The field of metabolic engineering has achieved biochemical routes for conversion of renewable inputs to structurally diverse chemicals, but these products contain a limited number of chemical functional groups. In this review, we provide an overview of the progression of uncommon or 'nonstandard' functional groups from the elucidation of their biosynthetic machinery to the pathway optimization framework of metabolic engineering. We highlight exemplary efforts from primarily the last 5 years for biosynthesis of aldehyde, ester, terminal alkyne, terminal alkene, fluoro, epoxide, nitro, nitroso, nitrile, and hydrazine functional groups. These representative nonstandard functional groups vary in development stage and showcase the pipeline of chemical diversity that could soon appear within customized, biologically produced molecules.

中文翻译：

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鲜为人知的途径：非标准官能团的工程生物合成。

代谢工程领域已经实现了将可再生输入转化为结构多样的化学物质的生化途径，但这些产品包含数量有限的化学官能团。在这篇综述中，我们概述了不常见或“非标准”官能团的进展，从阐明其生物合成机制到代谢工程的途径优化框架。我们强调了过去 5 年来在醛、酯、末端炔烃、末端烯烃、氟、环氧化物、硝基、亚硝基、腈和肼官能团的生物合成方面的典型努力。这些具有代表性的非标准官能团在开发阶段各不相同，并展示了可能很快出现在定制的生物生产分子中的化学多样性管道。