{{cs1 config|name-list-style=vanc}} {{chembox | Verifiedfields = changed | verifiedrevid = 477859381 | ImageFile=Stigmatellin.svg | ImageSize=250px | PIN=2-[(3''S'',4''S'',5''S'',6''S'',7''E'',9''E'',11''E'')-4,6-Dimethoxy-3,5,11-trimethyltrideca-7,9,11-trien-1-yl]-8-hydroxy-5,7-dimethoxy-3-methyl-4''H''-1-benzopyran-4-one |Section1={{Chembox Identifiers | CASNo_Ref = {{cascite|changed|??}} | CASNo=91682-96-1 | ChEBI_Ref = {{ebicite|changed|EBI}} | ChEBI = 32155 | ChEMBL_Ref = {{ebicite|correct|EBI}} | ChEMBL = 486556 | PubChem=447884 | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID = 394850 | SMILES = O=C\1c2c(O/C(=C/1C)CC[C@H](C)[C@H](OC)[C@H](C)[C@@H](OC)\C=C\C=C\C(=C\C)C)c(O)c(OC)cc2OC | InChI = 1/C30H42O7/c1-10-18(2)13-11-12-14-22(33-6)21(5)29(36-9)19(3)15-16-23-20(4)27(31)26-24(34-7)17-25(35-8)28(32)30(26)37-23/h10-14,17,19,21-22,29,32H,15-16H2,1-9H3/b13-11+,14-12+,18-10+/t19-,21+,22-,29-/m0/s1 | InChIKey = UZHDGDDPOPDJGM-CVOZLMQJBZ | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI = 1S/C30H42O7/c1-10-18(2)13-11-12-14-22(33-6)21(5)29(36-9)19(3)15-16-23-20(4)27(31)26-24(34-7)17-25(35-8)28(32)30(26)37-23/h10-14,17,19,21-22,29,32H,15-16H2,1-9H3/b13-11+,14-12+,18-10+/t19-,21+,22-,29-/m0/s1 | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = UZHDGDDPOPDJGM-CVOZLMQJSA-N | MeSHName=Stigmatellin }} |Section2={{Chembox Properties | Formula=C<sub>30</sub>H<sub>42</sub>O<sub>7</sub> | MolarMass=514.65 g/mol }} }} '''Stigmatellin''' is a potent inhibitor of the quinol oxidation (Qo) site of the cytochrome bc1 complex in mitochondria<ref>{{cite journal | vauthors = von Jagow G, Ohnishi T | title = The chromone inhibitor stigmatellin--binding to the ubiquinol oxidation center at the C-side of the mitochondrial membrane | journal = FEBS Letters | volume = 185 | issue = 2 | pages = 311–5 | date = June 1985 | pmid = 2987042 | doi = 10.1016/0014-5793(85)80929-7 | doi-access = | bibcode = 1985FEBSL.185..311V | s2cid = 37956153 }}</ref> and the cytochrome b6f complex of thylakoid membranes. At higher concentrations, stigmatellin also inhibits Complex I, as a "Class B" inhibitor of that enzyme.<ref>{{cite journal | vauthors = Fato R, Bergamini C, Bortolus M, Maniero AL, Leoni S, Ohnishi T, Lenaz G | title = Differential effects of mitochondrial Complex I inhibitors on production of reactive oxygen species | journal = Biochimica et Biophysica Acta (BBA) - Bioenergetics | volume = 1787 | issue = 5 | pages = 384–92 | date = May 2009 | pmid = 19059197 | pmc = 2724837 | doi = 10.1016/j.bbabio.2008.11.003 }}</ref>
Stigmatellin is isolated from the myxobacterium ''Stigmatella aurantica'', and contains a 5,7-dimethoxy-8-hydroxychromone aromatic headgroup with a hydrophobic alkenyl chain in position 2. Crystal structures for stigmatellin-inhibited bc1 complex from bovine, avian, yeast (''Saccharomyces cerevisiae'') and bacterial (''Rhodobacter capsulatus'', ''Cereibacter sphaeroides'', and ''Paracoccus denitrificans'') sources are available. Stigmatellin binds at the cytochrome b Qo site in the '(heme) bl distal' position, and associates with the Rieske iron-sulfur protein via a hydrogen bond to histidine residue 181 (His-181), a ligand to the [2Fe2S] iron-sulfur cluster of this subunit. This association raises the midpoint potential of the iron-sulfur cluster from 290 to 540 mV and restricts movement of the cytoplasmic domain of the Rieske protein.
== References == {{reflist}}
== Further reading == {{refbegin}} * {{cite book | vauthors = von Jagow G, Link TA | chapter = Use of specific inhibitors on the mitochondrial bc1 complex | title = Biomembranes Part N: Transport in Bacteria, Mitochondria, and Chloroplasts: Protonmotive Force | series = Methods in Enzymology | volume = 126 | pages = 253–71 | date = 1986 | pmid = 2856132 | doi = 10.1016/s0076-6879(86)26026-7 | isbn = 978-0-12-182026-8 }} {{refend}}
Category:O-methylated natural phenols Category:Chromones