In 1895 the German scientists Julius Bredt and Wilhelm Posh extracted helenin from Inula helenium and determined its physical and chemical properties.[1]
Alantolactone occurs in the roots of Inula helenium and other Inula species.[2] Helenin discovered in Stevia lucida for the first time, showcasing potential links within the Asteraceae family. [3]
Helenin can be extracted from the roots of Inula helenium using alcohol or other non-polar solvents to produce a mixture with a composition of about 40% alantolactone and 60% isoalantolactone.[4]
^Zhao, Peng (19 Jan 2015). "Alantolactone Induces Apoptosis and Cell Cycle Arrest on Lung Squamous Cancer SK-MES-1 Cells". Journal of Biochemical and Molecular Toxicology. 29 (5): 199–226. doi:10.1002/jbt.21685. PMID25597476. S2CID10440798.
^O'Shea, S (2009). "In vitro activity of Inula helenium against clinical Staphylococcus aureus strains including MRSA". British Journal of Biomedical Science. 66 (4): 186–9. doi:10.1080/09674845.2009.11730271. PMID20095126.
^Stampf, J (August 1978). "Allergic contact dermatitis due to sesquiterpene lactones. A comparative study of human and animal sensitivity to alpha-methylene-gamma-butyrolactone and derivatives". The British Journal of Dermatology. 99 (2): 163–9. doi:10.1111/j.1365-2133.1978.tb01977.x. PMID698105. S2CID73218116.