has role pyridoxal(1+) pyridoxal A pyridinecarbaldehyde that is pyridine-4-carbaldehyde bearing methyl, hydroxy and hydroxymethyl substituents at positions 2, 3 and 5 respectively. The 4-carboxyaldehyde form of vitamin B6, it is converted into pyridoxal phosphate, a coenzyme for the synthesis of amino acids, neurotransmitters, sphingolipids and aminolevulinic acid. cofactor methylpyridines vitamin B6 monohydroxypyridine pyridinecarbaldehyde hydroxymethylpyridine mouse metabolite Saccharomyces cerevisiae metabolite Escherichia coli metabolite human metabolite