Extraction of betulin from bark ofBetula platyphylla by supercritical carbon dioxide extraction

Abstract

Betulin, which is a medicinal pentacyclic triterpene, is abundant in the bark of white birch (Betula platyphlly). The bark of birch was collected at Tayuan Forest Farm of Jiagedaqi, Heilongjian Province in September 2000. Supercritical fluid extraction (SFE) that is a new separation technology has been used for the processing pharmaceutical and natural products. In this paper, the extraction of betulin from the bark of birch by supercritical CO₂ extraction was studied. The authors investigated and analyzed a few parameters such as modifier dosage, extraction pressure and extraction temperature. The optimal extraction conditions showed that the modifier dosage used for per gram bark powder was 1.5 mL, the extraction pressure was at 20 Mpa, and the extraction temperature was at 55 °C. The velocity of flow of liquid CO₂ was at 10 kg/h. The pressure and temperature in separation vessel were at 5.5 Mpa and 50 °C, respectively.

Keywords

Betula platyphlly / Betulin / Supercritical CO₂ extraction / Q946 / A

References

[1] Fujioka T., Kashiwada Y., Kilkuskie R.E. et al. Anti-AIDS agents, 11. Betulinic acid and platanic acid as anti-HIV principles fromSyzygium claviflorum, and the anti-HIV activity of structurally related triterpenoids [J]. Journal of Natural Products, 1994, 57(2): 243-247.

[2] Hayek E.W.H., Jordis U., Moche W. et al. A bicentennial of betulin [J]. Phytochemistry, 1989, 28: 2229-2242.

[3] Mayaux J.F., Bousseau A., Pauweis R. et al. Triterpene derivatives that block entry of human immunodeficiency virus type 1 into cells [J]. Proceedings of the National Academy of Sciences USA, 1994, 91(9): 3564-3568.

[4] O’Connell M.M., Bentley M.D., Campbell C.S. et al. Betulin and lupeol in bark from four white-barked birches [J]. Phytochemistry, 1988, 27(7): 2175-2176.

[5] Pisha E., Chai H., Lee I.S. et al. Discovery of betulinic acid as a selective inhibitor of human melanoma that functions by induction of apoptosis [J]. Nature Medicine, 1995, 1(10): 1046-1051.

[6] Tsuda T., Mizuno K., Ohshima K. et al. Supercritical carbon dioxide extraction of antioxidative components from tamarind (Tamarindus indica L.) seed coat [J]. Journal of Agriculture & Food Chemistry, 1995, 43: 2803-2806.