The glucosinolates (GSLs) is a well-defined group of plant metabolites characterized by having an S-β-d-glucopyrano unit anomerically connected to an O-sulfated (Z)-thiohydroximate function. After enzymatic hydrolysis, the sulfated aglucone can undergo rearrangement to an isothiocyanate, or form a nitrile or other products. The number of GSLs known from plants, satisfactorily characterized by modern spectroscopic methods (NMR and MS) by mid-2018, is 88. In addition, a group of partially characterized structures with highly variable evidence counts for approximately a further 49. This means that the total number of characterized GSLs from plants is somewhere between 88 and 137. The diversity of GSLs in plants is critically reviewed here, resulting in significant discrepancies with previous reviews. In general, the well-characterized GSLs show resemblance to C-skeletons of the amino acids Ala, Val, Leu, Trp, Ile, Phe/Tyr and Met, or to homologs of Ile, Phe/Tyr or Met. Insufficiently characterized, still hypothetic GSLs include straight-chain alkyl GSLs and chain-elongated GSLs derived from Leu. Additional reports (since 2011) of insufficiently characterized GSLs are reviewed. Usually the crucial missing information is correctly interpreted NMR, which is the most effective tool for GSL identification. Hence, modern use of NMR for GSL identification is also reviewed and exemplified. Apart from isolation, GSLs may be obtained by organic synthesis, allowing isotopically labeled GSLs and any kind of side chain. Enzymatic turnover of GSLs in plants depends on a considerable number of enzymes and other protein factors and furthermore depends on GSL structure. Identification of GSLs must be presented transparently and live up to standard requirements in natural product chemistry. Unfortunately, many recent reports fail in these respects, including reports based on chromatography hyphenated to MS. In particular, the possibility of isomers and isobaric structures is frequently ignored. Recent reports are re-evaluated and interpreted as evidence of the existence of "isoGSLs", i.e. non-GSL isomers of GSLs in plants. For GSL analysis, also with MS-detection, we stress the importance of using authentic standards.

中文翻译：

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植物中硫代葡萄糖苷的结构多样性、鉴定、化学合成和代谢

硫代葡萄糖苷 (GSL) 是一组明确定义的植物代谢物，其特征在于具有与 O-硫酸化 (Z)-硫代羟基肟酸功能异头连接的 S-β-d-吡喃葡萄糖单元。酶促水解后，硫酸化配基可以重排为异硫氰酸酯，或形成腈或其他产物。到 2018 年年中，通过现代光谱方法（NMR 和 MS）令人满意地表征了植物中已知的 GSL 数量为 88。此外，一组具有高度可变证据的部分表征的结构大约还有 49 个。这意味着植物中表征的 GSL 总数在 88 到 137 之间。这里对植物中 GSL 的多样性进行了严格审查，导致与之前的审查存在显着差异。一般来说，充分表征的 GSL 与氨基酸 Ala、Val、Leu、Trp、Ile、Phe/Tyr 和 Met 的 C 骨架相似，或与 Ile、Phe/Tyr 或 Met 的同源物相似。未充分表征，仍然假设的 GSL 包括直链烷基 GSL 和衍生自 Leu 的链延长 GSL。审查了未充分表征的 GSL 的其他报告（自 2011 年以来）。通常，关键的缺失信息是正确解释的 NMR，它是 GSL 识别的最有效工具。因此，还回顾和举例说明了核磁共振在 GSL 鉴定中的现代应用。除了分离外，GSL 还可以通过有机合成获得，允许同位素标记的 GSL 和任何种类的侧链。植物中 GSL 的酶促周转取决于相当数量的酶和其他蛋白质因子，此外还取决于 GSL 结构。GSL 的标识必须透明地呈现并符合天然产物化学的标准要求。不幸的是，最近的许多报告在这些方面都失败了，包括基于与 MS 联用的色谱法的报告。特别是，异构体和同量异位结构的可能性经常被忽略。最近的报告被重新评估并解释为“isoGSL”存在的证据，即植物中 GSL 的非 GSL 异构体。对于 GSL 分析以及 MS 检测，我们强调使用真实标准的重要性。异构体和同量异位结构的可能性经常被忽视。最近的报告被重新评估并解释为“isoGSL”存在的证据，即植物中 GSL 的非 GSL 异构体。对于 GSL 分析以及 MS 检测，我们强调使用真实标准的重要性。异构体和同量异位结构的可能性经常被忽视。最近的报告被重新评估并解释为“isoGSL”存在的证据，即植物中 GSL 的非 GSL 异构体。对于 GSL 分析以及 MS 检测，我们强调使用真实标准的重要性。