Synthesis of new antitumor phospholipids for the inhibition of the human enzyme cytidine triphosphate (CTP): phosphocholine cytidylyltransferase

Author(s)

Xisto Antonio de Oliveira Neto

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Farmacêuticas
• Defense date: 2022-07-28

Examining board members

Daniel Fábio Kawano; Peterson de Andrade; Rodrigo Ramos Catharino

• Advisor: Daniel Fábio Kawano

Abstract

Cancer is responsible for an enormous impact in public health around the world, posing as one of the main causes of death in the present. Classical chemotherapy for cancer treatment present several limitations, in particular the high incidence of adverse events and low occurrence of tumoral remission. Rescuing the mechanisms of apoptosis in the tumor cell constitutes the main strategy in the combat against cancer Antitumoral phospholipids represent a class of compounds with potential to restore the apoptotic process in cancerous cells, being edelfosine the prototype compound in the class. Despite the promising results in in vitro and in vivo assays, its insufficient potency during clinical trials poses as a limitation in regards to its application as a chemotherapeutic agent. The ability to be orally administered and its selectivity towards tumoral cells motivated the development of multiple edelfosine analogs through the last decades, however none o them were capable of reaching clinical practice. One of the theories regarding the antineoplastic activity of phospholipids postulates these compounds would act as direct inhibitors of cytidine triphosphate (CTP):phosphocholine cytidylyltransferase (CCT), an important enzyme in the biosynthesis of phosphatidylcholine which acts in the conversion of choline phosphate to CDP-choline. The inhibition of CCT leads to important pro-apoptotic signals, characterizing it as a potential oncologic target. The development of novel antitumoral phospholipids is commonly guided by the improvement to pharmacokinetic properties, whereas the rational design focused on CCT inhibition is an unprecedented strategy. This dissertation explores the binding mode of members of the phospholipid class with CCT through molecular docking analysis; the information obtained were employed in the proposal of a structural hybrid from edelfosine and CDP-choline. The novel compound would potentially act as a superior inhibitor, granting improved antineoplastic activity. Molecular docking studies were described for the prototype compound and its synthesis route proposed with the intent of enabling a posterior step of virtual screening, permitting the construction of a library of compounds for structure-activity relationship investigations. This work describes the synthesis of monotritylated batyl alcohol with good yields, the first intermediate in the route. Besides, three cloroacetylated compounds were synthesized, being suited for functionalization in the secondary hydroxyl of the main structure. Considering posterior complications met during intermediary synthesis, a modification was proposed to the route, allowing the synthesis of hybrid compounds from edelfosine and CDP-choline while maintaining the perspective of constructing an analog library, as it was initially proposed. The planned compounds were analyzed through molecular docking, confirming its potential as CCT inhibitors capable of exploring the active site in an analogous manner to edelfosine and CDP-choline. Two intermediaries common to both arms of the new route were properly synthesized and characterized with satisfactory yields. Additionally, the establishment of the synthesis of three other intermediates belonging to the triazole route was concluded, with due characterization being performed. The standardization of the first two reactions in the amine route were initiated, although no structural characterization was possible to this point. The reaction of phosphocholine insertion constitutes the final step in both routes, and although its standardization has been started no success was obtained with the proposed protocol. In total, 9 intermediaries have been synthesized and characterized throughout this work, remaining the conclusion of a single step in order to obtain the first antitumoral phospholipid planned as an inhibitor of CCT (AU)

• FAPESP's process: 18/22817-2 - Synthesis of new antitumor phospholipids as inhibitors of the human enzyme cytidine triphosphate (CTP): phosphocholine cytidylyltransferase
• Grantee: Xisto Antonio de Oliveira Neto
• Support Opportunities: Scholarships in Brazil - Master