Abstract
Strepyrazinone (1), a tricyclic diketopiperazine derivative with a carbon skeleton unprecedented in natural products, was isolated from the marine-derived Streptomyces sp. B223. Its structure was elucidated by spectroscopic analyses and electronic circular dichroism calculation. Compound 1 showed cytotoxic activity against HCT-116 cancer cell lines with an IC50 value of 0.34 µM.
Graphical abstract
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Disclosure statement
No potential conflict of interest was reported by the authors.