alantolactone

Alantolactone is a natural sesquiterpene lactone belonging to the germacranolide class. It features an α-methylene-γ-lactone moiety, a reactive Michael acceptor that contributes to its bioactivity. The compound has been isolated mainly from Inula helenium (elecampane) and related Inula species, with occasional reports in other members of the Asteraceae.

In biological studies, alantolactone shows antimicrobial, antifungal, antiparasitic, and anti-inflammatory effects. It can influence signaling pathways such as NF-κB and can induce apoptosis in various cancer cell lines through mitochondrial pathways and reactive oxygen species generation. The α-methylene-γ-lactone group enables covalent interaction with thiol groups in proteins, a key feature of its mechanism of action.

Clinical use is not established. Most evidence comes from in vitro and animal studies, and there are safety concerns due to its reactivity, potential toxicity, and irritant properties. Because of these factors, it is generally regarded as a research compound rather than an approved therapeutic agent, and purification and standardization are important considerations for any experimental work.

Isolation and chemistry: Alantolactone is typically extracted from plant material by organic solvent extraction and purified via chromatographic methods. Its study has contributed to the broader understanding of sesquiterpene lactones, including structure–activity relationships related to the germacranolide framework and the reactive α-methylene-γ-lactone moiety.