Abstract: Chiral diphosphines constituted by an aromatic pentatomic biheterocyclic system, suitable to act as chiral ligands, complexes between said diphosophines and transition metals, and their utilization as chiral catalysts in stereocontrolled reactions, such as diastereo- and enantioselective reduction reactions. Process for the preparation of said chiral diphosophines and process for the preparation of said complexes and for their utilization as chiral catalysts in stereocontrolled reaction.

Abstract: Chiral diphosphines constituted by an aromatic pentatomic biheterocyclic system, suitable to act as chiral ligands, complexes between said diphosophines and transition metals, and their utilization as chiral catalysts in stereocontrolled reactions, such as diastereo- and enantioselective reduction reactions. Process for the preparation of said chiral diphosophines and process for the preparation of said complexes and for their utilization as chiral catalysts in stereocontrolled reactions.

Abstract: Chiral diphosphines are constituted by an aromatic pentatomic biheterocyclic system, suitable to act as chiral ligands and complexes between the diphosphines and transition metals. They may be utilized as chiral catalysts in stereocontrolled reactions, such as diastereo- and enantioselective reduction reactions. Process is for the preparation of these chiral diphosphines; and process is for the preparation of these complexes and for their utilization as chiral catalysts in stereocontrolled reactions.

Abstract: Chiral diphosphines constituted by an aromatic pentatomic biheterocyclic system, suitable to act as chiral ligands, complexes between said diphosophines and transition metals, and their utilization as chiral catalysts in sterocontrolled reactions, such as diastereo- and enantioselective reduction reactions. Process for the preparation of said chiral diphosophines and process for the preparation of said complexes and for their utilization as chiral catalysts in sterocontrolled reactions.

Abstract: The invention relates to a process for the preparation of phosphatidylserines by reacting racemic or enantiomerically pure serine, preferably (L)-serine, with natural phosphatides, such as soybean or egg lecithin, or with synthetic phosphatides, in the presence of a phospholipase D, having transphosphatidylating activity, in an aqueous/organic diphasic system.

Abstract: A process for fractionating deacylated glycerophospholipids of the formula (I): ##STR1## wherein R is a negative charge; a hydrogen atom; a CH.sub.2 CH.sub.2 NR.sup.1 R.sup.2 residue wherein R.sup.1 and R.sup.2, which are the same or different, are H or C.sub.1 -C.sub.4 alkyl; a CH.sub.2 CH.sub.2 N.sup.+ (CH.sub.3).sub.3 residue; a CH.sub.2 CH(NH.sub.2)COOH residue or a residue of the formula: ##STR2## and X is OH or 0.sup.-, is described. The process involves subjecting an aqueous or hydroalcoholic mixture of two or more of the deacylated glycerophospholipids to electrodialysis in an electrolytic cell comprising a number of compartments. The compartments are separated by cation-exchange membranes, anion-exchange membranes or both cation-exchange and anion-exchange membranes, at a pH effective to differentiate the deacylated glycerophospholipids.