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Beatriz Baragaña

Publications and source records attributed to Beatriz Baragaña.

3 recordsLinked to original sources

Protease-catalyzed peptide synthesis on solid support.

The direct enzymatic synthesis of peptides from amino acids is widely used as a useful alternative to chemical synthesis. However, good yields of such enzyme-catalyzed reactions require altered reaction conditions to overcome the bias for hydrolysis in aqueous medium. We argue that the synthesis/hydrolysis equilibrium can be shifted toward synthesis in aqueous medium by immobilizing the amine on solid support. In this report, we show the first examples of solid-phase peptide synthesis catalyzed by a protease in bulk aqueous buffer.

Acrylamides↗

Enantioselective transport by a steroidal guanidinium receptor.

The cationic steroidal receptors 9 and 11 have been synthesized from cholic acid 3. Receptor 9 extracts N-acetyl-alpha-amino acids from aqueous media into chloroform with enantioselectivities (L:D) of 7-10:1. The lipophilic variant 11 has been employed for the enantioselective transport of N-acetylphenylalanine, a) through dichloromethane (DCM) and dichloroethane (DCE) bulk liquid membranes (U-tube apparatus), and b) through 2.5% (v/v) octanol/hexane via hollow fibre membrane contactors. Significant enantioselectivities and multiple turnovers were observed for both types of apparatus.

Carrier Proteins↗

Preparation and Synthetic Applications of Enantiopure (2S,3S)- or (2R,3S)-2-Halomethyl-1,2-epoxyalkan-3-amines.

Enantiomerically pure (2S,3S)-3 and its diastereoisomer (2R,3S)-2-halomethyl-1,2-epoxyalkan-3-amine 4 have been obtained from 1-aminoalkyl halomethyl ketones 1 and (iodomethyl)lithium or (chloromethyl)lithium, respectively. Some synthetic applications of compounds 3 are described: chiral unsaturated 1,3-aminoalcohols 8 or 2-(halomethylidene)-3-(dibenzylamino)-alkan-1-ol 11 is obtained from 3 by halogeno-lithium or by hydrogen-lithium exchange, respectively. Transformation of 8c into its methyl ester derivative 9c is also reported.

Journal Article↗