Flavonoids and alkaloids from Lysionotus pauciflorus (Gesneriaceae)

Abstract

The phytochemical investigation on the whole plant of Lysionotus pauciflorus led to the isolation of a new flavonoid (1), along with eight known flavonoids (2–9), as well as five alkaloids (10–14). Their structures were elucidated based on extensive spectroscopic methods (1D and 2D NMR, HRESIMS, IR, and UV experiments), coupled with comparison with literature data. Among these known compounds, compounds 2, 4–6, 10–14 were isolated from L. pauciflorus for the first time. What is particularly exciting is that alkaloid compounds, which possessed indole skeleton, were found in Gesneriaceae plants for the first time. The chemotaxonomic significance of these isolated compounds has also been discussed. The highly oxygenated flavones identified in the plant may be used as chemotaxonomic marker of Lysionotus.