The novel peptides WS-9326A, WS-9326B, their derivatives and pharmaceutically acceptable salts thereof have useful pharmacological activities, particularly in the treatment and/or prevention of asthma and/or pain. A method for the production of the peptides WS-9326A and WS-9326B and derivatives thereof using Streptomyces violaceoniger No. 9326 in a biologically pure form is described herein.