Determination of Loline Alkaloids and Mycelial Biomass in Endophyte-Infected Schedonorus pratensis by Near-Infrared Spectroscopy and Chemometrics

Abstract

Near infrared spectroscopy (NIRS) is an accurate, fast and nondestructive technique whose use in predicting forage quality has become increasingly relevant in recent decades. Epichloë-infected grass varieties are commonly used in areas with high pest pressure due to their better performances compared to endophyte-free varieties. The insect resistance of Epichloë-infected grasses has been associated with four main groups of endophyte secondary metabolites: ergot alkaloids, indole-diterpenes, lolines and peramine. Concentrations of these alkaloids are usually measured with high performance liquid chromatography or gas chromatography analysis, which are accurate methods but relatively expensive and laborious. In this paper, we developed a rapid method based on NIRS to detect and quantify loline alkaloids in wild accessions of Schedonorus pratensis infected with the fungal endophyte Epichloë uncinata. The quantitative NIR equations obtained by modified partial least squares algorithm had coefficients of correlation of 0.90, 0.78, 0.85, 0.90 for N-acetylloline, N-acetylnorloline and N-formylloline and the sum of the three, respectively. The acquired NIR spectra were also used for developing an equation to predict in planta fungal biomass with a coefficient of correlation of 0.75. These results showed that the use of NIRS and chemometrics allows the quantification of loline alkaloids and mycelial biomass in a heterogeneous set of endophyte-infected meadow fescue samples.

Interpol Review of Drug Analysis 2019-2022

“…2019 analysis of EAs in wheat and rye products in Italy [ 602 ]; LC-FLD method for the analysis of EAs in Rye Products using Lysergic Acid Diethylamide as an Internal Standard [ 603 ]; 2D LC-MS/MS method for the simultaneous determination of 350 pesticides, 16 mycotoxins, the six most important EAs (e.g. ergotamine/ergotaminine) and two modified mycotoxins (deoxynivalenol-3-glucoside and zearalenone-sulfate) [ 604 ]; 2020 a rapid NIRS method to detect and quantify alkaloids [ 605 ]; determination of the covariation of ergot severity and the content of 12 EAs using HPLC and ELISA [ 606 ]; NMR study for the complete assignment of the H-1, C-13, and N-15 NMR signals of two alkaloids [ 607 ]; LC-MS/MS method for determination of EAs and tropane alkaloids (TAs) [ 608 ]; 2021 review [ 609 ]; UHPLC-MS/MS analysis of EAs [ 610 ]; analytical workflow including mass spectral library, generic sample preparation, chromatographic separation, and analysis by HRMS was developed and applied to 156 compounds including 90 plant toxins (pyrrolizidine alkaloids (Pas), TAs, glycoalkaloids, isoquinoline alkaloids and aristolochic acids), 54 mycotoxins (including EAs and Alternaria toxins) and 12 phytoestrogens (including isoflavones, lignans and coumestan) [ 611 ]; UHPLC-MS/MS method for determination of major EAs (ergometrine, ergosine, ergotamine, ergocornine, ergokryptine, ergocristine) and their epimers (ergometrinine, ergosinine, ergotaminine, ergocorninine, ergokryptinine, and ergocristinine) [ 612 ]; review of analytical methods for EAs [ 613 ]; serotonin receptor activity profiles for nine commercialized EAs and corresponding risks of causing hallucinations [ 614 ]; UHPLC-MS/MS method for the quantification of six EAs (Ergocornine, ergocristine, ergometrine, ergosine, ergotamine, alpha-ergocryptine) and their corresponding epimers [ 615 ]; LC-MS/MS method for monitoring 12 EAs [ 616 ]; simultaneous determination of 11 EAs by UHPLC-MS/MS [ 617 ]; development and validation of an LC-MS/MS method to determine fifteen toxic alkaloids (EAs, PAs and TAs) [ 618 ]; UHPLC-MS/MS method to detect ten EAs [ 619 ]; UHPLC-q-Orbitrap MS method to monitor both mycotoxins, e.g., ochratoxin A (OTA) or deoxynivalenol (DON), and EAs [ 620 ]; detection of EAs and indole diterpenoids in ergot sclerotia using LC-HRMS/MS diagnostic fragment filtration [ 621 ];…”