"Aesculin" is a word in ENGLISH

A glucoside obtained from the Aesculus hippocastanum, or horse-chestnut, and characterized by its fine blue fluorescent solutions.

A colorless crystalline substance, regarded as a glucoside, and found in the bark of the ash (Fraxinus) and along with …

Pertaining to, or derived from, the yellow jasmine (Gelsemium sempervirens); as, gelseminic acid, a white crystalline substance resembling esculin.

Esculin; -- so called in allusion to its fluorescent solutions.