Pyrenocine A is a fungal metabolite that has been found in P. terrestris and has diverse biological activities.1 It inhibits the asexual spore germination of the plant pathogenic fungi F. oxysporum, F. solani, M. hiemalis, and R. stolonifer (EC50s = 14, 20, 20, and 25 µg/ml, respectively). Pyrenocine A is active against B. subtilis, S. aureus, and E. coli (IC50s = 30, 45, and 200 µg/ml, respectively). It inhibits onion seedling elongation (EC50 = 4 µg/ml). Pyrenocine A is also a phytotoxin that inhibits lettuce seed germination and rice seedling elongation.2,3
1.Sparace, S.A., Reeleder, R.D., and Khanizadeh, S.Antibiotic activity of the pyrenocinesCan. J. Microbiol.33(4)327-330(1987) 2.Sato, H., Konoma, K., and Sakamura, S.Phytotoxins produced by onion pink root fungus, Pyrenochaeta terrestrisAgric. BioI. Chem.43(11)2409-2411(1979) 3.Sato, H., Konoma, K., Sakamura, S., et al.X-Ray crystal structure of pyrenocine A, a phytotoxin from Pyrenochaeta terrestrisAgric. BioI. Chem.45(3)795-797(1981)