Application of comprehensive NMR‐based analysis strategy in annotation, isolation and structure elucidation of low molecular weight metabolites of Ricinus communis seeds

• Published in: Phytochemical analysis Vol. 27; no. 1; pp. 64 - 72
• Main Authors: Vučković, Ivan, Rapinoja, Marja-Leena, Vaismaa, Matti, Vanninen, Paula, Koskela, Harri
• Format: Journal Article
• Language: English
• Published: England Wiley 01.01.2016; Blackwell Publishing Ltd; Wiley Subscription Services, Inc
• Subjects: Alanine - analogs & derivatives; Alanine - analysis; Alanine - metabolism; analysis strategy; Chromatography, High Pressure Liquid - methods; Galactosides - analysis; Galactosides - chemistry; HPLC; Inositol - analogs & derivatives; Inositol - analysis; Inositol - chemistry; LC-MS; low molecular weight metabolites; Magnetic Resonance Spectroscopy - methods; Molecular Structure; Molecular Weight; NMR; Pyridones - analysis; Pyridones - metabolism; Ricin - metabolism; Ricinus - chemistry; Ricinus - metabolism; Ricinus communis; Seeds - chemistry; Seeds - metabolism; LC-MS; NMR; low molecular weight metabolites; analysis strategy; HPLC; Ricinus communis
• ISSN: 0958-0344; 1099-1565
• DOI: 10.1002/pca.2600

INTRODUCTION: Powder‐like extract of Ricinus communis seeds contain a toxic protein, ricin, which has a history of military, criminal and terroristic use. As the detection of ricin in this “terrorist powder” is difficult and time‐consuming, related low mass metabolites have been suggested to be useful for screening as biomarkers of ricin. OBJECTIVE: To apply a comprehensive NMR‐based analysis strategy for annotation, isolation and structure elucidation of low molecular weight plant metabolites of Ricinus communis seeds. METHODOLOGY: The seed extract was prepared with a well‐known acetone extraction approach. The common metabolites were annotated from seed extract dissolved in acidic solution using ¹H NMR spectroscopy with spectrum library comparison and standard addition, whereas unconfirmed metabolites were identified using multi‐step off‐line HPLC‐DAD‐NMR approach. RESULTS: In addition to the common plant metabolites, two previously unreported compounds, 1,3‐digalactoinositol and ricinyl‐alanine, were identified with support of MS analyses. CONCLUSION: The applied comprehensive NMR‐based analysis strategy provided identification of the prominent low molecular weight metabolites with high confidence.