Synthesis, structure and anticancer activity of novel 2,4-diamino-1,3,5-triazine derivatives

A series of 2-(4,6-diamino-1,3,5-triazin-2-yl)-2-{[4-(dimethylamino)-phenyl]imino}acetonitriles 19-27 have been synthesized by the reaction of 2-(4-amino-6-alkylamino-1,3,5-triazin-2-yl)acetonitriles 10-15 with p-nitrosodimethylaniline. Unexpectedly, a similar reaction of acetonitriles 10, 14, 15, 17 and 18 with nitrosobenzene led to the formation of 4,6-diamino-N-phenyl-1,3,5-triazine-2-carboxamides 28-32. The in vitro antitumor activity of the compounds obtained has been tested and 2-[4-Amino-6-(4-phenylpiperazin-1-yl)-1,3,5-triazin-2-yl]-2{[4-(dimethylamino)phenyl]imino}acetonitrile (19) having remarkable activity against melanoma MALME-3 M cell line (GI(50)=3.3 x 10(-8) M, TGI=1.1 x 10(-6) M) is a leading candidate for further development.     

Synthesis, structural characterization and antitumor activity of novel 2,4-diamino-1,3,5-triazine derivatives

The syntheses, structural elucidation based on NMR spectroscopy and X-ray analysis of 8 as well as antitumor activities of novel 2,4-diamino-1,3,5-triazine derivatives 5 and 7-22 are described. Screenings performed at NCI showed that most derivatives possessed a moderate to strong growth inhibition activity on various tumor panel cell lines between 0.148 and 56.2 microM concentrations. 2-Amino-6-bromomethyl-4-(3,5,5-trimethyl-2-pyrazoline)-1,3,5-triazine 11 showed the most potent antitumor activity with the mean midpoint values of log(10) GI50, log(10) TGI50 and log(10) LC50 of all tests equal to -5.26, -4.81 and -4.37, respectively and therefore, it can be considered as a lead structure for further development of anticancer agents.     

Synthesis and antitumor activity of novel 2-amino-4-(3,5,5-trimethyl-2-pyrazolino)-1,3,5-triazine derivatives

The syntheses and antitumor activities of novel 2-amino-4-(3,5,5-trimethyl-2-pyrazolino)-1,3,5-triazine derivatives 4-38 are described. All the compounds prepared were screened at the National Cancer Institute (NCI) for their activities against a panel of 60 tumor cell lines and relationships between structure and antitumor activity in vitro are discussed. The triazines 11, 16, 20, 23, 23 and 34-38 exhibited modest or fairly high activity against one or more human tumor cell lines. Prominent compound with remarkable activity (log GI50, < - 8.00- - 5.00) to all investigated cell lines and highly potent (log GI50 < - 8.00- - 7.64) against some cell lines of Leukemia (CCRF-CEM, K-562, RPMI-8226, SR), CNS Cancer (SF-539) and Breast Cancer (T-47D) was 2-[2-amino-4-(3,5,5-trimethyl-2-pyrazolino)-1,3,5-triazin-6-yl]-3-(5-nitro-2-thienyl)acrylonitrile (25).     

Synthesis and biological evaluation of novel pyrazole derivatives with anticancer activity

We synthesized thirty-six novel pyrazole derivatives and studied their antiproliferative activity in human ovarian adenocarcinoma A2780 cells, human lung carcinoma A549 cells, and murine P388 leukemia cells.Four of these substances were selected because of their higher antiproliferative activity and further analyses showed that they were all able to induce apoptosis, although to a different extent. The expression of p53 and p21^waf1, which induce apoptosis and cell cycle arrest, was evaluated by western blot analysis in cells treated with compound 12d.The analysis of the cell cycle showed that all the selected compounds cause a partial G2/M block and the formation of polyploid cells. Furthermore, the four selected compounds were tested for their interaction with the microtubular cytoskeletal system by docking analysis, tubulin polymerization assay and immunofluorescence staining, demonstrating that the compound 12d, unlike the other active derivatives, was able to significantly bind dimers of α- and β-tubulin, probably causing a molecular distortion resulting in the disassembly of microtubules.     

Synthesis, structure elucidation and identification of antitumoural properties of novel fused 1,2,4-triazine aryl derivatives

Synthesis, structure elucidation and anticancer activities of novel fused 1,2,4-triazine aryl derivatives containing the ethoxycarbonyl (6-10) and carbohydrazide formations (11-15) are presented. Molecular structures of the synthesized compounds were confirmed by IR, (1)H NMR, (13)C NMR, EI-MS spectra and elemental analyses. Antitumour activities in vitro for heterobicyclic hydrazides of the type 11-14 were evaluated by BrdU method for human LS180, SiHa and T47D carcinoma cells. Amongst them, hydrazide 14 has exhibited remarkable inhibitory effect against SiHa and LS180 tumour cells, and simultaneously was found to be non-toxic towards the human normal cell line-HSF cells. Furthermore, the pulse field gel electrophoresis experiment was performed for characterizing DNA-cleaving activity of heterobicycle 14. The DNA fragments of 2500, 2000 and 500 kilobase pairs (kbp) were commonly detected in the cancer cell lines (SiHa, LS180 and T47D) treated with compound 14. DNA fragmentation pattern, since three types of fragments induced by the tested hydrazide of the type 14 were detected, suggesting a way of interaction with DNA. It is worth pointing out, that DNA strand breaks were also produced in human breast cancer (T47D) cells, a cell line where the induction of DNA fragmentation is very difficult. Moreover, the statistically significant apoptotic activity in T47D human breast cancer cells for the tested heterobicycle 14 was proved using the annexin V-binding assay. The antiproliferative properties in vitro for compounds 6-14 were evaluated by MTT method for human leukaemic Jurkat cells. Significant viability decreases in Jurkat cells treated with different concentrations of compounds 10 and 11 were observed, suggesting that these derivatives have antiproliferative activities. Their acute toxicities were established. For these compounds the influence on the central nervous system of mice in behavioural tests was examined. Molecular structure for free base of the intermediate 4 was confirmed by (1)H-(1)H COSY, HMBC and HMQC correlations.     

Synthesis of novel alkyltriazole tagged pyrido[2,3-d]pyrimidine derivatives and their anticancer activity

A series of novel alkyltriazole tagged pyrido[2,3-d]pyrimidine derivatives 5 and 6 was prepared starting from 2,3-active functional pyridine 1via cyclization, propargylation followed by reaction with alkyl or perfluoroalkyl azides under Sharpless conditions. All the compounds 5 and 6 were screened for anticancer activity against three cancer cell lines such as U(937), THP-1 and Colo205. The promising compounds 5b and 5e have been identified.     

Synthesis, structural activity relationship and anti-tubercular activity of novel pyrazoline derivatives

In the present investigation, a series of 5-(-4-(substituted) phenyl)-3-(4-hydroxy-3-methylphenyl)-4,5-dihydro-1H-1-pyrazolyl-2-toluidino methane thione and 5-(substituted) phenyl-3-(4-hydroxy-3-methylphenyl)-4,5-dihydro-1H-1-pyrazolyl-2-methoxyanilino methane thione were synthesized by the reaction between hydrazine hydrate and chalcones (3a-k) followed by condensation with appropriate aryl isothiocyanate which yielded N-substituted pyrazoline derivatives. Newly synthesized compounds were tested for their in vitro anti-tubercular activity against Mycobacterium tuberculosis H37Rv using the BACTEC 460 radiometric system. Among the synthesized compounds, compound anilino-3-(4-hydroxy-3-methylphenyl)-5-(2,6-dichlorophenyl)-4,5-dihydro-1H-1-pyrazolylmethanethione (6i) was found to be more active agent against M. tuberculosis H37Rv with minimum inhibitory concentration of 0.0034 microM.     

Synthesis of some novel benzoxazole derivatives as anticancer, anti-HIV-1 and antimicrobial agents

In an effort to establish new candidates with improved antineoplastic, anti-HIV-1 and antimicrobial activities we report here the synthesis and in vitro biological evaluation of various series of 2-substituted benzoxazoles: 2-[(Arylhydrazono, arylidene, cycloalkylidene and N-substituted thiocarbamoyl)cyanomethyl]-benzoxazoles(2-4 and 7, respectively); 2-[(4- or 5-oxothiazoliden-2-yliden)benzoxazoles (5 and 6) and 2-(4-amino-3-substituted-2-thioxo-2,3-dihydrothiazol-5-yl)benzoxazoles (8), together with the synthesis of some substituted 3H-pyrido[2,1-b]benzoxazoles (9-11). The absolute configuration of compound 3b was determined by X-ray crystallography. The results of the in vitro anticancer screening revealed that some of the tested compounds exhibited broad spectrum antitumor activity. The most active compounds are 2a, 3b, 8a and 8d, their GI50 MG-MID values: 37.7, 19.1, 20.0 and 15.8 microM; TGI MG-MID values: 75.9, 53.7, 53.7, and 58.9 microM; and LC50 MG-MID values: 97.7, 93.3, 89.1 and 93.3 microM, respectively. The in vitro microbiological data showed that compound 7c was the most active against Staphylococcus aureus (minimal inhibitory concentration (MIC)<12.5 microg ml(-1). While compounds 5, 8a, and 8d were the most active against Bacillus subtilis (MIC values<12.5 microg ml(-1)). On the other hand, compounds 5 and 7c were the most active against Escherichia coli (MIC<25 microg ml(-1)), their activity is about half the activity of ampicillin and streptomycin . In addition, compound 4b and 7c were the most active against Pseudomonas aeruginosa (MIC<25, 50 microg ml(-1)). Compound 4b was two times as active as ampicillin and streptomycin while compound 7c was active as both. The results of antimycotic activity indicated that, Compound 7c showed mild activity against Candida albicans when compared with clotrimazole (MIC<100 microg ml(-1)). In vitro HIV-1 testing revealed that compound 7a displayed moderate anti-HIV-1 activity (maximum % cell protection, 36.6 at 2 x 10(-5) microM).     

Synthesis and anticancer activity of lavendustin A derivatives containing arylethenylchromone substituents

2-Styrylchromones, which are relatively scarce in nature, have been reported to possess potent cytotoxicities on KB cell line. Lavendustin A, a metabolite of Streptomyces griseolavendus, has been shown to inhibit a growth of A431 cell line. Accordingly, a series of compounds 3a-g having structural features of styrylchromones and lavendustin A were synthesized and evaluated for cytotoxicity using SRB assay on four tumor cell lines. Compounds 3a-g were synthesized by the condensation of 2-methylchromone derivative 7 with several aromatic aldehydes. Among synthesized, compound 3e showed the significant cytotoxic activity on HCT-15 cell line with IC(50) values of 7.17 microg/ml indicating that lavendustin A derivatives containing 2-arylethenylchromone ring have a potential in anti-tumor application.     

Synthesis, molecular modeling and biological evaluation of chalcone thiosemicarbazide derivatives as novel anticancer agents

A series of novel chalcone thiosemicarbazide derivatives (4a-4x) have been designed, synthesized, structurally determined, and their biological activities were also evaluated as potential EGFR kinase inhibitors. All the synthesized compounds are first reported. Among the compounds, compound 4r showed the most potent biological activity (IC(50) = 0.78 ± 0.05 μM for HepG2 and IC(50) = 0.35 μM for EGFR), which is comparable to the positive controls. Docking simulation was also performed to position compound 4r into the EGFR active site to determine the probable binding model. Antiproliferative assay results demonstrated that some of these compounds possessed good antiproliferative activity against HepG2. Compound 4r with potent inhibitory activity in tumor growth inhibition may be a potential anticancer agent.     

Synthesis, characterization, antiamoebic activity and toxicity of novel bisdioxazole derivatives

Cyclization of benzene-1,4-dicarbaldehyde dioxime 1 with different aromatic aldehydes in inert atmosphere yielded the corresponding new bisdioxazoles 2–11. The structure of 2–11 was elucidated by spectral data. In vitro antiamoebic activity was performed against HM1:IMSS strain of Entamoeba histolytica. The results showed that the compounds 3 (IC₅₀ = 1.22 μM), 4 (IC₅₀ = 1.41 μM), 7 (IC₅₀ = 1.05 μM) and 10 (IC₅₀ = 1.01 μM) exhibited better antiamoebic activity than the standard drug metronidazole (IC₅₀ = 1.80 μM). The compounds 3, 4, 7 and 10 were tested for toxicity by MTT assay on H9c2 cardiac myoblasts and the results showed that the compounds 3, 4, 7 and 10 offered remarkable viability of 96.2%, 83.5%, 82% and 89%, respectively at a concentration of 12.5 μg/ml.     

Identification of hydroxylamino-dinitroso-1,3,5-triazine as a transient intermediate formed during the anaerobic biodegradation of hexahydro-1,3,5-trinitro-1,3,5-triazine

The metabolic fate of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in a mixed culture incubated under methanogenic conditions was studied. Analysis by high-performance liquid chromatography (HPLC) confirmed the loss of RDX and the formation of mono-, di-, and trinitroso-RDX as transient biodegradation intermediates. An additional peak observed in the HPLC chromatograms was identified by liquid chromatography-mass spectrometry as hydroxylamino-dinitroso-1,3,5-triazine. This is the first report identifying hydroxylamino-dinitroso-1,3,5-triazine as a transient intermediate produced during the anaerobic biodegradation of RDX.     

Synthesis and anti-mycobacterial activity of novel amino alcohol derivatives

Thirteen new hydroxyethylamines have been synthesized from reactions of (2S,3S)Boc-phenylalanine epoxide, piperonylamine and arenesulfonyl chlorides in good yields. These compounds were evaluated as antibacterial agents against Mycobacterium tuberculosis H37Rv using the Alamar Blue susceptibility test and their activity expressed as the minimum inhibitory concentration (MIC) in μM. Two amino alcohols displayed significant activity when compared with first line drug ethambutol (EMB). Therefore this class of compounds could be a good starting point to develop new lead compounds in the treatment of tuberculosis.     

Synthesis, molecular structure and anticancer activity of 1-allyl-3-amino-2-(4-chloro-2-mercaptobenzenesulphonyl)guanidine derivatives

A series of 3-allylamino-6-chloro-7-R-1,1-dioxo-1,4,2-benzodithiazines (2a-e) was obtained by the reaction of 6-chloro-3-methylthio-1,4,2-benzodithiazine-1,1-dioxides (1a-e) with allylamine. Selective hydrazinolysis of the allylaminobenzodithiazines (2a-e) gave the appropriate 1-allyl-3-amino-2-(4-chloro-2-mercaptobenzenesulphonyl)guanidines (3a-e) in good yields. The reaction of 3a with dimethylsulphate under alkaline conditions provided the methylthio derivative 4. The structures of these compounds were confirmed on the basis of elemental analysis, spectral data (IR, 1H- and 13C-NMR) and X-ray analysis. Screening data indicated that the compounds 3a and 3d exhibited significant in vitro activities against numerous human tumour cell lines, whereas compounds 3b and 3c showed a moderate activity.     

Synthesis, crystal structure and antimicrobial activity of deoxybenzoin derivatives from genistein

A series of deoxybenzoin derivatives from genistein were synthesized and their structures were elucidated by (1)H NMR, mass spectral data and micro analyses. The structures of 2, 7 and 10 were determined by single-crystal X-ray analysis. These obtained compounds were evaluated for their assayed antibacterial (Bacillus subtilis, Escherichia coli, Pseudomonas fluorescence and Staphylococcus aureus) and antifungal (Aspergillus niger, Candida albicans and Trichophyton rubrum) activities by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) method. Most compounds have displayed comparable antibacterial activity against bacterial. On the basis of the biological results, structure-activity relationships are discussed.     

Synthesis, molecular docking study and antitumor activity of novel 2-phenylindole derivatives

The starting material, 4-(1-indol-2-yl)phenol 1 was obtained via Fischer synthesis. Vilsmeir Haack(')s formylation of 1 gave the carboxaldehyde derivative 2 which was subjected to different reactions affording the 3-substituted compounds 3-10. Compound 1 reacted with halo esters to give 11 and 12a,b. The reaction of 12a with various amino derivatives gave compounds 13-16. The hydrazide derivative 15a reacted with 1,3-diketones, ethyl acetoacetate and aromatic carboxylic acid derivatives to give 17a,b, 18 and 19a-e, respectively. Antitumor activity of target compounds were tested against breast cancer cell lines (MCF-7) and (MDA-MB-231). The most potent compound was 3e with IC(50)?=?1.60?nM against (MCF-7). Docking was performed on colchicine binding site of tubulin to study the binding mode of the designed compounds.     

Synthesis and anti-platelet activity of novel arylsulfonate--acylhydrazone derivatives, designed as antithrombotic candidates

In this work, we describe a new class of promising anti-platelet drug candidates with significant antithrombotic activity in vivo. This new series of compounds was structurally planned by modification of known thrombin inhibitors based on the use of acylhydrazone subunit, as a nonpeptide scaffold, and variations at P1 moiety. Three different families of arylsulfonate-acylhydrazone derivatives were designed. The bioassays indicated the first class of derivatives represented by 4f (LASSBio-693) and 4j (LASSBio-743), which were active in inhibiting the platelet aggregation induced by thrombin. The second class represented by compounds 4e (LASSBio-774) and 4h (LASSBio-480) that selectively inhibit the platelet aggregation involving TXA(2) formation. Finally, the third class of derivatives was identified acting as a novel symbiotic agent able to inhibit the platelet aggregation induced by collagen or AA and by thrombin, represented by compounds 4b (LASSBio-694) and 4g (LASSBio-770).     

Synthesis and in vivo anti-mutagenic activity of novel melatonin derivatives

Extensive literature suggests that melatonin play a role against the degenerative effect of central neurotoxins by its acting as free radical scavenger. This study aimed at evaluation of the anti-mutagenic activity of novel synthesized indole derivatives 2, 4a, and 8 in albino male mice in comparison with the parent melatonin. Efficacy of melatonin and its derivatives to influence cyclophosphamide (CP)-induced genotoxicity was tested using micronuclei (MN) formation in the bone marrow cells and determination of DNA, RNA and protein levels as well as cholinesterase and peroxidase activities in several organs of male mice. Following intragastrical injection of melatonin or one of its derivatives daily for 1 week, CP was given intraperitoneally, i.p., as a single dose of 25mg/kg BW. Pyridazin-4-yl thiadiazoloindole derivative 8, diaminothiophen-5-yl thiadiazoloindole derivative 4a and melatonin were significantly able to reduce the number of micronucleated polychromatic erythrocytes (MnPCEs) in the bone marrow cells induced by CP (P<0.0001, P<0.001, P<0.01, respectively). However, reduction of MN formation in the bone marrow cells was not significant when thiadiazoloindole derivative 2 was administered (P=0.14). Examination of the protective effect of melatonin and its derivatives on the levels of DNA, RNA and protein as well as enzyme activities showed that compound 8 had the ability to inhibit the clastogenic effect of CP in several organs of male mice. These findings suggest that compounds 4a, 8 and melatonin were able to reduce the mutagenicity effect of CP in male mice. The ability of compounds 4a, 8 and melatonin to reduce CP-related genotoxicity is possibly attributed to their antioxidant activity.     

Synthesis and in vitro anticancer evaluation of some novel hexahydroquinoline derivatives having a benzenesulfonamide moiety

Inhibition of carbonic anhydrase isozymes has been found to have a role in the treatment of cancer. Several sulfonamide compounds bearing an aromatic or a heteroaromatic ring were found to posses potent carbonic anhydrase inhibitory activity and so can be used in the treatment of several types of cancer. In this paper, we present the synthesis of some novel quinoline 7-13, 21-26, 28 and pyrimidoquinoline 14-18, 20, 27 derivatives having a sulfonamide moiety. All the newly synthesized compounds were evaluated for their in vitro anticancer activity. Several compounds showed interesting cytotoxic activities when compared with the used reference drug. In addition, docking of the synthesized compounds into carbonic anhydrase isozyme II (CA II) active site was performed in order to give a suggestion about the proposed mechanism of action.     

Ecotoxicological effects of hexahydro-1,3,5-trinitro-1,3,5-triazine on soil microbial activities

Although hexahydro-1,3,5-trinitro-1,3,5-triazine (also called RDX or hexogen) is a potentially toxic explosive compound that persists in soil, its ecotoxicological effects on soil organisms have rarely been assessed. In this study, two uncontaminated garden soils were spiked with 10 to 12,500 mg RDX/kg dry soil. Soil microbial activities, i.e., potential nitrification, nitrogen fixation, dehydrogenase, basal respiration, and substrate-induced respiration were chosen as bioindicators and were determined after 1-, 4-, and 12-weeks of exposure. Experimental results indicate that RDX showed significant inhibition (up to 36% of control) on indigenous soil microbial communities over the period of this study. All five bioindicators responded similarly to the RDX challenge. The length of exposure also affected the microbial toxicity of RDX, with 12-week exposure exerting more significant effects than the shorter exposure periods, suggesting that soil microorganisms might become more vulnerable to RDX when exposure is extended. The estimated lowest observable adverse effect concentration of RDX was 1,235 mg/kg. No biodegradation products of RDX were detected at all three sampling times. Compared with 2,4,6-trinitrotoluene (TNT), RDX is less toxic to microbes, probably because of its resistance to biodegradation under aerobic conditions, which precludes metabolic activation of nitro groups.