Design,synthesis, docking study and cytotoxic activity evaluation of some novel letrozole analogs

Background

Breast cancer is the most common type of female cancer. One class of hormonal therapy for breast cancer drugs -non steroidal aromatase inhibitors- are triazole analogues. In this work, some derivatives of these drugs was designed and synthesized. All synthesized compounds were evaluated for their cytotoxic activities on breast cancer cell lines (MDA-MB-231, T47D and MCF-7).

Methods

Our synthetic route for designed compounds started from 4-bromotolunitrile which was reacted with 1H-1,2,4-triazole to afford 4-(4-cyanobenzyl)-1,2,4-triazole. The reaction of later compound with aromatic aldehydes led to formation of the designed compounds. Eleven novel derivatives 1a-k were tested for their cytotoxic activities on three human breast cancer cell lines.

Results

Among the synthesized compound, 4-[2-(3-chlorophenyl)-1-(1H-1,2,4-triazol-1-yl)ethenyl]benzonitrile (1c) showed the highest activity against MCF-7 and MDA-MB-231 cell lines and 4-[2-(4-methoxyphenyl)-1-(1H-1,2,4-triazol-1-yl)ethenyl]benzonitrile (1 h) exhibited highest activity against T47D cell line. According to cytotoxic activities results, compound 4-[2-(4-dimethylamino)-1-(1H-1,2,4-triazol-1-yl)ethenyl]benzonitrile (1 k) showed comparative activity against T47D and MDA-MB-231 cell lines with compound (1 h) and our reference drug Etoposide.

Conclusion

In the process of anti-cancer drug discovery, to find new potential anti-breast cancer agents, we designed and synthesized a novel series of letrozole analogs. Cytotoxicity evaluation revealed that compounds (1c) and (1 k) were the most potent compounds with comparative activity with Etoposide. The results revealed that π-π interactions are responsible for the enzyme inhibitions of compounds (1 c) and (1 k).Keyword: Breast cancer, Non-steroidal aromatase inhibitor, Cytotoxic activity     

12-Amino-andrographolide analogues: synthesis and cytotoxic activity

Andrographolide, a diterpenoid lactone of the plant Andrographis paniculata, has been shown to be cytotoxic against various cancer cells in vitro. In the present study, a series of β-amino-γ-butyrolactone analogues has been synthesized from naturally occurring andrographolide via one pot tandem aza-conjugate addition–elimination reaction. By using economic procedure without any base or catalyst at room temperature, the products obtained were in fair to excellent yields with high stereoselectivity. The cytotoxicity of all new amino analogues were evaluated against six cancer cell lines and revealed their potential for being developed as promising anti-cancer agents.     

Amidine analogues of melphalan: synthesis, cytotoxic activity, and DNA binding properties

Design, synthesis, and cytotoxic activity of amidine derivatives of melphalan are described and structure-activity relationships are discussed. Evaluation of the cytotoxicity of these compounds employing a MTT assay and inhibition of [(3)H]thymidine incorporation into DNA in both MDA-MB-231 and MCF-7 human breast cancer cells demonstrated that these compounds were more active than melphalan. Data from the ethidium displacement assay showed that these compounds were able to bind in the minor groove-binding mode in AT sequences of DNA. The cytotoxic properties of the amidine analogues of melphalan towards cultured human breast cancer cells correlate with topoisomerase II inhibitory properties but not with DNA-binding properties.     

Design, synthesis, and in vitro evaluation of cytotoxic activity of new substituted 1,4-benzoquinones and hydroquinones

A new series of p-benzoquinones, hydroquinones, and quinol dimethyl ethers substituted by a pyrazole ring either directly or after an oxoethyl linker was synthesized and screened for in vitro cytotoxic activity. Compounds 8d, f, g, i, and 9c, f, and 13c exhibited broad-spectrum activity (GI₅₀ MG-MID values 9.27–14.72 μM). With regard to sensitivity, compounds 8f and 9c, f have proved to possess a remarkable activity against leukemia tumor cell lines (GI₅₀ = 3.43–5.03 μM). Indeed, compound 13c showed the highest activity profile against individual leukemia subpanel cell line SR (GI₅₀ = 0.91 μM).     

Total synthesis and cytotoxic activity of stellatin

Stellatin (3,4-dihydro-8-hydroxy-7-hydroxymethyl-6-methoxyisocoumarin) (8), an extrolite of fungal genera Emericella and Aspergillus, was synthesized. Thus, Vilsmeier-Haack formylation of methyl ester of 3,5-dimethoxy-4-methylphenylacetic acid (1) to afford the formyl ester (2) followed sulfamic acid-sodium chlorite oxidation of the aldehydic function to yield the carboxy ester (3). Chemoselective reduction of ester function in the latter using NaBH(4)/THF/MeOH furnished the corresponding hydroxy acid (4) that on cyclodehydration afforded the 3,4-dihydro-6,8-dimethoxy-7-methylisocoumarin (5). Benzylic bromination of the C-7 methyl in 5 using NBS/benzoyl peroxide to give the 7-bromomethyldihydroisocoumarin (6) followed the nucleophilic substitution using aqueous acetone to provide 7-hydroxymethyl-dihydroisocoumarin (7). Finally, the regioselective demethylation of 8-methoxyl group using anhydrous magnesium iodide furnished the stellatin (8). The dihydroisocoumarins (5-8) were screened for cytotoxic activity against human keratinocyte cell line and were found to exhibit moderate to good activity.     

Total synthesis and cytotoxic activity of stellatin

Stellatin (3,4-dihydro-8-hydroxy-7-hydroxymethyl-6-methoxyisocoumarin) (8), an extrolite of fungal genera Emericella and Aspergillus, was synthesized. Thus, Vilsmeier–Haack formylation of methyl ester of 3,5-dimethoxy-4-methylphenylacetic acid (1) to afford the formyl ester (2) followed sulfamic acid–sodium chlorite oxidation of the aldehydic function to yield the carboxy ester (3). Chemoselective reduction of ester function in the latter using NaBH₄/THF/MeOH furnished the corresponding hydroxy acid (4) that on cyclodehydration afforded the 3,4-dihydro-6,8-dimethoxy-7-methylisocoumarin (5). Benzylic bromination of the C-7 methyl in 5 using NBS/benzoyl peroxide to give the 7-bromomethyldihydroisocoumarin (6) followed the nucleophilic substitution using aqueous acetone to provide 7-hydroxymethyl-dihydroisocoumarin (7). Finally, the regioselective demethylation of 8-methoxyl group using anhydrous magnesium iodide furnished the stellatin (8). The dihydroisocoumarins (5–8) were screened for cytotoxic activity against human keratinocyte cell line and were found to exhibit moderate to good activity.     

Design,synthesis, and cytotoxic evaluation of novel scopoletin derivatives

A series of scopoletin derivatives were designed and synthesized by introducing α‐aminoacetamide, acrylamide and β‐aminopropamide, respectively, to 3‐position of scopoletin, and their chemical structures were confirmed by ESI‐MS, IR, ¹H NMR, and ¹³C NMR spectra. All target compounds were evaluated in vitro against four human cancer cell lines (MDA‐MB‐231, MCF‐7, HepG2, and A549) by MTT method. Cytotoxic assay showed that compounds 7a , 7b , 7e , 7f , 8a , and 8e exhibited more potent cytotoxicities compared to scopoletin. Besides, we have further evaluated the growth inhibitory activities of these selected compounds against normal tissue cell lines HFL‐1. Although compound 8a showed the strongest antiproliferative activity in vitro, it exhibited strong cytotoxicity on normal cells HFL‐1, which limited its further study. Compound 7a and 7b exhibited higher antiproliferative activity against MDA‐MB‐231 and HepG2 cells and weak cytotoxicity on HFL‐1, which suggested that 7a and 7b might be ideal anticancer candidates. The SARs showed that the introduction of the acrylamide and its analogues β‐aminopropamide could significantly improve activity, while the α‐aminoacetamide failed to enhance potency obviously. Therefore, the mechanism of compound 7a and 7b is worthy of further research and the structure of compound 8a should be further optimized.     

Design, synthesis, and cytotoxic activities of new 2,4,5-triarylimidazoles

A new group of 2,4,5-triarylimidazoles containing N,N-dimethylaminoethoxy or piperidinyl ethoxy group at the para position of the C-5 phenyl ring were synthesized and their cytotoxic activities were evaluated on three different breast cancer cell lines using MTT assay. The compounds contain various substituents at the para position of C-2 phenyl ring. Among the synthesized compounds, 4-(5-(4-(2-piperidin-1-yl)ethoxy)phenyl)-4-phenyl-1H-imidazol-2-yl)phenol (11e) and 1-2-(4-(2,4-diphenyl-1H-imidazol-5-yl)phenoxy)ethyl) piperidine (11h) with IC₅₀s of less than 0.1 μM on all three cell lines were the most potent cytotoxic compounds.     

Design,synthesis, structural characterization and in vitro cytotoxic activity of mononuclear Ru(II)complexes

The synthesis and characterization of ruthenium complexes (Ru-1–Ru-6) of the type [Ru(R)₂(K)]²⁺ (where R?=?1,10-phenanthroline/2,2′-bipyridyl and K?=?acetyl coumarin-inh, pyrazole-tch, acetyl coumarin-tsz, are described. These ligands form bidentate octahedral ruthenium complexes. The in vitro cytotoxic activities of the complexes measurement against the human cancer T-lymphocyte cell lines. In vitro evaluation of these title complexes revealed cytotoxicity from 0.34 to 1.4?µg/mL against CEM, 0.28 to 1.8?µg/mL against L1210, 0.44 to 2.5?µg/mL against Molt4/C₈, 0.98 to 1.6?µg/mL against HL60, and 0.66 to 1.4?µg/mL against BEL7402. Ruthenium complexes Ru-5 & Ru-6 showed that quite significant anticancer activities over standard drugs.     

Design,synthesis and cytotoxic activity of novel 1-aroyl-4-(2-chloroethyl)semicarbazides

A series of aroyl derivatives of 4-(2-chloroethyl)semicarbazide were designed and synthesized to explore their antiproliferative activity against human brain carcinoma (U251) and human liver carcinoma (Hepg2) cell lines. The synthesized compounds were characterized by elemental analyses and spectroscopic data. It was established that compounds in which semicarbazide fragments are substituted with a (2-indolyl)carbonyl moiety showed a higher cytotoxic activity than the corresponding benzoyl derivatives. 1-[(5-Benzyloxy-1H-indol-2-yl)carbonyl]-4-(2-chloroethyl)semicarbazide (24) showed the highest cytotoxic activity against Hepg2 (IC₅₀= 21 μg/ml), while 4-(2-chloroethyl)-1-[(5-methoxy-1H-indol-2-yl)carbonyl]semicarbazide (23) was the most active compound against U251 (IC₅₀ = 8 μg/ml). __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 41, No. 4, pp. 12–15, May, 2007.     

Ferrocenylselenoamides: synthesis, characterization and cytotoxic properties

A new series of ferrocenyl selenoamides 7-11 (FcSeNH(CH(2))(n)CH(2)(R)OH, n = 1, 2, 3, R = H, Me, Ph) were prepared in good yields by selenative demetalation of Fischer aminocarbene complexes. The crystal structures of 7 [FcSeNH(CH(2))(2)OH] and 19 [PhSeNH(CH(2))(2)OH] reveal their capability to form intermolecular hydrogen bonding in solid state. Results of SRB assays show that these new selenium compounds have a good anticancer potency superior to tamoxifen and cisplatin, with IC(50) values ranging from 4.5 to 13.32 μM against human breast cancer cell lines. A preliminary model to explain the structure-cytotoxic activity relation is proposed where different structural parameters such as the alkyl chain length, the presence of bulky groups in the same chain, the effect of hydroxyl group, and also the role of ferrocene moiety are included as being responsible for the cytotoxic response.     

Phenytoin-based bivalent ligands: Design, synthesis and anticonvulsant activity

Synthesis, characterization and anticonvulsant properties of new bivalent ligands derived from phenytoin were described. Initial anticonvulsant screening was performed using maximal electroshock (MES) and pentylenetetrazole (PTZ) screens in mice. The neurotoxicity for compounds that showed significant anticonvulsant activity was determined applying the rotorod test. Most of the test compounds were found to be effective in at least one seizure model in a dose of 100 mg/kg. Compound 5e exhibited marked anticonvulsant activity in both MES and PTZ screens. The computer-aided prediction of biological activity was carried out.     

Antitumor agents. 3. Design, synthesis, and biological evaluation of new pyridoisoquinolindione and dihydrothienoquinolindione derivatives with potent cytotoxic activity

New antiproliferative compounds, the 1-aryl-3-ethoxycarbonyl-pyrido[2,3-g]isoquinolin-5,10-diones (PIQDs, 1-7), were designed on the basis of a molecular model obtained by aligning the common quinolinquinone substructure of 5H-pyrido[3,2-a]phenoxazin-5-one (PPH) and some known anticancer agents. A Diels-Alder reaction between quinolin-5,8-dione (QD) and a 2-azadiene, formed by demolition of 2-aryl-1,3-thiazolidine ethyl esters (T compounds), was used to produce 1-7 and the isomeric 1-aryl-3-ethoxycarbonylpyrido[3,2-g]isoquinolin-5,10-diones (8-14). Two other compounds, the 3-amino-3-ethoxycarbonyldihydrothieno[2,3-g]quinolin-4,9-dione (15) and the 3-amino-3-ethoxycarbonyldihydrothieno[3,2-g]quinolin-4,9-dione (16), arising from a 1,4 Michael reaction of QD with a thiolate species formed by opening of T compounds, were recovered from the reaction mixture. The antiproliferative activity of 1-16 was evaluated against representative human liquid and solid neoplastic cell lines. The IC(50) of these compounds had median values in the range 2.00-0.01 microM, with 2-4 and 15 exhibiting significantly higher in vitro cytotoxic activity. Compound 2, also evaluated against KB subclones (KB(MDR), KB(7D), and KB(V20C)), was shown to be scarcely subject to the MDR1/P-glycoprotein drug efflux pump responsible for drug resistance. The noncovalent DNA-binding properties of PIQDs were examined using UV-vis and (1)H NMR spectroscopy experiments. Accordingly, these compounds were confirmed to have an ability to intercalate into double-stranded DNA by topoisomerase I superhelix unwinding assay. Interesting structure-activity relationships were found. Three important features seem to contribute to the cytotoxic activity of these anticancer ligands: (i) the DNA intercalating capability of the three-cyclic quinonic system, typical of this class of compounds, (ii) the position of the pendant phenyl ring that, according to the superimposition model, must occupy the same area of the corresponding benzo-fused ring A of PPH, and (iii) the effect of electron-withdrawing substituents on the phenyl ring, which can contribute improving the pi-pi stacking interactions between ligand and DNA base pairs. Besides, a mechanism of action suspected to involve topoisomerases could be hypothesized to interpret the antiproliferative activity of the thienoquinolindione 15, which can be regarded as a cyclic cysteine derivative.     

沙利度胺衍生物的设计合成及其抗肿瘤活性研究

目的设计合成1，3-二氢-1，3-二氧代．2H-异吲哚-N-取代沙利度胺衍生物。并对其进行体外抗肿瘤活性测试。方法以2．氨基-β-D-吡喃葡萄糖盐酸盐为原料，经过6步反应得到化合物N-（3’，4’，6＇-三乙酰-1’-溴代吡喃葡萄糖）-1,3-二氢-1，3-二氧代-2H-异吲哚，该化合物经过溴代、取代反应得到目标化合物。通过对4T1细胞存活率的测试测定20个目标化合物体外抗肿瘤活性。结果设计合成的20个目标化合物均未见文献报道。所有化合物均经过1H-NMR谱确证，部分化合物经IR、MS谱确证。结论所有目标化合物对4T1细胞均具有-定的抑制生长作用。表明所合成的沙利度胺衍生物均有-定的抗肿瘤活性。     

3‐Aminomethyl pyridine chalcone derivatives: Design,synthesis, DNA binding and cytotoxic studies

Herein we report design, synthesis, and anticancer activity of compounds 6a–h and 11a–j . Compounds 6a–f were designed based on 3‐aminomethyl pyridine attached to different acetamide derivatives and in compounds 6g–h it was attached to coumarin moiety. Coumarin containing compounds 6g–h showed very poor anticancer activity against both A549 (Lungs cancer cell line), and MCF‐7 (Breast cancer cell line) cell lines in MTT assay. Compounds 11a–j were designed as derivatives of 3‐aminomethyl pyridine and 4‐amino chalcones. A series of chalcone derivatives of 3‐aminomethyl pyridine 11a–j have been synthesized and screened for their in vitro anticancer activity and DNA binding affinity. Most of the compounds showed very good antimitotic activity against A549 cell line as compared to fluorouracil. Compounds 11g and 11i were selected for DNA‐binding studies as they showed excellent activity against cancer cell lines in MTT assay. CT‐DNA binding affinity of compounds 11g and 11i have been investigated by UV based DNA titration and fluorescence emission study against DNA‐EtBr complex. Interestingly, compound 11i has displayed excellent antiproliferative activity, with IC₅₀ 0.0067 ± 0.0002 μm , against MCF‐7 cell line. Compound 11i has been studied for its cytotoxicity using MTT, LDH, as well as EtBr/AO assay and was found to induce apoptosis in the cancerous cell line.     

Design, synthesis, and biologic evaluation of some novel N-arylpyrazole derivatives as cytotoxic agents

A novel series of N-arylpyrazole derivatives (5a–5d, 7a–7c) has been designed and synthesized via aromatic substitution reaction of N-nonsubstituted pyrazoles with 4-fluoronitrobenzene in the presence of base. The structures of these compounds were established on the basis of elemental (C, H, and N) and spectral analysis (¹H NMR, ¹³C NMR, HRMS, and FT-IR). All the compounds were tested for their cytotoxic activity in vitro against four human tumor cell lines: carcinoma (Bel-7402), nasopharyngeal carcinoma (KB), immature granulocyte leukemia (HL-60), and gastrocarcinoma (BGC-823) by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The results showed that most of the obtained compounds exhibited promising cytotoxicity against tested carcinoma cell lines with low IC₅₀ values. The bis-pyrazole derivative 7c, bearing alkoxy group on the 5-position of phenyl ring, was the most effective one. It is inhibition of cell growth of Bel-7402 cells was 1.5-fold higher than that found for cisplatin. And, also mono-pyrazole derivatives 5a and 5b, decorated with trifluoromethyl group on the phenyl ring, displayed better cytotoxicity than that of cisplatin against Bel-7402 cell line.     

二氢青蒿素-查尔酮杂合物的设计、合成及其抗肿瘤活性研究

目的设计合成二氢青蒿素-查尔酮杂合物,提高二氢青蒿素类化合物对白血病细胞的生长抑制活性。方法将取代查尔酮以醚键拼合到二氢青蒿素的C-10位,设计并合成了29个二氢青蒿素-查尔酮杂合物。采用细胞计数法测定目标化合物对人白血病HL-60细胞的生长抑制作用。结果得到了29个含有查尔酮侧链的二氢青蒿素衍生物,均为未见文献报道的新化合物,其结构经1H-NMR、MS和IR谱确证。所有目标化合物对人白血病HL-60细胞都有不同程度的生长抑制作用。结论所有目标化合物对HL-60细胞株的生长抑制活性均强于二氢青蒿素,GI50值均小于0.10μmol·L-1。连接链的改变、查尔酮A环和B环的调换以及取代基的改变对化合物活性的影响没有显著差异。     

AHPA衍生物的设计、合成及抗癌活性研究

目的 以基质金屑蛋白酶AP—N为靶点，寻找新的抗癌活性化合物。方法 以3—氨基—2—羟基--4—苯基丁酸—亮氨酸(AHPA-Leu)为先导化合物，借助计算机分子结构优化处理进行合理药物设计，合成了8个结构全新的AHPA衍生物，并对目标化合物进行了体内、体外初步药效学评价。结果与结论 初步药效学评价表明，所合成的化合物能增强小鼠的免疫功能，抑制S180肿瘤生长，其中化合物Ⅵ活性最强。     

奥莫康唑类似物的设计合成及其抗真菌活性研究

目的合成系列硝酸奥莫康唑的类似物并测试其体外抗真菌活性。方法以2-溴丙酰溴和取代苯为起始原料,经Friedel-Crafts酰化、N-烷基化、烯醇化、醚化等反应制得目标化合物。以氟康唑和奥莫康唑为阳性对照药,采用二倍浓度稀释法测试目标化合物对热带假丝酵母菌、白色念株菌、新生隐球菌格特变种、烟曲霉菌、耐氟康唑白色念珠菌100、103、SC5314的体外抗真菌活性。结果与结论合成18个目标化合物,其中17个是未见文献报道的新化合物,其结构经HRMS、~1H-NMR谱确证;活性测试结果表明,多个目标化合物对测试真菌表现出一定的体外抑菌活性。