艾蒿是一种传统的药食植物,产生各种具有药理活性的三萜类化合物,比如反病毒,抗癌,和抗氧化剂。A.argyi的2,3-氧化角鲨烯环化酶家族提供了对三萜途径的新颖见解,这可能有助于其组织提取物的药用价值。然而,艾蒿中活性三萜的生物合成仍不确定。在这项研究中,首先从A.argyi中分离并鉴定了四个推定的OSC(2,3-氧化角鲨烯环化酶)基因(AaOSC1-4)。通过酵母异源表达系统,三个AaOSCs被表征为生物合成不同的三萜类化合物,包括环阿烯醇,β-amyrin,(3S,13R)-malabarica-14(27),17,21-三烯-3β-醇,和Dammara-20,24-dien-3β-ol。AaOSC1是一种多功能的dammara-20,24-dien-3β-ol合酶,产生了8种不同的三萜类化合物,包括三环,和四环产品。AaOSC2和AaOSC3是环阿替恩醇,和β-淀粉酶,分别。因此,这些发现提供了一个更深入的了解三萜的生物合成途径。
Artemisia argyi is a traditional medicinal and edible plant, generating various triterpenoids with pharmacological activities, such as anti-virus, anti-cancer, and anti-oxidant. The 2,3-oxidosqualene cyclase family of A. argyi offers novel insights into the triterpenoid pathway, which might contribute to the medicinal value of its tissue extracts. Nevertheless, the biosynthesis of active triterpenoids in Artemisia argyi is still uncertain. In this study, four putative OSC (2,3-oxidosqualene cyclase) genes (AaOSC1-4) were first isolated and identified from A. argyi. Through the yeast heterologous expression system, three AaOSCs were characterized for the biosynthesis of diverse triterpenoids including cycloartenol, β-amyrin, (3S,13R)-malabarica-14(27),17,21-trien-3β-ol, and dammara-20,24-dien-3β-ol. AaOSC1 was a multifunctional dammara-20,24-dien-3β-ol synthase, which yielded 8 different triterpenoids, including tricyclic, and tetracyclic products. AaOSC2 and AaOSC3 were cycloartenol, and β-amyrin synthases, respectively. As a result, these findings provide a deeper understanding of the biosynthesis pathway of triterpenes in A. argyi.