Macbecin I

Formula : C30-H42-N2-O8
CAS : 73341-72-7 

From Norcardia sp. No. C-14919; belongs to ansamycin group of antibiotics.

Macbecin II

Formula : C30-H44-N2-O8
CAS : 73341-73-8 

From Norcardia sp. No. C-14919; belongs to ansamycin group of antibiotics.