An Improved HILIC HPLC-MS/MS Method for the Determination of β-ODAP and Its α Isomer in Lathyrus sativus.

Elsa Mecha,Maria Carlota Vaz Patto,Maria do Rosário Bronze,Filipe Pereira,Andreia Bento-Silva,Letice Gonçalves

doi:10.3390/molecules24173043

Abstract

β-N-Oxalyl-l-α,β-diaminopropionic acid (β-ODAP) is a non-protein amino acid present in Lathyrus sativus (grass pea) and other Lathyrus species, in parallel with its nontoxic isomer, α-ODAP. When consuming grass pea for several months as staple food, β-ODAP may cause neurolathyrism, a motor neuron degeneration syndrome. Therefore, the independent quantification of both ODAP isomers instead of only the total amount in grass pea allows the identification of less toxic varieties and the development of tools to support breeding for improving grass pea quality. In this work, a simple and fast HPLC-MS/MS method was developed without sample derivatization, using a hydrophilic interaction chromatography (HILIC) column and an isocratic gradient of eluents for 18 min, which allowed the determination of both α- and β-ODAP. The proposed method was fully validated and applied to the determination of α- and β-ODAP contents in a diverse collection of 107 grass pea accessions representative of the main grass pea-growing geographical regions in the world, with the prompt identification of contrasting accessions. β-ODAP content in the analyzed grass pea samples ranged from 0.45 ± 0.02 to 6.04 ± 0.45 mg g−1. The moderate correlation found between α- and β-ODAP contents (0.65) in this collection reinforces the importance of the independent quantification of both ODAP isomers.

Highlights

IntroductionGrass pea (Lathyrus sativus) is the most cultivated Lathyrus species [1,2], in South
Grass pea (Lathyrus sativus) is the most cultivated Lathyrus species [1,2], in SouthAsia and Sub-Saharan Africa [1], and has been used as human food and animal feed since ancient times as an important source of carbohydrates, proteins, and antioxidant compounds [3]
A higher concentration of ODAP was obtained when samples were extracted with 100% water, and this was the selected solvent for the extraction procedure from grass pea samples

Summary

Introduction

Grass pea (Lathyrus sativus) is the most cultivated Lathyrus species [1,2], in South. Asia and Sub-Saharan Africa [1], and has been used as human food and animal feed since ancient times as an important source of carbohydrates, proteins, and antioxidant compounds [3]. Lathyrus species have been implicated as the cause of a neurological disorder, called neurolathyrism, in both men and animals [2]. Neurolathyrism is caused by an excessive consumption of grass pea seeds as staple food for several months [5,6] and it is intricately linked to Molecules 2019, 24, 3043; doi:10.3390/molecules24173043 www.mdpi.com/journal/molecules. Grass pea is harmless to humans and animals when consumed as part of a balanced diet [1]

Methods

Results

Conclusion