Two new phenolic acids and one new phenolic glycoside from Hyssopus cuspidatus Boriss and their anti-inflammatory activities

Abstract

• Three new phenolic compounds ( 1 ‒ 3 ) were isolated from H. cuspidatus . • Their structures were established by comprehensive spectroscopic data. • One new natural compound ( 6 ) was firstly isolated from H. cuspidatus . • Compounds 3 showed significant anti-inflammatory activity in RAW 264.7 cells. Two new phenolic acids ( 1 ‒ 2 ), one new phenolic glycoside ( 3 ) and one new natural compound, 3-(4-hydroxy-3-methoxy-phenyl)acrylic acid carboxymethyl ester ( 6 ), together with eleven known polyphenolic substances, ferulic acid ( 4 ), ethyl ferulate ( 5 ), ( E )-3–4-hydroxy-3-methoxyphenyl)acrylic acid ( 7 ), 3,4-dihydroxy benzaldehyde ( 8 ), quercetin ( 9 ), quercetin-3-O-glucopyranoside ( 10 ), luteolin ( 11 ), luteolin-7-O-rutinoside ( 12 ), diosmetin ( 13 ), diosmetin-3′-O- β -D-glucopyranoside ( 14 ), and apigenin-6,8-di-C- β -D-glucopyranoside ( 15 ) were isolated and identified from Hyssopus cuspidatus Boriss for the first time. The structures of the new compounds were elucidated from the spectra of 1D NMR, 2D NMR, IR, UV and MS data. Compounds 1–15 were tested to determine their inhibitory effect on lipopolysaccharide (LPS)-induced NO production in RAW 264.7 cells. Novel compound 3 exhibited significant anti-inflammatory activity with an IC50 value of 35.88 μM, which was comparable to that of dexamethasone (positive control). This study provided phytochemical evidence for the further development of new anti-inflammatory lead compounds and investigation of their chemical modification and mechanism.