Hydrolysis of lipoproteins by sPLA2's enhances mitogenesis and eicosanoid release from vascular smooth muscle cells: Diverse activity of sPLA2's IIA, V and X.

Mitogenesis of Vascular Smooth Muscle Cells (VSMC) plays an important role in atherogenesis. Until recently, the effect of lipid subfractions has not been clarified. Secretory phospholipases A2 (sPLA2's) hydrolyse glycerophospholipids and release pro-inflammatory lyso-lipids, oxidized and non-oxidized fatty acids and isoprostanes.

Diverse activity of human secretory phospholipases A2 on the migration of human vascular smooth muscle cells.

Objective: Investigation of the diversity of human secretory phospholipases A2 (sPLA2) on the migration of human vascular smooth muscle cells (VSMC).

Material: We investigated the impact of sPLA2 IIA, V, and X and of oleic acid, linoleic acid and lysophosphatidylcholine on the migration of human VSMC.

Methods: Recombinant human sPLA2's and Boyden's chamber method were applied.

Dithiodiolate ligands: group 4 complexes and application in lactide polymerization.

Dithiodiolate ligands were synthesized by reacting 1,2-ethanedithiol or 1,2-benzenedithiol with 2,2-bis(trifluoromethyl)oxirane, led selectively to mononuclear octahedral group 4 complexes of the type [{OSSO}M(OR)(2)], which features C(2) symmetry and fluxional behavior, and were highly active in the ring-opening polymerization of rac- and L-lactide.

New facets of an old ligand: titanium and zirconium complexes of phenylenediamine bis(phenolate) in lactide polymerisation catalysis.

Phenylenediamine bis(phenolate) binds in the reduced dianionic form to titanium and zirconium alkoxides giving either mononuclear or bridging dinuclear complexes depending on the metal precursors; the fluxional mononuclear titanium complex is found to exhibit extremely high activity in polymerisation of rac-lactide in the melt.

2,2'-Bipyrrolidine versus 1,2-diaminocyclohexane as chiral cores for helically wrapping diamine-diolate ligands.

The synthesis of chiral tetradentate dianionic diamine-diolate ligands assembled around either N,N'-dimethyl-trans-1,2-diaminocyclohexane or 2,2'-bipyrrolidine is described. These ligands wrap in a fac-fac helical mode around octahedral titanium and zirconium centers giving chiral-at-metal complexes. Diaminocyclohexane was found to be a poor chiral motif for diastereoselective helical wrapping, and all complexes of this family were obtained as mixtures of stereoisomers.