Method for preparing 4-hydroxyisoleucine diastereoisomers and enantiomers and derivatives thereof
申请人:Mioskowski Charles
公开号:US20060205817A1
公开(公告)日:2006-09-14
The invention concerns a method for preparing 4-hydroxyisoleucine diastereoisomers and enantiomers and derivatives thereof of general formula (I), characterized in that it consists in reducing an isoxazole derivative of formula (II) in conditions directly resulting in the derivatives of formula (I), or in obtaining at least a lactone of structure (III) in racemic form(s), or a enantiomerically enriched mixture, followed by opening, in basic conditions, in an aprotic or protic solvent, the desired lactone(s) and, optionally, separating the desired form. The invention is useful for preparing in particular (2S, 3R, 4S)-4-hydroxyisoleucine
Method for preparing (2S, 3R, 4S) -4-hydroxyisoleucine and analogues thereof
申请人:Ouazzani Jamal
公开号:US20050079587A1
公开(公告)日:2005-04-14
The invention concerns a method for preparing a-amino acids of general formula (2S-1) wherein: the group R1 represents a hydrogen atom, a group protecting the amino group or a group of formula —COOR2 wherein the group R2 represents a C1-C6 alkyl group, an aryl or aralkyl group. The invention also concerns a-amino acids of general formula (2S-1) wherein the group R1 represents a group protecting the amino group or a group of formula —COOR2 wherein the group R2 represents a C1-C6 alkyl group, an aryl or aralkyl group and their use as medicine.
Method for preparing (2s,3r,4s)-4-hydroxyisoleucine and analogues thereof
申请人:——
公开号:US20030219880A1
公开(公告)日:2003-11-27
The invention concerns a method for preparing a-amino acids of general formula (2S-1) wherein: the group R1 represents a hydrogen atom, a group protecting the amino group or a group of formula —COOR2 wherein the group R2 represents a C1-C6 alkyl group, an aryl or aralkyl group. The invention also concerns a-amino acids of general formula (2S-1) wherein the group R1 represents a group protecting the amino group or a group of formula —COOR2 wherein the group R2 represents a C1-C6 alkyl group, an aryl or aralkyl group and their use as medicine.
The glucagon-like peptide-1 receptor (GLP-1R) is expressed in many tissues and has been implicated in diverse physiological functions, such as energy homeostasis and cognition. GLP-1 analogs are approved for treatment of type 2 diabetes and are undergoing clinical trials for other disorders, including neurodegenerative diseases. GLP-1 analog therapies maintain chronically high plasma levels of the analog and can lead to loss of spatiotemporal control of GLP-1R activation. To avoid adverse effects associated with current therapies, we characterized positive modulators of GLP-1R signaling. We screened extracts from edible plants using an intracellular cAMP biosensor and GLP-1R endocytosis assays. Ethanol extracts from fenugreek seeds enhanced GLP-1 signaling. These seeds have previously been found to reduce glucose and glycated hemoglobin levels in humans. An active compound (N55) with a new N-linoleoyl-2-amino-gamma-butyrolactone structure was purified from fenugreek seeds. N55 promoted GLP-1-dependent cAMP production and GLP-1R endocytosis in a dose-dependent and saturable manner. N55 specifically enhanced GLP-1 potency more than 40-fold, but not that of exendin 4, to stimulate cAMP production. In contrast to the current allosteric modulators that bind to GLP-1R, N55 binds to GLP-1 peptide and facilitates trypsinmediated GLP-1 inactivation. These findings identify a new class of modulators of GLP-1R signaling and suggest that GLP-1 might be a viable target for drug discovery. Our results also highlight a feasible approach for screening bioactive activity of plant extracts.