Distribution of the cis- sabinene hydrate acetate-chemotype in accessions of marjoram ( Origanum majorana L.)

Abstract

The bicyclic monoterpenes cis-sabinene hydrate and cis-sabinene hydrate acetate are considered to be responsible for the special flavor of marjoram (Origanum majorana L.). Analysis of single plants of different marjoram accessions revealed the presence of a chemotype that divided the samples into two groups, with cis-sabinene hydrate acetate present either at high amounts of above 19% or at low amounts below 2%. Additionally, an arrow negative correlation of the concentration of cis-sabinene hydrate to its acetate was observed (R2 = 0.92).Since no trans-sabinene hydrate acetate could be found in the analyzed samples, the formation of cis-sabinene hydrate acetate seems to be a result of a specific enzymatic conversion in marjoram. Among 20 accessions ofmarjoram studied, 17 were heterogeneous for the cis-sabinene hydrate acetate chemotype with frequencies of the low cis-sabinene hydrate acetate type between10% and 50%. If further sensorial studies can give leads as to which of the two compounds contributes to the preferred flavor, the variation observed in this study among natural populations could be used in breeding towards an optimized quality of marjoram. The analytical technique applied in this study can be used to screen high sample numbers with a reasonable effort and time.