A liquid chromatography-electrospray ionization-mass spectrometry method for quantification of cyclotides in plants avoiding sorption during sample preparation

TY - JOUR

T1 - A liquid chromatography-electrospray ionization-mass spectrometry method for quantification of cyclotides in plants avoiding sorption during sample preparation

AU - Ovesen, Rikke Gleerup

AU - Göransson, Ulf

AU - Hansen, Steen Honore'

AU - Nielsen, John

AU - Hansen, Hans Chr. Bruun

PY - 2011/11/4

Y1 - 2011/11/4

N2 - Cyclotides are plant-produced, bioactive, cyclic mini-proteins with interesting pharmaceutical and agricultural applications. A reverse phase liquid chromatography electrospray ionization mass spectrometry (RP-LC-ESI-MS) method for analysis of cyclotides in plant materials with a minimum of sample pre-treatment is presented. Three exemplary cyclotides (kalata B1, kalata B2 and cycloviolacin O2) were used as reference substances for the method development. Linearity (r 2>0.99) was achieved in the concentration range 0.05-10mg/L and the limit of detection was 1.7-4.0μg/L. The present study is the first to demonstrate that cyclotides dissolved in water sorb to glass vials, but the addition of 15% of acetonitrile or 40mg/L of bovine serum albumin is sufficient to keep the cyclotides in solution. Cyclotides were extracted from candied violets, violet tea, and the plants Oldenlandia affinis and Viola odorata using 70% methanol containing 0.1% formic acid (v/v). The plant content was determined to be 23.5-14,200μg/g (dry weight). The highest content of cyclotide was found in wild Danish V. odorata, and it is the highest content of cyclotide in a plant reported hitherto. Candied violets contained 0.00-8.66μg/g (dry weight), while no cyclotides were detected in commercial violet tea.

AB - Cyclotides are plant-produced, bioactive, cyclic mini-proteins with interesting pharmaceutical and agricultural applications. A reverse phase liquid chromatography electrospray ionization mass spectrometry (RP-LC-ESI-MS) method for analysis of cyclotides in plant materials with a minimum of sample pre-treatment is presented. Three exemplary cyclotides (kalata B1, kalata B2 and cycloviolacin O2) were used as reference substances for the method development. Linearity (r 2>0.99) was achieved in the concentration range 0.05-10mg/L and the limit of detection was 1.7-4.0μg/L. The present study is the first to demonstrate that cyclotides dissolved in water sorb to glass vials, but the addition of 15% of acetonitrile or 40mg/L of bovine serum albumin is sufficient to keep the cyclotides in solution. Cyclotides were extracted from candied violets, violet tea, and the plants Oldenlandia affinis and Viola odorata using 70% methanol containing 0.1% formic acid (v/v). The plant content was determined to be 23.5-14,200μg/g (dry weight). The highest content of cyclotide was found in wild Danish V. odorata, and it is the highest content of cyclotide in a plant reported hitherto. Candied violets contained 0.00-8.66μg/g (dry weight), while no cyclotides were detected in commercial violet tea.

U2 - 10.1016/j.chroma.2011.08.095

DO - 10.1016/j.chroma.2011.08.095

M3 - Journal article

SN - 0301-4770

VL - 1218

SP - 7964

EP - 7970

JO - Journal of Chromatography

JF - Journal of Chromatography

IS - 44

ER -