Neutron Diffraction Structure of (2R, 3R)-L-(-)-[2-D]Carnitine Tetrachloroaurate, [(CH_3)_3N-CH_2-CHOH-CHD-COOH]~+[AuCl_4]~-

摘要

(Title: Determination of the Absolute Stereochemistry of the Crotonobetaine-to-Carnitine Transformation Catalyzed by L-Carnitine Dehydratase from Escherichia coli) Single-crystal neutron diffraction has geen used to determine the stereochemical course of the hydration of trans-crotonobetaine to L-(-)- carnitine by the enzyme L-carnitine dehydratase. Firstly, an X-ray analysis of the undeuterated carnitinium slat [(CH_3)_3N-CH_2-CHOH-CHD-COOH]~+[AuCl_4]~- confirmed that the absorlute configuration at the C_3 position of L-(-)-carnitine (the CHOH group) is indeed R. This was accomplished using the gold atom as an anomalously-scattering source.