baicalein and 1-1-diphenyl-2-picrylhydrazyl

The localization and interaction of six naturally occurring flavones (FLV, 5HF, 6HF, 7HF, CHY and BLN) in DPPC bilayers were studied using DSC and multi-nuclear NMR. DSC results indicate that FLV and 6HF interact with alkyl chains. The (1)H NMR shows interaction of flavones with the sn-glycero region. Ring current induced chemical shifts indicate that 6HF and BLN acquire parallel orientation in bilayers. 2D NOESY spectra indicate partitioning of the B-ring into the alkyl chain region. The DSC, NMR and binding studies indicate that 5HF and 7HF are located near head group region, while 6HF, CHY and BLN are located in the vicinity of sn-glycero region, and FLV is inserted deepest in the membrane.

Topics: Biphenyl Compounds; Calorimetry, Differential Scanning; Cell Line, Tumor; Cell Membrane; Cell Proliferation; Flavones; Free Radical Scavengers; Humans; Hydroxides; Lipid Bilayers; Magnetic Resonance Spectroscopy; Picrates; Structure-Activity Relationship