Biomarker Quantification, Spectroscopic, and Molecular Docking Studies of the Active Compounds Isolated from the Edible Plant Sisymbrium irio L.

Phytochemical investigation of the ethanolic extract of the aerial parts of Sisymbrium irio L. led to the isolation of four unsaturated fatty acids (1-4), including a new one (4), and four indole alkaloids (5-8). The structures of the isolated compounds were characterized with the help of spectroscopic techniques such as 1D, 2D NMR, and mass spectroscopy, and by correlation with the known compounds. In terms of their notable structural diversity, a molecular docking approach with the AutoDock 4.2 program was used to analyze the interactions of the identified fatty acids with PPAR-gamma and the indole alkaloids with 5-HT1A and 5-HT2A, subtypes of serotonin receptors, respectively. Compared to the antidiabetic drug rivoglitazone, compound 3 acted as a potential PPAR-gamma agonist with a binding energy of -7.4 kcal mol(-1). Moreover, compound 8 displayed the strongest affinity, with binding energies of -6.9 kcal/mol to 5HT(1A) and -8.1 kcal/mol to 5HT(2A), using serotonin and the antipsychotic drug risperidone as positive controls, respectively. The results of docked conformations represent an interesting target for developing novel antidiabetic and antipsychotic drugs and warrant further evaluation of these ligands in vitro and in vivo. On the other hand, an HPTLC method was developed to quantify alpha-linolenic acid in the hexane fraction of the ethanol extract of S. irio. The regression equation/correlation coefficient (r(2)) for linolenic acid was Y = 6.49X + 2310.8/0.9971 in the linearity range of 100-1200 ng/band. The content of alpha-linolenic acid in S. irio aerial parts was found to be 28.67 mu g/mg of dried extract.

Automated summary

Phytochemical investigation of Sisymbrium irio L. led to the isolation of unsaturated fatty acids and indole alkaloids. Compound 3 showed potential PPAR-gamma agonist activity, while compound 8 displayed strong affinity towards 5-HT1A and 5-HT2A receptors. These compounds have the potential to be developed into novel antidiabetic and antipsychotic drugs.