New Okaramine Congeners, Okamines J, K, L, M and Related Compounds, from Penicillium simplicissimum ATCC 90288.

Four new okaramine congeners, okaramines J, K, L and M, were isolated from okara fermented with Penicillium simplicissimum ATCC 90288, together with five biogenetically related compounds, cyclo (8a-(α,α-dimethylallyl)-L-Trp-8a-(α,α-dimethylallyl)-L-Trp), cyclo (N (8)-(α,α-dimethylallyl)-L-Trp-6a'-(α,α-dimethylallyl)-L-Trp), cyclo (L-Trp-L-Trp), cyclo (6a'-(α,α-dimethylallyl)-L-Trp-L-Trp), and cyclo (N (8)-(α,α-dimethylallyl)-L-Trp-L-Trp). Their structures were elucidated on the basis of spectroscopic methods. The new okaramines exhibited no insecticidal activity against silkworms.