Search

Eighteen new lanostane-type triterpenoids, namely leucocontextins A-R (1-18) were isolated from the fruiting bodies of Ganoderma leucocontextum. Their structures were established by 1D and 2D NMR data in conjunction with HRESIMS/HREIMS, X-ray single crystal diffraction analysis. Compound 18 exhibited weak cytotoxicity against K562 and MCF-7 cell lines with IC50 of 20-30 μM.

Ten new highly oxygenated lanostane triterpenoids, stereinones A–J (1–10), were isolated from the fruiting bodies of the basidiomycete Stereum sp. Compounds 3 and 4 are structurally characterized as intact lanostane-type triterpenoids containing unusual 1,2-diketone functionality at C-11 and C-12, while compound 10 is a 24-methylene-lanostane. The structures of these new compounds were established based on detailed 1D and 2D NMR spectroscopic analyses, along with quantum chemical NMR calculations. All isolates were evaluated for their in vitro cytotoxicities against five human tumor cell lines (including HL-60, A-549, SMMC-7721, MCF-7, and SW480 cell lines). Compound 4 showed moderate cytotoxic activities against tumor cell lines SMMC-7721 and SW480 with IC50 values of 9.1 and 9.8 μM, respectively.

Ochracines A-E, five previously undescribed norsesquiterpenes featured by unusual scaffolds biogenetically related to chamigrane, were isolated from the cultures of Steccherinum ochraceum. Ochracines A (1) and B (2) represent the first examples of norsesquiterpenes with an unprecedented 1,2-6,7-diseco-1,8-cyclochamigrane scaffold. Ochracines C-D (3–5) possess an unusual 1,2-6,7-diseco-chamigrane skeleton. Their structures were elucidated by analysis of spectroscopic data. The absolute configuration of ochracine A (1), and the relative configuration of ochracine B (2) were determined by ECD and/or NMR calculations. The biosynthetic pathways for the norsesquiterpenes were proposed. All isolates were evaluated for their cytotoxicity against the five human cancer cell lines HL-60, SMMC-7721, A549, MCF-7, and SW-480.