Institute of Clinical Pharmacology, Medical Faculty Carl Gustav Carus, Technical University Dresden, Fiedlerstr. 27, 01307 Dresden, Germany.
J Chromatogr A. 2013 Feb 22;1278:69-75. doi: 10.1016/j.chroma.2012.12.063. Epub 2013 Jan 8.
The novel melatonin agonist Neu-P11 is used in treatment of physiological insomnia. In animal studies Neu-P11 showed sleep-promoting effects. In a phase 1 study Neu-P11 was administered to cohorts of healthy young male volunteers in an ascending single dose study. Up to now the metabolism of this new drug in humans has not been investigated. The first aim of this study was to identify possible metabolites in pooled urine samples of the first collecting period (0-8 h) of volunteers with the highest Neu-P11 oral dosage (200 mg). The objective of the second part of the study was to estimate the concentrations of the main metabolites of Neu-P11 - in this urine sample. The analyte Neu-P11 and metabolites were separated from human urine using dilution and precipitation with acetonitrile. Samples were analyzed for formation of both phase I and phase II metabolites using LC-MS/MS in precursor ion mode, product ion mode, neutral loss mode and the multi-reaction monitoring mode (MRM). Urine samples were analyzed before and after addition of beta-glucuronidase and sulfatase. In the pooled urine sample eight metabolites could be proved. The parent drug, the sulfated demethylated Neu-P11, the sulfated 6OH-Neu-P11 and the di-oxygenated product gave the highest signals in these urine samples and probably had the highest concentration. But quantification without reference substances is not possible. So in the second part of the study the urine samples were additionally analyzed with UV-detection for a better estimation of the metabolite concentrations. The concentration of the sulfated metabolites was more than ten times higher than the concentration of the unchanged drug in urine. Other metabolites were not measurable with UV-detection. The di-oxygenated Neu-P11 and an additional mono-oxygenated Neu-P11 showed relatively high signals in MS/MS. Probably the other metabolites, namely glucuronides, unconjugated demethylated Neu-P11 and unconjugated 6OH-Neu-P11, were formed at a lesser extent.
新型褪黑素激动剂 Neu-P11 被用于治疗生理性失眠。在动物研究中，Neu-P11 显示出促眠作用。在一项 1 期研究中，Neu-P11 被给予最高剂量（200mg）的健康年轻男性志愿者递增单剂量研究。到目前为止，尚未研究这种新药在人体中的代谢情况。本研究的首要目的是鉴定志愿者最高 Neu-P11 口服剂量（200mg）首个收集期（0-8 小时）的混合尿液样本中可能存在的代谢产物。研究的第二部分目的是估计 Neu-P11 的主要代谢物在该尿液样本中的浓度。Neu-P11 及其代谢物采用乙腈稀释沉淀法从人尿中分离。使用 LC-MS/MS 在母离子模式、产物离子模式、中性丢失模式和多反应监测模式（MRM）下分析分析物和代谢物的形成。对添加β-葡糖苷酸酶和硫酸酯酶前后的样品进行分析。在混合尿液样本中，共证实了 8 种代谢产物。原药、硫酸去甲基 Neu-P11、硫酸 6OH-Neu-P11 和双氧化产物在这些尿液样本中给出了最高信号，可能具有最高浓度。但是，没有参考物质的定量是不可能的。因此，在研究的第二部分，使用 UV 检测对尿液样本进行了额外分析，以便更好地估计代谢产物浓度。硫酸代谢产物的浓度比尿液中未改变药物的浓度高十多倍。其他代谢产物不能用 UV 检测到。双氧化 Neu-P11 和另外一种单氧化 Neu-P11 在 MS/MS 中显示出相对较高的信号。可能其他代谢产物，即葡萄糖醛酸苷、未结合去甲基 Neu-P11 和未结合 6OH-Neu-P11 的形成程度较低。
