Benzoxazinoids, comprising the classes of benzoxazinones and benzoxazolinones, are a set of specialised metabolites produced by the plant family Poaceae (formerly Gramineae), and some dicots. The family Poaceae in particular contains several important crops like maize and wheat. Benzoxazinoids play a role in allelopathy and as defence compounds against (micro)biological threats. The effectivity of benzoxazinones in these functionalities is largely imposed by the subclasses (determined by N substituent). In this review, we provide an overview of all currently known natural benzoxazinoids and a summary of the current state of knowledge of their biosynthesis. We also evaluated their antimicrobial activity based on minimum inhibitory concentration (MIC) values reported in literature. Monomeric natural benzoxazinoids seem to lack potency as antimicrobial agents. The 1,4-benzoxazin-3-one backbone, however, has been shown to be a potential scaffold for designing new antimicrobial compounds. This has been demonstrated by a number of studies that report potent activity of synthetic derivatives of 1,4-benzoxazin-3-one, which possess MIC values down to 6.25 μg mL-1 against pathogenic fungi (e.g. C. albicans) and 16 μg mL-1 against bacteria (e.g. S. aureus and E. coli). Observations on the structural requirements for allelopathy, insecticidal, and antimicrobial activity suggest that they are not necessarily conferred by similar mechanisms.

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苯并恶嗪类化合物的结构和生物合成：具有作为抗菌支架潜力的植物防御代谢物

苯并恶嗪类化合物包括苯并恶嗪酮和苯并恶唑啉酮类，是由禾本科（以前称为禾本科）和一些双子叶植物产生的一组特殊代谢物。禾本科尤其包含几种重要的作物，如玉米和小麦。苯并恶嗪类化合物在化感作用中发挥作用，并作为抵御（微）生物威胁的防御化合物。苯并嗪酮在这些官能团中的有效性很大程度上取决于亚类（由 N 取代基决定）。在这篇综述中，我们概述了所有目前已知的天然苯并恶嗪类化合物，并对其生物合成的当前知识状态进行了总结。我们还根据文献中报道的最小抑菌浓度 (MIC) 值评估了它们的抗菌活性。单体天然苯并恶嗪类似乎缺乏作为抗菌剂的效力。然而，1,4-benzoxazin-3-one 骨架已被证明是设计新抗菌化合物的潜在支架。许多研究证明了这一点，这些研究报告了 1,4-benzoxazin-3-one 的合成衍生物的有效活性，其对致病真菌（例如白色念珠菌）的 MIC 值低至 6.25 μg mL-1 和 16 μg mL-1 对抗细菌（例如金黄色葡萄球菌和大肠杆菌）。对化感作用、杀虫和抗微生物活性的结构要求的观察表明，它们不一定是由类似的机制赋予的。许多研究证明了这一点，这些研究报告了 1,4-benzoxazin-3-one 的合成衍生物的有效活性，其对致病真菌（例如白色念珠菌）的 MIC 值低至 6.25 μg mL-1 和 16 μg mL-1 对抗细菌（例如金黄色葡萄球菌和大肠杆菌）。对化感作用、杀虫和抗微生物活性的结构要求的观察表明，它们不一定是由类似的机制赋予的。许多研究证明了这一点，这些研究报告了 1,4-benzoxazin-3-one 的合成衍生物的有效活性，其对致病真菌（例如白色念珠菌）的 MIC 值低至 6.25 μg mL-1 和 16 μg mL-1 对抗细菌（例如金黄色葡萄球菌和大肠杆菌）。对化感作用、杀虫和抗微生物活性的结构要求的观察表明，它们不一定是由类似的机制赋予的。