Tropoflavin, also known as 7,8-dihydroxyflavone (7,8-DHF), is a naturally occurring flavone found in Godmania aesculifolia, Tridax procumbens, and Primula vulgaris. It has been found to act as a potent and selective small-molecule agonist of the tropomyosin receptor kinase B (TrkB), the main signaling receptor of the neurotrophin brain-derived neurotrophic factor (BDNF). Tropoflavin is both orally bioavailable and able to penetrate the blood–brain barrier. A prodrug of tropoflavin with greatly improved potency and pharmacokinetics, R13, is under development for the treatment of Alzheimer's disease.