Identification of mycolutein and pulvomycin as aureothin and labilomycin respectively.

Two antibiotics isolated from a culture MA-2465 were identified as aureothin and labilomycin, the chemical structures of which had been reported previously. It was also concluded that mycolutein and pulvomycin isolated as antibiotics in 1955 and 1957 respectively are also identical with aureothin and labilomycin. A cursory study of MA-2465 indicates that it is distinctly different from the culture which was first observed to produce labilomycin and is probably different from the organism first noted to produce aureothin.