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The Structure of the Antibiotic Hedamycin. V. Crystal structure and absolute configuration
Author(s) -
Zehnder Margareta,
Séquin Urs,
Nadig Heinz
Publication year - 1979
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19790620803
Subject(s) - orthorhombic crystal system , chemistry , absolute configuration , crystal structure , crystallography , ring (chemistry) , substituent , optical rotation , stereochemistry , organic chemistry
The crystal structure of the antibiotic hedamycin ( 1 ) has been solved by direct method and refined by least squares techniques to R = 0.091 for 2289 of 2643 independent reflexions. Crystals of C 41 H 50 N 2 O 11 are orthorhombic, space group P2 1 2 1 2 1 with lattice parameters a = 24.239 (12), b = 21.440 (10), c = 7.369 (4) Å, Z = 4. The structural features of hedamycin derived earlier by chemical and spectroscopical means are confirmed. Optical rotation and circular dichroism indicate that hedamycin ( 1 ) has the absolute configuration of the related antibiotic kidamycin ( 3 ). The conformation of ring F is a chair form with the aryl substituent almost axial. The bioxirane part of the antibiotic is in a synclinal conformation.