Some semi-synthetic derivatives of pyrrolizidine alkaloids.
D000470:Alkaloids; D000577:Amides / Q000138:chemical synthesis; D004952:Esters / Q000138:chemical synthesis; D011759:Pyrrolidines / Q000138:chemical synthesis*
D000470:Alkaloids; D000577:Amides; D004952:Esters; D011759:Pyrrolidines