Characterization of a new jasmonate derivative and chemotaxonomical significance of secondary metabolites in the seeds of black soybean (Glycine max)

A comprehensive phytochemical investigation of black soybean (Glycine max) led to the isolation of five compounds, including a new jasmonate derivative (1), a β-sitosterol glucoside derivative (2), two isoflavone glycosides (3 and 4), and an aurone glycoside derivative (5). Their chemical structures were determined using nuclear magnetic resonance (NMR) spectroscopy and comparison with previously reported data. The absolute configuration of the new jasmonate derivative (1) was determined through density functional theory calculations of NMR chemical shifts and DP4+ probability analysis. Additionally, marsuposide (5) was identified in black soybean for the first time, expanding the known chemical profile of this crop. Notably, the occurrence of these metabolites provides potential chemotaxonomic markers within the Fabaceae family, highlighting unique metabolic traits of black soybean. These findings contribute not only to the understanding of the secondary metabolism of the species but also to broader discussions on the diversification of legume-specific phytochemicals. The potential agricultural and biological significance of these metabolites is discussed, along with their chemotaxonomic significance, offering insights into the phytochemical composition of black soybean and its relevance to crop improvement and plant classification.