Synthesis of new 3-(3-phenyl-isoxazol-5-yl) or 3-[(3-phenyl-isoxazol-5-yl)-amino] substituted 4(3H)-quinazolinone derivatives with antineoplastic activity

A novel series of 3-(3-phenyl-isoxazol-5-yl) or 3-[(3-phenyl-isoxazol-5-yl)amino] substituted 4(3H)-quinazolinone derivatives was synthesized. The compounds were tested for their antineoplastic activity in vitro against Raji (human Burkitt limphoma). K-562 (human chronic myelogeneous leukemia) and U937 (human histiocytic limphoma) cell lines. The most active quinazolinones showed IC50 values in the range 16-30 microM.     

Synthesis and antiproliferative activity of novel 3-(indazol-3-yl)-quinazolin-4(3H)-one and 3-(indazol-3-yl)-benzotriazin-4(3H)-one derivatives.

Several new 3-(indazol-3-yl)-quinazolin-4(3H)-one and 3-(indazol-3-yl)-benzotriazin-4(3H)-one derivatives 5 and 6 were synthesized and tested for their in vitro antiproliferative activity against Raji, K562, and K562-R cell lines. The pharmacological screening showed that some 2, 6, or 7-substituted quinazolinones 5 posses a significant antiproliferative activity, with a percentage growth inhibition ranging from 44.8% to 100% at 50 microM, which was higher than that showed by the unsubstituted derivative 5a previously synthesized. For the most active compounds 5d, 5f, and 5g the IC50 were recorded.     

Synthesis and cytotoxic evaluation of cycloheximide derivatives as potential inhibitors of FKBP12 with neuroregenerative properties.

On the basis of the new finding that the protein synthesis inhibitor cycloheximide (1, 4-[2-(3, 5-dimethyl-2-oxocyclohexyl)-2-hydroxyethyl]-2,6-piperidinedione) is able to competitively inhibit hFKBP12 (K(i) = 3.4 microM) and homologous enzymes, a series of derivatives has been synthesized. The effect of the compounds on the activity of hFKBP12 and their cytotoxicity against eukaryotic cell lines (mouse L-929 fibroblasts, K-562 leukemic cells) were determined. As a result, several less toxic or nontoxic cycloheximide derivatives were identified by N-substitution of the glutarimide moiety and exhibit IC(50) values in the range of 22.0-4.4 microM for inhibition of hFKBP12. Among these compounds cycloheximide-N-(ethyl ethanoate) (10, K(i) = 4.1 microM), which exerted FKBP12 inhibition to an extent comparable to that of cycloheximide (1), was found to cause an approximately 1000-fold weaker inhibitory effect on eukaryotic protein synthesis (IC(50) = 115 microM). Cycloheximide-N-(ethyl ethanoate) (10) was able to significantly speed nerve regeneration in a rat sciatic nerve neurotomy model at dosages of 30 mg/kg.     

Synthesis and <Emphasis Type="Italic">In Vitro</Emphasis> antiproliferative activity of 2-methyl-3-(2-piperazin-1-yl-ethyl)-pyrido[1,2-a]pyrimidin-4-one derivatives against human cancer cell lines

A series of new 2-methyl-3-(2-piperazin-1-yl-ethyl)-pyrido[1,2-a]pyrimidin-4-one derivatives 6a-j were synthesized by a nucleophilic substitution reaction of 2-methyl-3-(2-piperazin-1-ylethyl)-pyrido[1,2-a]pyrimidin-4-one with various sulfonyl chlorides. The compounds were characterized by different spectral studies. All the compounds were evaluated for their antiproliferative effect using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay method against four human cancer cell lines (K562, Colo-205, MDA-MB 231, IMR-32) for the time period of 24 h. Among the series, compounds 6d, 6e and 6i showed good activity on all cell lines except K562, whereas the other compounds in the series exhibited moderate activity. Compound 6d could be a potential anticancer agent and therefore deserves further research.     

Synthesis of substituted benzylamino- and heterocyclylmethylamino carbodithioate derivatives of 4-(3H)-quinazolinone and their cytotoxic activity

A new series of substituted benzylamino- and heterocyclylmethylamino carbodithioate derivatives of 4-(3H)-quinazolinone were synthesized via four steps starting from 2-amino-5-methylbenzoic acid and initially screened against A-549 (human non-small cell lung cancer), HCT-8 (human colon cancer), and Bel-7402 (human liver cancer) cell lines at the single concentration of 5 microg/mL using the colorimetric MTT assay. The IC50 values were determined for the compounds reaching > or = 70% inhibition in primary screening by serial dilution. Among the newly synthesized compounds, 9n exhibited potent in vitro cytotoxicity against A-549, HCT-8, and Bel-7402 cell lines with the IC50 values of 1.65, 0.93, and 1.43 microM, respectively.     

Cytotoxicity of prenylated xanthones and other constituents from the wood of Garcinia merguensis

One new prenylated xanthone 5-farnesyltoxyloxanthone B ( 4), three known xanthones alpha-mangostin ( 1), rubraxanthone ( 2) and isocowanol ( 3) as well as (2 E,6 E,10 E)-4beta-hydroxy-3-methyl-5beta-(3,7,11,15-tetramethylhexadeca-2,6,10-tetraenyl)-cyclohex-2-en-1-one ( 5) and 3,3',4- O-trimethylellagic acid were isolated from the wood of GARCINIA MERGUENSIS Wight. The cytotoxic activities of compounds 1 - 5 were evaluated against the MCF-7, MDA-MB-231, NCI-H-460 and SF-268 cell lines with rubraxanthone 2 and 5 exhibiting the highest activity at 9.0 and 12.1 microM, respectively, against MCF-7 cells.     

Synthesis and antiviral and cytostatic evaluations of the new C-5 substituted pyrimidine and furo[2,3-d]pyrimidine 4',5'-didehydro-L-ascorbic acid derivatives

The novel C-5 alkynyl substituted pyrimidine (1-11) and furo[2,3-d]pyrimidine derivatives (12-22) of l-ascorbic acid were synthesized by coupling of 5-iodouracil-4',5'-didehydro-5',6'-dideoxy-l-ascorbic acid with terminal alkynes by using Sonogashira cross-coupling reaction conditions. The new compounds were evaluated for their cytostatic and antiviral activities. Among all evaluated compounds, the octynyl-substituted uracil derivative of l-ascorbic acid (3) exhibited the most pronounced cytostatic activities against all examined tumor cell lines (IC50 = 2-12 microM). Pyrimidine derivatives of l-ascorbic acid containing p-substituted phenylacetylene groups (8-11) displayed also a rather pronounced (IC50 = 3-37 microM) inhibitory effect toward all tumor cell lines. From the bicyclic series of compounds, 6-butylfuro[2,3-d]pyrimidine derivative (12) and 6-p-bromophenylfuro[2,3-d]pyrimidine derivative (19) showed the highest cytostatic activity (IC50 = 4.5-20 microM), particularly against malignant leukemia (L1210) and T-lymphocyte (Molt4/C8 and CEM) cells. Compounds 3 and 9 showed specific albeit moderate activity against cytomegalovirus (CMV, Davis strain, EC50 = 1.8 and 3.8 microM, respectively, for compounds 3 and 9) at a approximately 5-fold lower concentration than that required to show cytotoxicity.     

Synthesis and antileukemic activity of novel 2-(4-(2,4-dimethoxybenzoyl)phenoxy)-1-(4-(3-(piperidin-4-yl)propyl)piperidin-1-yl)ethanone derivatives

A series of novel 2-(4-(2,4-dimethoxybenzoyl)phenoxy)-1-(4-(3-(piperidin-4-yl)propyl) piperidin-1-yl)ethanone derivatives 9(a-e) and 10(a-g) were synthesized and characterized by (1) H NMR, IR, mass spectral, and elemental analysis. These novel compounds were evaluated for their antileukemic activity against two human leukemic cell lines (K562 and CEM) by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide assay. Some of the tested compounds showed good antiproliferative activity with IC(50) values ranging from 1.6 to 8.0 μm. Compound 9c, 9e, and 10f with an electron-withdrawing halogen substituent at the para position on the phenyl ring showed excellent in vitro potency against tested human leukemia cells (K562 and CEM).     

Synthesis and biological evaluation of 2-amino-3-(3',4',5'-trimethoxybenzoyl)-5-aryl thiophenes as a new class of potent antitubulin agents

A new series of compounds in which the 2-amino-5-chlorophenyl ring of phenstatin analogue 7 was replaced with a 2-amino-5-aryl thiophene was synthesized and evaluated for antiproliferative activity and for inhibition of tubulin polymerization and colchicine binding to tubulin. 2-Amino-3-(3',4',5'-trimethoxybenzoyl)-5-phenyl thiophene (9f) as well as the p-fluoro-, p-methyl-, and p-methoxyphenyl substituted analogues (9i, j, and l, respectively) displayed high antiproliferative activities with IC50 values from 2.5 to 6.5 nM against the L1210 and K562 cell lines. Compounds 9i and j were more active than combretastatin A-4 as inhibitors of tubulin polymerization. Molecular docking simulations to the colchicine site of tubulin were performed to determine the possible binding mode of 9i. The results obtained demonstrated that antiproliferative activity correlated well with the inhibition of tubulin polymerization and the lengthening of the G2/M phase of the cell cycle. Moreover, a good correlation was found between these inhibitory effects and the induction of apoptosis in cells treated with the compounds.     

Synthesis and Cytotoxicity Screening of Piperazine‐1‐carbodithioate Derivatives of 2‐Substituted Quinazolin‐4(3H)‐ones

A new series of piperazine‐1‐carbodithioate derivatives of 2‐substituted quinazolin‐4(3H)‐ones were synthesized via a five‐steps procedure starting from 2‐amino‐5‐methylbenzoic acid. The cytotoxicity of the resulting compounds against A‐549 (human lung cancer), HCT‐8 (human colon cancer), HepG2 (human liver cancer), and K562 (human myelogenous leukaemia) cell lines was determined by the MTT assay. Preliminary screening results of these compounds are reported.     

2-甲基-5-取代苯氧基伯氨喹的合成及其抗疟活性

为寻找高效低毒的间日疟根治药,合成了7个2-甲基-5-取代苯氧基伯氨喹Ⅱ_1～7,以与强效的4-甲基取代类似物比较,探索构效关系。初步生物评价结果表明,化合物Ⅱ_1～7对鼠疟Plasmodium berghei的抑制性治疗作用及对鼠疟P.yoelii的病因性预防作用均明显弱于其4-甲基对应物,略低于伯氨喹。     

New and cytotoxic anthraquinones from Pleospora sp. IFB-E006, an endophytic fungus in Imperata cylindrical

In addition to 7-methoxy-2-methyl-3,4,5-trihydroxyanthraquinone (1), physcion (2), macrosporin (3), deoxybostrycin (4), altersolanol B (5) and dactylariol (6), a new hexahydroanthraquinone named pleospdione (7) was isolated from the culture of Pleospora sp . IFB-E006, an endophytic fungus residing in the normal stem of Imperata cylindrical (Gramineae). Structure determination of pleospdione was accomplished using IR, HR-ESI-MS, 1D and 2D NMR spectral analysis. Compounds 4 - 6 exhibited significant cytotoxic activity against human colon cancer (SW1116) and leukemia (K562) cell lines while compounds 1, 2 and 7 were only weakly or moderately active.     

Sulfonate derivatives of naphtho[2,3-b]thiophen-4(9H)-one and 9(10H)-anthracenone as highly active antimicrotubule agents. Synthesis, antiproliferative activity, and inhibition of tubulin polymerization

Benzenesulfonate derivatives of naphtho[2,3-b]thiophen-4(9H)-one and 9(10H)-anthracenone were prepared and found to inhibit microtubule formation by an in vitro tubulin polymerization assay. Several analogues showed potent cytotoxic activity in an assay based on K562 leukemia cells with IC50 values of <100 nM. The methylamino analogue 14i was the most active compound in this assay (14i, IC50 K562: 0.05 muM). Antiproliferative activities of selected compounds were additionally evaluated against a panel of 12 tumor cell lines, including multi-drug-resistant phenotypes. All resistant cell lines were sensitive to these compounds. Concentration-dependent flow cytometric studies showed that KB/HeLa cells treated with selected compounds were arrested in the G2/M phases of the cell cycle. In competition experiments, these compounds strongly displaced radiolabeled colchicine from its binding site in the tubulin, showing IC50 values lower than that of colchicine. The results demonstrate that the antiproliferative activity is related to the inhibition of tubulin polymerization.     

Inhibitors of Trypanosoma cruzi trypanothione reductase revealed by virtual screening and parallel synthesis

In an approach to discover new inhibitors of trypanothione reductase from Trypanosoma cruzi, the causative agent of Chagas' disease, a virtual high-throughput screening was performed. Two structurally new types of inhibitors emerged, the antimicrobial chlorhexidine {1,1'-hexamethylenebis[5-(4-chlorophenyl)biguanide]}, a linear competitive inhibitor (K(i) = 2 +/- 1 microM), and a piperidine derivative acting as mixed inhibitor (K(i) = 6.2 +/- 2 microM and K(i)' = 8.5 +/- 2 microM). Neither compound interferes with human glutathione reductase. Based on chlorhexidine, different series of compounds were synthesized and studied as inhibitors of T. cruzi trypanothione reductase. Most efficient derivatives were three bis(amidines) showing mixed type inhibition with K(i,slope) and K(i,int) values of 2-5 microM and 16-47 microM, respectively. Although these compounds did not exert an improved inhibitory potency compared to chlorhexidine, the change from competitive to mixed-type inhibition is advantageous, since substrate accumulation does not overcome inhibition. Remarkably, all three derivatives carried two copies of an identical 2-methoxy-4-methyl-1-(phenylmethoxy)benzene substituent.     

Synthesis and anticancer activity of novel 2-amino-4-(4-phenylpiperazino)- 1,3,5-triazine derivatives

The synthesis and anticancer activity of novel 2-amino-4-(4-phenylpiperazino)-1,3,5-triazine derivatives 4a-b and 5a-f are described. Compounds 4a, 5a,c and 5f were evaluated by in vitro assays of growth inhibition against several human tumor cell lines. The vitro cytotoxic activity was found for 2-{2-amino-4-[4-(2-chlorophenyl)piperazino]- 1,3,5-triazin-6-yl}-3-(4-nitrophenyl)acrylonitrile (5f) (IC50 = 0.45 microM - 1.66 microM), whilst other tested compounds were inactive. Some of the molecular orbital calculations for the tested derivatives were also presented.     

Inhibition of ribonucleotide reductase and growth of human colon carcinoma HT-29 cells and mouse leukemia L1210 cells by N-hydroxy-N'-aminoguanidine derivatives

A series of N-hydroxy-N'-aminoguanidine (HAG) derivatives were studied and compared for their effects on ribonucleotide reductase activity in cell-free extracts; on nucleic acid synthesis and the growth of human colon carcinoma HT-29 cells; and on mouse leukemia L1210 cells in culture. The HAG derivatives [RCH=NNHC(=NH)NHOH-tosylate] studied could be grouped as: (1) hydroxybenzylidines; (2) methoxybenzylidines; and (3) nitrobenzylidines substituted at the R position. 2'-Hydroxybenzylidine-HAG, the lead compound, was relatively active in both HT-29 cells and L1210 cells (20 +/- 5 and 13 +/- 4 microM for 50% inhibition of HT-29 and L1210 cell growth respectively). The monohydroxybenzylidene compounds were generally more active than the dihydroxy- and trihydroxybenzylidene-HAG derivatives. The methoxybenzylidene-HAGs were as active as the monohydroxybenzylidene-HAGs. 2'-Hydroxy-4'-methoxybenzylidene-HAG was much more active than 2',4'-dihydroxybenzylidene-HAG. The mononitrobenzylidene-HAGs were more active than the dinitrobenzylidene-HAG compound. In general, L1210 cells were more sensitive to the effects of the HAG compounds than were HT-29 cells. There was good agreement between the concentration of drug required to inhibit the growth of HT-29 cells and that required to inhibit the growth of L1210 cells. There was also good correlation between the ability of HAG derivatives to inhibit ribonucleotide reductase activity and to inhibit tumor cell growth. Some derivatives, such as 2',3',4'- and 3',4',5'-trihydroxybenzylidene-HAG inhibited L1210 cell growth by 50% at lower concentrations (7.8 and 11.9 microM respectively) than the concentrations needed for 50% inhibition of HT-29 cell growth (196 and 234 microM respectively) and ribonucleotide reductase activity (122 and 188 microM respectively). The studies of nucleic acid synthesis in L1210 cells using [3H]cytidine as a precursor showed that 2',3',4'-trihydroxybenzylidine-HAG inhibited DNA synthesis at a lower concentration (29 microM for 50% inhibition) than was needed for the inhibition of RNA synthesis and formation of [3H]deoxycytidine nucleotides in the acid-soluble fraction (320 and 820 microM for 50% inhibition respectively). These results indicate that 2',3',4'-trihydroxybenzylidine-HAG inhibits DNA synthesis in L1210 cells through other mechanisms rather than exclusively through the inhibition of ribonucleotide reductase activity.     

Syntheses and biological activities of 3'-azido disaccharide analogues of daunorubicin against drug-resistant leukemia

Anthracyclines, such as daunorubicin (DNR) and doxorubicin (Dox), are widely used for cancer therapy but are limited by drug resistance and cardiotoxicity. To overcome drug resistance, we synthesized a novel class of disaccharide analogues of DNR against drug-resistant leukemia. In these disaccharide analogues (1-6) the first (inner) sugar in the carbohydrate chain is a 3-azido-2,3,6-trideoxy-L-lyxo-alpha-hexopyranose; the second (outer) sugars that are linked via alpha(1-->4) to the first sugar are a series of uncommon sugars. Their cytotoxicities were examined in drug-sensitive leukemia cells K562 and doxorubicin-resistant K562/Dox cells by MTS assay. In drug-sensitive cells, compounds 1-6 were found to be active against leukemia K562 cells with IC50 in the nanomolar range (200-1100 nM), while compounds 2-5 with 2,6-dideoxy sugars showed better activity than compounds 1 and 6 with 2,3,6-trideoxy sugars. In doxorubicin-resistant K562/Dox cells, compounds 1, 3, and 5 exhibited much better activities (with IC50 between 0.29 and 2.0 microM) than DNR (with IC50 > 5 microM). Compound 3 emerged as the most active compound, showing at least 17-fold higher activity against drug-resistant cells than parent compound DNR. The IC50 values of compound 3 in both drug-sensitive and drug-resistant cells are identical, which indicates that compound 3 completely overcomes drug resistance. Structure-activity relationship (SAR) studies showed that the substitution and orientation of the 3-OH group in the second sugar significantly influence its activity against drug-resistant leukemia. These results suggest that sugar modifications of anthracyclines change their activity and overcome drug resistance.     

伊马替尼类似物的合成及抑制K562细胞生长活性

目的设计、合成含2-苯胺基嘧啶结构的2-苯氧乙酰胺衍生物和芳酰基硫脲类衍生物,并对其体外抑制慢性粒细胞白血病生长活性进行初步的评价。方法以3-乙酰基吡啶、N,N-二甲基甲酰胺二甲基缩醛、邻甲基苯胺为起始原料,经硝化、加成、环合、还原反应得中间体6-甲基-N^1-（4-（吡啶-3-基）嘧啶-2-基）-1,3-苯二胺,经与不同的酰化试剂酰化得到目标产物。采用台盼蓝排染法,以伊马替尼为阳性对照药、以K562细胞为测试细胞株对目标化合物进行体外抗慢性粒细胞白血病活性评价。结果与结论所合成的16个新化合物经1H-NMR和HR-MS确证结构。初步药理实验结果表明,目标化合物抑制慢性粒细胞白血病生长活性低于阳性对照药。     

2,4-二氨基-5-甲基-6-取代苄氨基喹唑啉衍生物的合成及其抗疟和抗肿瘤作用

本文报道2,4-二氨基-5-甲基-6-取代苄氨基喹唑啉衍生物的合成及其抗疟和抗肿瘤活性。这类化合物由5-甲基-2,4,6-三氨基喹唑啉与相应的取代苯甲醛缩合成Schiff碱,然后经还原,甲酰化或亚硝化制得。经对伯氏鼠疟原虫(Plasmodium berghei)抑制性治疗筛选,有三个化合物Ⅳ_(2,5,6)剂量5mg/kg×4d抑制率为100%;体外抗肿瘤活性以Ⅱ_7和Ⅳ_8最强,对L1210白血病细胞株的IC_(50)分别为3.910×10~(-3)μg/ml和6.172×10~(-3)μg/ml,与MTX相当。