N-Acetyl-α-hydroxy-β-oxotryptamine, a racemic natural product isolated from Streptomyces sp. 80H647

N-acetyl-α-hydroxy-β-oxotryptamine (1) along with N-acetyl-β-oxotryptamine (2) and pimprinine (3) were isolated from the culture broth of Streptomyces sp. 80H647. Compound 1 was found to be a racemate via X-ray diffraction analysis and the enantiomers were successfully purified by chiral-phase HPLC. The absolute configuration was assigned by comparison of the calculated and experimental ECD spectra. The α-hydroxy moiety of 1 was vital for cytotoxicity against different cancer cell lines.