Stusies on the effect of trehalase inhibitors on insects and their possibility as a insect control agent.

预计水解海藻糖的海藻糖酶的抑制会对昆虫的生命产生严重影响，因为昆虫利用血淋巴海藻糖作为其能量来源。本研究观察了海藻糖酶特异性抑制剂井冈羟胺A（VAA）对昆虫生理的影响，并阐明了VAA的作用机制。VAA对甘蓝夜蛾（Mamestra brassicae）和斜纹夜蛾（Spodoptera litura）幼虫末龄早期的处理，引起节肌松弛、背侧血管搏动减弱等，并在化蛹时因蛹发育不完全而死亡。对<13>处理后幼虫营养成分的~ 1H和~ 1C-NMR分析表明，海藻糖酶抑制降低了昆虫组织中海藻糖的代谢，并且在大多数组织需要大量能量来源来重建蛹的阶段表现出强烈的影响。在主要利用海藻糖作为飞行能量的昆虫（美洲大蠊、家蝇、黄胸小蠊）中，VAA处理明显降低了飞行活性。VAA抑制了蝗虫肌肉海藻糖酶的活性，但对一些既能利用脂类又能利用碳水化合物的蝗虫（Locusta migratoria，Calliphora nigribabis）的飞行没有影响，但对海藻糖的代谢也有抑制作用。考虑到这些结果，海藻糖酶抑制剂的结论是特定的昆虫控制剂的候选人之一。然而，VAA本身对昆虫角质层的渗透性非常低，因此，预期不会有实际用途。一些化学改性，使渗透性尚未产生适当的化学品。

It is expected that the inhibition of trehalase which hydrolyzes trehalose gives severe effect on insect life, because insects utilize the haemolymph trehalose for their energy source. In the present studies, we observed the effect of a specific and potent trehalase inhibitor, validoxylamine A (VAA) on insect physiology and elucidated the mechanism of VAA action. And then, potency of VAA as a insect control agent was investigated.In Lepidopterous insect larvae (Mamestra brassicae, Spodoptera litura), VAA treatment at the early stage of the final instar evoked the relaxation of segmental muscles, decrease of the pulsation of dorsal vessel, etc. And at pupation, the insects died of incomplete pupal development. ^1H-and ^<13>C-NMR analysis of the nutrients of treated larvae showed that trehalose metabolism decreased by trehalase inhibition in insect tissues and that strong effect appeared at the stage when most of tissues needed great amount of energy source for their reconstruction for pupationIn insects which utilize mainly trehalose for their flight energy (Periplaneta americana, Musca domestica, Boettecherisca perigrina), VAA treatment apparently reduced flight activity. Their muscle trehalase activity was indicated to be inhibited by VAA.However, the flight of some species which were able to utilize lipids as well as carbohydrates for the energy (Locusta migratoria, Calliphora nigribarbis) was not affected by VAA treatment, though the trehalose metabolism was suppressed as other insects.Strong effect of VAA on the reproduction of the locust was recently observed. Taking these results into account, trehalase inhibitors were concluded to be one of the candidates for specific insect control agents. VAA itself, however, has very low permiability to insect cuticle, and so, practical usage was not expected. Some chemical modification to give the permiability have not yet produced appropriete chemicals.