Bergapten phototoxicity caused

Lactone An organic compound that contains an ester group incorporated into a carbon ring structure. Lactones include the coumarins, e.g. umbelliferone or 7-hydroxycoumarin. Lactones and furocoumarins, e.g. bergaptene, exist in small quantities in essential oils and should be used with care. Lactones can be neurotoxic (poisonous to the nervous system) and cause skin allergies. Bergaptene is well known for its phototoxicity on the skin. 

Use Mainly for the production of perfumes, especially Eau de Colognes and fresh toilet waters. Pressed B. contains up to ca. 1% of the furocoumarin bergap-ten which causes phototoxic reactions (so-called ber-lock or berloque (perfume) dermatitis). Thus mild rectification of B. is recommended before its use in perfume oils, since bergapten remains in the distillation residue. B. is also used in small amounts to aromatize confectionery and bakery products, often in combination with other citrus oils well known is the aromatization of tea ( Earl Grey tea). 

These furocoumarins are phototoxic compounds which cause phototoxic dermatitis. Many plants of the Apiaceae (Umbelliferae) and most of the Rutaceae contain 5-methoxypsoralen (bergapten) and 8-me-thoxypsoralen (xanthotoxin). Their spectra is in the UV-A range (300-360 nm). 

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