Flavonoids of Solanum rostratum seeds: identification and plant growth regulatory activity evaluation

For the first time, five flavonoids (1~5) were separated and characterised from seeds of the invasive Solanum rostratum dunal. through the analysis of spectroscopic data and comparison with published literature, the structures of these substances were ascertained. these flavonoids were apigenin (1), quercetin (2), kaempferol- 3-O-β-d-glucopyranoside (3), quercetin-3-O-β-d-glucopyranoside (4) and acacetin-7-O-[glucopyranosyl-(1→6)]-β-d-glucopyranoside (5). their plant growth regulatory activity was assessed using ryegrass (Lolium perenne) as the receiver species, which were all found to possess stimulatory activity. among them, quercetin-3-O-β-dglucopyranoside (4) exhibited the maximum promotive effect on ryegrass, at the concentration of 500μg/mL, it enhanced shoot growth by 117%. our study reveals that flavonoids in S. rostratum seeds have growth promotive effect, which might contribute to its invasion success by stimulating seed germination and seedling growth; meanwhile, our results also implies that these flavonoids might be developed into growth promoting compounds applicable in agricultural practices