Abstract: The invention provides novel compounds and methods to carry out organocatalytic Michael additions of aldehydes to nitroethylene catalyzed by a proline derivative to provide ?-substituted-?-nitroaldehydes. The reaction can be rendered enantioselective when a chiral pyrrolidine catalyst is used, allowing for Michael adducts in nearly optically pure form (e.g., 96-99% e.e.). The Michael adducts can bear a single substituent or dual substituents adjacent to the carbonyl. The Michael adducts can be efficiently converted to protected ?2-amino acids, which are essential for systematic conformational studies of ?-peptide foldamers.

Abstract: The invention provides amphiphiles for manipulating membrane proteins. The amphiphiles can feature carbohydrate-derived hydrophilic groups and branchpoints in the hydrophilic moiety and/or in a lipophilic moiety. Such amphiphiles are useful as detergents for solubilization and stabilization of membrane proteins, including photosynthetic protein superassemblies obtained from bacterial membranes.

Abstract: The invention provides novel compounds and methods to carry out organocatalytic Michael additions of aldehydes to nitroethylene catalyzed by a proline derivative to provide ?-substituted-?-nitroaldehydes. The reaction can be rendered enantioselective when a chiral pyrrolidine catalyst is used, allowing for Michael adducts in nearly optically pure form (e.g., 96-99% e.e.). The Michael adducts can bear a single substituent or dual substituents adjacent to the carbonyl. The Michael adducts can be efficiently converted to protected ?2-amino acids, which are essential for systematic conformational studies of ?-peptide foldamers.

Abstract: The invention provides amphiphiles for manipulating membrane proteins. The amphiphiles can feature carbohydrate-derived hydrophilic groups and branchpoints in the hydrophilic moiety and/or in a lipophilic moiety. Such amphiphiles are useful as detergents for solubilization and stabilization of membrane proteins, including photosynthetic protein superassemblies obtained from bacterial membranes.

Abstract: The invention provides compounds and methods, for example, to carry out organocatalytic Michael additions of aldehydes to cyclically constrained nitroethylene compounds catalyzed by a proline derivative to provide cyclically constrained ?-substituted-?-nitro-aldehydes. The reaction can be rendered enantioselective when a chiral pyrrolidine catalyst is used, allowing for Michael adducts in nearly optically pure form (e.g., 96 to >99% e.e.). The Michael adducts can bear a single substituent or dual substituents adjacent to the carbonyl. The Michael adducts can be efficiently converted to cyclically constrained protected ?-amino acid residues, which are essential for systematic conformational studies of ?-peptide foldamers. New methods are also provided to prepare other ?-amino acids and peptides. These new building blocks can be used to prepare foldamers, such as ?/?-peptide foldamers, that adopt specific helical conformations in solution and in the solid state.

Abstract: The invention provides amphiphilic compounds and methods for manipulating membrane proteins. Compounds of the invention, for example, the compounds of Formulas I-XIX, can be prepared from readily available starting materials. The amphiphilic compounds can manipulate membrane protein at relatively low concentrations compared to many known detergents. The compounds can be used to aid the isolation of membrane proteins, for example, to aid their solubilization and/or purification. The compounds can also be used to aid the functional and structural determination of membrane proteins, including their stabilization and crystallization.

Abstract: The invention provides amphiphiles for manipulating membrane proteins. The amphiphiles can feature carbohydrate-derived hydrophilic groups and branchpoints in the hydrophilic moiety and/or in a lipophilic moiety. Such amphiphiles are useful as detergents for solubilization and stabilization of membrane proteins, including photosynthetic protein superassemblies obtained from bacterial membranes.

Abstract: The invention provides novel compounds and methods to carry out organocatalytic Michael additions of aldehydes to nitroethylene catalyzed by a proline derivative to provide ?-substituted-?-nitroaldehydes. The reaction can be rendered enantioselective when a chiral pyrrolidine catalyst is used, allowing for Michael adducts in nearly optically pure form (e.g., 96-99% e.e.). The Michael adducts can bear a single substituent or dual substituents adjacent to the carbonyl. The Michael adducts can be efficiently converted to protected ?2-amino acids, which are essential for systematic conformational studies of ?-peptide foldamers.

Abstract: Disclosed are antimicrobial compositions containing &bgr;-peptides and methods of inhibiting microbial growth in mammals using the compositions. The &bgr;-peptides present in the compositions contain ring structures in the peptide backbone which limit the conformational flexibility of the peptide backbone.