[Search for new antibiotics of the cyclosporin group]

A total of 160 fungal cultures belonging to Trichoderma were isolated from soil samples collected in various regions of the USSR. The cultures were tested for production of antibiotics of the cyclosporin group, having a narrow antifungal spectrum. It was found that 7 cultures produced substances having a selective inhibitory effect on Asp. niger and no activity against gram-positive and gram-negative organisms. An antibiotic substance close by its physicochemical properties to cyclosporins was isolated from T. viride 122.