Development of a sensitive high-performance liquid chromatography-diode array detection assay for the detection and quantification of the beauveria metabolite oosporein from submerged culture broth and bio-control formulations.
A sensitive high-performance liquid chromatography-diode array detection (HPLC-DAD) assay is described for the detection and quantification of the Beauveria metabolite oosporein from fungal culture broth and two biocontrol agent formulations. In all cases, analyte recovery was achieved with a Britton-Robinson buffer system at pH 5.5 diluted with methanol 3:7 (v/v) (BR5.5-MeOH). The HPLC-DAD assay, using a binary solvent gradient with acidic modifiers and detecting the metabolite at 287 nm, showed linearity over 3 orders of magnitude and a limit of detection (LOD) of 6.0 +/- 2.3 microg of oosporein/L of BR5.5-MeOH. The oosporein content of the representative fungal culture broth samples and two Beauveria formulations (Melocont-Pilzgerste and Melocont-WP) was found to be 504.7 +/-13.6 mg of oosporein/L of culture filtrate, 7.4 +/- 0.6 mg of oosporein/kg of Melocont-Pilzgerste, and 38.2 +/- 1.3 mg of oosporein/kg of Melocont-WP with recovery rates of 93 +/- 2, 99 +/- 8, and 92 +/- 3%, respectively.
Seger
Christoph
C
Institute of Pharmacy, Department of Pharmacognosy, Leopold Franzens University Innsbruck, Innrain 52, A-6020 Innsbruck, Austria. christoph.seger@uibk.ac.at
Sturm
Sonja
S
Längle
Tobias
T
Wimmer
Waltraud
W
Stuppner
Hermann
H
Strasser
Hermann
H
D016227:Benzoquinones / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D017077:Culture Media, Conditioned; D001467:Hordeum / Q000382:microbiology; D006999:Hypocreales / Q000378:metabolism*; D010572:Pest Control, Biological; D012680:Sensitivity and Specificity
D016227:Benzoquinones; D017077:Culture Media, Conditioned; C008706:oosporein