Arojojoye Adedamola S, Holmes Justin, Buchart Miles P, Awuah Samuel G, Eisenberg Rodney, Fenger Clara K, Maylin George A, Tobin Thomas
Department of Chemistry, University of Kentucky, Lexington, Kentucky, USA.
The Department of Veterinary Science and the Maxwell H. Gluck Equine Research Center, Martin-Gatton College of Agriculture, Food and Environment and the Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, Kentucky, USA.
J Labelled Comp Radiopharm. 2025 Mar;68(3):e4132. doi: 10.1002/jlcr.4132.
Bupivacaine is a local anesthetic widely used in equine and human medicine. Use of bupivacaine in performance horses is regulated because its ability to block pain means that it can be misused for advantage in performance horses. In racing regulation, bupivacaine is classified by the Association of Racing Commissioners International (ARCI) as a Class 2 Penalty Class A Foreign substance, the detection of which can lead to significant penalties. In horses, bupivacaine is metabolized by Phase-I hydroxylation to yield 3-hydroxybupivacaine, which is then glucuronidated to yield the Phase-II metabolite bupivacaine-3-hydroxyglucuronide, which is excreted at relatively high concentrations in equine urine. Standard regulatory procedure during urinalysis is to perform an enzymatic hydrolysis, thereby enabling subsequent detection of 3-hydroxybupivacaine, the primary analyte used for bupivacaine regulation in urine samples from competition horses. We now report on the synthesis of 3-hydroxybupivacaine and deuterated 3-hydroxybupivacaine from piperidine-2-carboxylic acid in six successive steps with moderate yield. The compounds were characterized by H and C NMR and their purity ascertained by HPLC-MS. The deuterated bupivacaine and 3-hydroxybupivacaine were further confirmed by HRMS. The synthesis of these compounds provides certified reference standards and stable isotope-labeled internal standards for drug testing in competitive equine sports including horse racing.
布比卡因是一种广泛应用于马医学和人类医学的局部麻醉剂。布比卡因在竞技马匹中的使用受到监管，因为其阻断疼痛的能力意味着它可能被滥用于在竞技马匹中获取优势。在赛马规则中，国际赛马委员会协会（ARCI）将布比卡因归类为2类处罚等级A的外来物质，检测到该物质可能会导致重大处罚。在马匹中，布比卡因通过I相羟基化代谢生成3-羟基布比卡因，然后该物质被葡萄糖醛酸化生成II相代谢物布比卡因-3-羟基葡萄糖醛酸苷，其以相对较高的浓度排泄在马的尿液中。尿液分析的标准监管程序是进行酶促水解，从而能够随后检测3-羟基布比卡因，这是用于检测参赛马匹尿液样本中布比卡因的主要分析物。我们现在报告了从哌啶-2-羧酸分六个连续步骤以中等产率合成3-羟基布比卡因和氘代3-羟基布比卡因。通过氢核磁共振和碳核磁共振对化合物进行了表征，并通过高效液相色谱-质谱法确定了其纯度。通过高分辨质谱进一步确认了氘代布比卡因和3-羟基布比卡因。这些化合物的合成提供了认证参考标准品和稳定同位素标记的内标物，用于包括赛马在内的竞技马运动中的药物检测。
