Beaudry Francis, Vachon Pascal
Groupe de Recherche en Pharmacologie Animale du Québec (GREPAQ), Department of Veterinary Biomedicine, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Québec, Canada J2S 2M2.
Biomed Chromatogr. 2009 Feb;23(2):204-11. doi: 10.1002/bmc.1107.
Capsaicin is the most abundant pungent molecule present in red peppers and it is widely used for food flavoring, in pepper spray in self-defense devices and more recently in ointments for the relief of neuropathic pain. Capsaicin is a selective agonist of transient receptor potential channel, vanilloid subfamily member 1. A selective and sensitive quantitative method for the determination of capsaicin by LC-ESI/MS/MS was developed. The method consisted of a protein precipitation extraction followed by analysis using liquid chromatography electrospray quadrupole ion trap mass spectrometry. The chromatographic separation was achieved using a 100 x 2 mm C(18) Waters Symmetry column combined with a gradient mobile phase composed of acetonitrile and 0.1% formic acid aqueous solution at a flow rate of 220 microL/min. The mass spectrometer was operating in full-scan MS/MS mode using two-segment analysis. An analytical range of 10-5000 ng/mL was used in the calibration curve constructed in rat plasma. The interbatch precision and accuracy observed were 6.5, 6.7, 5.3 and 101.2, 102.7, 103.5% at 50, 500 and 5000 ng/mL, respectively. An in vitro metabolic stability study was performed in rat, dog and mouse liver microsomes and the novel analytical method was adapted and used to determine intrinsic clearance of capsaicin. Results suggest very rapid degradation with T(1/2) ranging from 2.3 to 4.1 min and high clearance values suggesting that drug bioavailability will be considerably reduced, consequently affecting drug response and efficacy.
辣椒素是红辣椒中含量最丰富的辛辣分子，广泛用于食品调味、自卫设备中的辣椒喷雾，以及最近用于缓解神经性疼痛的药膏中。辣椒素是瞬时受体电位通道香草酸亚家族成员1的选择性激动剂。开发了一种通过液相色谱-电喷雾串联质谱法（LC-ESI/MS/MS）测定辣椒素的选择性和灵敏的定量方法。该方法包括蛋白质沉淀提取，然后使用液相色谱电喷雾四极杆离子阱质谱进行分析。色谱分离使用100×2mm的沃特世Symmetry C(18)柱，结合由乙腈和0.1%甲酸水溶液组成的梯度流动相，流速为220微升/分钟。质谱仪以全扫描MS/MS模式运行，采用两段分析。在大鼠血浆中构建的校准曲线中使用的分析范围为10-5000纳克/毫升。在50、500和5000纳克/毫升时观察到的批间精密度和准确度分别为6.5%、6.7%、5.3%和101.2%、102.7%、103.5%。在大鼠、狗和小鼠肝微粒体中进行了体外代谢稳定性研究，并采用这种新的分析方法来测定辣椒素的内在清除率。结果表明降解非常迅速，半衰期在2.3至4.1分钟之间，清除率值较高，表明药物生物利用度将大幅降低，从而影响药物反应和疗效。
