Rijo, Patrícia, orient.Pereira, Ana Raquel Bento2022-01-282022-01-282020http://hdl.handle.net/10437/12576Orientação: Patricia RijoCancer is one of the most common causes of death worldwide. The growing incidence of cancer and the development of multidrug resistance has driven the search for novel and more effective drugs. Plants have been used for their medicinal properties since ancient times. In developing countries, herbal preparations are still a major way of disease prevention and treatment considering their availability and cost in comparison to medicines. Abietane diterpenoids mainly royleanones are bioactive compounds frequently found in the Plectranthus genus (Lamiaceae family). P. madagascariensis (Pers.) Benth essential oil is rich in 6-7-dehydroxyroyleanone (DHR), a cytotoxic royleanone. DHR molecule possesses hydroxyl groups suitable for derivatization, which have drawn attention to the possibility of exploring its reactivity to improve its cytotoxic potential. In this work, several hemi-synthetic reactions were performed, resourcing to reactions of carbamoylation and esterification. These reaction products were fully structurally characterized mainly by spectroscopic methods and afforded three unstable carbamoylation derivatives and three stable ester derivatives with overall good yields (86-95%). The three stable derivatives were also submitted to biological studies to access their antimicrobial activity,general toxicity, and cytotoxicity. The biological activity of all diterpenoids found in the literature was compared to understand which chemical features are important to identify and design hit molecules.application/pdfengembargoedAccessMESTRADO INTEGRADO EM CIÊNCIAS FARMACÊUTICASCIÊNCIAS FARMACÊUTICASCANCROPLANTAS MEDICINAISPHARMACEUTICAL SCIENCESCANCERMEDICINAL PLANTSmasterThesis202787630