Synthesis of new symmetrical and asymmetrical bis-amidines with high biological activity.

The main goal of this project is to obtain by chemical synthesis a series of new compounds from the bis-amidine group and preliminary analysis of their biological activity. This research will contribute to broadening the knowledge of organic synthesis (classical and using microwave radiation) used to obtain new chemical compounds. These studies will also allow the extension of the library of chemical compounds, which may be used in the future in various scientific research into other topics, but related to pentamidine derivatives. In my research work, I search for new chemotherapeutics in the group of compounds with two amidine groups, the so-called bis amidine. The best known drug in this group is pentamidine, used in the treatment of pneumocystis pneumonia (Pnemocystis carinii infections) and in the treatment of tropical diseases caused by protozoa (e.g. leishmaniasis). Compounds from the bis-amidine group are characterized by broad biological activity. Their activity may be e.g. antiprotozoal, antifungal, antimicrobial, antitumor, anti-inflammatory, they act on NMDA receptors. I have developed relatively efficient methods for the synthesis of new bis-amidines. They are obtained mainly by transforming the cyano group of the previously obtained bis-nitriles, which I synthesize with various methods, mainly in O-alkylation reactions of 4-hydroxybenzonitriles or aromatic nucleophilic substitution of para-substituted halogenobenzonitriles. I transform the cyano group mainly on the basis of proven methods: Pinera or obtaining an oxime and then reducing it. So far I have received several series of new bis-amidines with proven anti-Pneumocystis carinii and antibacterial activity. After receiving, appropriate purification and confirmation of their structure, the compounds are subjected to preliminary tests of biological activity. On the basis of these studies, I conduct a SAR (Structure Activity Relationship) analysis and select structures for further in vitro research and select leading structures for further syntheses. The project provides for obtaining a series of new compounds from the bis-amidine group with the expected high biological activity. I designed the compounds based on a literature review and with the support of molecular modeling methods. The structures of new compounds were also planned based on my previous research, in which I obtained a series of compounds with a number of different substituents on aromatic rings connected with each other by aliphatic or aliphatic-aromatic linkers. The activity profile (including their anti-P. carinii and antibacterial activity) was determined for the compounds obtained so far. The obtained results are optimistic and encourage further research. I have established, inter alia, that the introduction of nitro and amino groups into the rings significantly increases the activity of the compounds. These compounds act on P. carinii in nanomolar concentrations. I plan to obtain a series of new bis-amidines with asymmetric structure (differing in substitutions in aromatic rings) and a series of new symmetrical compounds with various combinations of substituents, the presence of which, according to the conducted SAR analysis, increases the activity of new derivatives. The compounds that I planned to synthesize under this project will be obtained as a result of multistage organic syntheses, in selected cases assisted by microwave radiation. Organic synthesis is based on certain and proven chemical reactions. All derivatives will be purified by means of crystallization and column chromatography (gravity or flash). The structure of new compounds will be confirmed by 1H NMR, 13C NMR, HSQC, HMBC, 13C CP / MAS, MS spectra, elemental analysis and crystallographic methods for selected compounds. Pneumocystosis, or severe opportunistic pneumocystic pneumonia (PCP - pneumocystis carinii pnemonia), affects people with a compromised immune system. This especially refers to AIDS patients. Although the number of PCP cases in the HIV-positive group has decreased with the introduction of HAART (High-Active Antiretroviral Therapy), PCP remains the main cause of mortality in this group. In addition, in recent years there have been many reports of PCP in patients after transplantation, chemotherapy for cancer treatment, chronic corticosteroid treatment or patients with autoimmune diseases (e.g. Crohn's disease). PCP is a disease that is very difficult to treat due to the unusual nature of the pathogen (insensitivity to anti-fungal drugs and most antibiotics) and relatively high toxicity of the drugs used (e.g. pentamidine). Therefore, there is a great need to search for new compounds with high biological activity that could potentially be used in the treatment of PCP in the future. 4. Expected effect. The main effect of the presented project will be the receipt, purification and confirmation of the structure of a series of planned compounds with the expected biological activity. The results of the work will be published in international journals. I plan to obtain a series of new bis-amidines of asymmetrical and symmetrical structure with various ring substituents. Such derivatives have not been described in the literature so far, nor have they been tested for their antibacterial and anti-Pneumocystis carinii activity. The project will enrich the library of pentamidine derivatives with new compounds. The obtained results will be part of the material for the project manager's habilitation dissertation. Due to the fact that this project is part of the medical chemistry framework, it will be necessary to conduct biological activity tests (apart from the presented application). The activity of the compounds will be determined on the basis of the in vitro activity study against Pneumocystis carinii (as part of scientific cooperation with the Department of Internal Medicine, University of Cincinnati) and antibacterial (as part of the scientific cooperation with the National Medicines Institute).