Recent advances in chemoenzymatic synthesis of natural products via site- selective P450 oxidation

doi:10.12211/2096-8280.2024-017

Abstract

Abstract:

Although bioactive natural products have played significant roles in pharmaceutical research, their application potential is still limited by low isolated yields and structural modification challenges. To overcome these obstacles, developing environmentally friendly and highly efficient synthetic strategies offers exceptional approaches to obtain complex bioactive natural products and their analogs. Driven by advancements in microbial genetics and enzyme engineering, chemoenzymatic strategies, which merge enzymatic and synthetic transformations, are steadily emerging as potent tools in the synthesis of bioactive natural products, pharmaceutical components and other valuable molecules. These fashionable strategies offer not only advantages of chemical synthesis, such as simplicity, flexibility and scalability, but also those of biosynthesis, including environmental friendliness, high selectivity and efficiency, which establish a linkage into the next-generation synthesis which is expected to break the boundary between chemistry and biology. Versatile cytochrome monooxygenases, P450s, can achieve inert C–H bond selective oxidation in mild and green conditions, a classically challenging organic transformation, which provide novel retrosynthetic plans for complex natural products and become one of the hotspots in synthetic science. This review summarizes the recent applications of chemoenzymatic synthesis of natural products using P450-catalyzed site-selective oxidations as critical steps to improve the synthetic efficiency and avoid unnecessary functional group transformations and protection/deprotection steps, categorizing the case studies by structure features, such as steroids, terpenoids, and other types of natural products. At the end of the review, the current challenges in this field, such as relying on the native activities of enzymes heavily, are also analyzed and discussed, along with emerging research directions and technologies in new enzyme mining and enzyme engineering that may provide solutions to these challenges in the future. With constantly cross fusion of biosynthesis, chemical synthesis, synthetic biology, protein engineering, machine learning and other research field, P450-catalyzed site-selective oxidations will be routine tools for synthetic chemists.

Key words: natural product synthesis, chemoenzymatic synthesis, P450 monooxygenase, C–H bond functionalization, chemo-selectivity

摘要：

随着基因挖掘、生物信息学、酶工程等多学科的交叉融合与协同创新，将绿色高效的酶催化反应与现代有机合成方法相结合的化学-酶法合成策略逐渐发展成为合成活性天然产物、药物分子和其它具有重要价值的有机分子的有力工具。其中细胞色素单加氧酶P450能够选择性地实现惰性C-H氧化这一经典的挑战性化学转化，为活性天然产物的高效合成提供了新的思路，成为合成科学领域的研究热点之一。本文以结构类型进行分类，综述了P450选择性氧化在甾体、萜类以及其他类型天然产物化学-酶法合成中的应用进展，并分析了相应的酶催化反应在提高目标产物合成效率方面起到的关键作用。此外，本文还讨论了该领域目前所面临的挑战，例如主要集中在对酶天然功能的利用，并缺乏对反应位点的准确预测等；同时从酶资源挖掘、酶的改造等多个角度出发展望了未来能够为这些挑战提供解决方案的研究方向和新兴技术，包括高通量筛选技术、AI辅助酶工程等等。

关键词: 天然产物合成, 化学-酶法合成, P450单加氧酶, C-H键官能化, 化学选择性

CLC Number:

Q629

Zhongyu CHENG, Fuzhuo LI. Recent advances in chemoenzymatic synthesis of natural products via site- selective P450 oxidation[J]. Synthetic Biology Journal, DOI: 10.12211/2096-8280.2024-017.

程中玉, 李付琸. 基于P450选择性氧化的天然产物化学-酶法合成进展[J]. 合成生物学, DOI: 10.12211/2096-8280.2024-017.

Figures/Tables 16

Fig. 1 Catalytic cycle of cytochrome P450 enzymes

Fig. 2 Chemoenzymatic synthesis of stereosteroids

Fig. 3 (a) Regioselectivity of CYP11411and CYP44476;(b) Chemoenzymatic synthesis of bufotalin, bufogenin and digitoxigenin

Fig. 4 (a) Regioselectivity of CYP14A I111L-V124W; (b) Comparison of the wide-type CYP14A and mutant; (c) Chemoenzymatic synthesis of digitoxigenin, 3α-hydroxyldigitoxigenin and periplogenin.

Fig. 5 Chemoenzymatic synthesis of trenbolone and related compounds.

Fig. 6 Chemoenzymatic synthesis of nigelladine A

Fig. 7 Chemoenzymatic synthesis of α-pyrone meroterpenoids

Fig. 8 Chemoenzymatic synthesis of meroditerpenoids

Fig. 9 Chemoenzymatic synthesis of trans-syn drimane-type meroterpenoids

Fig. 10 Chemoenzymatic synthesis of gedunin

Fig. 11 Chemoenzymatic synthesis of excolide B and related compounds.

Fig. 12 Chemoenzymatic synthesis of ent-kauranes, ent-atisanes, ent-trachylobanes

Fig. 13 Chemoenzymatic synthesis of aurothin

Fig. 14 Chemoenzymatic synthesis of vancomycin aglycone variant

Fig. 15 Chemoenzymatic synthesis of juvenimvins

Fig. 16 Sherman's chemoenzymatic synthesis of cryptophycins derivatives

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