Hamburger M, Wolfender J L, Hostettmann K
Institut de Pharmacognoise et Phytochimie, Ecole de Pharmacie, Université de Lausanne, Switzerland.
Nat Toxins. 1993;1(6):315-27. doi: 10.1002/nt.2620010602.
An HPLC method has been developed for the analysis of sesquiterpene lactones of the neurotoxic plant Centaurea solstitialis (Asteraceae). The presence of sesquiterpene lactone chlorohydrins in extracts was investigated by means of liquid chromatography-thermospray mass spectrometry. In contrast to earlier reports of a series of mono- and dichlorohydrins from this plant, traces only of two monochlorohydrins could be detected in lipophilic extracts. Model studies carried out with extracts and with the genuine sesquiterpene diepoxide repin and its epimer subluteolide showed that (i) monochlorohydrins can be formed in CHCl3 under usual laboratory conditions; (ii) the epoxide moiety at C-4 of the sesquiterpenes is extremely labile, reacting immediately and quantitatively with traces of HCl to the corresponding monohydrins; (iii) epoxide ring opening at the acyl side chain occurs only at higher HCl concentrations. Confirmation of the peak identity was obtained by the isotope ratio of chlorinated compounds and comparison with authentic samples. The structures of the mono- and dichlorohydrins were established by NMR spectroscopy.
已开发出一种高效液相色谱法，用于分析神经毒性植物夏至矢车菊（菊科）中的倍半萜内酯。通过液相色谱 - 热喷雾质谱法研究提取物中倍半萜内酯氯醇的存在情况。与该植物一系列单氯醇和二氯醇的早期报道不同，在亲脂性提取物中仅能检测到痕量的两种单氯醇。用提取物以及真正的倍半萜二环氧瑞平及其差向异构体亚黄独内酯进行的模型研究表明：（i）在常规实验室条件下，单氯醇可在氯仿中形成；（ii）倍半萜C - 4位的环氧部分极其不稳定，会立即与痕量的HCl定量反应生成相应的单醇；（iii）仅在较高HCl浓度下，酰基侧链处的环氧环才会开环。通过氯化化合物的同位素比并与真实样品比较来确认峰的同一性。单氯醇和二氯醇的结构通过核磁共振光谱确定。
