A biotransformation process for the production of cucurbitacin B from its glycoside using a selected Streptomyces sp.
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Cucurbitacin B (CuB) and its glycoside, cucurbitacin B 2-o-β-d-glucoside (CuBg), abundantly occur in the pedicels of Cucumis melo. Compared with CuB, CuBg is not efficiently extracted from the pedicels. Furthermore, the anticancer activity of CuBg is lower than that of the aglycone. A process for CuBg biotransformation to CuB was developed for the first time. A strain of Streptomyces species that converts CuBg into CuB was isolated from an enrichment culture of C. melo pedicels. After optimization of conditions for enzyme production and biotransformation, a maximum conversion rate of 92.6 % was obtained at a CuBg concentration of 0.25 g/L. When biotransformation was performed on C. melo pedicel extracts, the CuB concentration in the extracts increased from 1.50 to 3.27 g/L. The conversion rate was almost 100 %. The developed process may be an effective biotransformation method for industrial production CuB from C. melo pedicels for pharmaceuticals.
KeywordsCucurbitacin B 2-o-β-d-glucoside Cucurbitacin B Biotransformation Streptomyces sp.
The authors gratefully acknowledge the financial support from the Natural Science Foundation of Zhejiang Province (Grant No. LY13B020011).
- 4.Chen W, Leiter A, Dong Y, Meiring M, Louw VJ, Koeffler HP (2010) Cucurbitacin B inhibits growth, arrests the cell cycle, and potentiates antiproliferative efficacy of cisplatin in cutaneous squamous cell carcinoma cell lines. Int J Oncol 37:737–743Google Scholar
- 5.Thoennissen NH, Iwanski GB, Doan NB, Okamoto R, Lin P, Abbassi S, Song JH, Yin D, Toh M, Xie WD, Said JW, Koeffler HP (2009) Cucurbitacin B induces apoptosis by inhibition of the JAK/STAT pathway and potentiates antiproliferative effects of gemcitabine on pancreatic cancer cells. Cancer Res 69:5876–5884CrossRefGoogle Scholar