The invention provides novel Thuggacin-Type macrolide compounds which form rearrangement products forming a lacton bond to different carbon atoms. The novel compounds can be produced by fermentation of Sorangium cellulosum and Chondromyces crocatus and can be isolated by adsorption and chromoatograhic processing steps. The compounds are found to have antibiotic activity. The invention also relates to Thuggacin A, Thuggacin B, Thuggacin C, 13-Methyl-Thuggacin A, Thuggacin CMC-A, Thuggacin CMC-B and Thuggacin CMC-C AS Antimycobacterial Agents.