Aloin is a defined organic compound recorded by PubChem as Aloin. Its molecular formula is C21H22O9, and its relative molecular mass is approximately 418.4 g/mol. Aloin is a diastereoisomeric mixture of aloin A (barbaloin) and aloin B (isobarbaloin), which have similar properties. It is a bitter-tasting, yellow-brown colored compound found in the exudate of at least 68 Aloe species at levels of up to 6.6% of leaf dry weight (making between 3% and 35% of the total exudate), and in another 17 species at indeterminate levels.
It has a role as a laxative and an EC 1.14.18.1 (tyrosinase) inhibitor. Its biological or pharmacological significance is governed by the specific molecular form and the interactions described above; dose, exposure route, formulation, and metabolism determine whether an observed effect is therapeutic, toxicological, or simply physicochemical. Major uses may include medicinal or biochemical research, analytical reference standards, impurity and stability testing, formulation studies, and regulated manufacturing where identity and purity are controlled.
