New sesquiterpene derivatives from the sponge Dysidea species with a selective inhibitor profile against human phospholipase A(2) and other leukocytefunctions

Two new sesquiterpene cyclopentenones, dysidenones A and B (2, 33, and a ne w sesquiterpene aminoquinone, dysidine (4), all containing the same rearran ged drimane skeleton, have been isolated from a Dysidea sp. sponge, along w ith bolinaquinone (1). The structures were established fi om 2D NMR data. B olinaquinone (1), dysidine (4), and a 1:1 mixture of dysidenones A and B (2 , 3) significantly inhibited human synovial phospholipase A(2) (PLA(2)) at 10 muM. Compound 4, which shows an IC50 value of 2.0 muM, exerts a higher p otency and selectivity toward this enzyme than the reference inhibitor mano alide. In addition, all of these compounds modulated at 10 muM other human leukocyte functions such as the degranulation process measured as elastase release and the superoxide production measured by chemiluminescence.