aldehyde-lyase activity (S)-hydroxynitrile lyase activity https://github.com/geneontology/go-ontology/issues/16166 https://github.com/geneontology/go-ontology/issues/28199 https://github.com/geneontology/go-ontology/issues/30193 GO:0046991 oxynitrilase activity hydroxynitrile lyase activity Catalysis of the reaction: a (S)-hydroxynitrile = hydrogen cyanide + an aldehyde or ketone. EC:4.1.2.47 GO:0047606 alpha-hydroxynitrile lyase activity hydroxynitrilase activity molecular_function