Bioactive phenolics from Seriphidium stenocephalum

Abstract

Chromatographic separation of the ethyl acetate soluble part of the methanolic extract from Seriphidium stenocephalum yielded three new compounds: stenocepflavone (1), stenocepflavan (2), and stenocephol (3), together with cirsimaritin (4), 5,7,5′-trihydroxy-3′,4′,6-trimethoxyflavone (5), 5,6,7,5′-tetrahydroxy-4′-methoxyflavone (6), and axillaroside (7). All isolates were characterized with the help of spectroscopic data including 1D, 2D NMR, and high resolution mass spectrometry and/or in comparison with the related compounds in literature. All compounds were tested for in vitro enzyme inhibitory activities against acetylcholinesterase, butyrylcholinesterase, and lipoxygenase. Compounds 1 and 4–7 exhibited significant activity against all the tested enzymes, whereas compounds 2 and 3 were found inactive.

Keywords:

• Seriphidium stenocephalum
• methanolic extract
• secondary metabolites
• characterization
• phenolics
• enzyme inhibition

Acknowledgements

The authors are thankful to Higher Education Commission (HEC) of Pakistan for providing spectroscopic analysis facilities through its program of equipment access to national universities. Alexander von Humboldt (AvH) Foundation, Germany is also acknowledged for financial support to buy laboratory equipments.