Chemical constituents from the stems of Cinnamomum insulari-montanum

Anti-Inflammatory Activities of Constituents from Cinnamomum insularimontanum Hayata Leaves and Their Mechanisms

Cinnamomum insularimontanum is an endemic species of Taiwan. Although most Cinnamomum plants have significant biological activity, the bioactivity investment of C. insularimontanum is rare. Since inflammation plays an important role in many diseases, anti-inflammatory compounds can be developed into healthcare products. Therefore, we first conducted a study on the anti-inflammatory activity of C. insularimontanum leaves. First, we examined the antiinflammation activity of essential oil from C. insularimontanum leaves, and it revealed potent anti-inflammatory activity. A total of 23 volatile compounds were identified in C. insularimontanum leaves' essential oil by using GC/MS analysis. Among them were 1,8-cineole (35.94%), α-eudesmol (6.17%), pinene (7.55%), sabinene (5.06%), and isobornyl acetate (4.81%). According to previous studies, 1,8-cineole might be an anti-inflammation principal compound of C. insularimontanum leaves. Next, the ethanolic extracts of C. insularimontanum leaves also exhibited good anti-inflammatory activity. Two bioactive compounds, isoburmanol (F1) and burmanol (F2), were isolated from the ethyl acetate soluble fraction by using the bioactivity-guided separation protocol and spectroscopic analysis. F1 was obtained from C. insularimontanum for the first time, and F2 was isolated for the first time from natural resources. Both F1 and F2 could inhibit the production of nitric oxide (NO), and the IC₅₀ values were 14.0 μM and 43.8 μM, RAW 264.7 cells after induction of lipopolysaccharide. Furthermore, F1 and F2 also revealed significant inhabitation effects on iNOS and COX-2 protein expression. The anti-inflammation activity of F1 and F2 was different from the common pathway of inhibiting NF-κB. Both of them could inhibit the production of NO and PGE₂ by directly inhibiting the AP-1 (c-Jun) protein and then inhibiting the downstream iNOS and COX-2. Although both F1 and F2 possessed significant anti-inflammatory activity, the activity of F1 was better than F2. Through molecular docking simulation analysis, the results show that F1 and F2 interact with AP-1, inhibit the binding of AP-1 to DNA, and cause AP-1 to fail to transcribe the related factors of inflammation. The binding ability of AP-1 and F1 was stronger than F2, and that is the reason why F1 exhibited better activities in both downstream proteins and inflammatory cytokines. Based on the results obtained in this study, the essential oil and F1 and F2 isolated from C. insularimontanum leaves have good anti-inflammatory activities, and it is expected to be used as a reference for the development of medical care products in the future.

Chemical constituents and bioactivity of Formosan lauraceous plants

Taiwan is rich in lauraceous plants. A review of 197 references based on the chemical analysis and bioactivity of indigenous lauraceous plants carried out by native scientists from 1963 to 2014 has been compiled. About 303 new compounds and thousands of known compounds comprising alkaloids and non-alkaloids with diverse structures have been isolated or identified from indigenous plants belonging to the 11 lauraceous genera. The volatile components, however, have been excluded from this review. This review provides an overview of the past efforts of Taiwan scientists working on secondary metabolites and their bioactivity in native lauraceous plants. The potential of lauraceous plants worthy of further study is also noted. The contents will be helpful for the chemotaxonomy of Lauraceae and be of value for the development of native Formosan lauraceous plants.

A novel homosesquiterpenoid from the stems of Cinnamomum burmanii

A novel homosesquiterpenoid, burmanol (1), along with 16 known compounds, including one triterpenoid, one quinol, two chlorophylls, two coumarins, two steroids, three lignans and five benzenoids were obtained from the stems of Cinnamomum burmanii (Lauraceae). The structures of these compounds were determined on the basis of spectroscopic analysis.

A new benzodioxocinone from the leaves of Cinnamomum tenuifolium

Investigation of the leaves' extract of Cinnamomum tenuifolium (Lauraceae) led to the isolation of one novel benzodioxocinone, 2,3-dihydro-6,6-dimethylbenzo-[b][1,5]dioxocin-4(6 H)-one (1). The structure was determined through in-depth spectroscopic and mass-spectrometric analyses. The antioxidant potential was evaluated using the following in vitro method: scavenging of 1,1-diphenyl-2-picrylhydrazyl radical. We also detected the anti-proliferative effect of 1 on human oral cancer cells and its IC(50) is 107.7 µM.