This product is a mixture of oligomycin's A, B, and C. The molecular weight of each is as follows: :
Oligomycin A = 791 g/mol (approximately 65%)
Oligomycin B = 805.1 g/mol (amount not determined)
Oligomycin C = 775.1 g/mol (amount not determined)
Please see the link below to review the product datasheet:
https://www.sigmaaldrich.com/deepweb/assets/sigmaaldrich/product/documents/165/401/o4876pis.pdf