Synthesis ofAristotelia-Type Alkaloids. Part III. (3R,4R)- and (3R,4S)-1-p-menthene-3,8-diol and the corresponding racemates: Preparation and assignment of configuration

Three new guaiane-type sesquiterpenoids and a monoterpenoid from Litsea lancilimba Merr

Three undescribed guaiane-type sesquiterpenes (1-3), and a monoterpenoid (4) along with eleven known compounds (5 - 15) were isolated from the crude extract of Litsea lancilimba Merr. The structures of all the isolated compounds were extensively elucidated on the basis of comprehensive spectroscopic techniques (HRESIMS, 1 D NMR, and 2 D NMR). Their relative and absolute configurations were comprehensively established by NOESY spectroscopy, circular dichroism (ECD) and the calculated ECD analysis. All the isolates were tested for anti-inflammatory activity by measuring the amount of nitric oxide production. Amongst tested compounds, compounds 1 - 3 exhibited moderate inhibitory activities against the production of nitric oxide with IC₅₀ value of 35.5, 32.1, 46.7 μM in RAW264.7 cells stimulated by LPS, respectively.