Huang Ruoshi, Wu Duan, Ji Zhongju, Fan Baolian, She Yaru, Zhang Xiande, Duan Lixin, Shen Qi
Guangdong Provincial Key Laboratory of Translational Cancer Research of Chinese Medicines, Joint International Research Laboratory of Translational Cancer Research of Chinese Medicines, International Institute for Translational Chinese Medicine, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, P. R. China.
Institute of Medical Plant Physiology and Ecology, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, P. R. China.
J Agric Food Chem. 2023 Feb 8;71(5):2523-2531. doi: 10.1021/acs.jafc.2c07716. Epub 2023 Jan 27.
(L.), a traditional edible and medicinal crop, contains diverse triterpenes with multiple pharmacological properties. However, the biosynthesis of triterpenes in perilla remains rarely revelation. In this study, nine putative 2,3-oxidosqualene cyclase (OSC) genes () were screened from the genome and functionally characterized by heterologous expression. Camelliol C, a triterpenol with pharmacological effect, was first identified as abundant in perilla seeds, and the camelliol C synthase (PfOSC7) was first identified in utilizing a yeast system. In addition, PfOSC2, PfOSC4, and PfOSC9 were identified as cycloartenol, lupeol, and β-amyrin synthase, respectively. Molecular docking and site-directed mutagenesis revealed that changes in Leu253 of PfOSC4, Ala480 of PfOSC7, and Trp257 of PfOSC9 might lead to variations of catalytic specificity or efficiency. These results will provide key insights into the biosynthetic pathways of triterpenoids and have great significance for germplasm breeding in .
紫苏（L.）是一种传统的食用和药用作物，含有多种具有多种药理特性的三萜类化合物。然而，紫苏中三萜类化合物的生物合成仍鲜有揭示。在本研究中，从紫苏基因组中筛选出9个假定的2,3-氧化角鲨烯环化酶（OSC）基因（），并通过异源表达对其进行功能表征。首次在紫苏种子中鉴定出具有药理作用的三萜醇——茶螺烷醇C，并且首次利用酵母系统在紫苏中鉴定出茶螺烷醇C合酶（PfOSC7）。此外，PfOSC2、PfOSC4和PfOSC9分别被鉴定为环阿屯醇、羽扇豆醇和β-香树脂醇合酶。分子对接和定点诱变表明，PfOSC4的Leu253、PfOSC7的Ala480和PfOSC9的Trp257的变化可能导致催化特异性或效率的改变。这些结果将为三萜类化合物的生物合成途径提供关键见解，对紫苏种质育种具有重要意义。
