Atypical Nitrogen-Containing Flavonoid in the Fruits of Cumin (Cuminum cyminum L.) with Anti-inflammatory Activity.

The dried seeds of Cuminum cyminum L. have been traditionally used as food and medicine. To explore its chemical composition and anti-inflammatory activity, four new compounds (1-4) along with five known compounds (5-9) were isolated from the seeds in the present study. The chemical structures of the new compounds were identified as follows: methyl 3-((7H-purin-2-yl) amino)-3-(4-isopropylphenyl) propanoate (1), 8-(amino(4-isopropylphenyl)methyl)-5-hydroxy-2-(4-hydroxyphenyl)-7-methoxy-4-oxo-4H-chromene-6-carboxylic acid (2), (3,4,5-trihydroxy-6-((4-isopropylbenzyl)oxy)tetrahydro-2H-pyran-2-yl)methyl (E)-3-(4-propoxyphenyl)acrylate (3), and (3,4,5-trihydroxy-6-((5-hydroxy-2-(4-hydroxyphenyl)-4-oxo-4H-chromen-7-yl)oxy)tetrahydro-2H-pyran-2-yl)methyl 3-(4-isopropylphenyl)-2-methoxypropanoate (4). Compound 2, an atypical nitrogen-containing flavonoid, exhibited the most active inhibitory effect on nitride oxide, with IC₅₀ of 5.25 μM in the lipopolysaccharide-stimulated RAW264.7 cell assay. Compound 2 was found to suppress the expression levels of inducible nitric oxide synthase and cyclooxygenase-2. Furthermore, it was revealed that both nuclear factor κB and mitogen-activated protein kinase were involved in the anti-inflammatory process of compound 2.