<P>Precursor-fed cultivation of endophytic <I>Chaetomium globosum</I> 1C51 afforded nine novel “unnatural” halogenated chaetoglobosins including those with more preferable immunosuppressive activity.</P> <P>Graphic Abstract</P><P>Precursor-fed cultivation of <I>Chaetomium globosum</I> afforded nine novel “unnatural” halogenated chaetoglobosins including those with more preferable immunosuppressive activity.<BR><IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c0cc04183a'><BR></P>