Phytochemical investigation and bioactivity screening of promising medicinal plants of the families Combretaceae and Zingiberaceae

Abstract

Plant species remain key sources of novel bioactive molecules. This thesis explores secondary metabolites from three understudied medicinal plant species of the Combretaceae and Zingiberaceae families. Analysis of the mangrove Lumnitzera racemosa Willd. revealed diverse sulfated ellagic acid derivatives and led to the discovery of the novel compound lumnitzeralactone through extensive NMR spectroscopy. Antibacterial effects varied by growing location, suggesting environmental influence and possible synergism. Terminalia dhofarica (A.J.Scott) Gere & Boatwr. exhibits mostly simple phenolics and polyphenols, and the investigation yielded in twenty isolated compounds. Leaves of Hornstedtia scyphifera (J.Koenig) Steud. provided two new sesquiterpenoids together with 24 known metabolites. Overall, 53 compounds were isolated and fully characterized, expanding the phytochemical knowledge of these plant species.