Study On Metabolism And Pharmacokinetics Of CTN986 In Animals

Quercetin 3-O-β-D-apiofuranosyl- (1→2)-[α-L-rhamnopyranosyl- (1→6)]-β-D-glucopyranoside (code name CTN986), a flavonol triglycoside isolated from glandlesscottonseeds in our laboratory, showed specific 5HT_1A receptor binding activity in radio ligand competition experiment and notable antidepressant effect in forced swimming experiment on mice. It seems to be a potential antidepressant agent. Due to the lack of methodologies that meet the requirements of sensitivity and specificity for the determination of flavonoid glycosides in biological fluids, it has long been a controversy as to the absorption and bioavailability of flavonoid glycosides. CTN986 is highly polar and hydrophilic, so the investigation of its metabolism and pharmacokinetics in vivo is a challenge to the analytical methodology. The aim of this work is to investigate the metabolism and pharmacokinetics of CTN986 in vivo using the advanced LC/MS/MS method.1 Development of the quantitation methodsA sensitive and specific LC/MS/MS method was developed for the simultaneous determination of CTN986, its deglycosylation products and aglycone in biological samples, and used for the investigation of the pharmacokinetics of CTN986 in mice and rats.CTN986 and its deglycosylation products, rutin and hirsutin, were isolated from the biological samples prior to LC/MS/MS analysis using C₁₈ solid-phase extraction, and were separated on a Zorbax C₈ reversed-phase column with an isocratic mobile phase consisting of methanol-isopropanol-water-formic acid (20: 10: 70: 0.1, v/v). The protonated analytes generated in the positive ion mode were monitored through multiple reaction monitoring (MRM) in an eletrospray ionization source. Calibration was performed by internal standardization with CTN987, and regression curves were constructed ranging from 2 to 1000 ng/mL in 200 μL serum samples, using a weighing factor of 1/x².The aglycone (quercetin) was monitored in the negative ion mode with an isocratic mobile phase consisting of acetonitrile-methanol-isopropanol-water-formic acid (20: 16:...