What is ChemSpider?
This record (rifampicin) and http://www.chemspider.com/Chemical-Structure.10468813.html (rifampin) seem to relate to the same structure (although in the latter the stereocentres are defined). If all the references in this record refer to the true natural product drug rifampicin (with the correct stereochemistry), and are covered in the other record, then this record should be deprecated and the other renamed rifampicin with rifampin as a synonym, since the INN for the drug is rifampicin, and rifampin is only valid in the US. If there is a need for this second record to be kept (for example if some of the reference refer to other/mixed stereochemistries) then the structure requires some work as it currently looks quite confusing. in particular the two methyl groups on the left hand side of the macrocycle, especially the one where the upright of the H could easliy be mistaken for a bond between the two oxygen atoms...
Also from the RSC