https://www.selleckchem.com/pr....oducts/procyanidin-c
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. [Figure see text]. To determine whether central speech processing ability, as measured by hearing in noise, differs between right and left ears in adults