2,3- cis -3,4- trans -3,4-Dihydroxy-L-proline: Mass Spectrometry and X-Ray Analysis

Abstract
Mass spectrometry showed the new amino acid from diatomn cell walls to be a dihydroxyproline. X-ray analysis of the unmarked free amino acid by the use of the symbolic addition procedure revealed the comnplete three-dimtensional structure as 2, 3-cis-3, 4-trans-3, 4-dihydroxy-L-proline with carbon number 3 being 0.06 angstrom above the plane of the pyrrolidine ring.