In his regularly featured column, consultant Brian Lawrence reviews the findings of a number of researchers on the constituents in various essential oils. This month, he highlights marjoram oil.
The composition of marjoram oil, which is obtained from Origanum majorana L., differs from that of the plant because on steam distillation the heat labile cis- and trans-sabinene hydrate and their corresponding acetates can be converted to terpinen-4-ol.
A phenol-rich oil of O. marjorana that was produced in the laboratory from plants collected in Calabria (Italy) was found by Gionfriddo et al. (2001) to contain the following major components: camphor (1.8%) carvacrol (68.5%) thymol (12.2%). The results from other researchers are described herein.