carotenoid chi-end group triterpenoid Okenone 578.412 578.86630 C41H54O2 CHEBI:80417 COC(C)(C)CCC(=O)C(\C)=C\C=C\C(C)=C\C=C\C(C)=C\C=C\C=C(C)\C=C\C=C(C)\C=C\c1ccc(C)c(C)c1C FSQZIFSGNDUYRQ-TYKRLFMMSA-N InChI=1S/C41H54O2/c1-31(19-14-21-33(3)23-16-24-36(6)40(42)29-30-41(9,10)43-11)17-12-13-18-32(2)20-15-22-34(4)25-27-39-28-26-35(5)37(7)38(39)8/h12-28H,29-30H2,1-11H3/b13-12+,19-14+,20-15+,23-16+,27-25+,31-17+,32-18+,33-21+,34-22+,36-24+ KEGG:C16280 chebi_ontology