Two new bioactive lignans from leaves and twigs of Cleistanthus concinnus Croizat

Abstract

Two new lignans (1–2), along with five known compounds (3-7) with different structures were isolated from leaves and twigs of Cleistanthus concinnus Croizat. The new lignans were elucidated as (7′R,8′S)-3,3′,5′-trimethoxy-4,4′-dihydroxy-7-en-7′,9- epoxy-8,8′-lignan (1) and (7′R,8′S)-3,3′-dimethoxy-4,4′-dihydroxy-7-en-7′,9-epoxy-8, 8′-lignan (2) by comprehensive spectroscopic analysis including 1D and 2D NMR as well as HREIMS and comparing their NMR data with known compounds in the literature. Among these isolated compounds, compound 1, 2, 3, and 6 were tested for anti- inflammatory effects by inhibiting NO production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Compound 1, 2, and 6 exhibit NO inhibitory activity.

Keywords:

• Cleistanthus concinnus Croizat
• Euphorbiaceae
• lignans
• NO inhibitory activity

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant numbers 81773610 and 21432010], Central Asian Drug Discovery and Development Centre of Chinese Academy of Sciences [grant number CAM201702], Youth Innovation Promotion Association of CAS [grant number 2018429], Yunnan Applied Basic Research Projects [grant number 2016FB015], and the Foundation of State Key Laboratory of Phytochemistry and Plant Resources in West China (P2018-ZZ08).