Endoplasmic reticulum (ER) stress, caused by accumulation of misfolded proteins and a disruption of calcium homeostasis, has been linked to several neuronal diseases including, Parkinson's, Alzheimer's, and prion diseases. A screen for protective activity against ER stress-dependent cell death identified termitomycamides, extracts from the fruiting bodies of T. titanicus, a notably large edible mushroom that is cultivated symbiotically in the nests of termites. Termitomycamide E is a fatty acid isolated from T. titanicus that at a dose of 0.1 μg/ml protects against ER stress-dependent cell death in Neuro2a cells induced by tunicamycin.