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Updated: Jun 28, 2025

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Published on: March 28, 2017
Cytochrome P450 Mining for Bufadienolide Diversification
Xiaolai Lei1, Xiaozheng Wang1, Weiliang Xiong1
1State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
Researchers identified toad cytochrome P450 enzymes that produce novel bufadienolides with antitumor activity. These enzymes enable efficient, site-specific synthesis of valuable steroid compounds.
Area of Science:
- Biochemistry and Molecular Biology
- Natural Product Synthesis
- Pharmacology
Background:
- Bufadienolides are steroids with significant cardiotonic and antitumor properties, used in traditional Chinese medicine.
- Limited accessibility of bufadienolides due to costly extraction from toads and difficult chemical synthesis.
- Need for efficient methods to produce diverse bufadienolides with specific modifications.
Purpose of the Study:
- To identify enzymes involved in bufadienolide biosynthesis in toads.
- To develop a method for producing novel and modified bufadienolides.
- To evaluate the antitumor potential of newly synthesized bufadienolides.
Main Methods:
- Transcriptome and genome analyses to identify candidate cytochrome P450 (CYP) enzymes.
- Yeast-based screening platform for enzyme activity.
- Production, structural identification, and biological evaluation of bufadienolides.
Main Results:
- Eight toad CYP enzymes and one fungal CYP (Sth10) were identified as catalyzing bufadienolide hydroxylation.
- Fifteen bufadienolides were produced, including six novel compounds.
- 19-hydroxy-bufalin and 1β-hydroxy-bufalin, produced by CYP46A35, showed potent tumor cell proliferation inhibition.
- CYP46A35 demonstrated enhanced catalytic efficiency and expanded substrate range to progesterone and testosterone.
Conclusions:
- Elucidation of key enzymatic modifications in toad bufadienolide synthesis.
- Development of an effective platform for site-specific synthesis of valuable bufadienolides.
- Potential for producing novel steroid drugs with enhanced therapeutic activities.
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