Effect of manoalide on human 5-lipoxygenase activity

Antileukotrienic N-arylethyl-2-arylacetamides in the treatment of ulcerative colitis

A series of arylacetic acid derivatives bearing methyl(arylethyl)amino groups were prepared and their antileukotrienic activities involving LTB(4) were evaluated. Regression analysis has shown a strong dependence of these activities on lipophilicity for both LTB(4) receptor binding and inhibition of LTB(4) biosynthesis; parabolic relationships were derived. The values of slopes of the ascending linear parts of these dependences indicate various types of hydrophobic binding at the site of ligand interaction with relevant biomacromolecules. The anti-inflammatory effect of the compounds under study was also evaluated in three animal models of inflammation and their possible utilization in the treatment of ulcerative colitis (UC) was followed. The importance of antileukotrienic activities for the anti-inflammatory effect, especially in the model of UC was discussed, but further experiments are necessary to confirm the respective relations.

Probing sponge-derived terpenoids for human 15-lipoxygenase inhibitors

A human 15-lipoxygenase (15-HLO) assay has been employed to discover new marine-sponge-derived bioactive compounds. Extracts from two different sponges, Jaspis splendens (order Choristida, family Jaspidae) and Suberea sp. (order Verongida, family Aplysinellidae), exhibited potent IC(50) values of 0.4 and 0.1 microg/mL, respectively. Both are sources of terpenoids, and the former is a known source of (+)-jasplakinolide (7), which is inactive as a 15-HLO inhibitor. The terpenoids included (+)-(5S,6S)-subersin (1, IC(50) > 100 microM), (-)-(5R,10R)-subersic acid (2, IC(50) = 15 microM), jaspaquinol (3, IC(50) = 0.3 microM), and (-)-jaspic acid (4, IC(50) = 1.4 microM). Structure elucidations and lipoxygenase activity studies of these compounds are reported.