The oil obtained by steam distillation of the aerial parts of Mentha longif
olia (L.) Huds. was investigated by a combination of GC and GC/MS. Among th
e 15 compounds identified, the major components were piperitenone oxide (23
.5%), beta-caryophyllene (23.2%), piperitone oxide (17.5%), germacrene D (1
7.2%) and bicyclogermacrene (3.8%).