Dencichine is a plant-derived nature product that has found various pharmacological applications. Currently, its natural biosynthetic pathway is still elusive, posing challenge to its heterologous biosynthesis. In this work, we design artificial pathways through retro-biosynthesis approaches and achieve de novo production of dencichine. First, biosynthesis of the two direct precursors L−2, 3-diaminopropionate and oxalyl-CoA is achieved by screening and integrating microbial enzymes. Second, the solubility of dencichine synthase, which is the last and only plant-derived pathway enzyme, is significantly improved by introducing 28 synonymous rare codons into the codon-optimized gene to slow down its translation rate. Last, the metabolic network is systematically engineered to direct the carbon flux to dencichine production, and the final titer reaches 1.29 g L⁻¹ with a yield of 0.28 g g⁻¹ glycerol. This work lays the foundation for sustainable production of dencichine and represents an example of how synthetic biology can be harnessed to generate unnatural pathways to produce a desired molecule.

Dencichine 是一种植物衍生的天然产品，已发现多种药理应用。目前，其天然生物合成途径仍然难以捉摸，对其异源生物合成提出了挑战。在这项工作中，我们通过逆向生物合成方法设计了人工途径，并实现了 dencichine 的从头生产。首先，通过筛选和整合微生物酶来实现两种直接前体L -2, 3-二氨基丙酸和草酰辅酶A的生物合成。其次，通过将 28 个同义稀有密码子引入密码子优化基因以减慢其翻译速度，显着提高了 Dencichine 合酶（最后也是唯一的植物来源途径酶）的溶解度。最后，系统地设计了代谢网络，将碳通量引导至dencichine生产，最终滴度达到1.29 g L ^-1 ，甘油产量为0.28 gg ^-1 。这项工作为可持续生产 dencichine 奠定了基础，并代表了如何利用合成生物学产生非自然途径来生产所需分子的例子。