Cinnamomulactone, a new butyrolactone from the twigs of Cinnamomum cassia and its inhibitory activity of matrix metalloproteinases

Cinnamomum cassia (Lauraceae) has long been used as one of the most frequently used traditional oriental medicines for the treatment of gastritis, diabetes, blood circulation disturbance and inflammatory diseases. Cinnamomulactone (1), a new butyrolactone was isolated from the twigs of C. cassia together with nine known compounds, coumarin (2), trans-cinnamic acid (3), cinnamaldehyde (4), 2-hydroxycinnamaldehyde (5), 2-methoxycinnamaldehyde (6), 2-hydroxy-cinnamyl alcohol (7), benzoic acid (8), (+)-syringaresinol (9) and phenethyl (E)-3-[4-methoxyphenyl]-2-propenoate (10). The planar structure of 1 was elucidated on the basis of spectroscopic data analysis and its configurations were determined by coupling constant (³J_HH) analysis and a comparison with specific rotation data of related compounds on the literatures. The structures of known compounds were confirmed by the comparison of their spectroscopic data to the reported values. Compound 10 was isolated for the first time from this plant. Compounds 1, 2, 4, and 9 showed inhibitory activity against matrix metalloproteinases (MMPs) gene expression. Among them, compound 1 has been revealed to suppress the gene expression of MMP-3 and interleukin (IL)-1β as well as MMP-1 in tumor necrosis factor (TNF)-α stimulated rheumatoid arthritis synovial fibroblasts.