Abstract: The stability of hypocrellin from the liquid-cultured mycelia of a strain of anamorph (ZH-5-1) from Shiraia bambusicola was evaluated based on changes in the spectrophotometric absorbance of hypocrellin solutions. The anti-tumor activity was tested by Resazurin assay using CHO, HeLa, HL-60 and A-549 cells. The results showed that the hypocrellin was stable in acidic condition and had good thermal and light stability. Commonly used oxidant H2O2 and reducing agent Na2SO3 had no obvious effect on hypocrellin stability. The stability of the hypocrellin could not be influenced by low concentrations of metal ions, but among all the tested metal ions, Mn2+, Cu2+ and Fe2+ had more destructive effect. The hypocrellin inhibited the growth of all the four tested tumor cells. Hypocrellin inhibition on the growth of CHO, HL-60, and A-549 cells was in dose-dependent manner with an IC50 of 0.47, 0.11 mg/mL and 0.22 mg/mL, respectively. In conclusion, mycelium hypocrellin of strain ZH-5-1 is a stable natural product with anti-tumor activity and thus will have potentially promising applications in practice.

Key words: hypocrellin, stability, anti-tumor activity