Synthesis, Biological, and Computational Evaluation of Novel 1,3,5-Substituted Indolin-2-one Derivatives as Inhibitors of Src Tyrosine Kinase.

Several substituted indolin-2-one derivatives were synthesized and evaluated for their activities against Src kinase. Several compounds showed activity against Src, with IC50 values in the low micromolar range. Among them, compound 2f showed the most significant activity with an IC50 value of 1.02 µM. Molecular docking studies have been performed for evaluation of the binding modes of compound 2f into the Src active site. The docking structure of compound 2f disclosed that the indole NH forms a hydrogen bond with the carbonyl of Met341. These results suggest that our novel compound 2f is a promising compound for the further development of indole-based drugs targeting Src kinase.

Determination of Novel SARS-CoV-2 Inhibitors by Combination of Machine Learning and Molecular Modeling Methods.

INTRODUCTION: Within the scope of the project, this study aimed to find novel inhibitors by combining computational methods. In order to design inhibitors, it was aimed to produce molecules similar to the RdRp inhibitor drug Favipiravir by using the deep learning method. METHODS: For this purpose, a Trained Neural Network (TNN) was used to produce 75 molecules similar to Favipiravir by using Simplified Molecular Input Line Entry System (SMILES) representations. The binding properties of molecules to Viral RNA-dependent RNA polymerase (RdRp) were studied by using molecular docking studies. To confirm the accuracy of this method, compounds were also tested against 3CL protease (3CLpro), which is another important enzyme for the progression of SARS-CoV-2. Compounds having better binding energies and RMSD values than favipiravir were searched with similarity analysis on the ChEMBL drug database in order to find similar structures with RdRp and 3CLpro inhibitory activities. RESULTS: A similarity search found new 200 potential RdRp and 3CLpro inhibitors structurally similar to produced molecules, and these compounds were again evaluated for their receptor interactions with molecular docking studies. Compounds showed better interaction with RdRp protease than 3CLpro. This result presented that artificial intelligence correctly produced structures similar to favipiravir that act more specifically as RdRp inhibitors. In addition, Lipinski's rules were applied to the molecules that showed the best interaction with RdRp, and 7 compounds were determined to be potential drug candidates. Among these compounds, a Molecular Dynamic simulation study was applied for ChEMBL ID:1193133 to better understand the existence and duration of the compound in the receptor site. CONCLUSION: The results confirmed that the ChEMBL ID:1193133 compound showed good Root Mean Square Deviation (RMSD), Root Mean Square Fluctuation (RMSF), hydrogen bonding, and remaining time in the active site; therefore, it was considered that it could be active against the virus. This compound was also tested for antiviral activity, and it was determined that it did not delay viral infection, although it was cytotoxic between 5mg/mL-1.25mg/mL concentrations. However, if other compounds could be tested, it might provide a chance to obtain activity, and compounds should also be tested against the enzymes as well as the other types of viruses.

Synthesis of new indole-2-carboxamide and 3-acetamide derivatives and evaluation their antioxidant properties.

In recent years, antioxidant compounds play an important role as a health-protecting factor. Antioxidants protect cells against the damaging effects of reactive oxygen species (ROS). An imbalance between antioxidants and ROS results in oxidative stress, which leads to cellular damage and it is linked to many vital diseases. It was shown that heme oxygenase (HO) provides efficient cytoprotection against oxidative stress. In this study, a series of indole-2-carboxamide and 3-acetamide derivatives was tested for in vitro effects on HO activity and 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition. Among the synthesized compounds, N-[3-(dimethylamino)propyl]-1H-indole-2-carboxamide 3 was found as the most activator of HO and N-(2-(dimethylamino)ethyl)-2-(1H-indol-3-yl)acetamide 8 was found the most potent inhibitor for DPPH at 10(-4) M concentration.

Synthesis, biological evaluation and docking studies of new pyrrolo[2,3-d] pyrimidine derivatives as Src family-selective tyrosine kinase inhibitors.

In this study, the synthesis and potential enzyme interactions of new Pyrrolo[2,3-d]pyrimidine derivatives along with their inhibitory activity against SFK enzymes such as Fyn, Lyn, Hck, and c-Src were reported. The results indicated that compounds were slightly active of tested SFK enzymes in comparison with PP2 for Fyn, A-419259 for Lyn and CGP77675 for c-Src. Compound N-((2-amino-4-oxo-4,7-dihydro-3H-pyrrolo[2,3-d]pyrimidin-5-yl)methyl)-4-(3,4-dimethoxyphenyl)butanamide (5) was identified as a non-selective slight inhibitor against Fyn, Lyn and c-Src. However, compounds did not show any inhibitory effects on Hck. Docking studies were performed to analyze the binding mode of compounds against SFKs. The best interaction was obtained between compound 5 and the active site of Fyn and c-Src enzymes in comparison with reference compounds PP2 and CGP77675, respectively.

N-substituted Indole-2 and 3-carboxamide derivatives as inhibitors of human protein kinase CK2: in vitro assay and molecular modelling study.

Protein kinase CK2 (Casein Kinase 2) is involved in cell growth; proliferation and suppression of apoptosis. Hence, it strongly promotes cell survival and can be considered an important target for human cancers. In the present study, a series of N-substituted indole-2- and 3-carboxamide derivatives were tested for inhibitions of human recombinant protein kinase CK2 to evaluate their anticancer properties. The inhibition test revealed that the most active compound 4 (1-benzyl-N-(2,4-dichlorobenzyl)-1H-indole-2-carboxamide) showed an IC50 value of 14.6 µM towards human protein kinase CK2. A molecular docking study of the compounds with CK2 was performed and revealed the binding mode of the most active compound 4, underlying its inhibitory activity.

Synthesis and Anticancer Activity of Novel Indole Derivatives as Dual EGFR/SRC Kinase Inhibitors.

BACKGROUND: Recent studies showed that the cooperation between c-SRC and EGFR is responsible for more aggressive phenotype in diverse tumors, including glioblastomas and carcinomas of the colon, breast, and lung. Studies show that combination of SRC and EGFR inhibitors can induce apoptosis and delay the acquired resistance to chemotherapy. Therefore, such combination may lead to a new therapeutic strategy for the treatment of EGFR-mutant lung cancer. Osimertinib was developed as a third-generation EGFR-TKI to combat the toxicity of EGFR mutant inhibitors. Due to the resistance and adverse reaction of osimertinib and other kinase inhibitors, 12 novel compounds structurally similar to osimertinib were designed and synthesized. BACKGROUND: Recent studies showed that the cooperation between c-SRC and EGFR is responsible for more aggressive phenotype in diverse tumors, including glioblastomas and carcinomas of the colon, breast, and lung. Studies show that combination of SRC and EGFR inhibitors can induce apoptosis and delay the acquired resistance to chemotherapy. Therefore, such combination may lead to a new therapeutic strategy for the treatment of EGFR-mutant lung cancer. Osimertinib was developed as a third-generation EGFR-TKI to combat the toxicity of EGFR mutant inhibitors. Due to the resistance and adverse reaction of osimertinib and other kinase inhibitors, 12 novel compounds structurally similar to osimertinib were designed and synthesized. METHODS: Compounds were synthesized by developing novel original synthesis methods and receptor interactions were evaluated through a molecular docking study. To evaluate their inhibitory activities against EGFR and SRC kinase, in vitro enzyme assays were used. Anticancer potencies were determined using lung, breast, prostate (A549, MCF6, PC3) cancer cell lines. Compounds were also tested against normal (HEK293) cell line to evaluate their cyctotoxic effects. RESULTS: Although, none of compounds showed stronger inhibition compared to osimertinib in the EGFR enzyme inhibition studies, compound 16 showed the highest efficacy with an IC50 of 1.026 µM. It also presented potent activity against SRC kinase with an IC50 of 0.002 µM. Among the tested compounds, the urea containing derivatives 6-11 exhibited a strong inhibition profile (80.12-89.68%) against SRC kinase in comparison to the reference compound dasatinib (93.26%). Most of the compounds caused more than 50% of cell death in breast, lung and prostate cancer cell lines and weak toxicity for normal cells in comparison to reference compounds osimertinib, dasatinib and cisplatin. Compound 16 showed strong cytotoxicity on lung and prostate cancer cells. Treatment of prostate cancer cell lines with the most active compound, 16, significantly increased the caspase-3 (8-fold), caspase-8 (6-fold) and Bax (5.7-fold) levels and decreased the Bcl-2 level (2.3-fold) compared to the control group. These findings revealed that the compound 16 strongly induces apoptosis in the prostate cancer cell lines. CONCLUSION: Overall kinase inhibition, cytotoxicity and apoptosis assays presented that compound 16 has dual inhibitory activity against SRC and EGFR kinases while maintaining low toxicity against normal cells. Other compounds also showed considerable activity profiles in kinase and cell culture assays.

Investigating the Activity of Indole-2-on Derivative Src Kinase Inhibitors Against Chronic Myeloid Leukemia Cells.

BACKGROUND: Src family tyrosine kinases play a potential role in Bcr-Abl-induced leukemogenesis. Src kinase inhibitors are reported as selective inhibitors of chronic myeloid leukemia. OBJECTIVE: Since Src kinase inhibitors have an inhibitive effect on chronic myeloid leukemia, indole derivatives (C-1, C-2, C-3) previously found as potent inhibitors of Src kinase were tested against chronic myeloid leukemia in this study. METHODS: Cell viability of K562 and R/K562 cells, antiproliferative and antioxidant effects, and inhibition profiles of Bcr-Abl kinase of indole derivatives were determined compared to dasatinib and imatinib. RESULTS: The results showed that compounds affected cell proliferation and decreased the levels of Bcr/Abl. These results confirmed that the antileukemic activity of compounds was related to Bcr/Abl expression. Docking studies also presented that compounds are inhibitors of both Src and Abl kinases. Calculation of drug-like properties showed that compounds could be potential drug candidates. CONCLUSION: Among indole-2-on derivatives, previously identified as Src kinase inhibitors, C-2 has been discovered to be a strong anticancer drug that is active against susceptible and resistant K562 cell lines and induces apoptosis.

Evaluation of novel aminomethyl indole derivatives as Src kinase inhibitors and antioxidant agents.

BACKGROUND: Oxidative stress has been implicated in aging and in a variety of diseases affecting the nervous, respiratory, cardiovascular and gastrointestinal system in humans. Reactive oxygen species (ROS) have been associated with mechanisms to activate kinases, such as protein tyrosine kinases, which may initiate malignant transformation. Significant evidences of the activation of protein kinases by oxidative stress brought increased attention to the role of antioxidants in these mechanisms. Therefore, recent efforts have focused on revealing the relationship between protein kinase inhibition and the levels of ROS production. METHODS: Antioxidant properties of aminomethyl indole derivatives were investigated by employing various in vitro systems, microsomal NADPH-dependent inhibition of lipid peroxidation (LP), interaction of 2,2-diphenyl-1-picrylhydrazyl and scavenging of superoxide anion radical by virtue of superoxide dismutase inhibitory activity. In vitro tyrosine kinase assays of the aminomethyl indole derivatives were evaluated by changes in the enzymatic activity of pp60(c-Src) tyrosine kinase through alterations in the phosphorylation level of immobilized kinase substrate. RESULTS: Analysis of the antioxidant effects of indole 1a-c, bromo indole 2a-c and phenyl indole 3a-c derivatives revealed almost equal inhibition against LP for 5-bromo indole 2a-c and phenyl indole 3a-c derivatives and slight inhibition against superoxide dismutase only for 1a and 1c. Nonsubstituted compounds at position 5 showed half-inhibition of LP. Compound 1a has tyrosine kinase inhibition with an IC(50) of 102.6 ± 1.16 µM. CONCLUSION: The substitution feature at position 5 of the indole ring certainly plays an important role in both tyrosine kinase inhibition and antioxidant capacity. While certain lipophilicity of this substitution is important for antioxidant activity, it may, on the other hand, have a negative impact on the inhibition of Src kinase.

Investigation of aminomethyl indole derivatives as hyaluronidase inhibitors.

Hyaluronidase inhibitors are of potential therapeutic value for the treatment of a variety of diseases, such as cancer, arthrosis, or bacterial infections. Potent and selective hyaluronidase inhibitors are not known so far, and current approaches to the development of hyaluronidase inhibitors are limited. Elevated levels of hyaluronan (HA) are connected with most malignant tumours. Therefore, the search for drugs modulating the hyaluronidase activity became very important. In the present study, a new series of aminomethyl indole derivatives (AMIDs) were tested for inhibition of bovine testes hyaluronidase (BTH). In vitro assays were performed using stains-all at pH 7 and Morgan-Elson reaction at pH 3.5. Among the AMIDs, 3-[(4-methylpiperazin-1-yl)methyl]-5-phenyl-1H-indole (9) was found to be active with 23% inhibition at 50 microM and pH 7. All the other inhibitors showed less activity at pH 3.5 and pH 7. These activity results demonstrated that compounds with phenyl substitution at position 5 have higher activity. The results confirmed that more lipophilic compounds have better inhibition against the hyaluronidase enzyme.

N-substituted indole-3-imine derivatives and their amine congeners: antioxidant and Src kinase inhibitory effects.

Current evidences demonstrated that the activity of protein kinases can be controlled through oxidative stress induced by reactive oxygen species (ROS) and normalized by antioxidants. Recent studies with ROS, generated by mitochondria, suggested the potential signalling role of these species, where ROS, especially hydrogen peroxide, were proposed as membrane-related signalling components. The protein regulation by cellular redox states has shown that protein tyrosine kinase members, such as Src kinase and some of the members of the Src family kinases (SFKs), are proteins regulated by the cellular oxidation and reduction status. In this context, the oxidant or antioxidant potential of the synthetic Src kinase inhibitors previously synthesized and studied by our research group, such as N-substituted indole-3-imine and -amine derivatives, were investigated employing various acellular in vitro methods including microsomal NADPH-dependent inhibition of lipid peroxidation (LP), interaction of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and scavenging of superoxide anion radicals. Here, we report that some of the synthetic inhibitors designed for Src kinase target have both antioxidant and kinase inhibition properties.

Site-specific modification of Shigella flexneri virF mRNA by tRNA-guanine transglycosylase in vitro.

Shigella flexneri is an enteropathogen responsible for severe dysentery in humans. VirF is a key transcriptional regulator that activates the expression of the downstream virulence factors required for cellular invasion and cell-to-cell spread of this pathogen. There are several environmental factors that induce the translation of VirF including temperature, pH, osmolarity and post-transcriptional RNA modification. Durand and colleagues (vacC, a virulence-associated chromosomal locus of Shigella flexneri, is homologous to tgt, a gene encoding tRNA-guanine transglycosylase of Escherichia coli K-12. J. Bacteriol., 176, 4627-4634) have demonstrated a correlation between VirF and tRNA-guanine transglycosylase (TGT), which catalyzes the exchange of the hypermodified base queuine for the guanine in the wobble position of certain tRNAs. They characterized tgt- mutant S. flexneri strains in which the translation of VirF is markedly reduced and the bacteria are unable to invade host cells. Although the function of TGT is to modify tRNA, we report that the virF mRNA is recognized by the Escherichia coli TGT (99% identity to the S. flexneri TGT) in vitro. Further, we show that this recognition results in the site-specific modification of a single base in the virF mRNA. In the context of previous reports that small molecule binding motifs ('riboswitches') in mRNAs modulate mRNA conformation and translation, our observations suggest that TGT may modulate the translation of VirF by base modification of the VirF encoding mRNA.

Synthesis and pp60c-Src tyrosine kinase inhibitory activities of novel indole-3-imine and amine derivatives substituted at N1 and C5.

A series of novel 1,3,5-trisubstituted indole derivatives, namely, N-benzyl 5-phenyl indole-3-imine, N-benzyl-5-(p-fluorophenyl)indole-3-imine and their corresponding amine congeners, were designed and synthesized as pp60(c-Src) tyrosine kinase inhibitors, and their inhibitory activities toward pp60(c-Src) tyrosine kinase were evaluated by in-vitro kinase assay. Pre-screening at two doses of compounds against kinase target revealed that, except for the N-benzyl-5-phenyl indole imine derivatives 7a-7d, all indole derivatives show the target inhibition at varying levels. Consequently, the compounds, 8c, 8f, 8g, and 8h, were selected for prescreening tests. The dose-response curves for up to six concentrations (250 to 7.8 muM) of the active compounds were obtained by tyrosine kinase assay and the four-parameter logistic analysis of these data resulted in the IC(50)s of 4.69, 74.79, 75.06, and 84.23 muM for compounds 8c, 8f, 8g, and 8h, respectively. Therefore, compound 8c, 1-(1-benzyl-5-phenyl-1H-indole-3-yl)-N-(4-fluorobenzyl)methanamine.HCl, was the promising inhibitor for pp60(c-Src), followed by compounds 8g and 8h. Under the same conditions, compound 8f did not provide any reasonable inhibition pattern to be considered as active compound. Therefore, among all four active compounds, compound 8f was not found suitable for further analysis.

A study of 3-substituted benzylidene-1,3-dihydro-indoline derivatives as antimicrobial and antiviral agents.

3-Substituted benzylidene-1,3-dihydro-indoline derivatives were tested for their in vitro antibacterial activity against the Gram-negative bacteria Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and the Gram-positive bacteria Bacillus subtilis, Staphylococcus aureus, and for their their in vitro antifungal activity against Candida krusei and Candida albicans. The minimum inhibitory concentration (MIC) values were determined by the 2-fold serial dilution technique in Mueller Hinton broth and Sabouraud dextrose agar using antibacterial and antifungal assays, respectively. For comparison of the antimicrobial activity, rifampicin, ampicillin trihydrate, gentamicin sulfate, and ofloxacin were used as reference antibacterial agents, and fluconazole and amphotericin B were employed as reference antifungal agents. The most active compound 10 showed notable inhibition against Bacillus subtilis, Staphylococcus aureus, and Candida krusei. Compounds 1 and 6 were found slightly effective against Klebsiella pneumoniae and Escherichia coli. In addition, compounds 13 and 14 showed inhibition against Bacillus subtilis and Staphylococcus aureus. Indole derivatives were also tested in vitro for replication of the HepAD38 cell line and compared with lamivudine (3TC, L-2',3'-dideoxy-3'-thiacytidine). The IC50 values of the compounds were found to be >1000 microM against HBV except for compound 13 which exhibited activity with an IC50 value of 500 microM.

Drug Repurposing in the Development of Anticancer Agents.

BACKGROUND: Research into repositioning known drugs to treat cancer other than the originally intended disease continues to grow and develop, encouraged in part, by several recent success stories. Many of the studies in this article are geared towards repurposing generic drugs because additional clinical trials are relatively easy to perform and the drug safety profiles have previously been established. OBJECTIVE: This review provides an overview of anticancer drug development strategies which is one of the important areas of drug restructuring. METHODS: Repurposed drugs for cancer treatments are classified by their pharmacological effects. The successes and failures of important repurposed drugs as anticancer agents are evaluated in this review. RESULTS AND CONCLUSION: Drugs could have many off-target effects, and can be intelligently repurposed if the off-target effects can be employed for therapeutic purposes. In cancer, due to the heterogeneity of the disease, often targets are quite diverse, hence a number of already known drugs that interfere with these targets could be deployed or repurposed with appropriate research and development.

Synthesis, biological evaluation, and molecular modeling studies of methylene imidazole substituted biaryls as inhibitors of human 17alpha-hydroxylase-17,20-lyase (CYP17)--part II: Core rigidification and influence of substituents at the methylene bridge.

Thirty-five novel substituted imidazolyl methylene biphenyls have been synthesized as CYP17 inhibitors for the potential treatment of prostate cancer. Their activities have been tested with recombinant human CYP17 expressed in Escherichia coli. Promising compounds were tested for selectivity against CYP11B1, CYP11B2, and hepatic CYP enzymes 3A4, 1A2, 2B6 and 2D6. The core rigidified compounds (30-35) were the most active ones, being much more potent than Ketoconazole and reaching the activity of Abiraterone. However, they were not very selective. Another rather potent and more selective inhibitor (compound 23, IC(50)=345 nM) was further examined in rats regarding plasma testosterone levels and pharmacokinetic properties. Compared to the reference Abiraterone, 23 was more active in vivo, showed a longer plasma half-life (10h) and a higher bioavailability. Using our CYP17 homology protein model, docking studies with selected compounds were performed to study possible interactions between inhibitors and amino acid residues of the active site.

Synthesis and evaluation of N-substituted indole-3-carboxamide derivatives as inhibitors of lipid peroxidation and superoxide anion formation.

The in vitro antioxidant effects of novel N-substituted indole-3-carboxamides (I3CDs) 1-10 on rat liver microsomal NADPH-dependent lipid peroxidation (LP) levels and their free radicals scavenging properties were determined by the inhibition of superoxide anion formation (SOD). Among the synthesized compounds, 4, 5, 8 and 9 significantly inhibited SOD with an inhibition range at 84-100% at 10(-3) M concentration. The presence of halo substituents both ortho- and para- positions of these compounds resulted 100% inhibition of SOD. Comparison the activity results of halogenated and non-halogenated derivatives suggested that the halogenated compounds are more active than the non-halogenated compounds. On the other hand, the introduction of a para fluoro benzyl in the 1-position of indole (compounds 7, 8) has more impact on the SOD inhibition when the benzamide ring was mono halogenated. However, none of other compounds had a significant inhibitory effects on the level of lipid peroxidation.

Antimicrobial and antiviral screening of novel indole carboxamide and propanamide derivatives.

A few series of indole derivatives were screened for antimicrobial, antifungal and anti-HBV activities. The compounds were tested for their in vitro antibacterial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and for their antifungal activity against Candida albicans using a disc diffusion method, which measures the diameter of the inhibition zone around a paper disc soaked in a solution of the test compounds. The antimicrobial activity results showed that all compounds are as a active as the standard compound ampicillin against Staphylococcus aureus. It was also found that indole carboxamide derivatives, substituted at 3-position with several benzyl groups, showed better inhibition of Bacillus subtilis than their congeners substituted at 2-position. Activity patterns of the compounds against Escherichia coli and Staphylococcus aureus were found slightly different by the same method. In this case, there was no correlation between structure and activity of the compounds. The antifungal activity of carboxamide derivatives was found higher compared to that of the propanamide derivatives. The minimum inhibitory concentration (MIC) values of some indole derivatives were also determined by the tube dilution technique. The MIC values of the compounds were found nearly 20- to 100-fold smaller compared to the standard compounds ciprofloxacin and ampicillin (1.56-3.13 microg/ml and 1.56-12.5 microg/ml, respectively) against Staphylococcus aureus, Bacillus subtilis and Escherichia coli. The MIC values of the tested compounds showed that these are better inhibitors for Candida albicans. Indole derivatives were screened by the anti-HBV susceptibility test. No compound showed good inhibition against the HBV virus.

Overview on Anticancer Drug Design and Development.

BACKGROUND: Many impediments of current anti-cancer therapies have urged scientists to discover new agents. As a result of growing spectrums of new targets and strategies and recent biological and biotechnological progresses, many anti-cancer agents such as monoclonal antibodies, small molecule tyrosine kinase inhibitors and epigenetic drugs have been reached to clinical trials. OBJECTIVES: This review helps to understand the rationale for the development of inhibitors against major targets such as cell growth, proliferation, survival, angiogenesis and recent targets such as proteasome, heat shock proteins, and epigenetics. METHODS: Recent approaches of the target-based anti-cancer drug developments were highlighted to giving some examples from approved agents. Many factors, such as metabolic change, hypoxia, cancer precursors and cancer resistant cells, and their effect on drug resistance mechanisms were discussed. The impacts of advanced computational techniques to identify targets of cancer and designing more selective inhibitors were explained. RESULTS: Contributions of recent techniques such as a network analysis, the precise modes of action and computational methodologies especially simulation of bio-molecular processes to clarify targets, mechanism actions and reasons of lack of efficacy of anti-cancer drugs have been explained. The relationship between the several mechanisms and molecular design strategies has been discussed. CONCLUSION: This review provides an overview of important targets and design strategies of anti-cancer drugs, advantages and disadvantages of these methods and evaluation of some currently used anticancer targets in clinical studies.

SAHAquines, Novel Hybrids Based on SAHA and Primaquine Motifs, as Potential Cytostatic and Antiplasmodial Agents.

We report the synthesis of SAHAquines and related primaquine (PQ) derivatives. SAHAquines are novel hybrid compounds that combine moieties of suberoylanilide hydroxamic acid (SAHA), an anticancer agent with weak antiplasmodial activity, and PQ, an antimalarial drug with low antiproliferative activity. The preparation of SAHAquines is simple, cheap, and high yielding. It includes the following steps: coupling reaction between primaquine and a dicarboxylic acid monoester, hydrolysis, a new coupling reaction with O-protected hydroxylamine, and deprotection. SAHAquines 5 a-d showed significant reduction in cell viability. Among the three human cancer cell lines (U2OS, HepG2, and MCF-7), the most responsive were the MCF-7 cells. The antibodies against acetylated histone H3K9/H3K14 in MCF-7 cells revealed a significant enhancement following treatment with N-hydroxy-N'-{4-[(6-methoxyquinolin-8-yl)amino]pentyl}pentanediamide (5 b). Ethyl (2E)-3-({4-[(6-methoxyquinolin-8-yl)amino]pentyl}carbamoyl)prop-2-enoate (2 b) and SAHAquines were the most active compounds against both the hepatic and erythrocytic stages of Plasmodium parasites, some of them at sub-micromolar concentrations. The results of our research suggest that SAHAquines are promising leads for new anticancer and antimalarial agents.

The Effects of 1,3,5-trisubstituted Indole Derivatives on Cell Growth, Apoptosis and MMP-2/9 mRNA Expression of MCF-7 Human Breast Cancer Cells.

BACKGROUND: Matrix metalloproteinases are known as extracellular matrix degrading enzymes and have important role on tumor progression. OBJECTIVE: This study reports the effects of 1,3,5-trisubstituted indole derivatives on cytotoxicity, apoptosis and MMP- 2/MMP-9 mRNA expression of MCF-7 human breast carcinoma cells. METHOD: The cytotoxic effects of the compounds on MCF-7 cells were performed by MTT test, and cell proliferation was determined via BrdU incorporation. The apoptotic effects were observed by cell death detection elisa. The effects of the compounds on MMP-2/-9 enzyme activity and mRNA expression were also performed. RESULTS: The compounds inhibited the proliferation of MCF-7 breast carcinoma cells significantly in a dose dependent manner. All compounds were able to induce DNA fragmentation, especially compound 1. The IC50 values of compound 2 and 4 for MMP-2 were 0.42 µM and 1.88 µM, respectively. MMP-2 mRNA expression results were correlated with the inhibition of enzyme activity, such compound 4 inhibited MMP-2 mRNA expression at all treated concentrations. Docking simulation has also been performed to analyze the binding mode of compounds and the results showed that compound 2, the most active compound, formed a hydrogen bond with Glu202 for binding to the MMP-2 active site. In addition, the hydrophobic parts of compound 2 are in contact with nonpolar surface areas of MMP-2, such as His201, His211, Tyr223 and Tyr193. CONCLUSION: According to the molecular docking results along with the biological assay data, it is suggested that compound 2 might be used for further design and development of MMP-2 inhibitors.