ChEBI: Leucine is a branched-chain amino acid that consists of glycine in which one of the hydrogens attached to the alpha-carbon is substituted by an isobutyl group. It has a role as a Daphnia magna metabolite. It is a branched-chain amino acid and an alpha-amino acid. It contains an isobutyl group. It is a conjugate base of a leucinium. It is a conjugate acid of a leucinate.