Schnabel Arianne, Cotinguiba Fernando, Athmer Benedikt, Vogt Thomas
Leibniz Institute of Plant Biochemistry, Department Cell and Metabolic Biology, Weinberg 3, D-06120 Halle (Saale), Germany.
Instituto de Pesquisas de Produtos Naturais (IPPN), Universidade Federal do Rio de Janeiro (UFRJ), Avenida Carlos Chagas Filho, 373, 21941-902 Rio de Janeiro/RJ, Brazil.
Plants (Basel). 2021 Jan 9;10(1):128. doi: 10.3390/plants10010128.
Black pepper () is among the world's most popular spices. Its pungent principle, piperine, has already been identified 200 years ago, yet the biosynthesis of piperine in black pepper remains largely enigmatic. In this report we analyzed the characteristic methylenedioxy bridge formation of the aromatic part of piperine by a combination of RNA-sequencing, functional expression in yeast, and LC-MS based analysis of substrate and product profiles. We identified a single cytochrome P450 transcript, specifically expressed in black pepper immature fruits. The corresponding gene was functionally expressed in yeast () and characterized for substrate specificity with a series of putative aromatic precursors with an aromatic vanilloid structure. Methylenedioxy bridge formation was only detected when feruperic acid (5-(4-hydroxy-3-methoxyphenyl)-2,4-pentadienoic acid) was used as a substrate, and the corresponding product was identified as piperic acid. Two alternative precursors, ferulic acid and feruperine, were not accepted. Our data provide experimental evidence that formation of the piperine methylenedioxy bridge takes place in young black pepper fruits after a currently hypothetical chain elongation of ferulic acid and before the formation of the amide bond. The partially characterized enzyme was classified as CYP719A37 and is discussed in terms of specificity, storage, and phylogenetic origin of CYP719 catalyzed reactions in magnoliids and eudicots.
黑胡椒（）是世界上最受欢迎的香料之一。其辛辣成分胡椒碱早在200年前就已被鉴定出来，但黑胡椒中胡椒碱的生物合成在很大程度上仍不为人知。在本报告中，我们通过RNA测序、在酵母中的功能表达以及基于液相色谱 - 质谱联用的底物和产物谱分析相结合的方法，分析了胡椒碱芳香部分特征性亚甲二氧基桥的形成。我们鉴定出一个细胞色素P450转录本，它在黑胡椒未成熟果实中特异性表达。相应的基因在酵母（）中进行了功能表达，并对一系列具有芳香类香草酸结构的推定芳香前体的底物特异性进行了表征。仅当以阿魏酸（5 - （4 - 羟基 - 3 - 甲氧基苯基） - 2,4 - 戊二烯酸）作为底物时才检测到亚甲二氧基桥的形成，并且相应的产物被鉴定为胡椒酸。另外两种前体，阿魏酸和阿魏碱，未被接受。我们的数据提供了实验证据，表明胡椒碱亚甲二氧基桥的形成发生在黑胡椒幼果中，是在阿魏酸目前假设的链延长之后且酰胺键形成之前。部分表征的酶被归类为CYP719A37，并从木兰类植物和真双子叶植物中CYP719催化反应的特异性、储存和系统发育起源方面进行了讨论。
