Abstract: Four compounds were isolated from EtoAc fraction of the fementation of actinomyces A5 by silica gel,antiphase and Sephadex LH-20 column chromatography. The structure of the four compounds were identified by MS, ¹H-NMR, ¹³C-NMR,COSY, etc. The four compounds are 6-benzyl-3-isopropylpyrazin-2(1H)-one (1), N-(4-hydroxyphenethyl)acetamide (2), 3-(4-hydroxyphenyl)-2-((2-oxotetrahydro-2H-pyran-3-yl)oxy) propanoic acid (3) and uracil (4). The spectral date of compound 3 was the first reported. The result of brine shrimp bioassay showed the mortality rates of compound 1 to 3 to Artemia salina were 43.2%,38.3% and 43.2% respectively at 0.1 mg/mL,showing certain cytotoxic activity.

Key words: endophytic actinomycetes, metabolite, isolation and identification, biological activity