Evolution of rosmarinic acid biosynthesis

迷迭香酸合成酶(RAS：羟基肉桂酰辅酶A：羟基苯基乳酸-羟基肉桂酰基转移酶)是迷迭香酸(RA)生物合成的关键酶，在分子中的羟基肉桂酰基部分和羟基苯乳酸部分之间形成了酯键。因此，RAS应该存在于所有积累迷迭香酸(RA)的植物中，这些植物广泛分布于整个植物界。在低等植物中，维甲酸存在于金鱼草(如花椒)和蕨类植物(金缕梅)中。此外，RA还存在于单子叶和双子叶被子植物的几个家族中，因此是一种在广泛的陆地植物中发现的天然化合物。最近从冬虫夏科植物Coleus blumei中克隆了RAS基因，并将其作为从植物中进一步分离RAS基因/cDNA并表达编码蛋白进行活性检测的基础。对这些不同植物群的RAS序列的分子特征和系统发育分析将为RA生物合成的进化提供迹象，要么是作为一个在许多分类群中被关闭的单系性状，要么是作为一种能力已经独立获得了几次。

Rosmarinic acid synthase (RAS; hydroxycinnamoyl-CoA:hydroxyphenyllactate hydroxycinna-moyltransferase) is the essential enzyme for the biosynthesis of rosmarinic acid (RA) forming the ester linkage between the hydroxycinnamoyl part and the hydroxyphenyllactate moiety of the molecule. RAS should therefore be present in all rosmarinic acid (RA)-accumulating plants which can be found widely distributed throughout the plant kingdom. In lower plants, RA is present in hornworts (e.g. Anthoceros) and ferns (Blechnum). RA is moreover documented from several families of monocotyledonous and dicotyledonous angiosperms, thus being a natural compound found in a wide range of land plants. RAS from Coleus blumei (Lamiaceae) has been cloned recently and will be used as basis to isolate further RAS-genes/cDNAs from plants and express the encoded proteins for activity assays. A molecular characterization of RAS-sequences from these different plant groups and phylogenetic analyses will give indications on the evolution of RA-biosynthesis either as a monophyletic trait which has been switched off in many taxa or as an ability that has been gained several times independently.