Theophylline is a phytonutrient found in tea.

It was first extracted from tea leaves around 1888 by the German biologist Albrecht Kossel and by the the 1950's was being used clinically to treat asthma.

References

Ito K, Lim S, Caramori G, et al (2002). "A molecular mechanism of action of theophylline: Induction of histone deacetylase activity to decrease inflammatory gene expression". Proc. Natl. Acad. Sci. U.S.A. 99 (13): 8921–6. doi:10.1073/pnas.132556899. PMID 12070353.