Terpineols have been isolated from a variety of sources such as cardamom, cajuput oil, pine oil, and petitgrain oil. Four isomers exist: α-, β-, γ-terpineol, and terpinen-4-ol.
The passage describes the presence of terpineols in different natural sources like cardamom, cajuput oil, pine oil, and petitgrain oil. It also mentions that there are four distinct types of terpineols: α-, β-, γ-terpineol, and terpinen-4-ol.