Abstract
A sesquiterpene acetate, sugetriol triacetate, was isolated from nutsedge essential oil, and several derivatives were synthesized. Their plant physiological activities and inhibitory activities on the growth of lettuce and large crabgrass seedlings were investigated.
1) Complete hydrolysis of sugetriol triacetate (I) yielded the free tri-alcohol, sugetriol (II). When the triacetate (I) was subjected to partial hydrolysis, the triol 6, 9-deacetate (III) and triol 9-acetate (IV) were obtained. On the other hand, the oxidation of sugetriol (II) with the chromium trioxide-pyridine complex resulted in the tormation of the diketoalcohol (VI) and the triketone (V) (Fig. 1).
2) Sugetriol triacetate did not inhibit the growth of lettuce and large crabgrass seedlings at the concentration of 1000ppm. The triol 6, 9-deacetate, the triol 9-acetate and the triol derivatives promoted the radicle elongation of lettuce seedlings. On the contrary, these compounds all strongly inhibited the radicle elongation of large crabgrass seedlings (Tables 1 and 2).
3) The triketone and diketo-alcohol induced a chlorosis to the seedlings at the concentration of 500ppm. At the concentration of 1000ppm, a necrosis in the seedlings of lettuce exhibited necrotic changes and the plant died. However, the diketo-alcohol was less active than the triketone (Tables 1, 2 and Fig. 2).
