6-O-demethylmenisporphine, a major active oxoisoaporphine alkaloid isolated from Menispermi Rhizoma, has been confirmed to possess significant bioactivities, including anti-cancer and anti-hypoxia effects. However, few researches on quantifying 6-O-demethylmenisporphine in biosamples have been performed. In this research, a sensitive HPLC-MS/MS approach for determining 6-O-demethylmenisporphine in various biological matrices (plasma, tissue, urine, bile and feces) of rat has been constructed. Carbamazepine was chosen as the internal standard (IS). All biosamples were prepared using a simple one-step acetonitrile precipitation. A Capcell Pak C₁₈ column coupled with an isocratic mobile phase consisted of acetonitrile (0.1% formic acid)-water (90:10, v/v), was employed to separate 6-O-demethylmenisporphine from endogenous interferences. Peak responses were detected by multiple reaction monitoring (MRM) transitions with m/z 308.0 → 264.9 for 6-O-demethylmenisporphine and m/z 237.0 → 194.1 for IS in positive-ion mode. The approach exhibited perfect linearity over a range of 5–2000 ng/mL for plasma and 2–1000 ng/mL for various tissue, urine, bile and feces. The lower limit of quantification (LLOQ) for analyte among different biological samples ranged from 2 ng/mL to 5 ng/mL. The newly established method was simple, efficient and sensitive, which was successfully applied to investigate the absorption, distribution, and excretion of 6-O-demethylmenisporphine after oral dosing to rats. The results indicated that 6-O-demethylmenisporphine could be well absorbed into blood circulation and widely distributed in various tissues after oral dosing, the oral bioavailability was up to 51.52%. Meanwhile, it was widely metabolized in vivo and eliminated as the metabolites, the unconverted form was excreted mainly by feces route. The bioavailability, tissue distribution and excretion characteristics of 6-O-demethylmenisporphine were firstly revealed, which will provide references for further development of 6-O-demethylmenisporphine as an anti-tumor drug candidate.

6- O-去甲基menisporphine是一种从半月板瘤分离的主要活性氧代异吗啡碱生物碱，已被证实具有重要的生物活性，包括抗癌和抗缺氧作用。然而，关于定量生物样品中6- O-去甲基甲氨蝶呤的研究很少。在这项研究中，已经建立了一种灵敏的HPLC-MS / MS方法，用于测定大鼠各种生物基质（血浆，组织，尿液，胆汁和粪便）中的6- O-去甲基menisporphine。选择卡马西平作为内标（IS）。所有生物样品均使用简单的一步式乙腈沉淀法制备。Capcell Pak C ₁₈色谱柱与由乙腈（0.1％甲酸）-水（90:10，v / v）组成的等度流动相耦合，用于从内源性干扰物中分离6- O-脱甲基menisporphine。峰应答通过多反应监测与（MRM）转变检测米/ ž 308.0→264.9为6- ö -demethylmenisporphine和米/ ž237.0→194.1（对于IS在正离子模式下）。该方法在5-2000 ng / mL的血浆范围和2-1000 ng / mL的各种组织，尿液，胆汁和粪便范围内显示出完美的线性。不同生物样品中分析物的定量下限（LLOQ）为2 ng / mL至5 ng / mL。新建立的方法简便，高效，灵敏，已成功应用于大鼠口服给药后6- O-去甲基甲氨蝶呤的吸收，分布和排泄。结果表明，口服后6- O-去甲基甲氨蝶呤可以很好地吸收到血液循环中，并广泛分布在各个组织中，口服生物利用度高达51.52％。同时，它在体内被广泛代谢并作为代谢产物消除，未转化形式主要通过粪便途径排泄。首次揭示了6- O-去甲基menisporphine的生物利用度，组织分布和排泄特性，为进一步开发6- O-去甲基menisporphine作为抗肿瘤药物提供了参考。