WWamide-1, -2 and -3: novel neuromodulatory peptides isolated from ganglia of the African giant snail, Achatina fulica

Three novel neuropeptides, isolated from ganglia of the African giant snail, Achatina fulica, were named WWamide-1, -2 and -3. These substances were biologically active heptapeptide amides with a Trp residue at both the N- and C-termini. WWamide-1, which displayed an inhibitory activity on a central neuron of the snail, exhibited peripherally modulatory effects on muscular contractions of not only the gut and other tissues of the snail but also certain tissues of other molluscs.