Chemical constituents from Lobelia davidii Franch. and their chemotaxonomic significance

The phytochemical study on the whole plant of Lobelia davidii Franch. (Campanulaceae) resulted in the isolation of one new polyacetylene, davidiotylin A (1), one new natural compound, (5R) N-methyl-5-acetophenone-pyrrolidine-2-one (6), along with six known compounds including lobetyolin (2), choushenpilosulyne A (3), lobetyol (4), fissistigmol A (5), pistaciamide (7), N, N′-dicoumaroylputrescine (8). Their structures were characterized by the comprehensive analysis of their NMR, IR, UV, ECD spectra and HRESIMS data. All the isolated compounds were reported from L. davidii for the first time. The chemotaxonomic significance of these compounds was discussed.