58(P-33) ポリエーテル抗生物質monensinおよび誘導体のNMRを用いた溶液中の立体配座推定へのアプローチ : Long range C-H結合定数を利用して(ポスター発表の部)

概要

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Antibiotic monensin (1), isolated from Streptomyces cinnamonensis, selectively transports Na^+ ion in particular across the lipophilic biological membrane. Since the strucure of monensin is interesting, X-ray crystal structure was studied and exhibited that monensin wraps Na^+ ion in the center of its pseudocyclic conformation. In general, the comformation of monensin in solution is considered to be the same as in crystal. However, it is natural to consider that the conformations in solvents should be different from those in crystal. Thus, we carried out J-HMBC experiment on monensin Na to obtain long range C-H coupling constants in order to compare the ^3J(^<13>C-^1H) in solvents with those in crystal. Some ^3J(^<13>C-^1H) obtained from J-HMBC measurement in both CDCl_3 and CD_3OD were unambiguously different from those calculated from X-ray crystal structure analysis. This result indicated that the conformations of monensin Na in solvents were different from those in crystal. Investigation to obtain conformation of monensin Na in detail is now in progress. The conformation analysis of other metal salts of monensin derivatives in solvents is also in progress.
天然有機化合物討論会の論文
2000-10-01