fatty acid 18:1 long-chain fatty acid monounsaturated fatty acid monounsaturated fatty acid octadecenoic acid PMID:7276754 282.25588 CHEBI:25634 0 282.462 PMID:18832207 C18H34O2 PMID:19106329 octadecenoic acid chebi_ontology Any member of the group of C18 monounsaturated fatty acids with the double bond located at any position in the chain. olefinic fatty acid octadecenoate