Subrizi Fabiana, Wang Yu, Thair Benjamin, Méndez-Sánchez Daniel, Roddan Rebecca, Cárdenas-Fernández Max, Siegrist Jutta, Richter Michael, Andexer Jennifer N, Ward John M, Hailes Helen C
Department of Chemistry University College London 20 Gordon Street London WC1H 0AJ UK.
Department of Biochemical Engineering University College London Bernard Katz Building London WC1E 6BT UK.
Angew Chem Weinheim Bergstr Ger. 2021 Aug 16;133(34):18821-18827. doi: 10.1002/ange.202104476. Epub 2021 Jul 16.
The tetrahydroisoquinoline (THIQ) ring system is present in a large variety of structurally diverse natural products exhibiting a wide range of biological activities. Routes to mimic the biosynthetic pathways to such alkaloids, by building cascade reactions in vitro, represents a successful strategy and can offer better stereoselectivities than traditional synthetic methods. -Adenosylmethionine (SAM)-dependent methyltransferases are crucial in the biosynthesis and diversification of THIQs; however, their application is often limited in vitro by the high cost of SAM and low substrate scope. In this study, we describe the use of methyltransferases in vitro in multi-enzyme cascades, including for the generation of SAM in situ. Up to seven enzymes were used for the regioselective diversification of natural and non-natural THIQs on an enzymatic preparative scale. Regioselectivites of the methyltransferases were dependent on the group at C-1 and presence of fluorine in the THIQs. An interesting dual activity was also discovered for the catechol methyltransferases used, which were found to be able to regioselectively methylate two different catechols in a single molecule.
四氢异喹啉（THIQ）环系存在于多种结构多样的天然产物中，这些天然产物具有广泛的生物活性。通过在体外构建级联反应来模拟此类生物碱生物合成途径的方法，是一种成功的策略，并且比传统合成方法具有更好的立体选择性。S-腺苷甲硫氨酸（SAM）依赖性甲基转移酶在THIQs的生物合成和多样化过程中至关重要；然而，它们在体外的应用常常受到SAM高成本和低底物范围的限制。在本研究中，我们描述了甲基转移酶在体外多酶级联反应中的应用，包括原位生成SAM。在酶促制备规模上，多达七种酶被用于天然和非天然THIQs的区域选择性多样化修饰。甲基转移酶的区域选择性取决于THIQs中C-1位的基团和氟的存在情况。我们还发现所使用的儿茶酚甲基转移酶具有一种有趣的双重活性，即它们能够在单个分子中对两种不同的儿茶酚进行区域选择性甲基化。
