Chemical diversity of the essential oils of twenty populations of Tanacetum polycephalum Sch. Bip. from Iran.

Chemical diversity of the essential oils of twenty wild populations of Tanacetum polycephalum Sch. Bip., was investigated. The aerial parts of T. polycephalum were collected at full flowering stage from West Azerbaijan Province of Iran, air-dried; hydrodistilled to produce essential oils. The essential oils were analyzed by GC-FID and GC-MS. A total of forty compounds were identified accounting for 96.4-99.9% of the total oils. The most principal compounds were cis-thujone (0-82.3%), trans-thujone (0-79.8%), camphor (1.3-75.0%), 1,8-cineole (4.5-43.3%), borneol (1.0-36.2%) and bornyl acetate (0-26.8%). Hierarchical cluster analysis based on the percentages (>0.5%) of the essential oils components was carried out to determine the chemical diversity among the populations studied. The cluster analysis resulted in the identification of four main chemotypes namely: 'camphor + 1,8-cineole', 'mixed', 'cis-thujone' and 'trans-thujone'.