Anti-inflammatory constituents of the red alga Gracilaria verrucosa and their synthetic analogues

A chemical study on the anti-inflammatory components of the red alga Gracilaria verrucosa led to the isolation of new 11 -deoxyprostaglandins (1-4), a ceramide (5), and a C-16 keto fatty acid (6), along with known oxygenated fatty acids (7-14). Their structures were elucidated on the basis of NMR and MS data. The absolute configurations of compounds 1-5 were determined by Mosher's method. The anti-inflammatory activity of the isolated compounds (1-14) was evaluated by determining their inhibitory effects on the production of pro-inflammatory mediators (NO, IL-6, and TNF-alpha) in lipopolysaccharide (LPS)-activated RAW 264.7 murine macrophage cells. Compounds 9 and 10 exhibited the most potent activity. In the evaluation of these two compounds and derivatized analogues (15-40), the anti-inflammatory activity was enhanced in some synthetic analogues. These enone fatty acids were investigated as potential anti-inflammatory leads for the first time.