Methopreneのカイコに対する幼若ホルモン活性へのcyclodextrin包接化の影響

It has been known that the application of methoprene, one of Cecropia juveinle hormone(JH) analogues, delays metamorphosis in 5th instar larvae of silkworm, Bombyx moli L., and results in the increase of silk production. This study was carried out to know the effect of cyclodextrin inclusion of methoprene on the JH activity. Methoprene was included with α and β-cyclodextrins(CD) and α and β-cyclodextrin peracetates (CDA). In the application with dimethylsulfoxide-methanol mixture as a common solvent, the feeding period after the applcation was clearly prolonged in β-CD and β-CDA complexes but nearly equivalent in α-CD and α-CDA complexes in comparison with free methoprene. While, in the application with acetone as solvent, the activity of α-CDA and β-CDA complexes was equally superior to that of free methoprene. For a good activity, the selection of solvent was important. The cocoon weight was apparently increased with the prolongation of feeding period, whereas the cocoon layer weight was not always so and the cocoon layer ratio was decreased with the high activity. On the cuticle of larvae, the disappearance rate of methoprene in β-CD and β-CDA complexes was apparently slow compared to free methoprene. It appears that the slow release of methoprene resulted in high activity of the complexes.