Identification of uncommon plant metabolites based on calculation of elemental compositions using gas chromatography and quadrupole mass spectrometry
Identification of uncommon plant metabolites based on calculation of elemental compositions using gas chromatography and quadrupole mass spectrometry
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DOI：
10.1021/ac991142i
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发表时间：
2000-08-01
影响因子：
7.4
通讯作者：
Willmitzer, L
中科院分区：
文献类型：
--
作者：
Fiehn, O;Kopka, J;Willmitzer, L
利用气相色谱/低分辨率四极杆质谱数据对拟南芥粗叶提取物极性组分进行了元素组成计算，鉴定了极性组分中的未知化合物。在分析之前，植物代谢物被甲氧基化和硅基化。所有已知峰作为内部参考，从原始质谱数据构建多项式再校准曲线。质量精度为0.005 +/- 0.003 amu，同位素比值误差分别为0.5 +/- 0.3% （A + 1/A）和0.3 +/- 0.2% （A + 2/A）。在计算未知峰的元素组成时，将质量和同位素比值结合起来。计算后，通过检索代谢数据库，解释光谱，最后与参比化合物比较，确定了化合物的身份。在单张GC/MS色谱图中确定了70多个峰的和公式，并通过高分辨率质谱数据确定了准确的质量。在拟南芥中发现了15种罕见的植物代谢物，其中一些是新发现的，如酒石酸酯半醛、柠檬酸、异丙苏氨酸或乙醇酰胺。
Unknown compounds in polar fractions of Arabidopsis thaliana crude leaf extracts were identified on the basis of calculations of elemental compositions obtained from gas chromatography/low-resolution quadrupole mass spectrometric data. Plant metabolites were methoximated and silylated prior to analysis. All known peaks were used as internal references to construct polynomial recalibration curves of from raw mass spectrometric data. Mass accuracies of 0.005 +/- 0.003 amu and isotope ratio errors of 0.5 +/- 0.3% (A + 1/A), respectively, 0.3 +/- 0.2% (A + 2/A), could be achieved. Both masses and isotope ratios were combined when the elemental compositions of unknown peaks were calculated. After calculation, compound identities were elucidated by searching metabolic databases, interpreting spectra, and, finally, by comparison with reference compounds. Sum formulas of more than 70 peaks were determined throughout single GC/MS chromatograms, Exact masses were confirmed by high-resolution mass spectrometric data. More than 15 uncommon plant metabolites were identified, some of which are novel in Arabidopsis, such as tartronate semialdehyde, citramalic acid, allothreonine, or glycolic amide.