Tabernaemontana catharinensis A. DC: estudo dos metabólitos secundários, atividade biológica, cultivo in vitro e quantificação por RMN de alcaloides majoritarios

Abstract

The phytochemical investigation of the fractions from the leaves of Tabernaemontana catharinensis (Apocynaceae, popularly known as cobrina), led to the isolation of seven componds, three steroids: stigmasterol, β-sitosterol acetate and glycosylated β-sitosterol, a triterpene: betulinic acid, a flavonoid: quercitin, and two phenolic compounds: chlorogenic acid and caffeic acid. Derivation reactions were performed for the alkaloids ethyl apovincamine, voachalotine and affinisine, obtaining seven derivatives. The fractions and isolated compounds showed promising antibacterial, antifungal and antibiofilm activity against the tested strains. The derivatives obtained were more active against fungi of the genus Candida. The alkaloid affinisin was strongly active against the tumor cell lines tested, and in many cases it was more active than the chemotherapeutic doxorubicin, in addition to having cytocidal and cytotoxic potential and high levels of selectivity. Protocols for asepsis and in vitro proliferation of T. catharinensis seeds were defined, where cultivation in solid and liquid culture medium was possible, the latter being reported for the first time for the genus. After in vitro cultivation and obtaining large populations of seedlings, microextractions were performed in order to obtain acidic, basic and neutral fractions that were quantified by NMR, making it possible to quantify four alkaloids in the acidic fractions and two in the basic fractions. The present work adds great results to the studies of the species T. catharinensis A.DC., since this species has great ethnopharmacological applicability, many of which still do not have scientific records, but are kept in popular culture.