The Absolute Stereochemistry of Cascarillic Acid.

Cyclopropane-Containing Fatty Acids from the Marine Bacterium Labrenzia sp. 011 with Antimicrobial and GPR84 Activity

“…The chemical shift of H-11b (δ H −0.13 ppm) suggested the three-membered ring to be cis configured [ 30 ] as in compound 1 . 2 is thus the cis derivative of cascarillic acid ( Figure 1 ) [ 27 ].…”

“…In this respect, it is worth noting that cascarillic acid, the trans isomer of compound 2 ( Figure 1 ), is the main component of cascarilla essential oil. Interestingly, the latter has been utilized for many years as an inhalant to palliate the inflammatory symptoms of respiratory ailments in folk medicine [ 27 , 47 , 48 ]. NMR analysis also showed the presence of a small amount of the cis-disubstituted cyclopropane in natural cascarillic acid [ 27 ].…”

“…Interestingly, the latter has been utilized for many years as an inhalant to palliate the inflammatory symptoms of respiratory ailments in folk medicine [ 27 , 47 , 48 ]. NMR analysis also showed the presence of a small amount of the cis-disubstituted cyclopropane in natural cascarillic acid [ 27 ]. However, deeper investigation, including in vivo testing is required in order to assign a role to compound 2 in inflammation.…”

“… Structures of the cyclopropane fatty acids 1 and 2 (relative configuration) produced by Labrenzia sp. strain 011, of cascarillic acid (reproduced from [ 27 ], Copyright © 2004 Elsevier Ltd.), lyngbyoic acid (reproduced from [ 28 ], Copyright © 2011 The Royal Society of Chemistry), majusculoic acid (reproduced from [ 23 ], Copyright © 2005, American Chemical Society), and grenadamide (reproduced from [ 29 ], Copyright © 1998, American Chemical Society). …”