A chemotaxonomic analysis of terpenes variation in Metasequoia glyptostroboides and Sequoiadendron giganteum resins

Abstract

To determine whether the terpene composition of the resins of Metasequoia and Sequoiadendron genera is useful for chemotaxonomic discrimination, extracts of resins from trunks, needles, and female cones were analysed by gas chromatography. High levels of α-pinene and trace amounts of sesqui- and diterpenes were typical for resins from trunks and needles of M. glyptostroboides. Resins from cones contained also a higher level of (E)-β-caryophyllene. In resins of S. giganteum, the levels of monoterpenes and diterpenes were nearly balanced. The resins from cones were an exception: 14-isopropylpodocarpa-8,11,13-trien-13-ol predominates noticeably over α-pinene. Using cluster analysis of the terpenes from needle resins, a distinct proximity of Sequoiadendron from USA and Metasequoia from Japan and Sequoiadendron from France and Metasequoia from the Czech Republic was proven. This proximity was caused by the presence of the monoterpene a-pinene in a very high quantity. On the contrary, great differences among S. giganteum growing in Corsica, Croatia, and the Czech Republic were caused by the presence of high levels of different terpenes such as elemicin, safrole, and 14-isopropylpodocarpa-8,11,13-trien-13-ol, each of them being detected only in a single study. The results therefore indicated that there is a proximity between Metasequoia and Sequoiadendron genera but only in some populations.