Glucosinolate turnover in Brassicales species to an oxazolidin-2-one, formed via the 2-thione and without formation of thioamide
Glucosinolate turnover in Brassicales species to an oxazolidin-2-one, formed via the 2-thione and without formation of thioamide
复制标题
DOI：
10.1016/j.phytochem.2018.05.006
复制
发表时间：
2018-09-01
期刊：
影响因子：
3.8
通讯作者：
Lazzeri, Luca
中科院分区：
文献类型：
--
作者：
Agerbirk, Niels;Matthes, Annemarie;Lazzeri, Luca
芥子油苷存在于油菜目植物中，并水解为不同的分解产物，特别是在组织损伤后。在欧洲山芥（Barbarea vulgaris R.Br.）（菊科植物）中，G型的主要硫代葡萄糖苷是（S）-2-羟基-2-苯乙基硫代葡萄糖苷。在体外观察到从葡糖巴灵形成腈，而先前提出的硫代酰胺（同义词硫代酰胺）未得到证实。在压碎的B中，在葡糖巴灵水解后检测到瑞西丁（5-苯基-1，3-恶唑烷-2-酮）。vulgaris叶和长角果，但不是在完整部分。水解完成后几个小时内丰度增加。相应的1，3-恶唑烷-2-酮（OAT），与共同名称barbarin，也形成了，似乎是resedine的前体。向叶匀浆中添加两种非内源性OAT（S）-5-乙基-5-甲基OAT和（R）-5-乙烯基OAT（R-甲状腺肿素），导致形成相应的1，3-恶唑烷-2-酮（OAO），证实了OAT与OAO的代谢联系。OAOs的形成被抑制之前短暂加热的匀浆，这表明酶参与。我们建议OAT转化为OAOs由负责完整植物中形成的OAT周转的酶（“恶唑烷硫酮酶”）催化。Resedine是另一种植物--雷塞达（Reseda luteola L.）（Resedaceae）-天然含有硫代葡萄糖苷（glucosinolate）。然而，在完整的R中未检测到resedine。植物，但组织损伤后形成的。在两个家庭的形成resedine表明广泛分布的推定OATases在apericales;可能参与硫代葡萄糖苷营业额，需要黑芥子酶活性作为承诺的步骤。与OAT酶的功能一致，在B中发现了几个黑芥子酶在完整植物中硫代葡萄糖苷周转中的候选基因。普通基因组我们还建议，生物技术转换的燕麦OAOs可能会提高的营养价值的海藻目蛋白。描述了用于检测这些葡糖巴灵产物的HPLC-MS/MS方法。(C)2018爱思唯尔有限公司版权所有
Glucosinolates are found in plants of the order Brassicales and hydrolyzed to different breakdown products, particularly after tissue damage. In Barbarea vulgaris R.Br. (Brassicaceae), the dominant glucosinolate in the investigated "G-type" is glucobarbarin, (S)-2-hydroxy-2-phenylethylglucosinolate. Formation of the nitrile from glucobarbarin was observed in vitro, while a previously suggested thioamide (synonym thionamide) was not confirmed. Resedine (5-phenyl-1,3-oxazolidin-2-one) was detected after glucobarbarin hydrolysis in crushed B. vulgaris leaves and siliques, but not in intact parts. The abundance increased for several hours after completion of hydrolysis. The corresponding 1,3-oxazolidine-2-thione (OAT), with the common name barbarin, was also formed, and appeared to be the precursor of resedine. Addition of each of two non-endogenous OATs, (S)-5-ethyl-5-methylOAT and (R)-5-vinylOAT (R-goitrin), to a leaf homogenate resulted in formation of the corresponding 1,3-oxazolidin-2-ones (OAOs), confirming the metabolic connection of OAT to OAO. Formation of OAOs was inhibited by prior brief heating of the homogenate, suggesting enzyme involvement. We suggest the conversion of OATs to OAOs to be catalyzed by an enzyme ("oxazolidinethionase") responsible for turnover of OAT formed in intact plants. Resedine had been reported as an alkaloid from another species - Reseda luteola L. (Resedaceae) - naturally containing the glucosinolate glucobarbarin. However, resedine was not detected in intact R. luteola plants, but formed after tissue damage. The formation of resedine in two families suggests a broad distribution of putative OATases in the Brassicales; potentially involved in glucosinolate turnover that needs myrosinase activity as the committed step. In agreement with the proposed function of OATase, several candidate genes for myrosinases in glucosinolate turnover in intact plants were discovered in the B. vulgaris genome. We also suggest that biotechnological conversion of OATs to OAOs might improve the nutritional value of Brassicales protein. HPLC-MS/MS methods for detection of these glucobarbarin products are described. (C) 2018 Elsevier Ltd. All rights reserved.