Chemical Ecology of Teak (Tectona grandis Linn.) Floral Volatiles

In present work, the GC, GC-MS and GC-olfactory techniques were applied for the first time for the analysis of floral volatiles of teak. Chemical ecology of the teak flower is also studied by correlating each of the components in its volatile profile with the major classes of insect visitors and pollinators with the help of the internet databases. Sixty six components consisting of 84% of the oil were identified in the GC-MS analysis. Out of these 78% were oxygenated compounds while only 20% were various hydrocarbons, either sesquiterpenes or diterpenes. All the monoterpenes were in the oxidized form which reduces the therapeutic potentials of the oil while improving its perfumery value. The olfactory evaluation of the oil revealed the presence of a wide spectrum of impressions ranging from spicy-floral to mushroom-metallic and woody-earthy to honey-like. The main reason for the enormous number of insects visiting teak flower is the presence of large number of volatile compounds with diverge semiochemical behaviour. At the same time the presence of some specific allomones and alarm pheromones results in the repulsion of some effective pollinators. This leads to ineffective pollination and comparatively low fruit development in teak.