Cyclo(L-Phe-L-Val) is a metabolite of the sponge bacterium Pseudoalteromonas sp. NJ6-3-1 that can autoinduce production of antibacterial substances active against S. aureus when co-cultured at a low cell density. It induces neurite outgrowth and branching of chick cortical neurons in vitro when used at concentrations of 16 and 32 μM. It increases phosphorylation of the PI3K substrate Akt, and neurite outgrowth induced by cyclo(L-Phe-L-Val) can be blocked by the PI3K inhibitor LY294002 . Cyclo(L-Phe-L-Val) enhances axon sprouting of calcitonin gene-related protein positive (CGRP+) primary afferents in the spinal cord following crush injury and of serotonin neurons in uninjured spinal cord. Cyclo(L-Phe-L-Val) is also a bitter taste component of cocoa and roasted coffee.
