Liebes L, Conaway C C, Hochster H, Mendoza S, Hecht S S, Crowell J, Chung F L
Division of Oncology, Department of Medicine, New York University Medical Center, New York, New York 10016, USA.
Anal Biochem. 2001 Apr 15;291(2):279-89. doi: 10.1006/abio.2001.5030.
Dietary and pharmacologic isothiocyanates (ITCs) may play a role in reducing the risk of certain cancers. The quantification of ITCs in humans is important both for epidemiological and pharmacokinetic studies. We describe a modification of an HPLC-based assay of urinary ITCs for use with human plasma. The assay utilizes the cyclocondensation reaction of 1,2-benzenedithiol with ITCs present in human plasma, followed by a two-step hexane extraction and analysis by HPLC using UV detection at 365 nm. The method shows linearity and reproducibility with human plasma over a range of 49-3003 nM phenethyl isothiocyanate (PEITC) (r(2) = 0.996 +/- 0.003). A similar degree of linearity was seen with two other biologically occurring conjugates of PEITC: PEITC--N-acetylcysteine (PEITC--NAC) and PEITC--glutathione (PEITC--GSH). The recovery of PEITC assessed on multiple days was 96.6 +/- 1.5% and was 100% for PEITC--GSH and PEITC--NAC. The reproducibility of the assay on multiday samplings showed a mean %CV of 6.5 +/- 0.3% for PEITC, 6.4 +/- 4.3 for PEITC--NAC and 12.3 +/- 3.9 for PEITC--GSH. In clinical studies, mean plasma ITC level of 413 +/- 193 nM PEITC equivalents was determined for a non-dietary-controlled group of 23 subjects. Multiday analysis data from pharmacokinetic plasma sets of 3 subjects taking a single dose of PEITC at 40 mg showed a good CV (range: 16-21%). The applicability of the methodology to pharmacokinetic studies of PEITC in humans is demonstrated.
饮食和药理学上的异硫氰酸盐（ITCs）可能在降低某些癌症风险中发挥作用。对人类体内ITCs进行定量分析对于流行病学和药代动力学研究都很重要。我们描述了一种基于高效液相色谱（HPLC）的尿液ITCs检测方法的改良，使其可用于人体血浆。该检测方法利用1,2 - 苯二硫醇与人体血浆中存在的ITCs的环缩合反应，随后进行两步己烷萃取，并通过HPLC在365 nm处进行紫外检测分析。该方法在49 - 3003 nM苯乙基异硫氰酸盐（PEITC）范围内对人体血浆显示出线性和重现性（r(2) = 0.996 ± 0.003）。对于PEITC的另外两种生物共轭物：PEITC - N - 乙酰半胱氨酸（PEITC - NAC）和PEITC - 谷胱甘肽（PEITC - GSH），也观察到了相似程度的线性。多天评估的PEITC回收率为96.6 ± 1.5%，PEITC - GSH和PEITC - NAC的回收率为100%。多天采样检测的重现性显示，PEITC的平均变异系数（%CV）为6.5 ± 0.3%，PEITC - NAC为6.4 ± 4.3%，PEITC - GSH为12.3 ± 3.9%。在临床研究中，对23名未进行饮食控制的受试者组成的群体测定的平均血浆ITC水平为413 ± 193 nM PEITC当量。对3名单次服用40 mg PEITC的受试者的药代动力学血浆样本进行的多天分析数据显示变异系数良好（范围：16 - 21%）。证明了该方法在人体中对PEITC进行药代动力学研究的适用性。
