Bergapten

Bergapten is a natural chemical compound that belongs to the furanocoumarin family, a subset of psoralen derivatives. It is a photoactive substance most notably associated with bergamot oil but is also found in other citrus species and in certain plants of the Apiaceae family, such as celery and parsley. In essential oils and plant extracts, bergapten is among the compounds responsible for the characteristic photosensitivity of these plants.

Chemically, bergapten is a substituted psoralen. It absorbs ultraviolet A radiation (320–400 nm) and, upon light exposure, can form covalent bonds with pyrimidine bases in DNA. This photoinduced reactivity underpins its biological activity, including its potential to cause skin phototoxicity in humans and its historical use as a photosensitizer in dermatological therapies.

Applications and research history have focused on bergapten’s role in phototherapy and photosensitization. In medicine, similar psoralen compounds have been used in combination with UVA light (PUVA therapy) to treat certain skin conditions such as psoriasis, vitiligo, and eczema, though specific use of bergapten varies by region and patient. In modern safety contexts, bergapten is of concern because contact with photosensitizing plant materials followed by sun exposure can trigger phytophotodermatitis, a sunburn-like skin reaction.

Regulatory and safety notes emphasize limiting exposure to bergapten-containing plant materials on skin, particularly in cosmetic and consumer products, due to the risk of phototoxic reactions. The compound remains a point of interest in phytochemistry and photobiology for its dual roles as a natural product and a photosensitizer.