Medicinal Chemistry - Volume 13, Issue 2, 2017

Background: Cystic fibrosis (CF) is an incurable, chronic disease, which causes severe damages to respiratory and digestive tracts. It is the most common genetically inherited disease among caucasians. This disease is caused by defects in CF genes, the so-called mutations in cystic fibrosis transmembrane conductance regulator (CFTR) gene population. At present over 100,000 people suffer from this disease worldwide. Objective: The purpose of this review study is to describe the pathophysiology of CF and provide the latest information on its diagnosis and treatment therapies with respect to the improvement of patient’s quality of life and emphasis on targeted specialized care. Method: The methodological approaches include a method of literature review of available sources exploring the issue of cystic fibrosis both from a global and specific perspective point of view. A search was performed in the databases PubMed, MEDLINE, Web of Science, Scopus, Springer and ScienceDirect. Furthermore, other sources cited in the analyzed studies were also examined. On the basis of evaluation of these literature sources, the research issue was explored. Results: The main benefits (e.g., specialized centres for the treatment of CF exist or a new breakthrough in the gene therapy of CF has been made) and limitations (e.g., comorbidity of CF, lifelong and costly treatment, or adverse impact on patient’s and caregiver’s quality of life) in the treatment of narcolepsy are highlighted. Conclusion: CF requires an integrated treatment approach in specialized CF centers, involving various factors contributing to a better patient’s state of health in the form of relevant and well-balanced non-pharmacological and pharmacological therapies. In addition, further large scale clinical trials are needed in order to develop compounds that are aimed at the most common classes of CFTR.

Background: Trypanosomiasis and leishmaniasis cause severe infections in humans and domestic animals in the tropics. Although typical diseases in Latin America, globalization and the migration of infected people has spread these diseases to countries in North America, Asia and Europe. Currently available drugs are not effective in the chronic phase, as well as cause side effects and develop resistance. Results: Among the chemical groups studied as potential anti-T. cruzi and anti-Leishmania are the thio-and semicarbazones, which are easy to obtain, possess structural versatility and can sequester metal. In this article, we present an overview of thio-and semicarbazones associated with heterocycles, indanones, and styryl and aryl skeletons, including their metal complexes with antimony, platinum, palladium, copper, ruthenium, rhenium, manganese and vanadium. Conclusion: Because of the efficiency and selectivity that some of these derivatives have shown, it can be concluded that thio-and semicarbazones constitute promising chemical scaffolds in the search for new anti-parasitic agents.

Background: Pharmacophore hybridization by bioconjugation, in which two bioactive moieties are covalently linked, is one of the current strategies in drug discovery for the development of new compounds with improved affinity and efficacy relative to those of the parent molecules. Prompted by the idea that cancer cells may be effectively killed by 3'-azido-3'-deoxythymidine (AZT) and salinomycin (SAL) individually, we synthesized hybrids of these compounds. The development of this type of derivatives, which can easily penetrate the lipid-rich cell membranes and then undergo hydrolysis inside the cancer cells, is an important research area. Methods: Efficient methods for the synthesis of two new conjugates are presented. The first method is based on the ‘click’ chemistry and involves the copper(I) catalysed 1,3-dipolar Huisgen cycloaddition reaction. In the second method AZT as well as SAL are connected by the ester bond under mild reaction conditions. The in vitro anti-proliferative activity of both conjugates against several drugsensitive and drug-resistant cancer cell lines as well as toxicity against normal murine embryonic fibroblasts are also determined. Results: Our studies clearly showed that the hybrid obtained via esterification reaction (SAL-OAZT) seems to be attractive in the fight against neoplastic diseases because it helps to overcome a strong drug-resistance of the cancer cell lines examined at low micromolar concentrations. The anticancer activity of this hybrid is also connected with high selectivity indexes (low toxicity) against normal cells.On the other hand, the ‘click’ conjugate (SAL-AZT) is practically inactive against the drug-resistant cancer cell lines tested and weakly active against the drug-sensitive ones. Also no synergistic effect has been found between SAL and AZT against eight cancer cell lines studied. Conclusion: All of our findings support a strategy to decrease the doxorubicin concentration in combination with SAL-O-AZT hybrid in order to reduce the toxicity of this drug, as recently demonstrated for SAL. The advantages of the SAL-O-AZT conjugate over SAL are better RI and SI parameters at similar IC50 values.

Background: We designed hybrid molecules between propamidine and benzimidazole in order to retain the antiprotozoal action, but decreasing the toxic effect of the molecule. Objective: Design and prepare 12 hybrids for testing their antiparasitic effect over three protozoa: Giardia intestinalis, Trichomonas vaginalis and Leishmania mexicana, as well as conduct several in silico simulations such as toxicological profile, molecular docking and molecular dynamics in order to understand their potential mode of action. Methods: Hybrids 1-3, 6-9 and 12 were obtained using a chemical pathway previously reported. Compounds 4, 5, 10 and 11 were prepared using a one-pot reduction–cyclization reaction. The in vitro antiparasitic and cytotoxic activities of these compounds were conducted. It was calculated several properties such as toxicity, PK behavior, as well as docking studies and molecular dynamics of the most active compound performed in a DNA sequence dodecamer in comparison with propamidine. Results: Compound 2 was 183, 127 and 202 times more active against G. intestinalis than metronidazole, pentamidine and propamidine. It was eleven times more active than pentamidine against L. mexicana. This compound showed low in vitro mammalian cytotoxicity. Molecular simulations showed a stable complex 2-DNA that occurred in the minor groove, analogous to propamidine-DNA complex. Conclusion: Compound 2, exhibited the higher bioactivity, especially towards G. intestinalis and L. mexicana. This study demonstrated that the replacement of benzimidazole scaffold instead of toxic amidine group in propamidine, results in an enhancement of antiprotozoal bioactivity. The preliminary molecular dynamics simulation suggests that the ligand–DNA complex is stable.

Background: Chagas disease is a public health problem caused by Trypanosoma cruzi. Cruzain is a pharmacological target for designing a new drug against this parasite. Hydrazone and Nacylhydrazone derivatives have been traditionally associated as potential Cruzain inhibitors. Additionally, benzenesulfonyl derivatives show trypanocidal activity. Therefore, in this study, the combination of both structures has been taken into account for drug design. Methods: Seven benzenesulfonylhydrazone (BS-H) and seven N-propionyl benzenesulfonylhydrazone (BS-NAH) derivatives were synthetized and elucidated by infrared spectroscopy, nuclear magnetic resonance, and elemental analysis. All compounds were evaluated biologically in vitro against two strains of Trypanosoma cruzi (NINOA and INC-5), which are endemic in Mexico, and compared with the reference drugs nifurtimox and benznidazole. In order to gain insight into the putative molecular origin of the trypanocidal properties of these derivatives, docking studies were carried out with Cruzain. Results: Compounds 4 and 6 (BS-H) and 10, 12-14 (BS-NAH) showed the best biological activity against NINOA and INC-5 strains, respectively. Compound 13 was the most potent trypanocidal compound showing a LC50 of 0.06 μM against INC-5 strain. However, compound 4 showed the best activity against both strains (LC50 <30 μM). Theoretical binding modes obtained suggested covalent binding that could explain their biological activity. Conclusion: Benzenesulfonyl and N-propionyl benzenesulfonyl hydrazone derivatives are good options for developing new trypanocidal agents. Particularly, compound 4 could be considered a lead compound.

Background: Immunosuppressive drugs are widely used to prevent and treat allograft rejection and autoimmune diseases. Mycophenolic acid (MPA) and its derivatives are currently one of the most prescribed immunosuppressive drugs; however, metabolic drawbacks and variable interand intrapatient responses limit their use. Objective: In order to find out new safe and effective immunosuppressive compounds, we report here the synthesis and pharmacological evaluation of hybrid MPA derivatives containing the thalidomide/ phthalimide subunits. Results: All compounds 3a-d exhibited an enhanced ability to reduce the levels of pro-inflammatory cytokines compared to the parental drugs MPA and thalidomide. The mixed lymphocyte reaction assay has demonstrated that compound 3d - (E)-(3-(1,3-dioxoisoindolin-2-yl)-2,6-dioxopiperidin-1- yl)methyl-6-(4-hydroxy-6-methoxy-7-methyl-3-oxo-1,3-dihydroisobenzofuran-5-yl)-4-methylhex-4- enoate – has superior activity compared to that of MPA. In addition, compound 3d was less cytotoxic against Jurkat cells than MPA and did not demonstrate in vivo genotoxic effect. Conclusion: All these data have shown that compound 3d is a promising lead compound useful in the immunosuppressive therapy.

Background: Since flavonoids fused by benzene have been known for their potent chemopreventive effects, in this study, we examined the relationship between the structures and activities of benzoflavones, benzoflavanones, benzochalcones, and benzochalcone derivatives bearing the pyrazole moiety against human colon cancer cells. Methods: We investigated the effect of 34 benzoflavonoids on the inhibition of colon cancer cells based on the clonogenicity. The biological activity values used for the quantitative structure-activity relationship (QSAR) calculations were obtained from the cell growth inhibition on the basis of clonogenicity. 3D-QSAR calculations were performed using comparative molecular field analyses (CoMFA) and comparative molecular similarity index analyses (CoMSIA). Results: Of several CoMFA and CoMSIA models, the best models showing the highest cross validated correlation coefficient were selected and validated. The cell growth inhibition values were calculated using the above models. The structural conditions to show good cell growth inhibitory effects on human colon cancer cells were analyzed by CoMFA and CoMSIA contour maps. The contribution of steric fields remarkably decreased without any change in the contribution of the electrostatic field, which means that electrostatic contribution is more crucial than the steric contribution in the modification of benzoflavonoids. Furthermore, the increase in the hydrogen bond donor contribution was approximately proportional to the decrease in steric field contribution. Conclusion: This study demonstrated that benzoflavonoids structure hinders colon cancer clonogenicity. Most of the benzoflavonoids structures comprised a C-3 linkage between the naphthalene and phenyl moieties, which contained diverse functional moieties such as oxygen-fused rings, double bonds, pyrazole rings, and sulfur constituents, and were able to exhibit great potential in diverse anticancer effects. Also, the positions of the hydroxyl group close to the naphthalene and phenyl rings were crucial for activity against colon cancer. The structural conditions obtained here may help us design potent benzoflavonoids against colon cancer cells and predict their activities.

Background: Sorafenib is an important VEGFR2/KDR inhibitor which is widely used for the treatment of cancer. Objective: In this paper, two series of sorafenib analogues N-(3-fluoro-4-(pyridin-4-yloxy)phenyl)-4- phenylpicolinamides(13a–k) and N-(3-fluoro-4-(pyridin-4-yloxy)phenyl)-5-phenylpicolinamides (14a–k) were designed and synthesized. Methods: Their structures were confirmed by various analytical methods, such as 1 H and 13 C NMR, m.p., MS, HRMS. All of them were evaluated for IC50 values against three cancer cell lines (A549, PC-3 and MCF-7). Results: Eleven of the synthesized compounds showed moderate to excellent cytotoxicity activity against different cancer cells, whose potency from single-digit μM to nanomolar range. And five of them were equal to more potent than sorafenib against one or more cell lines. The most promising compound 14c showed excellent antitumor activities against PC-3 and MCF-7 cell lines with IC50 values of 2.62±1.07 μM and 1.14±0.92 μM, which were 1.15 to 2.75-fold more active than sorafenib (3.03±1.01 μM, 3.14±1.65 μM), respectively. Conclusion: Structure-activity relationships (SARs) and docking studies indicated that the replacement of diarylurea of sorafenib with phenylpicolinamide moiety benefited to the activity. The position of aryl group and the substituents of aryl group had a great influence on antitumor activity and selectivity. The aryl groups with the substitute of alkyl groups (-CH3), halogen atoms (-F,Cl) were favorable to the cytotoxicity. However, this series of compounds showed moderate activity against VEGFR2/KDR kinase. Mechanism of target compounds was not quite clear and further study will be carried out to identify the possible target.

Background: Nonsteriodal anti-inflammatory drugs (NSAIDs) are numerous and widely used for more than 60 years, but there is still a strong need for developing novel selective NSAIDs. The need is justified by the fact that nonselective NSAIDs can produce serious gastric side effects and that some of the selective NSAID are withdrawn due to their cardiotoxic side effects. Methods: Eight β-hydroxy-β-arylpropanoic acids, which belong to the arylpropanoic acid class of compounds, structurally similar to some nonsteroidal anti-inflammatory drugs (NSAIDs), were docked into 3D catalytic site of both cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2). Seven out of those eight acids were synthesized using already published modification of Reformatsky reaction additionally optimized by increasing temperature. Synthesized compounds were tested in vivo in order to elucidate anti-inflammatory activity, gastric tolerability and impact on liver function of rats. Results: Results of docking studies have indicated that all compounds have potential to selectively inhibit COX-2 isoform, but that the compounds containing polar substituents on phenyl ring are better inhibitors. Results of carrageenan-induced rat paw oedema test have shown that all compounds exhibit dose dependence and good gastric tolerability and none of the tested compounds have shown negative effect on liver function compared to ibuprofen. Conclusion: The compound containing polar nitro group in para position has shown the best docking results, anti-inflammatory activity, low hepatotoxicity and good gastric tolerability.

Background: In spite of substantial progress in scientific cognizance and medical technology, still infectious diseases are among the leading cause of morbidity and mortality. Creatinine and Schiff bases are well known for their diverse range of biological activities and thought to be emerging and useful therapeutic target for the treatment of several diseases. Methods: The present work was aimed to illustrate the influence of substitution of amides and Schiff bases on creatinine and their antimicrobial, antioxidant and anti-urease effectiveness was determined. Creatinine substituted amides (1-2) and creatinine Schiff bases (3-7) were synthesized and characterized by NMR and IR spectral data in combination with elemental analysis. All the compounds (1-7) were investigated on Jack bean urease for their urease inhibitory potential. Investigation of antimicrobial activity of the compounds was made by the agar dilution method. Moreover, 1,1-diphenyl-2- picrylhydrazyl (DPPH) method was used to determine their antioxidant potential. Molecular docking studies were also carried out to elucidate their relationship with the binding pockets of the enzyme. Results: The compounds were found to be potent inhibitors of urease. The synthesized derivatives exhibited significant inhibition against Gram-positive and Gram-negative bacterial strains, as compared to standard, ciprofloxacin. Creatinine based derivatives exhibited potential antifungal activity when tested on infectious and pathogenic fungal strains. Similarly, most of the compounds exhibited good antioxidant activity. Conclusion: These derivatives may serve as a source of potential antioxidants and also help to retard microbial growth in food industry. Similarly, the studies provide a basis for further research to develop more potent urease inhibitory compounds of medicinal /agricultural interest.