New benzoic acid and caffeoyl derivatives with anti-inflammatory activities isolated from leaves of Ilex kaushue

Abstract

A new benzoic acid, 3-[2-(2-hydroxyphenyl)acetoxy]benzoic acid (1), and two new caffeoyl derivatives, methyl (3E,5Z)-di-O-caffeoylquinate (2) and dhurrin 6′-O-caffeate (3), along with 20 known compounds were isolated from the leaves of Ilex kaushue collected in Vietnam. Their structures were elucidated on the basis of 1 D and 2 D NMR spectroscopy, and high-resolution MS spectrometry. The absolute configuration of 2 and 3 was unambiguously established by comparison of experimental and calculated ECD spectra and/or chemical reactivity. In addition, new compounds were evaluated for inhibitory effects of their tumor necrosis factor-α (TNF-α) production and cell cytotoxicity on lipopolysaccharide-induced RAW264 macrophage cells. All of those moderately suppressed TNF-α production in ratios of approximately 50% or higher at 25–100 µM, without cell cytotoxicity.

Graphical Abstract

Keywords:

• Ilex kaushue
• Aquifoliaceae
• Kuding tea
• phenolic compounds
• anti-inflammation
• tumor necrosis factor-α

Acknowledgements

The authors are grateful to Dr. Do Ngoc Dai (Faculty of Agriculture, Forestry and Fishery, Nghe An Economics University, Vietnam) and Dr. Tran Thi Phuong Anh (Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Vietnam) for plant identification.

Disclosure statements

No potential conflict of interest was reported by authors.