abstract the chemical components of the essential oil obtained from the steam-distillation of microtoena patchoulii leaves were investigated by gc and gc/ms, and twenty-one compounds were identified. the major compounds of the oil were patchouli alcohol (54.4%), 1-octen-3-ol (21.4%), and -guaiene (2.4%). the composition of m. patchoulii oil is similar to that of commercial patchouli oil, and similar pharmacological effects could be expected when it is used as a substitute for pogostemon cablin.