fellutamide fellutamide fellutamides are tripeptide derivatives from penicillium fellutanum and other fungi. they are potent proteasome inhibitor that stimulates nerve growth factor synthesis in vitro. fellutamide afellutamide b fellutamides a and f were first isolated from aspergillus versicolor. fellutamides c and d were first isolated from an undescribed metulocladosporiella (chaetothyriales). fellutamide b strongly inhibits the growth of the tuberculosis-causing bacterium mycobacterium tuberculosis. its biosynthetic pathway has been determined in the filamentous fungus aspergillus nidulans.