Publications (1)0 Total impact
ABSTRACT: Eight naturally occurring marine-sponge derived sesquiterpenoid quinones wereevaluated as potential inhibitors of pyruvate phosphate dikinase (PPDK), a C4 plantregulatory enzyme. Of these, the hydroxyquinones ilimaquinone, ethylsmenoquinone andsmenoquinone inhibited PPDK activity with IC50Ã¢Â€Â™s (reported with 95% confidenceintervals) of 285.4 (256.4 Ã¢Â€Â“ 317.7), 316.2 (279.2 Ã¢Â€Â“ 358.1) and 556.0 (505.9 Ã¢Â€Â“ 611.0) ÃŽÂ¼M,respectively, as well as being phytotoxic to the C4 plant Digitaria ciliaris. The potentialanti-inflammatory activity of these compounds, using bee venom phospholipase A2(PLA2), was also evaluated. Ethylsmenoquinone, smenospongiarine, smenospongidine andilimaquinone inhibited PLA2 activity (% inhibition of 73.2 + 4.8 at 269 ÃŽÂ¼M, 61.5 + 6.1 at242 ÃŽÂ¼M, 41.0 + 0.6 at 224 ÃŽÂ¼M and 36.4 + 8.2 at 279 ÃŽÂ¼M, respectively). SAR analysesindicate that a hydroxyquinone functionality and a short, hydroxide/alkoxide side-chain atC-20 is preferred for inhibition of PPDK activity, and that a larger amine side-chain at C-20 is tolerated for PLA2 inhibitory activity.