Mueller M J, Brodschelm W
Lehrstuhl für Pharmazeutische Biologie, Universität München, Germany.
Anal Biochem. 1994 May 1;218(2):425-35. doi: 10.1006/abio.1994.1202.
Jasmonic acid can be assayed by the highly sensitive and reproducible gas chromatography-negative ion chemical ionization-mass spectrometry (GC-NICI-MS) technique. We describe an optimized sample preparation method for routine analysis of jasmonic acids which allows the analysis of more than 10 samples/day. The basis of the method resides in a one-step extraction and phase partition, selective adsorption/elution of acids with an aminopropyl column, conversion of acids to pentafluorobenzyl esters, final purification using a silica column, and GC-NICI-MS. Extracted standard curves were linear over an assay range of 1 to 1000 ng; correlation coefficients were typically greater than 0.9999. The limit of detection was 500 fg (2.4 fmol) jasmonic acid/injection at a signal to noise ratio of 10:1. Furthermore, the method was modified for steric analysis of jasmonic acid stereoisomers at the nanogram level. (3R,7S)-(+)-7-Iso-jasmonic acid was found to be biosynthesized from plant tissue cell cultures upon elicitation. This stereoisomer epimerizes rapidly under alkaline and acidic conditions and in the presence of albumin. Epimerization rate constants were determined at different pH values.
茉莉酸可以通过高灵敏度且可重复的气相色谱-负离子化学电离-质谱联用（GC-NICI-MS）技术进行测定。我们描述了一种优化的样品制备方法，用于茉莉酸的常规分析，该方法允许每天分析超过10个样品。该方法的基础在于一步萃取和相分配、用氨丙基柱选择性吸附/洗脱酸、将酸转化为五氟苄基酯、最后用硅胶柱纯化以及GC-NICI-MS。提取的标准曲线在1至1000 ng的测定范围内呈线性；相关系数通常大于0.9999。在信噪比为10:1时，检测限为500 fg（2.4 fmol）茉莉酸/进样量。此外，该方法经过改进，可用于纳克级茉莉酸立体异构体的立体分析。发现(3R,7S)-(+)-7-异茉莉酸在诱导后从植物组织细胞培养物中生物合成。这种立体异构体在碱性和酸性条件下以及在白蛋白存在下会迅速差向异构化。在不同pH值下测定了差向异构化速率常数。
