A method for dextruxin analysis by HPLC-PDA-ELSD-MS

Abstract

Destruxinas (Dtx) são ciclodepsipetídeos produzidos por fungos entomopatogênicos, que são utilizados como controle biológico em insetos pragas em diferentes agriculturas. A presente investigação reporta uma nova abordagem para análises de destruxinas produzidas por uma linhagem do fungo Beauveria felina, utilizando-se de LC-PDA-ELSD-MS. Em comparação com os métodos anteriores, a nova abordagem utiliza-se de uma limpeza prévia da amostra em cartuchos C 18 que removem efetivamente os constituintes do meio de cultura. Além disso, o uso dos solventes MeCN/MeOH 50:50, (v/v) como eluentes mais fortes no sistema de gradiente em 0,1% de H 2 O demonstrou fornecer a melhor resolução dos picos cromatográficos. Detecções simultâneas usando arranjo de fotodiodos (PDA), detector de espalhamento de luz evaporativa (ELSD) e espectrometria de massas (MS) indicaram praticamente uma resposta idêntica de todos os detectores na análise das destruxinas. Cinco amostras obtidas da cultura de B. felina foram analisadas, e indicaram a presença de 20 destruxinas conhecidas e de 6 ciclodepsipetídeos ainda não reportados. Considerando a redução do uso do MeCN, e a eficácia do ELSD como detector para destruxina, o método prova que pode ser de grande valia e de baixo custo operacional para controle de qualidade nas análises de destruxinas produzidas por linhagens de fungos.Destruxins (Dtx) are cyclodepsipeptides produced by enthomopathogenic fungi, which are used in biological control of different agricultural insect plagues. The present investigation reports a new approach for analysis of destruxins produced by the fungal strain Beauveria felina, using LC-PDA-ELSD-MS. Compared to previous methods, the new approach uses a clean-up on C 18 cartridges, which effectively removes growth media constituents. Moreover, the use of 50:50 (v/v) MeCN/MeOH as the strongest eluting solvent in a gradient system over 0.1% H 2 O proved to give a better resolution of chromatographic peaks. Simultaneous detection using photodiode array (PDA), evaporative light scattering detector (ELSD) and mass spectrometry (MS) indicated a practically identical response of all detectors for destruxins analysis. Five samples obtained from the culture media of B. felina were analysed, and indicated the presence of twenty known destruxins and six yet unreported cyclodepsipeptides. Considering the reduced use of MeCN, and the effectiveness of ELSD as a detector for destruxins, the method proved to be valuable and cost-effective for quality control analysis of destruxin-producing fungal strains.Keywords: destruxin, Beauveria felina, LC-PDA-ELSD-MS, light scattering, marine fungus Morais et al. 2263 Vol. 21, No. 12, 2010 Introduction Destruxins (Dtx) are cyclodepsipeptides isolated from entomopathogenic fungal strains of economic importance. Dry spores of the fungus Metarhizium anisopliae are currently used in biological control of agricultural plagues such as several Hemiptera and Lepidoptera species affecting sugar cane cultures and citrus plantations.1-3 Dry spores of Beauve...

Identification of immunity-related genes in Plutella xylostella in response to fungal peptide destruxin A: RNA-Seq and DGE analysis

“…Chemically, destruxins have a typical composition containing α-hydroxy acid and five amino acids which form cyclic hexadepsipeptides. Until now, 39 analogs of destruxins have been extracted from various fungal species 15 – 17 . Among them, few destruxins such as Destruxin A, Destruxin B, and Destruxin E have exhibited significant insecticidal activities against various insect pests 12 , 18 , 19 .…”

Quantitative Assessment of Destruxins from Strawberry and Maize in the Lower Parts per Billion Range: Combination of a QuEChERS-Based Extraction Protocol with a Fast and Selective UHPLC-QTOF-MS Assay

“…To date, several chromatographic assays such as HPLC methods, one recently published UHPLC assay, and one capillary electrophoresis assay are reported for destruxin analysis. − Most of these studies use UV or diode array detection (DAD) for the quantitative analysis of destruxins in combination with reference material. Hyphenation of HPLC with mass spectrometry was only used for destruxin identification, comparing exact masses and destruxin fragmentation pattern with reference material.…”

Gene Expression Profile of Bombyx mori Hemocyte under the Stress of Destruxin A

“…Chemically, destruxins are cyclic hexadepsipeptides composed of an α-hydroxy acid and five amino acid residues. So far, 39 destruxins analogues have been isolated from M. anisopliae and other fungal species [13] – [15] . The common analogues, Destruxin A (DA), Destruxins B (DB) and Destruxins (DE) exhibit a substantial insecticidal activities against many species of pests such as Plutella xylostella , Spodoptera litura , Manduca sexta and Pieris brassicae [16] – [18] , etc.…”