Tracheal Muscle Contracting Action of Metabolites Produced by Air-Borne Fungi

Summary

1 From a room of 4 bronchial asthma patients were isolated and cultured 120 strains of fungi, including penicillium, aspergillus, cladosporium, chaetomium, etc. Among them was found a new strain of Oospora, which was designated Oospora astringenes Yamamoto. 2 Culture broths of these 120 strains were investigated as to their action on the tracheal muscle preparation from the guinea pig. A marked contracting action was observed for culture broths of Oospora astringenes, one species of penicillium, 3 species of aspergillus, and one species each of trichoderma and fusarium. Culture broths of one species of penicillium and 2 unclassified strains relaxed the tracheal muscle remarkably. 3 Three new isocoumarine derivatives were discovered in the metabolites of Oospora astringenes. Their chemical properties were clearly identified, and they were designated Oosponol, Oospolactone and K-I, respectively. Oosponol strongly contracted the tracheal muscle preparation in the in vitro experiment. This action is considered to be different from that of the known tracheal muscle contracting agents. K-I relaxed contraction of the tracheal muscle produced with serotonine, barium chloride, Oosponol, antigen, histamine, but not contraction produced with acetylcholine. 4 Patulin, one of the fungus metabolites, also strongly contracted the tracheal muscle. Its mode of action resembled that of Oosponol.