Pharmacokinetics and metabolite identification of a novel VEGFR-2 and Src dual inhibitor 6-chloro-2-methoxy-N-(2-methoxybenzyl) acridin-9-amine in rats by liquid chromatography tandem mass spectrometry.

A novel VEGFR-2 and Src dual inhibitor, 6-Chloro-2-methoxy-N-(2-methoxybenzyl) acridin-9-amine (MBAA), is a 9-aminoacridine derivative, but its pharmacokinetics and metabolism in body remain unknown. Using liquid chromatography tandem electrospray ionization mass spectrometry with the multiple reaction monitoring modes, we developed and validated a simple, rapid, sensitive and accurate technology for analyses of MBAA in the rat plasma, urine and bile. The micro samples were quickly prepared by 96-well plate. Chromatographic separation was performed on a C(18) column with gradient elution. High-quality linearity calibration curves were achieved over a concentration range of 1.00-3000 ng mL(-1). Intra- and inter-day precisions (RSD) were less than 8.5%, and accuracy (RE%) ranged from -2.9% to 12%. Extraction recoveries of MBAA were consistent with an average of 82.2-111.4% at three QC concentrations. When administered intravenously at a single dose of 2.0 mg kg(-1) to male SD rats, MBAA was rapidly eliminated with a T(1/2) of 0.9 ± 0.1h and AUC(0-t) of 369 ± 44.7 ng mL(-1). We identified four direct phase I and phase II metabolites by mass difference of molecular ions between metabolites and the parent compound. Various fragmentation patterns of MBAA were used to identify and characterize its metabolites. This LC-MS/MS analysis provides a useful approach to the pharmacokinetic and metabolic study of MBAA.

Early indication of effects of puromycin aminonucleoside using a fluorimetric assay of 2-aminoacridone-derivatized carbohydrates in urine.

This paper describes a novel noninvasive method to study the changes in free carbohydrates excreted in urine as a result of toxicity in the rat induced by the administration of puromycin aminonucleoside (PAN). Urine samples were collected for 24 h prior to dosing and at 8, 24, and 32 h postdosing. For each sample, free carbohydrates were extracted from the urine using a graphitized carbon column and then labeled with 2-aminoacridone (2-AMAC) prior to analysis by hydrophilic interaction liquid chromatography (HILC). Dramatic changes were seen in the profile of the carbohydrates at the 8- and 24-h time points. These changes in carbohydrate profiles may be useful as early indicators of toxicity.

In vivo metabolism of the antitumor imidazoacridinone C1311 in the mouse and in vitro comparison with humans.

C1311 has emerged as the lead compound from a novel group of anticancer agents, the imidazoacridinones, and will be entering clinical trials shortly. Previous murine pharmacokinetic studies have shown C1311 to be rapidly and extensively distributed into tissues including tumor. This study has identified two major metabolites of C1311 and describes their pharmacokinetics in mice. M1 is a glucuronide of the parent compound with high concentrations in both plasma and liver. Calculated area under the plasma concentration versus time curve values were 6-fold and 2-fold greater, respectively, than C1311. Based on these studies, we propose M2 to be a nonfluorescent oxidation product because electrospray ionization-mass spectroscopy/mass spectroscopy analysis gave a molecular ion at m/z 367, 16 U greater than the parent compound. It formed rapidly in liver preparations in vitro, both murine and human, by a cytosolic process in the presence of NADPH and in vivo was detected in liver tissues at concentrations equivalent to those of C1311 but was not detectable in plasma. Preliminary in vitro toxicity studies showed M2 to be as potent as C1311 against MAC15A tumor cells. Over the first 24 h, 39% of the administered dose is eliminated via the bile (28%) mostly as C1311 or the kidneys (11%) as the glucuronide (M1). This study has given valuable information as to the likely metabolic pathway to occur in humans, and the cytotoxic metabolite M2 may play a role in the antitumor activity or toxicity of C1311 in the clinic.

Metabolism of the experimental antitumor agent acridine carboxamide in the mouse.

The metabolism of the experimental antitumor agent acridine carboxamide (AC) has been examined in the male BDF1 mouse. [3H]AC was administered at the optimal single intraperitoneal dose for antitumor activity (410 mumol/kg body weight) and the metabolites in urine, bile, and feces characterized using reversed-phase HPLC. In urine (0-24 hr) the main product appears to be a glucuronide, also present in bile, with lesser amounts of AC, AC-N-oxide, and at least 10 minor products. Biliary excretion of AC metabolites (examined after removal of the gallbladder at the appropriate times) is greatest at 1-2 hr after treatment when at least 14 products are detected, including AC, AC-N-oxide, and other products with UV/visible spectra characteristic of ring hydroxylated and/or acridone derivatives. In feces (0-24 hr) no AC-N-oxide is detected, the major metabolites being two polar species and AC. These polar species are both present in urine and bile where they are increased on incubation with crude beta-glucuronidase. These aglycones have been identified as the 7-hydroxy-9(10H)acridone derivatives of AC and N-monomethyl-AC by [1H]NMR and mass spectrometry. Thus the main pathways of elimination of AC appear to be 1) N-oxidation and 2) 9(10H)acridone formation plus 7-hydroxylation of both AC and its N-demethylated product followed by glucuronidation. Reduction of AC-N-oxide in the gut may allow reabsorption of AC. Both the back-reduction and reabsorption of AC, and enterohepatic circulation of the 7-hydroxyacridone derivatives may contribute to the slow elimination of AC metabolites.

Reversal of clinical features of Hurler's disease and biochemical improvement after treatment by bone-marrow transplantation.

A one-year-old boy with type I H mucopolysaccharidosis (Hurler's disease) was given a bone-marrow transplant (BMT) from his mother in an attempt to replace the deficient enzyme, alpha-L-iduronidase (iduronidase). These is definite evidence of engraftment, the enzyme activity of the recipient's leucocytes reaching heterozygote levels within 37 days of the BMT. Graft-versus-host disease (GVHD) developed but was partially controlled by steroids. From 3-4 months after graft until the present (13 months after the graft) iduronidase activity has been present in the serum and the urine and there has been evidence of considerable degradation of glycosaminoglycans excreted in the urine. The hepatosplenomegaly has disappeared, corneal clouding has cleared, and deterioration in the child's development seems to have been arrested.