Applications of TiCl3 as a Diagnostic Reagent for the Detection of Nitro- and N-Oxide-Containing Compounds as Potentially Mutagenic Impurities Using Ultrahigh-Performance Liquid Chromatography Coupled with High-Resolution Mass Spectrometry
摘要:
The ICH has strict guidelines for limiting the presence of potentially mutagenic impurities (PMIs) in marketed drugs. Therefore, it is important to fully characterize and quantitate all possible PMIs that could arise during the process of synthesizing and developing a drug. Two important and prevalent examples of PMIs are compounds containing N-oxide and nitro functional groups. TiCl3 derivatization is an established method for determining the presence or absence of N-oxide metabolites by reduction to the corresponding amine. In this study, we demonstrate a novel application of TiCl3 reduction combined with high-resolution UHPLC/HRMS to analyze PMIs. The results indicate that a variety of N-oxide- and nitro-containing compounds can be readily characterized by this facile platform method. In addition, we show that this chemical derivatization method can be utilized to enhance the ionization of nitro-containing compounds for LC/MS analysis.
Selective Monodeoxygenation of Methyl 3-(2-Quinoxalinylmethylene)carbazate N1, N4-Dioxide (Carbadox)
作者:D. J. R. Massy、A. McKillop
DOI:10.1055/s-1996-4420
日期:1996.12
The veterinary drug methyl 3-(2-quinoxalinylmethylene)carbazate N 1, N 4-dioxide (Carbadox) has been selectively reduced in good yield at either N 1 or N 4 with the reagents sodium dithionite or phosphorus trichloride, respectively. The identity of the products, which are important metabolites, was established by 1H NMR and by an X-ray crystal structure of the N 1-monodeoxygenated product. The further metabolite, bis(desoxy) Carbadox, was prepared by reduction of Carbadox with a slight excess of sodium dithionite/acetic acid. When a large excess of this reagent was used, a new compound, methyl 3-(2-quinoxalinylmethyl)carbazate, was also formed.
兽药 3-(2-喹喔啉基亚甲基)咔唑酸甲酯 N 1、N 4-二氧化物(Carbadox)分别在 N 1 或 N 4 处用二亚硫酸钠或三氯化磷试剂进行了选择性还原,收率很高。通过 1H NMR 和 N 1-单脱氧产物的 X 射线晶体结构,确定了重要代谢产物的身份。另一种代谢物--双(脱氧)卡巴多,是用少量过量的二亚硫酸钠/乙酸还原卡巴多制备的。当使用大量过量的这种试剂时,还会生成一种新的化合物,即 3-(2-喹喔啉基甲基)咔唑酸甲酯。
Applications of TiCl<sub>3</sub> as a Diagnostic Reagent for the Detection of Nitro- and <i>N</i>-Oxide-Containing Compounds as Potentially Mutagenic Impurities Using Ultrahigh-Performance Liquid Chromatography Coupled with High-Resolution Mass Spectrometry
The ICH has strict guidelines for limiting the presence of potentially mutagenic impurities (PMIs) in marketed drugs. Therefore, it is important to fully characterize and quantitate all possible PMIs that could arise during the process of synthesizing and developing a drug. Two important and prevalent examples of PMIs are compounds containing N-oxide and nitro functional groups. TiCl3 derivatization is an established method for determining the presence or absence of N-oxide metabolites by reduction to the corresponding amine. In this study, we demonstrate a novel application of TiCl3 reduction combined with high-resolution UHPLC/HRMS to analyze PMIs. The results indicate that a variety of N-oxide- and nitro-containing compounds can be readily characterized by this facile platform method. In addition, we show that this chemical derivatization method can be utilized to enhance the ionization of nitro-containing compounds for LC/MS analysis.