Aerial parts from five populations of Chelidonium majus were collected from the wild at the flowering stage (hereafter referred to as 'wild') for chemical analysis and biological activity testing during May 2019. Ten randomly selected plantlets were also collected from the same five populations in 2019 and planted in an organically certified experimental field of IES (57° 19′ 11.7″ N 25° 19′ 18.8″ E, 115 m altitude). The plot size was 0.8 m², and the plant spacing was 0.2 × 0.5 m. A year later, aerial parts were collected during the flowering stage from the same populations in the experimental field (hereafter referred to as 'cultivated').

The total content of alkaloids in aqueous ethanol extracts prepared from cultivated C. majus specimens was higher than that observed in extracts prepared from wild-grown plant material. Chelidonine, sanguinarine, and chelerythrine were the main contributors to the total increase in alkaloid content. The cultivation of C. majus did not significantly affect the total content of flavonol glycosides. The observed differences in the phytochemical compositions of the C. majus extracts resulted in significant increases in the cytotoxic activities of the preparations.