Antitumor agents. 2. Synthesis,structure-activity relationships,and biological evaluation of substituted 5H-pyridophenoxazin-5-ones with potent antiproliferative activity

New antiproliferative compounds, 5H-pyrido[3,2-a]phenoxazin-5-ones (1-10), 5H-benzophenoxazin-5-one (11), 5H-pyrido[2,3-a]phenoxazin-5-one (12), 5H-pyrido[3,4-a]phenoxazin-5-one (13), and 5H-pyrido[4,3-a]phenoxazin-5-one (14), were synthesized and evaluated against representative human neoplastic cell lines. The excellent cytotoxic activity of these polycyclic phenoxazinones, structurally related to the actinomycin chromophore, is discussed in terms of structural changes made to rings A and D (Chart 1). Electron-withdrawing or electron-donating substituents were introduced at different positions of ring A to probe the electronic and positional effects of the substitution. A nitro group in R(2) or in R(1) increases the cytotoxic activity, whereas electron-donating methyl groups in any position lead to 10- to 100-fold decreasing of the activity. The low antiproliferative activity of benzophenoxazinone 11 and pyridophenoxazinones 13 and 14 confirms the crucial role of pyridine nitrogen in the W position of ring D in DNA binding. The unexpected high activity exhibited by 12, which has the nitrogen in the X position, could be ascribed to a different mechanism of action, which needs further investigation.     

Derivatives of 1,2-condensed pyrimidines. II. Synthesis and pharmacological study of N,N-disubstituted 5-amino-7H-thiazol [3,2-a]pyrimdine-7-ones

Reaction of 2-aminothiazole with the N,N-dialkyl or (N-alkyl, N-phenyl) ethoxycarbonylacetamide/POCl3 reactant (I), in refluxing 1,2-dichloroethane, yielded the corresponding N,N-disubstituted 5-amino-7H-thiazolo[3,2-a]pyrimidin-7-ones (VII) along with lower quantities of isomeric N,N-disubstituted 7-amino-5H-thiazolo[3,2-a]pyrimidin-5-ones (VIII). Structures attributed to isomeric compounds (VII) and (VIII) were supported both by spectroscopic and chemical evidences. Some compounds (VII) were submitted to pharmacological investigation and results are described: only (N-alkyl, N-phenyl)derivatives (VII f,g) showed a significant, even if mild, activity as peripheral analgesics.     

Antitumor agents. 1. Synthesis,biological evaluation,and molecular modeling of 5H-pyrido[3,2-a]phenoxazin-5-one,a compound with potent antiproliferative activity

The iminoquinone is an important moiety of a large number of antineoplastic drugs and plays a significant role in the nucleus of actinomycins, powerful, highly toxic, natural antibiotics that target DNA as intercalating agents. A series of polycyclic iminoquinonic compounds, 2-amino-3H-phenoxazin-3-one (1), 2-amino-1,9-diacetyl-3H-phenoxazin-3-one (2), 2-acetylamino-3H-phenoxazin-3-one (3), 3H-phenoxazin-3-one (4), 5H-pyrido[3,2-a]phenoxazin-5-one (5), and 5H-pyrido[3,2-a]phenothiazin-5-one (6), strictly related to the actinomycin chromophore, were synthesized for developing new anticancer intercalating drugs. The antiproliferative activity of these compounds, evaluated against representative human liquid and solid neoplastic cell lines, showed that 5 and its isoster 6 were the most active compounds inhibiting cell proliferation in a submicromolar range. Compound 5 was also evaluated against KB subclones (KBMDR, KB7D, and KBV20C), which overexpress the MDR1/P-glycoprotein drug efflux pump responsible for drug resistance. All the above KB subclones did not show altered sensitivity to the antiproliferative activity of 5. UV-vis and (1)H NMR spectroscopy experiments support the phenoxazinone 5/DNA binding. Molecular mechanics methods were used to build a three-dimensional model of the 5/[d(GAAGCTTC)]2 complex. Electrostatic interactions between the hydrogen of the positively charged pyridine nitrogen of 5 and the negatively charged oxygen atoms (O4' and O5') of the cytosine C5 residue together with stacking forces contribute to the high antiproliferative activity. The metal(II)-assisted synthesis procedure of 5 is described, and the formation mechanism is proposed.     

3-(氨基烷氧基芳基)-7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物的设计、合成与乙酰胆碱酯酶抑制活性

目的初步探讨在7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物母核C-3位苯环侧链中引入二乙胺基团的3-(氨基烷氧基芳基)-7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物的合成及其乙酰胆碱酯酶抑制活性。方法以取代的苯甲醛和乙酰甘氨酸为初始原料,经Erlenmeyer-Plchl反应、缩合反应、水解反应、缩合反应,生成6-芳甲基-3-硫代-1,2,4-三嗪-5(2H)-酮类化合物,再与取代的α-氯代苯乙酮反应,得到6-芳甲基-3-(羟基芳基)-7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物;以芳基乙烯为原料,经温和的氧化反应、缩合反应得到3,4-二氢-6-芳基-3-硫代-1,2,4-三嗪-5(2H)-酮类化合物,再与取代的α-氯代苯乙酮在乙酸中反应得到6-芳基-3-(羟基芳基)-7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物。两条合成路线得到的3-(羟基芳基)-7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物进一步经Williamson反应制备得到10个3-(烷氧基芳基)-7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物。所有目标化合物结构均经质谱、红外光谱和核磁共振氢谱确证。采用Ellman法对目标化合物进行体外乙酰胆碱酯酶抑制活性筛选。结果根据前期已筛选化合物的活性数据和总结出的初步构效关系,设计并合成了10个C-3位苯环侧链中含有二乙胺基团的3-(氨基烷氧基芳基)-7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物。体外乙酰胆碱酯酶抑制活性筛选表明,所有目标化合物均具有乙酰胆碱酯酶抑制活性,其中7个化合物在10μmol.L-1浓度水平抑制活性超过了50%。结论根据体外重组人源AChE(rhAChE)抑制活性的测试结果,发现C-3位苯环侧链中含有二乙胺基团的7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物均具有较好的rh-AChE抑制活性。在这一位置的侧链中引入二乙胺基团,可以增强化合物对rhAChE的抑制活性。     

Convenient synthesis of fused heterocyclic 1,3,5-triazines from some N-acyl imidates and heterocyclic amines as anticancer and antioxidant agents

N-Acyl imidates (2), reacting with 5-amino pyrazole (3), 2-aminobenzimidazole (4), 3-amino-1,2,4-triazole (5), 3,5-diamino-1,2,4-triazole (6), and 5-aminotetrazole (7) give pyrazolo[1,5-a][1,3,5]triazine (8), benzo[4,5]imidazo[1,2-a][1,3,5]triazine (9), [1,2,4]triazolo [2,3-a][1,3,5]triazine (10), [1,2,4]tri azolo[2,3-a][1,3,5]triazin-5-ylamine (12), and tetrazolo-[1,5-a][1,3,5]triazine (14) derivatives, respectively. The synthesized compounds were characterized on the basis of IR, (1)H-NMR, (13)C-NMR, and mass spectral data and elemental analyses results. Five of the newly synthesized compounds, 8a, 9a, 10a, 12a, and 14a, were selected by National Cancer Institute and screened for their anticancer activity against three cancer cell lines MCF7, NCI-H460, and SF-268, where 12a exhibited moderate anti-proliferation potential. 12a was, thus, further tested for anticancer activity against 60 human cancer cell lines and showed moderate growth inhibition potency. 12a showed a high growth inhibitory activity against A498 renal cancer cell line. All of the newly synthesized compounds 8-10, 12 and 14 were tested for their antioxidant capacity where they exhibited very high activity, even higher than the widely used reference antioxidants butylated hydroxytoluene and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox). Compound 12a also showed the highest antioxidant activity.     

1-Methyl-3H-pyrazolo[1,2-a]benzo[1,2,3,4]tetrazin-3-ones. Design, synthesis, and biological activity of new antitumor agents

1-Methylpyrazolo[1,2-a]benzo[1,2,3,4]tetrazin-3-ones 4, synthesized in good to excellent yields, were designed as novel alkylating agents because of their peculiar chemical behavior. All derivatives showed antiproliferative activity against more than 50 types of tumor cell lines with GI(50) reaching sub-micromolar values. SAR studies revealed that the presence of a chlorine atom is well-tolerated in both positions 8 and 9, whereas in the case of the methyl group, switching from the 8 to the 9 position gives rise to the most active compound of the series, 4g, either for the number of cell lines inhibited and for selectivity against leukaemia and renal cancer subpanels. COMPARE and 3D-MIND computations indicate, for compounds 4, an activity profile analogous to rifamycins and cytidine analogues.     

Hydrazonoyl halides as precursors for new fused heterocycles of 5α-reductase inhibitors

A new series of benzo[6,7]cyclohepta[1,2-d]triazolo[4,3-a]pyrimidines 8a-l was synthesized via reaction of heterocyclic thione 4 or its methyl derivatives 10 with hydrazonoyl halides 5a-l. Also, reaction of compound 4 with a mixture of chloroacetic acid and aromatic aldehyde derivatives gave benzo[6,7]cyclohepta[1,2-d]thiazolo[3,2-a]pyrimidin-3-ones 12-14. The microanalyses and spectral data of the synthesized compounds are in full agreement with their molecular structure. All the newly synthesized products were screened against 5α-reductase and showed activities with good ED(50) for all compounds.     

Synthesis and anti-inflammatory activity of 3,3a-dihydro-2H,9H-isoxazolo [3,2-b] [1,3]benzoxazin-9-ones and related compounds.

A series of 3,3a-dihydro-2H,9H-isoxazolo[3,2-b]-[1,3]benzoxazin-9-ones was synthesized and evaluated for anti-inflammatory, antipyretic and analgesic activity. Since many of these compounds exhibited promising activity, particularly in the anti-inflammatory tests, a number of homologous 2,3,4,4a-tetrahydro-10H-1,2-oxazino[3,2-b]-[1,3]benzoxazin-10-ones and one 3,4,5,5a-tetrahydro-2H, 11H,-1,2-oxazepino [3,2-b][1,3]benzoxazin-11-one, the 9-chloro analog, were also prepared and evaluated. The expanded ring members were generally less active than the tricyclic compounds containing the isoxazolidine ring.     

7-trans-(2-Pyridylethenyl)-5H-thiazolo[3,2-a]pyrimidine-5-ones: synthesis and pharmacological activity

A series of 7-trans-(2-pyridylethenyl)-5H-thiazolo[3,2-a]pyrimidine-5-ones was synthesized and evaluated for their pharmacological activity. Some compounds were found to be effective in inhibiting restraint ulcers in the rat. Two of them also showed interesting antiinflammatory activity.     

2,3-Dihydro-9H-isoxazolo[3,2-b]quinazolin-9-ones and 3,4-dihydro-(1,2)-oxazino [3,2-b]quinazolin-10(2H)-ones.

Two series of compounds, 2,3-dihydro-9H-isoxazolo[3,2-b]quinazolin-9-ones and 3,4-dihydro-(1,2)-oxazino-[3,2-b]quinazolin-10(2H)-ones, were synthesized and evaluated for anti-inflammatory, antipyretic and analgesic activity. The isoxazolo compounds were generally more active than their oxazino homologs. Three compounds, i.e., 2,3-dihydro-9H-isoxazolo [3,2-b]quinazolin-9-one (W-2429) and its 2- and 3-methyl congeners, were the most active of all compounds tested in this study. On the basis of the biological results herein reported, W-2429 is considerably more effective than acetylsalicylic acid in inhibiting carrageenan-induced edema and in reducing brewer's yeast-induced fever in rats. Also, it was found to be more potent than propoxyphene hydrochloride in the Randall-Selitto test for analgesic activity.     

新型乙酰胆碱酯酶抑制剂5H-噻唑并[3,2-a]嘧啶类化合物的设计、合成与生物活性研究

目的 寻找作为乙酰胆碱酯酶抑制剂的具有新化学结构类型的化合物。方法 采用分子对接的虚拟筛选方法寻找新型乙酰胆碱酯酶抑制剂，设计了10个5H-噻唑并[3,2-a]嘧啶类化合物。以芳醛、硫脲等为起始原料，通过Biginelli反应生成二氢嘧啶类化合物，再与氯代苯乙酮作用经Hantzsch环合反应制得目标化合物，其结构经红外光谱、质谱、核磁共振氢谱和碳谱确证。采用Ellman方法进行体外抑制乙酰胆碱酯酶活性测试。 结果 合成了10个5H-噻唑并[3,2-a]嘧啶类化合物，体外抑制乙酰胆碱酯酶活性测试结果显示，所有目标化合物均具有乙酰胆碱酯酶抑制活性，其中3个目标化合物在10 μmol.L^-1时抑制活性均超过50%。结论5H-噻唑并[3,2-a]嘧啶类化合物是潜在的乙酰胆碱酯酶抑制剂。将计算机辅助药物分子设计、有机合成和生物活性测试相结合是发现和设计新型乙酰胆碱酯酶抑制剂的有效途径。     

乙酰胆碱酯酶抑制剂3,6-二芳基-7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物的设计、合成与生物活性

目的 初步探讨乙酰胆碱酯酶(AChE)抑制剂7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物的合成及构效关系.方法 利用分子对接技术设计一些新的7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物,采用化学方法合成这些目标化合物,采用Ellman法对目标化合物进行体外乙酰胆碱酯酶抑制活性筛选.首先由...     

Synthesis and structure-activity relationships of 1-arylmethyl-5-aryl-6-methyluracils as potent gonadotropin-releasing hormone receptor antagonists

Based on the SAR from bicyclic gonadotropin-releasing hormone (GnRH) antagonists such as 6-aminomethyl-7-aryl-pyrrolo[1,2-a]pyrimid-4-ones (5) and 2-aryl-3-aminomethyl-imidazolo[1,2-a]pyrimid-5-ones (6a,b), a series of novel uracil compounds (8) were derived as GnRH antagonists. The synthesis and SAR studies of 6-methyluracils as human GnRH receptor antagonists are discussed herein. Introduction of a small methyl substituent at the beta-position of the N3 side-chain improved the GnRH binding potency by 5-10-fold. Introduction of a methyl group of (R)-configuration at the alpha-carbon of the N-3 side-chain gave a modest improvement in binding affinity over the unsubstituted ethylene analogues. This modification enabled us to make uracil compounds without the labile 2-pyridylethyl motif on the basic nitrogen while still maintained excellent potency against the hGnRH receptor.     

Synthesis and study the pharmacological activity of derivatives of 5-dimethylaminopyrano[3,2-c]quinolin-2-ones

A simple method of synthesizing derivatives of 5-dimethylaminopyrano[3,2-c]quinolin-2-ones is proposed which involves obttaining 4-chloro- or 4-oxo-3-formylquinolines using compounds having an active methylene group. The pharmacological activity of the synthesized compounds is studied.     

Synthesis of some triazolophthalazine derivatives for their anti-inflammatory and antimicrobial activities

Several novel series of triazolophthalazine derivatives namely; pyrazolylethenyltriazolophthalazinones (4a-d), styryltriazolophthalazinones (5a,b), aryloxopropenyltriazolophthalazinones (7a,b), pyrazolinyl- (8a,b), (9a,b) and (10a-f), pyrazolyl- (11a-d), (1,2-oxazol-5-yl)-1,2,4-triazolo[3,4-a]phthalazin-6(5H)-ones (14a,b), triazolo[3,4-a]phthalazin-3-yl-pyridine-3-carbonitriles (12a,b), triazolo[3,4-a]phthalazin-3-yl)ethylthioacetic acids (13a,b) and 2-aryl-5-arylamino-1H,5H-pyrazolo[2″,3″-1',5']imidazo[3',4'-1,5]-1,2,4-triazolo[3,4-a]phthalazin-12(13H)-ones (15a-c) have been synthesized. The anti-inflammatory activity of representative compounds has been studied. Compounds 8b, 10c, 10f, 11b, 12a, 13b, and 15a showed anti-inflammatory activities comparable to that of the reference standard, indomethacin. They exhibit also minimal ulcerogenic effect relevant to the reference standard and were found to be non-toxic up to 120 mg/kg orally or up to 75 mg/kg through parenteral route. Concerning the antimicrobial activity; compounds 12b and 13b were found to be equipotent to ampicillin against Staphylococcus aureus, while compounds 10a and 10f were found to be as potent as ampicillin against E. coli, whereas compound 14b exhibited equipotency to clotrimazole against Candida albicans. Compounds 8b, 10f, 11b, 12a, and 13b exhibited, besides their antimicrobial activity, moderate to potent anti-inflammatory profiles. This represents a fruitful matrix for the development of a new class of dual non-acidic anti-inflammatory/antimicrobial agents.     

Synthesis and cytotoxicity testing of novel 2-(3-substituted-6-chloro-1,1-dioxo-1,4,2-benzodithiazin-7-yl)-3-phenyl-4(3H)-quinazolinones

A new series of thirteen 2-[3-(substituted amino)-6-chloro-1,1-dioxo-1,4,2-benzodithiazin-7-yl]-3-phenyl-4(3H)-quinazolinones 4-16 were prepared in order to evaluate their cytotoxic activity against 12 human cancer cell lines. The bioassay indicated that the quinazolinone derivatives 5, 8-12, 15, and 16 possess cancer-cell growth-inhibitory properties. Compounds 5 and 12 showed a high level of selectivity for certain cell lines. The most active compounds 9, 10, 15, and 16 showed moderate antiproliferative activity and were approximately 4-fold less potent than cisplatin.     

Synthesis and evaluation of anti-inflammatory activity of some thiazolo[3,2-b]-1,2,4-triazole-5(6H)-ones and their Michael addition products

Thiazolo[3,2-b]-1,2,4-triazole-5(6H)-ones (4-10) were obtained in a one step synthesis by heating 3-aryl-5-mercapto-1,2,4-triazoles (3a-d) with chloroacetic acid and appropriate aromatic aldehyde in acetic acid and acetic anhydride in the presence of anhydrous NaOAc. Michael type addition of cyclic secondary amines (N-methylpiperazine, piperidine) to 4-10 gave 2-phenyl-6-(alpha-aminoarylmethyl)thiazolo[3,2-b]-1,2,4-triazole-5 -ols (4a-10b). The structures of the compounds were confirmed by spectral and elementary analysis. The compounds synthesized in previous and present studies were investigated for their anti-inflammatory activities.     

Synthesis, antitumor activity, and mechanism of action of benzo[a]pyrano[3,2-h]acridin-7-one analogues of acronycine

Twenty-two derivatives belonging to the cis-1,2-diacyloxy-6-methoxy-3,3,14-trimethyl-1,2,3,14-tetrahydro-7H-benzo[a]pyrano[3,2-h]acridin-7-one series were synthesized in nine steps starting from 3,5-dimethoxyacetanilide (5) and 2-methoxy-1-naphthalenecarboxylic acid (7). Most of them exhibited submicromolar cytotoxicity when tested against murine leukemia (L1210) and human epidermoid carcinoma (KB-3-1) cell lines. The cytotoxic activity correlated strongly with the ability of the compounds to form covalent adducts with purified DNA. Among the most active compounds, 25, with IC50 values of 0.7 and 0.15 microM against L1210 and KB-3-1, respectively, was selected for evaluation in vivo against Colon 38 adenocarcinoma implanted in mice. This compound was active at 3 mg/kg i.v. (day 12 and 24) with 3/7 tumor free mice by day 80.     

Synthesis and antitumour activity of 1H,3H-thiazolo[3,4-a]benzimidazole derivatives

A series of 1H,3H-thiazolo[3,4-a]benzimidazoles were synthesized and tested for their in vitro antitumour activity against 60 human tumour cell lines. Some derivatives exhibited both tumour growth inhibition activity and cellular selectivity. In particular, compound 8c, the most active of the series, was very active towards all cell lines at concentrations ranging from 10(-7)-10(-5) M. Compound 4a, on the other hand, was highly selective against the CNS cancer cell line.     

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.