Medicinal Chemistry - Volume 11, Issue 6, 2015

The synthesis and antitumor activity screening of 4-aminothiazol-2(5H)-one derivatives were performed. The absence of possible 4-amino-imino tautomerism of thiazolidinones-2 has been confirmed based on the study of the molecule structures. The existence of the alone amino-form was confirmed. An anticancer activity screening was performed within the Developmental Therapeutics Program (National Cancer Institute/NIH, USA). Tested compounds possess low to moderate anticancer activity (average values - 60 cancer cell lines assay) with significant selective action on certain cancer cell lines (CCRF-CEM and RPMI-8226/leukemia, U251/CNS cancer, RFX 393/renal cancer, OVCAR/ovarian cancer etc.). The advantage of 5-ylidene-4-R-amino derivatives in comparison with compounds with free amino group was shown. Some structure-activity findings, the comparison of target compounds with isomeric 5-ylidene-2-imino(amino)thiazol-4(5H)-ones, as well as COMPARE analysis were described. Among the tested compounds (Z)-5-(furan-2-ylmethylidene)-4-(4-chlorophenylamino)thiazol-2(5H)-one (IIIk) and (Z)-5-(4-diethylaminophenylmethylidene)-4-(4-hydroxy-5-isopropyl-2-methylphenylamino)thiazol-2(5H)-one (IIIp) possessed the highest levels of activity.

Prostate cancer (PC) is a major health issue in the world. Treatments of localized PC are quite efficient and usually involve surgery, radiotherapy and/or hormonal therapy. Metastatic PC is however rarely curable to this day. Treatments of metastatic PC involve radiotherapy, chemotherapy and hormonal treatment such as orchiectomy, antiandrogens and luteinizing hormone-releasing hormone agonists. The suppression of tumor growth by hormonal treatment is efficient but overtime resistance still occurs and the disease progresses. Thus, more urgently than ever there is a need for discovery of new treatment options for castration-resistant PC (CRPC). Hence, we designed and tested a series of amide derivatives located at position 7α of testosterone as prospective “natural” or “semisynthetic” anticancer agents against CRPC with the goal of discovering therapeutic alternatives for the disease. This manuscript describes an efficient path towards the target molecules that are made in only 6 or 7 chemical steps from testosterone in good overall yields. This strategy can be used to make several compounds of interest that present higher biological activity than the classic antiandrogen; cyproterone acetate (3). The best testosterone-7α-amide was the N-2-pyridylethylamide (25) which was as active as the antiandrogen cyproterone acetate (3) on androgen-dependent LNCaP cells and 2.7 times more active on androgen-independent PC3 prostate cancer cells. The results obtained show the synthetic feasibility and the potential for future development of this unique class of semi-synthetic anticancer agents that offer the premise of new treatment modalities for patients afflicted with CRPC.

The aim of the present study was to examine the impact of a four platinum complexes of formula [Pt2L4(berenil)2]Cl4 where L is 3-ethylpyridine (Pt10), 3-(n-butyl)pyridine (Pt11), 4- ethylpyridine (Pt12) and 4-(t-butyl)pyridine (Pt13) on viability of Ishikawa endometrial cancer cells using the MTT assay and inhibition of [3H]thymidine incorporation into DNA. Our results confirm that compounds Pt10-Pt13 are more potent antiproliferative agents than cisplatin in endometrial cancer cells. Moreover, it was shown that all examined compounds Pt10-Pt13 inhibit collagen biosynthesis in neoplastic cells stronger than cisplatin. Flow cytometric analysis after annexin V-FITC and propidium iodide staining confirmed also that apoptosis was the main response of Ishikawa endometrial cancer cells to Pt10-Pt13 treatment. Our results suggest that apoptosis of Ishikawa endometrial cancer cell lines in the presence of Pt10-Pt13 follows the mitochondrial pathway, with the decrease in mitochondrial membrane potential and activation of caspase 9, as well as by the external pathway with the significant increase in FADD protein expression and caspase 8.

Cutaneous melanoma (CM) is a malignant skin cancer with the high incidence in whiteskinned populations. Host genetic factors (such as: genes in nucleotide excision repair system or cell proliferation regulation system) interacted with ultraviolet radiation are potential reasons for CM. Previous studies about associations between CM and the rs4444903 (+61A>G) in the Epidermal growth factor gene (EGF) or rs13181 (+35931 A>C) in the xeroderma pigmentosum group D gene (XPD) have produced inconsistent results. To clarify these associations, metaanalyses of available candidate case-control association studies about Caucasians were performed. Data of each study were gathered according to the “Quality-Evaluation Score” (Ver.1.0). Finally, the meta-analysis with 2167 cases/4211 controls showed that the EGF rs4444903 had no significant association with CM (p>0.05), while the analysis with 3,492 cases/5,381 controls indicated the A allele of XPD rs13181 was significantly associated with CM (odds ratio= 0.93, 95% CI: 0.87–0.99; p=0.019). These results are also supported with linkage disequilibrium (LD) structure analysis. The current meta-analyses results suggest that the XPD gene, but not the EGF gene, has contributed to CM susceptibility, and XPD is a possible drug target.

Nuclear factor kappa B (NF-kB) is one of the most important transcription factors whose modulation triggers a cascade of signaling events, namely the expression of many cytokines, enzymes, chemokines, and adhesion molecules, some of which being potential key targets for intervention in the treatment of inflammatory conditions. The 2-styrylchromones (2-SC) designation represents a well-recognized group of natural and synthetic chromones, vinylogues of flavones (2-phenylchromones). Several 2-SC were recently tested for their anti-inflammatory potential, regarding the arachidonic acid metabolic cascade, showing some motivating results. In addition, several flavones with structural similarities to 2-SC have shown NF-kB inhibitory properties. Hence, the aim of the present work was to continue the investigation on the interference of 2-SC in inflammatory pathways. Herein we report their effects on lipopolysaccharide (LPS)-induced NF-kB activation and consequent production of proinflammatory cytokines/chemokine, using a human monocytic cell line (THP-1). From the twelve 2-SC tested, three of them were able to significantly inhibit the NF-kB activation and to reduce the production of the proinflammatory cytokines/chemokine. The compound 3’,4’,5-trihydroxy-2- styrylchromone stood up as the most active in both assays, being a promising candidate for an anti-inflammatory drug.

37 acetylenic chalcones were designed, synthesized by the Pd/Cu catalyzed Sonogashira coupling reaction, and evaluated for anti-inflammatory activities. A majority of these compounds showed remarkable inhibitions of the expression of inflammatory cytokines in LPS-stimulated macrophages. Six of them demonstrated the dose-dependent inhibition of inflammatory cytokines, and 4f is the most potent antiinflammatory compound. Our results suggest that these active acetylenic chalcones could be further developed as promising candidates for the treatment of inflammatory diseases.

MK2 (or MAPKAPK2) was already known for its role in the inflammatory response, however recent studies indicate the involvement of this protein kinase in the DNA damage response mechanism. Within its kinase family the enzyme MK3 shows the highest identity with MK2. Here we report a theoretical study on the binding of two molecules, 05B and P4O, to the proteins MK2 and MK3. The data here obtained may shed light on the contribution of individual residues and binding site water molecules for the binding of potential inhibitors to these two kinases.

Mitochondrial enzymes monoamine oxidases were thought to be an emerging and useful therapeutic target for neurodegenerative disorders. Monoamine oxidases have two isoforms, A and B. MAO-A is related with metabolism of amine neurotransmitters in the brain whereas MAO-B is concerned with aging related neurodegenerative disorders. Therefore the identification, characterization and discovery of potent MAO-A and B inhibitors is very crucial in research. A series of quinolyl-thienyl chalcones were tested against MAO-A and B. Among the screened compounds, most of them revealed potent MAO-A and B inhibition. Compound 5i presented most potent MAO-A inhibition having IC50 values 0.047 µM, while 4l showed excellent inhibitory potency against MAO-B among all the tested compound having IC50 values 0.063 µM. Molecular modelling studies were performed against human MAO-A and MAO-B for the explanation of binding site interactions.

A method of detecting Escherichia coli (EC) in in vivo blood with septicemia was sought using a handmade macro three-electrode (ME) system. Towards this end, an analytical ME probe was prepared using mercury immobilized on a carbon nanotube working electrode, and two graphite pencils were used as counter and reference electrodes instead of the expensive Ag/AgCl standard and Pt counter electrode. Under the optimum conditions, the cyclic potential was obtained at a 0.05 V anodic, then the square-wave stripping working range was obtained at 0.5-3.5 ml (3x102~4x102CFU/1ml) EC. Also under the optimum conditions, the statistic stability was examined in 1 ml EC 15th repeat anodic, with a relative standard deviation of RSD=0.98x10-2. The developed method was applied to non treated blood, using only one drop. The patient blood with septicemia had a fast accumulation time (30 sec). A diagnostic detection limit of 0.06 ml EC was obtained. The recognition methods can be applied to in vivo vascular blood and real organic fluids, and can be used for poisoning control.

Aim to find new compounds with stronger anticonvulsant activity and lower neurotoxicity, a novel series of 6-substituted-pyrido[3,2-d]pyridazine derivatives was synthesized using furo[3,4-b]pyridine-5,7-dione as the starting material. We evaluated their anticonvulsant activity and neurotoxicity using by maximal electroshock (MES) and rotarod neurotoxicity (TOX) tests. The results showed that N-m-chlorophenyl-[1,2,4]triazolo- [4,3-b]-pyrido[3,2- d]pyridazin-6-amine (3) was the most potent anticonvulsant, with ED50 value of 13.6 mg/kg and protective index ( PI = TD50/ED50) values of 7.2 in the MES test. Compound N-m-chlorophenyltetriazolo[5,1-b]-pyrido[3,2-d]pyridazin-6-amine (19), exhibited significant anticonvulsant activity in maximal electroshock test with PI value of 13.4, which was safer than marketed drug carbamazepine.

Undoubtedly, efficient cancer treatment has been a significant challenge for the scientific community over the last decades. Despite tremendous progress made towards this direction, there are still efforts needed to discover new anticancer drugs. In this work, a series of N-substituted pyrrolebased scaffolds have been synthesized and evaluated for antiproliferative activity against a panel of cancer cell lines (L1210, CEM and HeLa). Furthermore, in order to discover new scaffolds as antiviral agents, all the examined compounds were evaluated for activity against different types of DNA and RNA viruses. The key feature of the above structures is the existence of an aromatic ring with at least one hydrogen-bonding donor and acceptor group. Results have shown noteworthy cytostatic activity for three of the synthesized compounds (1, 3 and 9). Especially, compound 1, containing a tropolone ring, proved to be the most promising scaffold (IC50:10-14 µM) for the development of novel potential anticancer agents. In addition, compound 1 has shown modest anti-HSV-1, -HSV2 activity in HEL cell cultures (EC50: 27-40 µM).