Chemosystematic analyses of Gingidia volatiles.

The leave volatiles of six Gingidia species from New Zealand and Australia and the seed volatiles of G. grisea were characterized by solid-phase microextraction (SPME)-GC/MS analysis. This technique, using a small quantity of samples and automated extraction, gave repeatable results, with maximum sensitivity for medium volatility compounds. The major monoterpenes among the volatiles, i.e., β-phellandrene (4), limonene (6), and γ-terpinene (5), and phenylpropanoids, i.e., estragole (3), (E)-anethole (7), and myristicin (1), showed to be useful chemotaxonomic markers. For G. grisea leaves and seeds, similar compositions were detected, characterized by high contents of 4. As leaves were more readily available for study than seeds, they were used for further investigations. The G. grisea leaf volatiles showed infraspecific variation in the ratio of 4/5 between and within sites of collection. The G. montana leaf volatiles also showed infraspecific variation, with high contents of 3 at one site and high contents of 7 at another. The SPME-GC/MS analysis of G. montana herbarium voucher specimens resulted in the identification of further chemotypes for this species. The volatiles of the G. amphistoma samples were all dominated by 7 and those of the G. haematitica samples were rich in 5. Moreover, single plants of two Australian Gingidia species were analyzed; the volatiles of G. harveyana showed high concentrations of 5 and 7, whereas those of G. rupicola were dominated by 5 and 1.