Why does quinine react to uv light?

Quinine reacts to UV light due to its fluorescent properties. When exposed to UV radiation, the electrons in quinine are excited to a higher energy state. As these electrons return to their ground state, they release energy in the form of visible light, which is why quinine can be seen glowing under UV light. This fluorescence is often utilized in various applications, including in the identification of quinine in tonic water.