, b = 11.529(8) A, c = 11.402(12) A, alpha = beta = gamma = 90 degrees, V = 1516(2) A(3), Z = 4), while treatment with triphosgene, a well-known dehydrating agent, resulted in the formation of a highly unusual 2,3-bis(p-carboranylimino)azetidine derivative. This particular compound, in the presence of Re(I), was hydrolyzed to give the corresponding amide, which is the first example of a 2,3-bis(imino)azetidine that has been characterized crystallographically (a = 38.496(13) A, b = 11.920(4) A, c = 27.523(10) A, beta = 127.050(5) degrees, V = 10079(6) A(3), Z = 8).     

An efficient synthesis of a probe for protein function: 2,3-diaminopropionic acid with orthogonal protecting groups

[reaction: see text] An efficient and cost-effective synthesis of N(alpha)-Boc2-N(beta)-Cbz-2,3-diaminopropionic acid is reported. The synthesis starts from commercially available N(alpha)-Boc-Asp(OBn)-OH and employs a Curtius rearrangement to establish the beta-nitrogen. Proper protection of the alpha-nitrogen is essential for the success of the Curtius rearrangement.     

A peptide hydroxamate library for enrichment of metalloproteinases: towards an affinity-based metalloproteinase profiling protocol

A compound library of 96 enantiopure N-terminal succinyl hydroxamate functionalized peptides was synthesized on solid phase. All compounds were tested for their inhibitory potential towards MMP-9, MMP-12 and ADAM-17, which led to the identification of both broad spectrum inhibitors and metalloproteinase-selective ones. Eight potent and less potent inhibitors were immobilized on Sepharose beads and evaluated in solid-phase enrichment of active MMP-9, MMP-12 and ADAM-17. In addition, one of these inhibitors was used for solid-phase enrichment of endogenous ADAM-17 from a complex proteome (a lysate prepared from cultured A549 cells).     

Synthesis of 3,4-Biheterylthieno[2,3-b]-thiophenes. Part I: Synthesis of 3,4-Bi(1′,3′,4′-thiadiazolyl-, s-triazolyl-,1′,3′,4′-thiadiazinyl-, 1′,3′,4′-triazinyl-, thiazolyl-, 1′,3′-thiazinyl- and primidinyl)-thieno[2,3-b]thiophenes

3,4-Diamino-2,5-dicarbethoxythieno[2,3-b]thiophene ( 1 ) was allowed to react with NaNO 2 and active methylenes to afford the corresponding azo compounds 2a-c . Hydrazonyl chloride 2a was treated with carbon disulfide, phenyl isothiocyanate, benzonitrile, benzyl cyanide, malononitrile, benzalaniline, ethyl mercaptoacetate, and ethyl glycinate to give 1,3,4-thiadiazolyl-, s-triazolyl-, 1,3,4-thiadiazinyl-, 1,3,4-triazinylthieno[2,3-b]thiophenes 3-6 respectively. The reaction of 2b,c with urea, thiourea, and guanidine afforded pyrimidinyl- and thiazinylazothieno [2,3-b]thiophenes 7-10 respectively. Bithiazolylthieno[2,3-b]thiophenes 11 and 13 were synthesized by treating compound 1 with CS 2 along with halo compounds. The addition of S,S-, N,S-, and N,O-acetals to the Schiff base 14 afforded compounds 15-17 respectively.     

Antimicrobial Properties of Some New Synthesized Benzothiazole Linked Carboxamide,Acetohydrazide, and Sulfonamide Systems

We report herein the interaction of diethylethoxymethylene malonate ( 1 ) with 2‐cyanomethylbenzothiazole ( 7 ) to give diethyl 2‐(2‐benzothiazole‐2‐(3H)‐ylidiene)‐2‐(cyano ethyl) malonate ( 8a ) in excellent yield. Ethyl 4‐cyano‐1‐oxo‐1H‐benzo[4,5]thiazolo[3,2‐a]pyridine‐2‐carboxylate (9) was synthesized from 8a and subjected to react with hydrazine hydrate to give its corresponding acid hydrazide 10 . Condensation of 10 with different acid anhydrides afforded the corresponding benzothiazolo pyridine carboxamide derivatives 11 – 15 . In addition, we report a simple synthesis of N′‐(benzo[d]thiazol‐2‐yl)‐2‐((4‐ayl)amino)acetohydrazide derivative ( 17 ), which then reacted with different amines to give the corresponding acetohydrazide derivatives 19a – c . Moreover, compound 17 reacted with some sulfonamide derivatives to give the corresponding sulfonamide derivatives 20 and 22a , b .The newly synthesized compounds were established their structures on the bases of their correct analytical and spectral data and evaluated their antimicrobial activity. It was found that compounds 22a , b displayed the highest antimicrobial activity against the tested organisms.     

The synthesis of new 2,4‐diaminofuro[2,3‐d]pyrimidines with 5‐biphenyl,phenoxyphenyl and tricyclic substitutions as dihydrofolate reductase inhibitors

Nonclassical 2,4‐diamino‐5‐substituted furo[2,3‐d]pyrimidines 4a‐i, 5a‐b and 7a‐f were synthesized as extended aromatic ring appended analogs of previously reported antifolates 1a‐b. The extended aromatic system was designed to better interact with a phenylalanine residue (Phe69) of dihydrofolate reductase from the opportunistic pathogen Pneumocystis carinii to afford potent and selective inhibitors of Pneumocystis carinii dihydrofolate reductase. The target compounds were synthesized by nucleophilic displacement of 2,4‐diamino‐5‐(chloromethyl)furo[2,3‐d]pyrimidine 3 with the appropriate aromatic amine or thiol. The compounds were evaluated as inhibitors of dihydrofolate reductase from Pneumocystis carinii and Toxoplasma gondii, and their selectivity was determined using rat liver dihydrofolate reductase as the mammalian reference. In the C8‐N9 bridged series, compound 4e , with a 3‐(2‐methoxydibenzofuran)‐ side chain, exhibited greatest potency and was more than 3 times as selective for Pneumocystis carinii dihydrofolate reductase compared to rat liver dihydrofolate reductase. Compounds 4b and 4c also exhibited selectivity. Compounds in the C8‐S9 bridged series showed comparable potencies, and each showed higher selectivity for Pneumocystis carinii dihydrofolate reductase compared to rat liver dihydrofolate reductase.     

Synthesis and aldose reductase-inhibitory activity of benzo[b]furan derivatives possessing a carboxymethylsulfamoyl group

Various benzo[b]furan derivatives with a carboxymethylsulfamoyl group were prepared and evaluated for aldose reductase-inhibitory potency. Most of the compounds displayed significant inhibitory activities (IC50, 10(-8)-10(-7) M). Among the test compounds, the compounds having a carboxymethylsulfamoyl group at the 3- or 4-position exhibited the greatest inhibitory potency. Structure-activity trends of the tested compounds are discussed.     

Synthetic approaches to bridgehead nitrogen methanesulfonamide derivatives of 3‐amino‐2‐thioxo‐2,3‐dihydrothieno[2,3‐d]pyrimidin‐4(1H)‐ones,potential cox‐2 selective inhibitors

Methane sulfonamide derivatives of 3‐amino‐2‐thioxo‐2,3‐dihydrothieno[2,3‐d]pyimidin‐4(1H)‐one, potential selective COX‐2 inhibitors, were synthesized and their structural elucidation is here reported. Some derivatives, at 10 μM concentration, showed a significant percentage of inhibition in some in vitro experiments.     

Inhibition of Insulin-Regulated Aminopeptidase (IRAP) by Arylsulfonamides

The inhibition of insulin-regulated aminopeptidase (IRAP, EC 3.4.11.3) by angiotenesin IV is known to improve memory and learning in rats. Screening 10 500 low-molecular-weight compounds in an enzyme inhibition assay with IRAP from Chinese Hamster Ovary (CHO) cells provided an arylsulfonamide (N-(3-(1H-tetrazol-5-yl)phenyl)-4-bromo-5-chlorothiophene-2-sulfonamide), comprising a tetrazole in the meta position of the aromatic ring, as a hit. Analogues of this hit were synthesized, and their inhibitory capacities were determined. A small structure–activity relationship study revealed that the sulfonamide function and the tetrazole ring are crucial for IRAP inhibition. The inhibitors exhibited a moderate inhibitory potency with an IC₅₀=1.1±0.5 μm for the best inhibitor in the series. Further optimization of this new class of IRAP inhibitors is required to make them attractive as research tools and as potential cognitive enhancers.     

Determination of Neurotoxin b-ODAP and Non-protein Amino Acids in Lathyrus Sativus by High-Performance Liquid Chromatography with Precolumn Derivatization with 6-Amino quinolyl-N-hydroxysuccinimidyl Carbamate (AQC)

A new method was developed for the quantitative determination of the neurotoxic non-protein amino acid, 3-N-oxalyl-L-2,3-diaminopropionic acid (b -ODAP), its nontoxic a -isomer and other non-protein amino acids in the plant samples of Lathyrus sativus after derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) by reversed-phase high-performance liquid chromatography (HPLC). 2-Amino butyric acid (ABA) was used as an internal standard. The RP HPLC detection limit for both isomers is 1.8 ng with good response linearity. The results are compared with a colorimetric method.     

Design,Synthesis, and Biological Evaluation of Some Cyclohepta[b]Thiophene and Substituted Pentahydrocycloheptathieno[2,3‐d]Pyrimidine Derivatives

This investigation describes the design of a series of cycloheptathieno[2,3‐d]pyrimidines along with their synthetic strategy. The target compounds were screened for their PARP‐1 inhibitory activity. The modeling study declared that most of the docked compounds showed the same interactions as 3‐aminobenzamide, where Gly 894, His 862, Tyr 896, Arg 878, and Ser 864 were the main residues involved in hydrogen bond formation. Compounds eliciting the top ranked docking results were screened for their PARP‐1 inhibitory activity giving promising results, and three representative compounds were tested for their cytotoxic activity using Doxorubicin as a reference standard. The target compounds 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 including cyclohepta[b]thiophene and pentahydrocycloheptathieno[2,3‐d]pyrimidine cores were designed, prepared, and tested for their PARP‐1 inhibitory activity. Compounds 16 (R: ―NHC(S)NH2) and 11 (R: ―CS) were the most potent ones.     

Synthesis and aldose reductase inhibitory activity of triazine derivatives possessing acetic acid group.

N-Acetic acid derivatives of 6-aryl-pyrazolo-triazin-4-ones were synthesized for evaluation as new aldose reductase inhibitors. The intrinsic activity of each compound was assessed by measuring the inhibition of enzymatic activity in an isolated pig lens enzyme preparation. All the prepared compounds exhibited a significant in vitro aldose reductase inhibitory effect (10(-6) M less than or equal to IC50 less than or equal to 10(-4) M). Furthermore, biological activity (log 1/IC50) for most of the data sets could be correlated directly to electronic and steric parameters. Finally, spatial configuration of the most active derivative 6c (IC50 = 2 x 10(-6) M) was compared with that of tolrestat and with pharmacophor requirements of the aldose reductase inhibitor site using a molecular modeling system.     

Design and Synthesis of Pyrido[1,2-e]purin-4（3H）-one Derivatives as Potential PDE 5 Inhibitors

A novel series of pyrido[ 1,2-e]purin-4（3H）-one derivatives containing polar substituents on 5＇-position were designed and prepared as potential PDE5 inhibitors. This paper reports the synthetic routes, 1H-NMR data, and the PDE5 inhibitory activities of the target compounds. The polar piperazinyl group contained （on 5＇-position） compound, 3B2, showed the highest activity among the tested derivatives but less potency than sildenafil 1.