Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5276082 | Tetrahedron Letters | 2009 | 4 Pages |
Abstract
Kulokekahilide-2 is a 26-membered cyclic depsipeptide that exhibits potent cytotoxicity against HeLa and P388 cells with IC50 values of 3.2 and 16Â ng/mL, respectively. We have achieved a total synthesis of natural kulokekahilide-2, the NMR spectra of which showed complex signals because of trans and cis conformers at the amide bond. Besides, the spectra revealed that a mixture of 26- and 24-membered cyclic depsipeptides had been produced due to intramolecular ester exchange. The isolated 24-membered compound was transformed into the 26-membered compound over a period of several days. The two isomers have been shown to be in equilibrium and to display almost the same cytotoxicity.
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Related Topics
Physical Sciences and Engineering
Chemistry
Organic Chemistry
Authors
Masahiro Umehara, Yuuki Takada, Yoichi Nakao, Junji Kimura,