State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, The Key Laboratory of Medicinal Plant Biology of Yunnan Province, National and Local Joint Engineering Research Center on Gemplasm Utilization and Innovation of Chinese Medicinal Materials in Southwest China, Yunnan Agricultural University, Kunming, 650201, Yunnan, People's Republic of China.
Key Laboratory of National Forestry and Grassland Administration on Biodiversity Conservation in Southwest China, Southwest Forestry University, Kunming, 650224, Yunnan, People's Republic of China.
Planta. 2021 Apr 5;253(5):91. doi: 10.1007/s00425-021-03617-0.
Two UDP-glycosyltransferases from Panax japonicus var. major were identified, and the biosynthetic pathways of three oleanane-type ginsenosides (chikusetsusaponin IVa, ginsenoside Ro, zingibroside R) were elucidated. Chikusetsusaponin IVa and ginsenoside Ro are primary active components formed by stepwise glycosylation of oleanolic acid in five medicinal plants of the genus Panax. However, the key UDP-glycosyltransferases (UGTs) in the biosynthetic pathway of chikusetsusaponin IVa and ginsenoside Ro are still unclear. In this study, two UGTs (PjmUGT1 and PjmUGT2) from Panax japonicus var. major involved in the biosynthesis of chikusetsusaponin IVa and ginsenoside Ro were identified based on bioinformatics analysis, heterologous expression and enzyme assays. The results show that PjmUGT1 can transfer a glucose moiety to the C-28 carboxyl groups of oleanolic acid 3-O-β-D-glucuronide and zingibroside R to form chikusetsusaponin IVa and ginsenoside Ro, respectively. Meanwhile, PjmUGT2 can transfer a glucose moiety to oleanolic acid 3-O-β-D-glucuronide and chikusetsusaponin IVa to form zingibroside R and ginsenoside Ro. This work uncovered the biosynthetic mechanism of chikusetsusaponin IVa and ginsenoside Ro, providing the rational production of valuable saponins through synthetic biology strategy.
从 Panax japonicus var. major 中鉴定出两种 UDP-糖基转移酶，并阐明了三种齐墩果烷型人参皂苷（柴胡皂苷 IVa、人参皂苷 Ro、姜黄素 R）的生物合成途径。柴胡皂苷 IVa 和人参皂苷 Ro 是五加属五种药用植物中齐墩果酸逐步糖基化形成的主要活性成分。然而，柴胡皂苷 IVa 和人参皂苷 Ro 生物合成途径中的关键 UDP-糖基转移酶（UGTs）仍不清楚。本研究基于生物信息学分析、异源表达和酶活性测定，从 Panax japonicus var. major 中鉴定出两种参与柴胡皂苷 IVa 和人参皂苷 Ro 生物合成的 UGTs（PjmUGT1 和 PjmUGT2）。结果表明，PjmUGT1 可以将一个葡萄糖基转移到齐墩果酸 3-O-β-D-葡萄糖醛酸和姜黄素 R 的 C-28 羧基上，分别形成柴胡皂苷 IVa 和人参皂苷 Ro。同时，PjmUGT2 可以将一个葡萄糖基转移到齐墩果酸 3-O-β-D-葡萄糖醛酸和柴胡皂苷 IVa 上，形成姜黄素 R 和人参皂苷 Ro。这项工作揭示了柴胡皂苷 IVa 和人参皂苷 Ro 的生物合成机制，为通过合成生物学策略合理生产有价值的皂苷提供了依据。
