Inhibitors of platelet lipoxygenase from Ponkan fruit

An activity-guided separation for inhibitors of rat platelet 12-lipoxygenas e led to the isolation of two compounds, 4-O-feruloyl-5-O-caffeoylquinic ac id (IC50; 5.5 muM) and methyl 4-O-feruloyl-5-O-caffeoylquinate (IC50; 1.9 m uM) from the peel of Ponkan fruit (Citrus reticulata). The complete structu re of each phenolic ester was determined by NMR spectroscopy [H-1 and C-13 NMR speclra, H-1-H-1 correlation spectroscopy (COSY),H-1-detected heteronuc lear multiple quantum coherence (HMQC), and heteronuclear multiple bond con nectivity (HMBC) spectroscopies] and other spectral methods. (C) 2001 Elsev ier Science Ltd. All rights reserved.