Tetrahydroxy-1,4-benzoquinone

Tetrahydroxy-1,4-benzoquinone, also called tetrahydroxy-p-benzoquinone, tetrahydroxybenzoquinone, or tetrahydroxyquinone (THBQ, THQ), is an organic compound with formula C6O2(OH)4. Its molecular structure consists of a cyclohexadiene ring with four hydroxyl groups and two ketone groups in opposite (para) positions.

Source: Wikipedia — Tetrahydroxy-1,4-benzoquinone (CC BY-SA 4.0)