Discrepancy of the spectral data between adunctin E and the synthetic one

Conarubins A-D: Four Monoterpene-Chalcone Conjugates from Conamomum rubidum and Their Anti-inflammatory and Cytotoxic Activities

Four novel compounds, conarubins A-D (1-4), were isolated from the whole plants of Conamomum rubidum collected in Vietnam. Their structures were elucidated by extensive spectroscopic analyses and by quantum chemical calculations of NMR and ECD. Compounds 1 and 2 were the first examples of monoterpene-monoterpene-chalcone conjugates in nature, whereas compound 4 was an unprecedented monoterpene-substituted chalcone containing a 3,4,5-trioxygenated cyclohexa-2,5-diene-1-one ring. The anti-inflammatory and cytotoxic activities of all isolates were investigated.

Bioactive Components of Fissistigma cupreonitens

Phytochemical investigation of Fissistigma cupreonitens (Annonaceae) led to the isolation of 34 compounds. The chemical structures of all compounds were determined by spectroscopic methods. Among the isolates, compounds 20–27 and 31–34 were reported from this genus for the first time. From the results of the cytotoxicity assay against three human cancer cell lines (NCI-H226, NPC-TW01, and Jurkat E6–1), oxoaporphine compounds oxoxylopine (1), oxocrebanine (3), kuafumine (4) and lysicamine (5), and the flavonoid adunctin E (26) displayed significant cytotoxicity against NCI-H226 cell line, with IC50 values of 8.45, 8.10, 8.54, 12.83 and 12.00 μM, respectively, in comparison with the standard drug, cisplatin with IC50 of 13.37 μM.

Reaction of 2a,8b-Dihydrobenzo[b]cyclobute[d]pyran-3-ones with Dimethylsulfoxonium Methylide

Using dimethylsulfoxonium methylide as the methylene transfer reagent, 2a,8b-dihydrobenzo[b]cyclobute[d]pyran-3-ones were converted into 2,2'-biphenol derivatives as major products and dihydrodibenzofurans as minor products. The reaction mechanism was extrapolated from a deuteration experiment with CD2=S(O)(CD3)2.