Rubradirin B

Rubradirin B, C40H33N3O15, was separated from other components of the rubradirin complex by chromatographic and crystallization procedures. The spectrum of antibacterial activity is similar to that of rubradirin, but the antibiotic is less active.

We report the 9.2 Mb genome of the azureomycin A and B antibiotic producing strain Amycolatopsis azurea isolated from a Japanese soil sample. The draft genome of strain DSM 43854(T) consists of 9,223,451 bp with a G + C content of 69.0% and the genome contains 3 rRNA genes (5S-23S-16S) and 58 aminoacyl-tRNA synthetase genes. The homology searches revealed that the PKS gene clusters are supposed to be responsible for the biosynthesis of naptomycin, macbecin, rifamycin, mitomycin, maduropeptin enediyne, neocarzinostatin enediyne, C-1027 enediyne, calicheamicin enediyne, landomycin, simocyclinone, medermycin, granaticin, polyketomycin, teicoplanin, balhimycin, vancomycin, staurosporine, rubradirin and complestatin.

The antibiotic rubradirin, C48H46N4O20 was cleaved at an ester function by aqueous methylamine into rubransarol A, C23H23NO8, and a methyl amide, C26H28N4O12. Rubradirin B, C40H33N3O15, was similarly cleaved in methanolic ammonia into rubransarol B, C23H23NO8, and the primary amide, C17H13N3O7. The rubransarols are shown to be unique ansamycins which are isomeric at a double bond in the large ring.