Identification and catalytic mechanisms of key enzymes in the biosynthesis of asperosaponin VI from Dipsacus asperoides

Asperosaponin VI is the major active compound in the traditional Chinese medcinal herb Dipsacus asperoides (Xu-Duan), exhibits diverse pharmacological activities, including treating osteoporosis, anti-inflammatory effects, and neuroprotective properties. However, due to limited natural sources and challenges in chemical extraction, heterologous biosynthesis offers a strategy for efficient production of asperosaponin VI and its intermediates and derivatives. Despite its potential, the biosynthetic pathway of asperosaponin VI remains poorly understood, primarily due to its complex multi-step reaction network. Here, key enzymes involved in the biosynthesis of asperosaponin VI were identified through transcriptomic, phylogenetic, and WGCNA analysis. Two β-amyrin synthases (DaOSC2 and DaOSC5), two cytochrome P450 enzymes (DaCYP714E29 and DaCYP714E30), and an arabinosyltransferase (DaUGT85J2) were characterized. Moreover, DaOSC2 and DaOSC5 represent the first reported β-amyrin synthases in the Dipsacus genus; DaCYP714E29 and DaCYP714E30 are the first cytochromes P450 enzymes identified in Dipsacaceae family to catalyze the oxidation of oleanolic acid at C-23 position; Additionally, DaUGT85J2 was identified as the first arabinosyltransferase responsible for catalyzing the 3-O-arabinosylation of hederagenin. To further elucidate the catalytic mechanisms of DaCYP714E29 and DaUGT85J2, molecular docking and mutagenesis experiments were conducted. These findings provide insights into the biosynthetic pathway of asperosaponin VI and lay the foundation for engineering efficient production pathways for this valuable compound.

Citation

R. Yang, C. Fu, X. Zhao, G. Xiang, W. Song, T.C. Baldwin, G. Chen, Y. Wang, Y. Zhao, Y. Xu, Y. Shu, S. Duan, B. Hao, S. He, G. Zhang, S. Yang, Y. Liang (2025) Identification and Catalytic Mechanisms of Key Enzymes in the Biosynthesis of Asperosaponin VI from Dipsacus asperoides, Plant Physiology et Biochemistry, 227, article number 110166. https://doi.org/10.1016/j.plaphy.2025.110166.

Type

Journal article

Language

en

Description

This is an author's accepted manuscript of an article published by Elsevier in Plant Physiology and Biochemistry on 24/06/2025, available at: https://doi.org/10.1016/j.plaphy.2025.110166 The accepted manuscript may differ from the final published version.

ISSN

0981-9428

Collections

Faculty of Science and Engineering