Improved method for quantitative analysis of the cyclotide kalata B1 in plasma and brain homogenate.
This study provides a new method for quantifying the cyclotide kalata B1 in both plasma and brain homogenate. Cyclotides are ultra-stable peptides with three disulfide bonds that are interesting from a drug development perspective as they can be used as scaffolds. In this study we describe a new validated LC-MS/MS method with high sensitivity and specificity for kalata B1. The limit of quantification was 2 ng/mL in plasma and 5 ng/gmL in brain homogenate. The method was linear in the range 2-10,000 ng/mL for plasma and 5-2000 ng/g for brain. Liquid Chromatographic separation was performed on a HyPurity C18 column, 50 × 4.6 mm, 3 µm particle size. The method had inter- and intra-day precision and accuracy levels <15% and 12% respectively. Applying the method to in vivo plasma samples and brain homogenate samples from equilibrium dialysis yielded satisfying results and was able to describe the plasma pharmacokinetics and brain tissue binding of kalata B1. The described method is quick, reproducible and well suited to quantifying kalata B1 in biological matrices.
Department of Pharmaceutical Biosciences, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden.
Erik
E
Melander
Division of Pharmacognosy, Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden.
Camilla
C
Eriksson
Department of Pharmaceutical Biosciences, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden.
Britt
B
Jansson
Division of Pharmacognosy, Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden.
Ulf
U
Göransson
Department of Pharmaceutical Biosciences, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden.
Margareta
M
Hammarlund-Udenaes
D000818:Animals; D001921:Brain / Q000378:metabolism*; D047169:Cyclotides / Q000493:pharmacokinetics* / Q000494:pharmacology; D008297:Male; D013058:Mass Spectrometry; D008954:Models, Biological; D010949:Plasma / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
D047169:Cyclotides; C091930:kalata B1
brain; cyclotides; kalata B1; liquid chromatography; mass spectrometry; pharmacokinetics