AUTHOR=Huang Hung-Tse , Lo I-Wen , Liao Geng-You , Lin Yu-Chi , Shen Yuh-Chiang , Huang Hui-Chi , Li Tsung-Lin , Lee Kung-Ta , Kuo Yao-Haur , Liaw Chia-Ching 

TITLE=Anti-inflammatory sesquiterpene and triterpene acids from Mesona procumbens Hemsley

JOURNAL=Frontiers in Chemistry

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2022.1003356

DOI=10.3389/fchem.2022.1003356

ISSN=2296-2646

ABSTRACT=<p><italic>Mesona</italic><italic>procumbens</italic> Hemsley is a plant conventionally processed to provide popular food materials and herbal medicines in Asia. In this study, six triterpene acids, including five new ones (mesonaic acids D-H, <bold>1</bold>–<bold>5</bold>), and one proximadiol-type sesquiterpene (<bold>7</bold>) were isolated from the methanolic extract of the air-dried <italic>M. procumbens</italic>. Chemical structures of <bold>1</bold>‒<bold>7</bold> were established by spectroscopic methods, especially 2D NMR techniques (<sup>1</sup>H–<sup>1</sup>H COSY, HSQC, HMBC, and NOESY) and HRESIMS. Concerning their biological activities, compounds <bold>1</bold>, <bold>2</bold>, <bold>6</bold>, and <bold>7</bold> were examined manifesting high inhibition toward the pro-inflammatory NO production with EC<sub>50</sub> values ranging from 12.88 to 21.21 µM, outrunning the positive control quercetin (24.12 µM). The mesoeudesmol B (<bold>7</bold>) identified from <italic>M. procumbens</italic> is the very first example, which exhibited high anti-inflammatory activity diminishing the level of the lipopolysaccharide-induced NO in RAW264.7 macrophage cells, thereby suppressing the secretion of pro-inflammatory cytokines TNF-α and IL-6 and the level of two critical downstream inflammatory mediators iNOS and COX-2.</p>