Rychlewska Urszula, Warzajtis Beata, Glisic Biljana D, Rajkovic Snezana, Djuran Milos
Department of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60-780 Poznań, Poland.
Acta Crystallogr C. 2010 Feb;66(Pt 2):m51-4. doi: 10.1107/S0108270110001666. Epub 2010 Jan 26.
Crystallographic analysis of a solid solution of two diastereoisomers, i.e. ({(1S,R)-1-carboxy-3-[(R,S)-methylsulfinyl]propyl}aminocarbonyl)methanaminium tetrachloridoaurate(III) and ({(1S,R)-1-carboxy-3-[(S,R)-methylsulfinyl]propyl}aminocarbonyl)methanaminium tetrachloridoaurate(III), (C(7)H(15)N(2)O(4)S)[AuCl(4)], has shown that in the presence of gold(III), the methionine part of the Gly-D,L-Met dipeptide is oxidized to sulfoxide, and no coordination to the Au(III) cation through the S atom of the sulfoxide is observed. In view of our observation, literature reports that methionine acts as an N,S-bidentate donor ligand forming stable gold(III) complexes require verification. Moreover, it has been demonstrated that crystallization of the oxidation product leads to a substantial 77:23 excess of both S-methionine/R-sulfoxide and R-methionine/S-sulfoxide over S-methionine/S-sulfoxide and R-methionine/R-sulfoxide. The presence of two different diastereoisomers at the same crystallographic site is a source of static disorder at this site.
两种非对映异构体的固溶体，即（{(1S,R)-1-羧基-3-[(R,S)-甲亚磺酰基]丙基}氨基甲酰基）甲铵四氯合金酸盐(III)和（{(1S,R)-1-羧基-3-[(S,R)-甲亚磺酰基]丙基}氨基甲酰基）甲铵四氯合金酸盐(III)，(C(7)H(15)N(2)O(4)S)[AuCl(4)]的晶体学分析表明，在金(III)存在的情况下，甘氨酰-D,L-蛋氨酸二肽的蛋氨酸部分被氧化为亚砜，并且未观察到通过亚砜的S原子与Au(III)阳离子配位。鉴于我们的观察结果，文献中关于蛋氨酸作为形成稳定金(III)配合物的N,S-双齿供体配体的报道需要验证。此外，已证明氧化产物的结晶导致S-蛋氨酸/R-亚砜和R-蛋氨酸/S-亚砜相对于S-蛋氨酸/S-亚砜和R-蛋氨酸/R-亚砜有77:23的大量过量。在同一晶体学位置存在两种不同的非对映异构体是该位置静态无序的一个来源。
