Graf Tyler N, Cech Nadja B, Polyak Stephen J, Oberlies Nicholas H
Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, 27402, USA.
Department of Laboratory Medicine, University of Washington, Seattle, WA, 98104, USA; Department of Global Health, University of Washington, Seattle, WA, 98104, USA; Department of Microbiology, University of Washington, Seattle, WA, 98104, USA.
J Pharm Biomed Anal. 2016 Jul 15;126:26-33. doi: 10.1016/j.jpba.2016.04.028. Epub 2016 Apr 22.
Validated methods are needed for the analysis of natural product secondary metabolites. These methods are particularly important to translate in vitro observations to in vivo studies. Herein, a method is reported for the analysis of the key secondary metabolites, a series of flavonolignans and a flavonoid, from an extract prepared from the seeds of milk thistle [Silybum marianum (L.) Gaertn. (Asteraceae)]. This report represents the first UHPLC MS-MS method validated for quantitative analysis of these compounds. The method takes advantage of the excellent resolution achievable with UHPLC to provide a complete analysis in less than 7min. The method is validated using both UV and MS detectors, making it applicable in laboratories with different types of analytical instrumentation available. Lower limits of quantitation achieved with this method range from 0.0400μM to 0.160μM with UV and from 0.0800μM to 0.160μM with MS. The new method is employed to evaluate variability in constituent composition in various commercial S. marianum extracts, and to show that storage of the milk thistle compounds in DMSO leads to degradation.
天然产物次生代谢产物的分析需要经过验证的方法。这些方法对于将体外观察结果转化为体内研究尤为重要。本文报道了一种用于分析关键次生代谢产物的方法，该方法可从水飞蓟[水飞蓟（L.）Gaertn.（菊科）]种子提取物中分析一系列黄酮木脂素和一种黄酮类化合物。本报告介绍了首个经过验证的用于这些化合物定量分析的超高效液相色谱-质谱联用（UHPLC MS-MS）方法。该方法利用超高效液相色谱可实现的出色分离度，在不到7分钟的时间内完成全面分析。该方法通过紫外（UV）和质谱（MS）检测器进行了验证，使其适用于配备不同类型分析仪器的实验室。使用该方法获得的定量下限，紫外检测时为0.0400μM至0.160μM，质谱检测时为0.0800μM至0.160μM。该新方法用于评估各种市售水飞蓟提取物中成分组成的变异性，并表明水飞蓟化合物在二甲基亚砜（DMSO）中的储存会导致降解。
