Chemotypes in Melaleuca quinquenervia (Cav.) S.T.Blake (Niaouli) from Benin Using Multivariate Statistical Analysis of Their Essential Oils

摘要

Forty compounds have been characterized by GC and GC/MS and relative retention times in 300 samples of Niaouli (Melaleuca quinquenervia) oils collected on 75 different trees during four seasons.Twenty-one compounds were submitted to multivariate statistical analyses using Principal Component Analysis (PCA).Factorial Discriminant Analysis (FDA) revealed the presence of three chemotypes.Chemotype I is already known (1,8-cineole;50%),chemo-type II had an equal content in 1,8-cineole (33%) and viridiflorol (32%).The third (chemotype III) was characterized by a high content in viridiflorol (50%).The 1,8-cineole chemotype represented 58% of three populations.Seasonal differentiation does not occur,showing that Niaouli oil composition is stable all year.