The Composition of Commercial Manuka Oils from New Zealand

Abstract

Within 16 different commercial samples of manuka oil from New Zealand 51 constituents corresponding to about 95% of the oils could be identified by GC and GC/MS. AU oils investigated consisted of a group of about 35 sesquiterpene hydrocarbons (60% and 70% of the oils) with (−)-trans-calamenene (mean 12.5%), δ-cadinene (6.3%), cadina-3,5-diene (6.3%), α-copaene (5.3%), and cadina-1,4-diene (4.7%) being the most prominent ones. The oil characterizing triketones, namely leptospermone, flavesone, and isoleptospermone amounted to about 20% (mean 22.1%). Monoterpene hydrocarbons were present in the range of 2.2% to l4.1% (mean 4.5%). Four samples differed distinctly from all the others by a lower percentage of triketones (mean 14%). On the contrary they contained higher percentages of α-pinene (8-11%).