In a previous communication,1} we reported that an isolate of Penicillium simplicissimum AK-40 produced a novel heptacyclic indole alkaloid, okaramine A (1), which showed insecticidal activity against silkworms. During the continuing investigation, we found that a new metabolite related to okaramine A was also produced by the same strain. In this paper, we report the isolation and structural elucidation of this new metabolite that is designated as okaramine B. We also report the insecticidal activities of okaramines A and B.