Phenethylamine in hot water extract of Chlorella pyrenoidosa expands lifespan of SOD1 mutant adults of Drosophila melanogaster at very low dose

Hot water extract of chlorella (WEC) increased the lifespan of superoxide dismutase (SOD1)mutant adults of Drosophila melanogaster in a dose dependent manner (200–800 µg/mL). Compounds in WEC were successively fractionated by solid phase extraction using a Sep-Pak C18 cartridge and size exclusion chromatography (SEC). Amino compounds in SEC fractions were derivatized with 6-aminoquinolyl-N-hydroxylsuccinimidyl carbamate and analyzed by reversed phased-liquid chromatography-tandem mass spectrometry. Phenylalanine, phenethylamine, isopentylamine, and 2-methylbutylamine were identified in the SEC fraction, which increased the lifespan of the D. melanogaster mutant adults. Phenethylamine, at very low doses (6–60 ng/g of diet) that roughly corresponded to those of phenethylamine in WEC (200–800 μg/mL), increased the lifespan of the D. melanogaster adults, while isopentylamine did not exert the lifespan elongation activity. Since phenethylamine did not show SOD-like activity, it did not increase lifespan by direct antioxidant activity.