GSK3B and type 2 diabetes mellitus: In extracts of B. mediterranea strain LF657, isolated from a deep-sea sediment of the Eastern Mediterranean Sea at 2800 m water depth, the new isopyrrolonaphthoquinone compound biscogniauxone (1) was identified and found to exhibit inhibitory activity against the enzyme GSK-3β, which is an important target for the treatment of diseases such as diabetes type 2, neurological disorders, and cancer [19,20,21].