Identification and structural analysis of new phenylphenalenones from Strelitzia nicolai Regel. and Körn

Phenylphenalenones (PPs) are specialised metabolites found in select plant families, including Strelitziaceae. Despite their structural diversity and potential taxonomic significance, their distribution and variations in this family remain largely unexplored. This study aimed to characterise PPs from Strelitzia nicolai Regel. and Körn. through chromatographic isolation and spectroscopic analysis. Eight PPs were identified, including a new phenylphenalenone, strenicolone A (1), and three novel PP glycosides, strenicolosides A-C (2, 3, and 5). Notably, this is the first report of PP glycosides containing disaccharides, with 3 featuring β-vicianose [ara-(1→6)-glc]. These findings expand the known chemical diversity of PPs in S. nicolai and provide insights into their structural variations and biosynthetic pathways. Furthermore, the identification of these glycosylated derivatives suggests a broader distribution of PP modifications within Strelitziaceae, emphasising the need for further phytochemical investigations in this family.