Department for Research & Development, Central Laboratory of German Pharmacists, Eschborn, Germany.
Planta Med. 2011 Mar;77(5):450-4. doi: 10.1055/s-0030-1250459. Epub 2010 Nov 3.
Recent studies revealed that the non-prenylated acylphloroglucinol myrtucommulone (MC) from myrtle ( MYRTUS COMMUNIS) potently suppresses the biosynthesis of eicosanoids by direct inhibition of cyclooxygenase-1, microsomal prostaglandin E2 synthase (mPGES)-1, and 5-lipoxygenase at IC₅₀ values in the range of 1 to 29 µM. Moreover, MC showed potent efficacy in animal models of inflammation after intraperitoneal administration. Since the main prerequisite for therapeutic efficacy is sufficient bioavailability, it is important to evaluate whether the concentrations of MC achieved in plasma coincide with the pharmacological active concentrations determined in vitro. For that reason, a sensitive LC/MS/MS method has been developed and validated for the determination of MC in human plasma. This method is based on liquid-liquid extraction of plasma samples with 20 % ethyl acetate in tert-butyl methyl ether using the structurally related acylphloroglucinol hyperforin as the internal standard. Chromatographic separation was achieved on a Gemini C6 Phenyl column using a mixture of acetonitrile/water (85 : 15 v/v) containing 6 mM ammonium formate in a run time of 15 min at a flow rate of 1 mL/min, a column temperature of 40 °C, and an autosampler temperature of 5 °C. Mass spectrometric quantification was carried out in the negative ion mode using electrospray ionization (ESI) and multiple-reaction monitoring (MRM). The most intense [M-H]⁻ MRM transition at m/z 667.4 → m/z 194.9 was used for quantification of MC and the transition at m/z 535.4 to m/z 383.2 was used to monitor hyperforin. The method was linear in the range of 1-100 ng/mL with r > 0.998, an intra- and inter-day RSD of 1.1-8.4 and 7.1-11.8 %, respectively, and a maximum R. E. of 13.8 % at the lowest concentration level. Moreover, cross validation revealed the suitability of the developed LC/MS method for application in rat studies.
最近的研究表明，桃金娘科植物桃金娘（Myrtus communis）中的非prenylated 酰基间苯三酚衍生物 myrtucommulone（MC）通过直接抑制环加氧酶-1、微粒体前列腺素 E2 合酶（mPGES）-1 和 5-脂氧合酶，在 1 到 29 µM 的 IC50 值范围内强烈抑制类二十烷酸的生物合成。此外，MC 在腹腔内给药的炎症动物模型中表现出强大的疗效。由于治疗功效的主要前提是足够的生物利用度，因此评估 MC 在血浆中的浓度是否与体外确定的药理活性浓度相吻合非常重要。出于这个原因，开发并验证了一种用于测定人血浆中 MC 的灵敏 LC/MS/MS 方法。该方法基于用 20%叔丁基甲基醚中的乙酸乙酯对血浆样品进行液-液萃取，使用结构相关的酰基间苯三酚 hyperforin 作为内标。在 15 分钟的运行时间内，使用 Gemini C6 Phenyl 柱，在含有 6 mM 甲酸铵的乙腈/水（85:15 v/v）混合物中，在 40°C 的柱温下，以 1 mL/min 的流速实现色谱分离，进样器温度为 5°C。采用电喷雾电离（ESI）和多反应监测（MRM），在负离子模式下进行质谱定量分析。使用 m/z 667.4→m/z 194.9 的最强 [M-H]-MRM 跃迁进行 MC 的定量，使用 m/z 535.4→m/z 383.2 的跃迁监测 hyperforin。该方法在 1-100 ng/mL 范围内呈线性，r > 0.998，日内和日间 RSD 分别为 1.1-8.4%和 7.1-11.8%，最低浓度水平的最大 R. E. 为 13.8%。此外，交叉验证表明，所开发的 LC/MS 方法适用于大鼠研究。
