amino-acid betaine L-aspartic acid 4-semialdehyde betaine (2S)-2-ammonio-4-oxobutanoate 117.043 117.10330 C4H7NO3 CHEBI:40847 CHEBI:537519 HOSWPDPVFBCLSY-VKHMYHEASA-N InChI=1S/C4H7NO3/c5-3(1-2-6)4(7)8/h2-3H,1,5H2,(H,7,8)/t3-/m0/s1 L-2-ammonio-4-oxobutanoate L-aspartate 4-semialdehyde PDBeChem:AS2 PMID:18054225 The betaine obtained by transfer of a proton from the carboxylic acid group to the amino group of L-aspartic acid 4-semialdehyde. [H]C(=O)C[C@H]([NH3+])C([O-])=O aspartate semi-aldehyde chebi_ontology