Cruentaren
{{Short description|Group of chemical compounds}}
Cruentarens are a group of macrolides secreted by the myxobacteria Byssovorax cruenta.{{cite journal | journal = Journal of Antibiotics | issn = 0021-8820 | year = 2006 | volume = 59 | issue = 10 | title = Cruentaren, a new antifungal salicylate-type macrolide from Byssovorax cruenta (Myxobacteria) with inhibitory effect on mitochondrial ATPase activity : Fermentation and biological properties | pages = 664–668 | last = Kunze | first = Brigitte |author2=Heinrich Steinmetz |author3=Gerhard Höfle |author4=Markus Huss |author5=Helmut Wieczorek |author6=Hans Reichenbach | doi = 10.1038/ja.2006.89 | pmid = 17191683| doi-access = free }} There are two isomers (cruentaren A and B) have been isolated.{{cite journal | doi = 10.1002/ejoc.200600421 | title = Isolation and Structure Elucidation of Cruentarens A and B — Novel Members of the Benzolactone Class of ATPase Inhibitors from the Myxobacterium Byssovorax cruenta | journal = European Journal of Organic Chemistry | date = 2006 | issue = 22 | pages = 5036–5044 | last1 = Jundt | first1 = Larissa | last2 = Steinmetz | first2 = Heinrich | last3 = Luger | first3 = Peter | last4 = Weber | first4 = Manuela | last5 = Kunze | first5 = Brigitte | last6 = Reichenbach | first6 = Hans | last7 = Höfle | first7 = Gerhard | volume = 2006 }} They each have a molecular formula of C33H51NO8 and molecular weight 589 g/mol. Cruentaren A strongly inhibits the growth of yeasts and filamentous fungi, and inhibits the proliferation of different cancer cell lines in vitro,{{cite journal | doi = 10.1016/j.febslet.2007.06.069| pmid = 17624334| title = Cruentaren A, a highly cytotoxic benzolactone from Myxobacteriais a novel selective inhibitor of mitochondrial F1-ATPases| journal = FEBS Letters| volume = 581| issue = 18| pages = 3523–3527| year = 2007| last1 = Kunze| first1 = Brigitte| last2 = Sasse| first2 = Florenz| last3 = Wieczorek| first3 = Helmut| last4 = Huss| first4 = Markus| doi-access = free}} including a multidrug-resistant KB line. Cruentaren B shows only marginal cytotoxicity and no antifungal activity.