Many beverages are made with gentian root. Gentiana lutea is used to produce gentian, a distilled beverage produced in the Alps. Some species are harvested for the manufacture of apéritifs, liqueurs, and tonics. Gentian root is a common beverage flavouring for bitters. The soft drink Moxie contains gentian root. The Swiss apéritif Suze is made with gentian. Americano apéritifs contain gentian root for bitter flavoring. It is an ingredient in the Italian liqueur Aperol. It is also used as the main flavor in the German after-dinner digestif called Underberg, and the main ingredient in Angostura bitters and Peychaud's Bitters. The bitter principle of gentian root is primarily gentiopicrin (also called gentiopicroside), a glycoside. A 2007 paper by a Japanese group identified 23 compounds in fresh gentian root. Gentiopicrin was absent from fresh root, so it possibly develops during drying and storage of the root.