Plasma pharmacokinetics and bioavailability of verticillin A following different routes of administration in mice using liquid chromatography tandem mass spectrometry

Abstract

Verticillin A is a natural product isolated from fungal cultures and has displayed potent antibiotic, antiviral, nematocidal, and anticancer properties in vitro. While in vivo studies have been limited due to sparse supply, the in vivo efficacy data that does exist demonstrates potent anti-tumor activity in murine cancer models. The current study aims to investigate the pharmacokinetics and bioavailability of verticillin A in mice to provide guidance for further efficacy assessment in mouse models. A sensitive and specific liquid chromatography-tandem mass spectrometry method was developed and validated for the quantification of verticillin A in mouse plasma. Sample preparation was accomplished through protein precipitation, and chromatographic separation was achieved on an Agilent Zorbax Extend C18 column with a security guard cartridge C8 using a binary gradient with mobile phase A (water/0.1% formic acid) and B (ACN/0.1% formic acid) at a flow rate of 400 μl/min. Elution of verticillin A and internal standard, hesperetin, occurred at 4.87 and 2.06 min, respectively. The total chromatographic run time was 8 min., and the assay was linear in the concentration range of 1–1000 nM. The within- and between day precisions and accuracy were in the range of 2.58–8.71 and 90–105%, respectively. The assay was applied to determine plasma drug concentration in a mouse pharmacokinetic study. It was found that intraperitoneal dosing of 3 mg/kg resulted in high systemic exposure and achieved Cmax of 110 nM with plasma concentrations sustained above 10 nM for the 24-hour duration of the study. Intravenous and oral dosing achieved observed Cmax of 73 nM and 9 nM, respectively. Oral dosing resulted in an approximate 9% bioavailability. Comparing with previously published in vitro studies that demonstrated verticillin A is active in the 20 nM to 130 nM range, the pharmacokinetic data demonstrate similar levels are achieved in mouse plasma via intravenous or intraperitoneal dosing routes.

Melinacidin-Producing Acrostalagmus luteoalbus, a Major Constituent of Mixed Mycobiota Contaminating Insulation Material in an Outdoor Wall

“…The obtained MS/MS data of compounds 1 – 3 were similar to those reported for the dimeric epipolythiodioxopiperazines [ 76 , 77 , 78 ]. The MS/MS spectrum fragmentation patterns ( Figure 6 A) of compound 1 were identical to the reported MS/MS spectrum of melinacidin IV [ 76 ].…”

Exploration of Verticillins in High-Grade Serous Ovarian Cancer and Evaluation of Multiple Formulations in Preclinical In Vitro and In Vivo Models

“…Therefore, sufficient verticillin A succinate was generated to perform a tolerability study in female athymic nude mice to identify tolerated doses to be used in subsequent efficacy studies in an ovarian cancer xenograft model and in an assessment of mouse pharmacokinetics. Dose levels were informed by previous efficacy and pharmacokinetic studies with verticillin A with molar equivalent doses chosen for the succinate form …”

“…Dose levels were informed by previous efficacy and pharmacokinetic studies with verticillin A with molar equivalent doses chosen for the succinate form. 30 The two lower dose levels of each compound (0.100 and 0.250 mg/kg of verticillin A and 0.114 and 0.285 mg/kg of verticillin A succinate) were well tolerated. Mice in these groups maintained their body weights throughout the study (Figure 1) with no remarkable findings at necropsy.…”

“…The verticillin A mouse plasma samples were within the linear range (1−1000 nM) for mice dosed by IV and IP, but most results were just above the lower limit, which was broadly consistent with prior evaluations of verticillin A pharmacokinetics 30 given the lower dose levels administered in our studies. Oral gavage samples were BLOQ for verticillin A.…”

“…Verticillin A and verticillin A succinate concentrations in mouse plasma were measured using a liquid chromatographytandem mass spectrometry (LC−MS/MS) method based on Wang et al with modifications. 30 Stock solutions of verticillin A and verticillin A succinate were prepared at 0.5 and 2 mg/ mL in a mixture of acetonitrile and DMSO, respectively. An intermediate working stock solution was prepared containing 10,000 nM of each analyte.…”