Rational design and synthesis of small molecule, non-oligosaccharide selectin inhibitors: (alpha-D-mannopyranosyloxy)biphenyl-substituted carboxylic acids

The calcium dependent E-selectin/sialyl Lewis(x) (sLe(x)) interaction plays a key role in inflammation where it mediates the rolling of leukocytes prior to firm adhesion and extravasation from the vasculature. A model of E-selectin/sLe(x) binding, along with previously reported structure-activity relationships of sLe(x)-related oligosaccharide, was used in the rational design of non-oligosaccharide inhibitors of this pivotal interaction. A palladium-mediated biaryl-coupling (Suzuki) reaction was used as the key step to prepare a number of substituted biphenyls which were assayed for their ability to inhibit the binding of E-, P-, and L-selectin-IgG fusion proteins to sLe(x) expressed on the surface of HL60 cells. Some of the compounds developed had greater in vitro potency than the parent sLe(x) tetrasaccharide and are currently being evaluated in in vivo models of inflammation to select a candidate for clinical development.