Isolation of new isoflavonoids derivatives from Genista carinalis Griseb. and biological activity

The genus Genista L. has been used in the treatment of rheumatic, diabetic and ulcerous diseases. Herein, the antioxidant, anticholinesterase, and antidiabetic activities of Genista carinalis Griseb. extracts were determined. The antioxidant activity was performed FRAP, DPPH, CUPRAC, and TEAC assays, while anticholinesterase activity was performed against acetylcholinesterase and butyrylcholinesterase, and antidiabetic activity against alpha-amylase and alpha-glucosidase, spectrophotometrically. The activity results allowed for the study of the phytochemistry of the ethyl acetate extract that exhibited the best activity. Three new isoflavonoids, 5-methyl-7-methoxy-4 '-hydroxy isoflavone (3), 7-acetyl-5-hydroxy-4 '-methoxy isoflavone (4) and 7-O-[beta-D-glucopyranosyl-(6 ''-> 6 ''')-beta-D-glucopyranosyl]-5-4 '-dihydroxy isoflavone (5), together with two known compounds, isoprunetin (1) and 6-hydroxy biochanin A (2) were isolated from the ethyl acetate extract. Their structures were elucidated by extensive 1D-, 2D-NMR, and MS data analyses. Compound (3) showed the highest antioxidant potential in TEAC, FRAP, and CUPRAC assays, while (2) exhibited higher butyrylcholinesterase enzyme inhibitory activity among the isolated compounds.