Thienopyrimidine Derivatives Research Articles

Synthesis, Characterization and Cytotoxicity of Substituted [1]Benzothieno[3,2-e][1,2,4]triazolo [4,3-a]pyrimidines.

A new series of 4-benzyl-6,7,8,9-tetrahydro[1]benzothieno[3,2-e][1,2,4]triazolo[4,3-a]pyrimidines was synthesized motivated by the widely reported anticancer activity of thieno[2,3-d]pyrimidines and triazolothienopyrimidines. The in vitro cytotoxic activity of some selected compounds was evaluated against two human cell lines: prostate cancer (PC-3) and colon cancer (HCT-116). A preliminary study of the structure-activity relationship of the target compounds was discussed. Most of the synthesized compounds showed remarkable activity on the tested cell lines, while compound 16c had the highest potency against the PC-3 cell line with an IC50 of 5.48 μM compared to Doxorubicin (IC50 = 7.7 μM), the reference standard used in this study. On the other hand, 6c and 18c were the most active against HCT-116 (IC50 = 6.12 and 6.56 μM, respectively) relative to IC50 = 15.82 μM of the standard. Thus, some of the synthesized thienopyrimidine derivatives, specially 6c, 16c and 18c, have the potential to be developed into potent anticancer agents.

The stimulating effect of thienopyrimidines structurally similar to Org 43553 on adenylate cyclase activity in the testes and on testosterone production in male rats

The functional activity of the luteinizing hormone (LH) receptor can be regulated not only by gonadotropins, but also by its low molecular weight agonists, which, in contrast to gonadotropins, bind to the allosteric site located in the transmembrane channel of the receptor. The most promising low molecular weight agonists are thienopyrimidine derivatives, which are structural analogs of the Org 43553 compound. The purpose of this work was to synthesize novel thienopyrimidine derivatives—5-amino-N-(tert-butyl)-4-(3-(2-methoxynicotinamido)-phenyl)-2-(methylthio)thieno[2,3-d]pyrimidine-6-carboxamide (TP-21), 4-((3-(5-amino-6-(tert-butylcarbamoyl)-2-(methylthio)thieno[2,3-d]pyrimidine-4-yl)phenyl)carbamoyl)pyridine 1-oxide (TP-22), and 5-amino-N-(tert-butyl)-4-(3-(2-chloroxynicotinamido)phenyl)-2-(methylthio)thieno[2,3-d]pyrimidine-6-carboxamide (TP-23)—and to investigate their effects on adenylate cyclase (AC) activity in rat testicular membranes in vitro and on testosterone levels in male rats following intratesticular or intraperitoneal administration in vivo. Compounds TP-21, TP-22, and TP-23 stimulated basal AC activity in rat testicular membranes with EC50 values of 1556, 358, and 372 nM; their efficiency was ordered as follows: TP-23 > TP-21 ≈ TP-22. When thienopyrimidines (10–4 M) were applied in combination with human chorionic gonadotropin (HCG, 10–8 M), the AC-stimulating effect of HCG was maintained, and, at an HCG concentration of 10–10 M, the effects of thienopyrimidines and HCG on AC activity were additive. Intratesticular administration of 10 mg/kg TP-21, TP-22, and TP-23 increased testosterone levels in male rats: in 5 h after treatment, its levels were 32.8, 36.4, and 76.9 nM, respectively, higher than in the control group. Following intraperitoneal administration, TP-21 and TP-22 had little effect on testosterone levels, while TP-23 induced a significant increase in testosterone levels (by 34.8 and 18.9 nM in comparison to control in 1 and 3 h, respectively). These data suggest that compound TP-23 is an active stimulator of testosterone synthesis and secretion and represents a promising basis for development of highly efficient LH receptor agonists.

Anti-inflammatory, analgesic and COX-2 inhibitory activity of novel thiadiazoles in irradiated rats

In this work, novel series of pyran, thiophene and thienopyrimidine derivatives based on 2-acetamide-thiadiazole scaffold were designed and synthesized for evaluation as selective COX-2 inhibitors in-vitro and investigated in-vivo as anti-inflammatory and analgesic agents against carrageenan-induced rat paw oedema model in irradiated rats, since its well-known that ionizing radiation plays an important role in exaggerating the inflammatory responses and in enhancing the release of inflammatory mediators in experimental animals. Toxicological studies were carried out to evaluate the ulcerogenic activity, acute toxicity and kidney and liver functions for the most potent compounds. In order to understand the binding mode of the synthesized compounds into the active site of COX-2, docking study was performed. Most of the tested compounds showed high inhibitory ability to COX-2. Among them, thiadiazole derivatives bearing thiophene and thienopyrimidine moieties were the most active derivatives, compound 26 showed extremely high selectivity index (SI) of >555.5μM which is nearly two folds better than celecoxib (>277.7μM), in addition to compounds 3, 16, 17, 21 and 26 with SI in the range of >308.6- >384.6μM. The 4-chlorothieno[2.3-d]pyrimidine derivative of thiadiazole 21 showed the highest anti-inflammatory activity in this study having 24.49% of oedema compared to celecoxib (18.61%) in addition to compounds 17 and 26 with 24.70 and 25.40% of oedema, respectively, while the thiadiazol-2-acetamide derivative 2 was the most potent analgesic compound with the highest nociceptive threshold (85.72g) very close to that of celecoxib (90.23g). These compounds showed high safety margin on gastric mucosa with no ulceration effect. Also the most active in-vivo anti-inflammatory compounds 17, 21 and 26 were found to be non-toxic in experimental rats with normal kidney and liver functions. Docking study of the synthesized compounds showed similar orientation as celecoxib within the active site of COX-2 enzyme and similar ability to emerge deeply in the additional pocket and binding with Arg513 and His90 the key amino acids responsible for selectivity.

In vitro and in vivo studies of functional activity of new low molecular weight agonists of the luteinizing hormone receptor

The use of luteinizing hormone (LH) and its structural and functional homolog human chorionic gonadotropin (hCG) leads to hyperstimulation of LH-dependent signalling pathways and to desensitization of LH receptors. Therefore, the development of low molecular weight agonists of the LH receptor without these disadvantages has been carried out in recent years. These agonists, unlike gonadotropins, are active when administered orally. The greatest prospects are associated with the development of the thienopyrimidine derivatives structurally similar to compound Org 43553. The purpose of this work was the synthesis of new thienopyrimidine derivatives TP03 and TP04, the study of the regulation of LH-sensitive adenylyl cyclase signalling system in rat testes, and the evaluation of the ability of TP03 and TP04 to stimulate testosterone synthesis in male rats at different routes of administration. In the concentration range 10–7–10–3 M, TP03 and TP04 induced an increase of the basal adenylyl cyclase (AC) activity in rat testicular membranes with the EC50 values of 390 and 759 nM, respectively. At a concentration of 10–4 M, AC-stimulating effects of TP03 and TP04 were 213 and 122%, respectively, which indicates a higher activity of TP03 under in vitro conditions. At the same time, the AC-stimulating effect of TP03 was approximately 2.5-fold weaker than that of hCG (10–8 M). Upon simultaneous administration of hCG and thienopyrimidine derivatives, their stimulating effects on the AC activity were additive due to the different localization of their binding sites in the LH receptor. Compound TP03 (25 mg/kg), when administered intraperitoneally to male rats, was more efficient than TP04: the maximal increase in the testosterone level (3 h after administration) was by 60% higher than that induced by TP04. TP03 increased the testosterone level after oral administration (50 mg/kg) as well, but the effect was weaker than in the case of the intraperitoneal injection. Orally administered TP04 exhibited a low activity. The results suggest that 5-amino-N-tert-butyl-2-(methylsulfonyl)-4-(3-(nicotinamide)phenyl) thieno[2,3-d]pyrimidine-6-carboxamide (TP03) can be used for the development of the drugs that stimulate steroidogenesis in Leydig cells.

Computer-aided identification, synthesis and evaluation of substituted thienopyrimidines as novel inhibitors of HCV replication

A structure-based virtual screening technique was applied to the study of the HCV NS3 helicase, with the aim to find novel inhibitors of the HCV replication. A library of ∼450000 commercially available compounds was analysed in silico and 21 structures were selected for biological evaluation in the HCV replicon assay. One hit characterized by a substituted thieno-pyrimidine scaffold was found to inhibit the viral replication with an EC50 value in the sub-micromolar range and a good selectivity index. Different series of novel thieno-pyrimidine derivatives were designed and synthesised; several new structures showed antiviral activity in the low or sub-micromolar range.

Synthesis and Reaction of Some New Thienopyridine and Thienopyrimidine Derivatives

Synthesis and Reaction of Some New Thienopyridine and Thienopyrimidine Derivatives

Synthesis and Reaction of Some New Thienopyridine and Thienopyrimidine Derivatives

Synthesis and Reaction of Some New Thienopyridine and Thienopyrimidine Derivatives

Synthesis and biological evaluation of di-aryl urea derivatives as c-Kit inhibitors

Inhibition of receptor tyrosine kinases (RTKs) continued to be a successful approach for the treatment of many types of human cancers and many potent small molecules kinase inhibitors have been discovered the last decade. In the present study, we describe the synthesis of thienopyrimidine derivatives and their pharmacological evaluation against nine kinases (EGFR, PDGFR-ß, c-Kit, c-Met, Src, Raf, VEGFR-1, -2 and -3). Most of the synthesized compounds showed from moderate to potent activities against c-Kit with IC50 values in the nanomolar range. Among them, 4-anilino(urea)thienopyrimidine analogs showed selectivity and potent c-Kit inhibition with IC50 values less than 6nM. Docking simulation was performed for the most promising compound 9 into the c-Kit active site to determine the potential binding mode. This study reveal that the 4-anilino(urea)thienopyrimidine is an interesting scaffold to design novel potent and selective c-Kit inhibitors which may make promising candidates for cancers where c-Kit receptors are overexpressed.

Selective and Orally Bioavailable CHK1 Inhibitors of Some Synthesized Substituted Thieno[2,3-b]pyridine Candidates

A series of the newly substituted thienopyrimidine derivatives 2-13 were synthesized by using 3-amino-6-(4-chlorophenyl)-4-(4-isopropylphenyl) thieno[2,3-b]pyridine-2-carbohydrazide 1 as starting material. Reaction of compound 1 with p-nitrobenzaldehyde in refluxing ethanol afforded the corresponding Shiff base 2, which was cyclized with triethyl orthoformate to give thienopyrimidine derivative 3. Compound 1 was treated with formic acid or acetic anhydride to afford the corresponding thienopyrimidines 4 and 5, respectively. Treatment of 1 with acetylacetone afforded pyrazolothienopyrimidine 6. Treatment of 1 with triethyl orthoformate, carbon disulfide, dimethylformamide and ethyl acetoacetate or diethyl malonate gave compounds 7-11, respectively. Cyclization of 1 with m-nitrophthalic anhydride or formaldehyde afforded thienopyrimidines 12 and 13, respectively. The newly synthesized compounds were found to be potent selective and orally bioavailable CHK1 inhibitors. This elucidated and confirmed via determination of checkpoint abrogation, antiproliferative activity and potentiation of genotoxic drug efficacy in cancer cell lines and also determination of compound concentrations in vivo at selected time points following i.v. and oral dosing.

3D-QSAR (CoMFA, CoMFA-RG, CoMSIA) and molecular docking study of thienopyrimidine and thienopyridine derivatives to explore structural requirements for aurora-B kinase inhibition

Aurora-B kinase plays a crucial role in cell cycle events and is identified as an important factor in regulation of spindle check point assembly. Thus, it can be proved as an important target in the field of oncology. 3D-QSAR model was generated using 54 molecules reported in literature containing thienopyrimidine and thienopyridine as scaffolds. All molecules were aligned using Distill function in Sybyl X1.2. This generated best model of CoMFA-RG (Region focusing) and CoMSIA were statistically significant with correlation coefficient r2ncv of 0.97, for both & Leave one out coefficient (LOO) q2 of 0.70 and 0.72, respectively. Best CoMSIA model was built up using various combination of descriptors and proved statistical significant among all models. Best CoMFA-RG and CoMSIA models were validated by 12 test set molecules giving satisfactory prediction (r2pred) values of 0.86 and 0.88, respectively. External test set validation was performed using 20 molecules and satisfactory prediction of their biological activity was found. Active compounds were docked on protein (PDB ID: 4C2V) by GOLD module and revealed important interactions with amino acids at ATP-binding region. These data explored insight requirements for Aurora-B inhibition which might be fruitful for understanding mechanisms with kinase ligand interactions.

Identification of a thienopyrimidine derivatives target by a kinome and chemical biology approach.

Target identification through chemical biology has been considered one of the most efficient approaches for drug discovery. Thienopyrimidine derivatives were designed to discover potent IκB kinase β (IKKβ) inhibitors based on a known IKKβ inhibitor library. Most of the thienopyrimidine derivatives inhibited nitric oxide and tumor necrosis factor alpha, which are downstream of the NF-κB signaling pathway, but not IKKβ. To identify the appropriate targets of thienopyrimidine analogues, chemical biology approaches, including text mining and a subsequent kinase panel assay from the kinome profiling were used. Based on the results, Fms-like tyrosine kinase 3 was found to be the target for thienopyrimidine derivatives, and was confirmed to be a potent inhibitor for acute myeloid leukemia.

ChemInform Abstract: Serendipitous Discovery of 2‐((Phenylsulfonyl)methyl)‐thieno[3,2‐d]pyrimidine Derivatives as Novel HIV‐1 Replication Inhibitors.

AbstractNew thienopyrimidine derivatives (IIa) and (IIb) exhibit significant inhibitory activities against HIV‐1 replication.

Thienopyrimidines - the new class of low molecular weight regulators of the female reproductive system

The authors analyse the original and literature data concerning thienopyrimidine derivatives showing the activity of luteinizing hormone (LH) receptor agonists. These compounds are known to specifically interact with the allosteric site of LH receptors localized in the transmembrane channels and activate the LH-sensitive adenylate cyclase signal system. The thienopyrimidine derivatives were shown to stimulate steroidogenesis and ovulation both in vitro and in vivo by acting on the cells that have not only normal but also mutant receptors. The thienopyrimidine derivatives are believed to be efficacious inducers of ovulation in the women.

Discovery of a Novel Series of Thienopyrimidine as Highly Potent and Selective PI3K Inhibitors.

Inhibition of the phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway provides a promising new approach for cancer therapy. Through a rational design, a novel series of thienopyrimidine was discovered as highly potent and selective PI3K inhibitors. These thienopyrimidine derivatives were demonstrated to bear nanomolar PI3Kα inhibitory potency with over 100-fold selectivity against mTOR kinase. The lead compounds 6g and 6k showed good developability profiles in cell-based proliferation and ADME assays. In this communication, their design, synthesis, structure-activity relationship, selectivity, and some developability properties are described.

Design, synthesis and docking studies of novel thienopyrimidine derivatives bearing chromone moiety as mTOR/PI3Kα inhibitors

Two series of thienopyrimidine derivatives (10a–k, 16a–j) bearing chromone moiety were designed and synthesized. All the compounds were evaluated for inhibitory activity against mTOR kinase at a concentration of 10uM. Four selected compounds were further evaluated for the IC50 values against mTOR kinase, PI3Kα kinase and two cancer cell lines. Some of the target compounds exhibited moderate to excellent mTOR/PI3Kα kinase inhibitory activity and cytotoxicity. The most promising compound 16i showed good inhibitory activity against mTOR/PI3Kα kinase and good antitumor potency for H460 and PC-3 cell lines with IC50 values of 0.16 ± 0.03 μM, 2.35 ± 0.19 μM, 1.20 ± 0.23 μM and 0.85 ± 0.04 μM, which were 8.6, >5, 7.9 and 19.1 times more active than compound I (1.37 ± 0.07 μM, >10 μM, 9.52 ± 0.29 μM, 16.27 ± 0.54 μM), respectively. Structure–activity relationships (SARs) and docking studies indicated that the chromone moiety is necessary for the potent antitumor activity and cytotoxicity of these compounds. Substitution of the chromone moiety at the 6-position has a significant impact to the inhibitory activity, in particular a carboxylic acid group, produced the best potency.

Discovery of New Uncompetitive Inhibitors of Glucose-6-Phosphate Dehydrogenase

The enzyme glucose-6-phosphate dehydrogenase (G6PDH) catalyzes the first step of the oxidative branch of the pentose phosphate pathway, which provides cells with NADPH, an essential cofactor for many biosynthetic pathways and antioxidizing enzymes. In Trypanosoma cruzi, the G6PDH has being pursued as a relevant target for the development of new drugs against Chagas disease. At present, the best characterized inhibitors of T. cruzi G6PDH are steroidal halogenated compounds derivatives from the mammalian hormone precursor dehydroepiandrosterone, which indeed are also good inhibitors of the human homologue enzyme. The lack of target selectivity might result in hemolytic side effects due to partial inhibition of human G6PDH in red blood cells. Moreover, the treatment of Chagas patients with steroidal drugs might also cause undesired androgenic side effects. Aiming to identify of new chemical classes of T. cruzi G6PDH inhibitors, we performed a target-based high-throughput screen campaign against a commercial library of diverse compounds. Novel TcG6PDH inhibitors were identified among thienopyrimidine and quinazolinone derivatives. Preliminary structure activity relationships for the identified hits are presented, including structural features that contribute for selectivity toward the parasite enzyme. Our results indicate that quinazolinones are promising hits that should be considered for further optimization.

Intratesticular, intraperitoneal, and oral administration of thienopyrimidine derivatives increases the testosterone level in male rats.

Intratesticular, intraperitoneal, and oral administration of thienopyrimidine derivatives increases the testosterone level in male rats.

ChemInform Abstract: Facile Synthesis of Thieno[2,3‐d]pyrimidine Derivatives Using Inorganic Base Catalysis.

AbstractA facile and efficient synthesis of thienopyrimidine derivatives (IV) via reaction of carbodiimide derived from iminophosphorane (I) with secondary amines is developed using potassium carbonate as inorganic base catalyst.

A Synthesis of Novel Pyrazolylthienopyrimidine Derivatives as IL-6/STAT3 Inhibitors

The interleukin-6 (IL-6) as a pro-inflammatory cytokine with TNF-α and IL-8 plays a central role in the induction of inflammation as well as in the continuation of a chronic inflammatory immune response. And, an over-production of IL-6 have been found in inflammatory tissues of several diseases, such as rheumatoid arthritis, psoriasis, inflammatory bowel disease, osteoarthritis, multiple myeloma, and also in human atherosclerotic plaque. IL-6 binds to its receptor (IL-6R, a ligand-binding 80 kDa glycoprotein chain) and induces the homodimerization of a signal transducing glycoprotein 130 (gp130), leading to the activation of the Janus kinase (Jak)/signal transducer and signal activator of transcription-3 (STAT3). STAT3 is also frequently overexpressed or persistently activated in most tumors and cancer, and activated STAT3 was found to suppress tumorimmune surveillance. Therefore, the blockade of STAT3 activation pathway stimulated by IL-6 could be an attractive therapeutic target for discovery of new drugs and is currently under intense investigation. In the other hand, thienopyrimidine and their derivatives are an important class of the most biologically active compounds, having diverse activities such as antibacterial, analgesic, antitumor, antioxidant, P2Y12 platelet aggregation inhibitor, and Aurora kinase inhibitor. We have synthesized over the years thienopyrimidine derivatives of promising biological activity. As part of a programme to discover novel inhibitors using thienopyrimidines, some of these compounds were found to possess potent IL-6/STAT3 inhibition. This result encouraged us to prepare new thienopyrimidines having pyrazole moiety in attempt to improve the IL-6/STAT3 inhibitory activity. Pyrazoles have been also reported to have a wide range of biological properties. Moreover, incorporation of pyrazole moiety into other heterocycles gave various pharmacological activities. Although a lot of methodologies have been developed over the years, the regiocontrolled and practical synthesis of 1,5-pyrazoles over 1,3-pyrazole is still less literature precedent and remains a noteworthy challenge. To the best of our knowledge no report have so far made in the synthesis of regioselective pyrazolylthienopyrimidine by the one pot reaction of (E)-3-(dimethylamino)-1-phenylprop-2en-1-one 2 with 4-hydrazinothienopyrimidine 1. Herein we report the efficient synthesis and biological activity of novel pyrazolylthienopyrimidine derivatives, 3A and 3B, as IL-6/ STAT3 inhibitor. The required reactant 2 can be easily prepared by the reaction of acetophenone with N,N-dimethylformamide dimethyl acetal (DMFDMA) in refluxing xylene. The reactants, 1A and 1B, were also obtained according to the procedure we have previously reported. In our initial studies toward synthesis of substituted pyrazolylthienopyrimidine, (E)-3-(dimethylamino)-1-phenylprop-2-en-1-one (2a) was reacted with 4-hydrazinothieno[2,3-d]pyrimidine (1A) in THF at reflux for 10 h. It was found that three products from the reaction mixture were formed, respectively, 4-(5-phenyl1H-pyrazol-1-yl)thieno[2,3-d]pyrimidine (3Aa, 1,5-isomer, 35%), 4-(3-phenyl-1H-pyrazol-1-yl)thieno[2,3-d]pyrimidine (4Aa, 1,3-isomer, 20%) and 1,2-adduct (5Aa, 15%), as shown Table 1. Accordingly, reaction optimization for the regioselective formation of 1,5-isomer was investigated at the various conditions (catalyst, reaction temperature and solvent). When the same reaction was carried out in refluxing ethanol in the presence of 1 equiv HCl as a catalyst, 3Aa was obtained as a major product in optimum yield (65%, Table 1, entry 6) within 6 h. Next, as depicted in Table 2, the reaction of 1A with 2b-h Table 1. Optimization for the reaction of 1A with 2a

Activation of adenylyl cyclase by thienopyrimidine derivatives in rat testes and ovaries

An important role in functioning of reproductive tissues is played by signaling systems that are regulated by luteinizing hormone (LH) and human chorionic gonadotropin (hCG) that include LH receptors as sensor components. Use of LH and hCG in medicine for treatment of diseases of the reproductive system and for solution of tasks of auxiliary reproductive technologies is restricted by their high cost, the necessity of parenteral introduction, and the presence of side effects. However, in the last few years, low molecular weight agonists of LH receptor have been developed that are devoid of these shortcomings and can be administered perorally. The most effective of them are thienopyrimidine derivatives, in particular the Org 43553 compound. The goal of this work was to study the effect of newly synthesized analogs of Org 43553, 5-amino-N-(tert-butyl)-4-(3-(isonicotinamide)phenyl)-2-(methylthio)thieno[2,3-d]pyrimidine-6-carboxamide (compound 1) and 5-amino-N-(tert-butyl)-2-(methylthio)-4-(3-(thiophene-3-carboxamido)phenyl)thieno[2,3-d]pyrimidine-6-carboxamide (compound 2), on the basal and LH-stimulated adenylyl cyclase (AC) activity in the plasma-membrane fractions isolated from testes and ovaries of rats. Compounds 1 and 2 have been shown to stimulate in a dose-dependent manner the basal AC activity in the membranes isolated from the testes and ovaries, compound 2 being more effective as compared with compound 1. The EC50 values for compounds 1 and 2 on AC activity were 1.05–1.12 and 0.28–0.37 μM, respectively. The stimulating effect of hCG on AC activity was retained in the presence of the thienopyrimidine derivatives, while at low, nonsaturating hormone concentrations, the additivity of the effects of hCG and of compounds 1 and 2 on the AC activity was observed. This indicates that the thienopyrimidine derivatives interact with the allosteric site located in the LH receptor transmembrane channel and does not overlap with the binding site of gonadotropins located in the N-terminal ectodomain. The action of compounds 1 and 2 was tissue-specific and not found in tissues with no LH receptors present. Our obtained data indicate that compounds 1 and 2 may become prototypes for creation of drugs that are regulators of functions of the male and female reproductive systems.