Imai Takanori, Nomura Masaki, Fukushima Kazuhiko
Laboratory of Biomass Resources Utilization, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.
J Plant Physiol. 2006 Mar;163(5):483-7. doi: 10.1016/j.jplph.2005.08.009. Epub 2005 Oct 25.
In order to study the biosynthesis of agatharesinol, a norlignan, l-phenylalanine-[ring-2,3,4,5,6-2H] and trans-cinnamic acid-[ring-13C6] were administered to fresh sapwood sticks of Cryptomeria japonica (sugi, Japanese cedar), that is, the labeled precursors were allowed to be absorbed through the tangential section of the wood sticks. The wood sticks were then maintained in high humidity desiccators for approximately 20 d after which ethyl acetate (EtOAc) extracts of the wood sticks were analyzed by gas chromatography-mass spectrometry (GC-MS). Native agatharesinol (trimethylsilylated) produces an m/z 369 ion and an m/z 484 ion that are characteristic of its structure. Agatharesinol formed in the sapwood sticks treated with the deuterium-labeled l-phenylalanine generated both of these ions together with m/z 373 and 377 ions (m/z 369+4 and +8, respectively), and also m/z 488 and 492 ions (m/z 484+4 and +8, respectively). Generation of m/z 373 and 488 ions is attributed to the substitution by deuterium of the four hydrogen atoms of either of the p-hydroxyphenyl rings of agatharesinol, and that of m/z 377 and 492 ions is attributed to the substitution by deuterium of the eight hydrogen atoms of both p-hydroxyphenyl rings. In the administration of the 13C-labeled trans-cinnamic acid, m/z 375 and 381 ions (m/z 369+6 and +12, respectively), and also m/z 490 and 496 ions (m/z 484+6 and +12, respectively) were found, indicating that either aromatic ring or both aromatic rings of agatharesinol were 13C-labeled. Consequently, assimilation of the labeled precursors into agatharesinol was clearly detected, and an experimental procedure for studies on the biosynthesis was developed.
为了研究去甲木脂素类化合物阿加他树脂醇的生物合成，将L-苯丙氨酸-[环-2,3,4,5,6-2H]和反式肉桂酸-[环-13C6]施用于日本柳杉（柳杉，日本雪松）的新鲜边材枝条，即让标记的前体通过枝条的弦向切面被吸收。然后将枝条置于高湿度干燥器中约20天，之后对枝条的乙酸乙酯（EtOAc）提取物进行气相色谱-质谱联用（GC-MS）分析。天然阿加他树脂醇（三甲基硅烷化）产生m/z 369离子和m/z 484离子，这是其结构的特征离子。在用氘标记的L-苯丙氨酸处理的边材枝条中形成的阿加他树脂醇产生了这两种离子以及m/z 373和377离子（分别为m/z 369 + 4和+ 8），还有m/z 488和492离子（分别为m/z 484 + 4和+ 8）。m/z 373和488离子的产生归因于阿加他树脂醇的对羟基苯环之一的四个氢原子被氘取代，而m/z 377和492离子的产生归因于两个对羟基苯环的八个氢原子被氘取代。在用13C标记的反式肉桂酸处理时，发现了m/z 375和381离子（分别为m/z 369 + 6和+ 12），还有m/z 490和496离子（分别为m/z 484 + 6和+ 12），这表明阿加他树脂醇的一个芳环或两个芳环都被13C标记。因此，清楚地检测到标记前体被同化到阿加他树脂醇中，并开发了一种用于生物合成研究的实验方法。
