Biosynthesis of curcuminoids and gingerols in turmeric (Curcuma longa) and ginger (Zingiber officinale):: Identification of curcuminoid synthase and hydroxycinnamoyl-CoA thioesterases
Biosynthesis of curcuminoids and gingerols in turmeric (Curcuma longa) and ginger (Zingiber officinale):: Identification of curcuminoid synthase and hydroxycinnamoyl-CoA thioesterases
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DOI：
10.1016/j.phytochem.2006.06.028
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发表时间：
2006-09-01
期刊：
影响因子：
3.8
通讯作者：
Gang, David R.
中科院分区：
文献类型：
--
作者：
Ramirez-Ahumada, Maria Del Carmen;Timmermann, Barbara N.;Gang, David R.
姜黄科的成员如姜黄（Curcuma longa L.）和生姜（学名：CumberofficinaleRose.）在其根茎中积累高水平的重要的植物活性代谢物，这些代谢物似乎来自苯丙烷途径。在生姜中，这些化合物是姜辣素;在姜黄中，这些是姜黄素。尽管它们很重要，但对这些化合物的生物合成知之甚少。本研究描述了导致这些生物活性天然产物的生产的生物合成途径中的酶的鉴定。苯丙素途径中的酶的测定鉴定了姜和姜黄的叶、茎和根茎组织的蛋白质粗提取物中相应的酶活性。这些酶包括苯丙氨酸解氨酶、聚酮酶、p-香豆酰莽草酸转移酶、p-香豆酰奎尼酸转移酶、咖啡酸O-甲基转移酶和咖啡酰-CoA O-甲基转移酶，因为它们在控制某些类别的姜辣素和类姜黄素的生产中的潜在作用而对其进行评估。所有的粗提物具有所有这些酶的活性，与聚酮酶的例外。聚酮合酶测定的结果显示，姜黄提取物中可检测到姜黄素合酶活性，其中在叶提取物中发现的活性最高。然而，没有姜辣素合酶活性可以确定。这一结果是由硫酯酶活性的裂解苯丙烷途径CoA酯，并被发现存在于所有组织中，特别是在生姜组织中的高水平的鉴定。这些活动可能分流苯丙烷类途径中间体远离姜黄素和姜辣素的生产，从而可能在这些化合物的生物合成中发挥调节作用。(c)2006爱思唯尔有限公司保留所有权利。
Members of the Zingiberaceae such as turmeric (Curcuma longa L.) and ginger (Zingiber officinale Rose.) accumulate at high levels in their rhizomes important pharmacologically active metabolites that appear to be derived from the phenylpropanoid pathway. In ginger, these compounds are the gingerols; in turmeric these are the curcuminoids. Despite their importance, little is known about the biosynthesis of these compounds. This investigation describes the identification of enzymes in the biosynthetic pathway leading to the production of these bioactive natural products. Assays for enzymes in the phenylpropanoid pathway identified the corresponding enzyme activities in protein crude extracts from leaf, shoot and rhizome tissues from ginger and turmeric. These enzymes included phenylalanine ammonia lyase, polyketide synthases, p-coumaroyl shikimate transferase, p-coumaroyl quinate transferase, caffeic acid O-methyltransferase, and caffeoyl-CoA O-methyltransferase, which were evaluated because of their potential roles in controlling production of certain classes of gingerols and curcuminoids. All crude extracts possessed activity for all of these enzymes, with the exception of polyketide synthases. The results of polyketide synthase assays showed detectable curcuminoid synthase activity in the extracts from turmeric with the highest activity found in extracts from leaves. However, no gingerol synthase activity could be identified. This result was explained by the identification of thioesterase activities that cleaved phenylpropanoid pathway CoA esters, and which were found to be present at high levels in all tissues, especially in ginger tissues. These activities may shunt phenylpropanoid pathway intermediates away from the production of curcuminoids and gingerols, thereby potentially playing a regulatory role in the biosynthesis of these compounds. (c) 2006 Elsevier Ltd. All rights reserved.