Studies of the Essential Oil of Mentha rotundifolia

Rotundifolone, a new terpenic ketone, C₁₀H₁₄O₂ has been isolated from the essential oil of M. rotundifolia in Japan. This ketone is highly dextro-rotatory, and has a low, melting point 27.5° The wave lengths of the ultraviolet absorption maxima of rotundifolone and its semicarbazone are 260 mμ (log ε = 3.95) and 273 mμ (log ε = 4.12) respectively. This indicates that rotundifolone has an α,β-unsaturated carbonylic system.