The compound known as Allin is primarily found in Garlic (Allium sativum).
Allin is an odorless organosulfur compound present in raw garlic. When garlic is crushed or cut, an enzyme called alliinase converts Allin into Allicin. Allicin is responsible for garlic's characteristic pungent smell and many of its potential health benefits.
Therefore, Allin is a compound characteristically found in Garlic.