esculetin

Esculetin, also known as 6,7-dihydroxycoumarin, is a naturally occurring hydroxycoumarin. It consists of the coumarin core with hydroxyl groups at the 6 and 7 positions. The compound has the molecular formula C9H6O4 and typically appears as a pale yellow crystalline solid. Esculetin is found in a range of plant species as a secondary metabolite and is often isolated from plant extracts for research and analytical purposes.

In plants, esculetin arises through the phenylpropanoid pathway, involving oxidation of o-hydroxycinnamic derivatives and subsequent lactonization to form the coumarin nucleus. The dihydroxy substitution enhances polarity relative to unsubstituted coumarin and can influence redox properties and reactivity.

In research, esculetin is used as an analytical standard for high-performance liquid chromatography and as a probe in studies of antioxidant, anti-inflammatory, antimicrobial, and anticancer activities in vitro. Some investigations report enzyme inhibition and modulation of signaling pathways, but findings are preliminary and do not establish therapeutic efficacy. Its activity is typically studied in isolated systems or cell cultures, and in vivo effects require further validation.

Safety and handling information on esculetin is limited, and there is no approved medical use. As with many natural products and hydroxycoumarins, standard laboratory precautions apply, including protection from light and proper storage. Researchers assess toxicity and pharmacology in controlled studies before drawing conclusions about potential applications.