This constituent has five isomers: Germacrene-A, B, C, D, and E. The two prominent molecules are Germacrene-A and Germacrene-D. Germacrene-A is believed to have invigorating properties. Germacrene-D is a major constituent of essential oils such as Clary Sage, Ylang-ylang, and Tulsi (Holy Basil). It has been known to show significant cleansing properties.