Novel terpenoid-type quinones which can be obtained from Pycnanthus spp., processes for obtaining the novel terpenoid-type quinones and methods for their use as hypoglycemic agents, for example, in the treatment of diabetes are described. In a preferred embodiment, the novel terpenoid-type quinones are obtained from the leaves and stems of Pycnanthus angolensis. As agents for the treatment of diabetes, the novel terpenoid quinones are useful for treating insulin-dependent (type I) and/or non-insulin-dependent (type II) diabetes.