Epimedium plants are globally known for gardening and medicinal purposes. They are a potential resource of biologically active pharmaceutical compounds that can be used to treat various diseases. Among these compounds, icariin, a glycosylated flavonoid, has significant anti-tumor, bone growth, and neuroprotective effects; however, its biosynthetic pathway remains unknown. In this study, icariin accumulation during the development of leaves of Epimedium sagittatum was investigated. We identified a glycosyltransferase (Epimedium sagittatum glycosyltransferase, EsGT1) gene from this species using transcriptional analysis. Heterogeneously expressed EsGT1 protein transferred icariside II to icariin at the 7-OH site and its catalytic function was validated in vivo by the overexpression of the gene. In the recombinant protein assay, EsGT1 was also active in the glycosylation of kaempferol, an intermediate product of icariin. These results characterized the final step of glycosyltransferase in icariin synthesis and suggested an economical and efficient alternative source of icariin using a tobacco biotechnological method.

淫羊plants植物因园艺和药用目的而闻名全球。它们是可用于治疗各种疾病的生物活性药物化合物的潜在资源。在这些化合物中，糖精类黄酮​​icariin具有显着的抗肿瘤，骨骼生长和神经保护作用。然而，其生物合成途径仍然未知。在这项研究中，研究了淫羊Epi叶片发育过程中柠檬素的积累。我们鉴定出糖基转移酶（淫羊sa糖基转移酶EsGT1）使用转录分析获得该物种的基因。异源表达的EsGT1蛋白在7-OH位点将icariside II转移至icariin，并通过基因的过表达在体内验证了其催化功能。在重组蛋白测定中，EsGT1在山emp酚的糖基化中也有活性，山emp酚是一种伞形素的中间产物。这些结果表征了糖基转移酶在甘氨酸合成中的最后一步，并提出了使用烟草生物技术方法经济有效的替代甘氨酸的来源。