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  • 09월 08일 17시 이후 : 초록수정 불가능, 일정확인 및 검색만 가능

제116회 대한화학회 학술발표회, 총회 및 기기전시회 안내 Discrimination of α/β-Amino Saccharide Anomers by Cucurbit[7]uril

2015년 8월 27일 16시 07분 51초
KCS.O-5 이곳을 클릭하시면 발표코드에 대한 설명을 보실 수 있습니다.
목 09시 : 40분
Oral Presentation for Young International Chemists
저자 및
KHEDKAR JAYSHREE KESHAV, 장윤정1, 김용휘2, 이영민1,*, 김기문1,*
기초과학연구원 복잡계 자기조립 연구단, Korea
1포항공과대학교(POSTECH) 화학과, Korea
2기초과학연구원 복잡계자기조립연구단, Korea
Amino saccharides (galactosamine (GalN), glucosamine (GluN) and mannosamine (MaN)) have recently been shown to bind cucurbit[7]uril (CB[7]) with excellent affinity in water and higher preference for α-anomers [Jang et al., Angew. Chem. Int. Ed., 2014, 53, 1003-1007]. Here, we present detail studies on this anomer selectivity through X-ray crystallography and computational methods. The crystal structures of GalN@CB[7] and GluN@CB[7] showed the complete encapsulation of α-GalN and α-GluN within the CB[7] cavity, respectively. The calculated structures in the gas phase using density functional theory (DFT) calculations and molecular dynamic (MD) simulations correlated well with the crystal structures. However, these gas phase calculations preferred β-anomers over α-anomers, in contrast to the experimental result in aqueous solution. Hence, we performed MD simulations with explicit water molecules on the complexes to calculate the binding free energies and consequently demonstrate the consistent preferences for α-anomers over their β-counterparts as already reported in the solution phase. Further, the similarity and dissimilarity between the crystal/gas phase features and the solution phase features are also explained. The relative solvation/desolvation free energies of amino saccharides indeed identify the effect of aqueous environment on α/β discrimination and the subsequent stabilization of α-forms. Our study suggest that the solvent contributions in non-covalent binding should be carefully considered while designing new supramolecular architects.