Chemical constituents from cultures of the basidiomycete Trichaptum pargamenum

Ten undescribed cadinane-type sesquiterpenoids from Eupatorium chinense

Ten undescribed cadinane-type sesquiterpenes (1-10) were isolated from the whole plant of Eupatorium chinense. Their planar structures were mainly elucidated by extensive analysis of spectroscopic data and DFT NMR calculations. The absolute configurations of 1, 2, and 3 were determined by TDDFT ECD calculations while those of compounds 4-7 and 9 were confirmed by single crystal X-ray diffraction experiments. Compounds 2 and 3 are a pair of C-10 epimers, compounds 4 and 5 a pair of C-1 epimers, and compounds 9 and 10 a pair of compounds isomerized at both C-1 and C-10. A possible biosynthetic pathway for these new sesquiterpenes was proposed.

Plant-like cadinane sesquiterpenes from an actinobacterial mangrove endophyte

Cadinanes are typical plant sesquiterpenes with a broad range of biological functions. We report the isolation of three cadinanes (1-3) from a bacterial endophyte (Streptomyces sp.) of the mangrove plant Bruguiera gymnorrhiza. The structures of two new cadinenes, (+)-11-hydroxy-epicubenol (1) and (+)-12-hydroxy-epicubenol (2) were elucidated by nuclear magnetic resonance (NMR) and mass spectrometry. The bacterial product (+)-11-hydroxy-epicubenol was elucidated to be an enantiomer of the plant product pubinernoid C. (+)-12-Hydroxy-epicubenol was established as a diastereomer of the basidiomycete product trichapargin A. In addition, a crystal structure analysis corroborated the structure and configuration of 5,11-epoxy-10-cadinanol (3), a cadinane cycloether initially described as a natural product from liverwort. The discovery of oxygenated cadinanes from a bacterial endophyte may set the basis for the production of cadinanes by bacterial fermentation.

Two new cadinane-type sesquiterpenes from cultures of the basidiomycete Trichaptum pargamenum

Two new cadinane-type sesquiterpenes, trichapargins A (1) and B (2), were isolated from cultures of the basidiomycete Trichaptum pargamenum. Their structures were elucidated on the basis of extensive spectroscopic methods. Trichapargin A showed weak activity to SW480 with an IC₅₀ value of 24.8 μM.

Isolation and absolute configurations of diastereomers of 8α-hydroxy-T-muurolol and (1α,6β,7β)-cadinane-4-en-8α,10α-diol from Chimonanthus salicifolius

Phytochemical investigation of the aerial parts of Chimonanthus salicifolius resulted in the isolation of two sesquiterpenoids, 8α-hydroxy-T-muurolol and (1α,6β,7β)-cadinane-4-en-8α,10α-diol, together with 13 known compounds. The 15 structures were established by means of 1D and 2D NMR spectroscopy. The relative and absolute configurations of 8α-hydroxy-T-muurolol and 8α,11-elemodiol were achieved by NOESY experiments and X-ray crystallography using CuKα radiation. 8α-hydroxy-T-muurolol and (1α,6β,7β)-cadinane-4-en-8α,10α-diol showed immunosuppressive activities in a dose-dependent manner.

Steroids and Sesquiterpenes From Cultures of the Fungus Phellinus igniarius

Two new steroids, 3α,17α,19,20-tetrahydroxy-4α-methylpregn-8-ene (1) and 3α,12α,17α,20-tetrahydroxy-4α-methylpregn-8-ene (2) and three new sesquiterpenoids, 12-hydroxy-α-cadinol (3), 3α,12-dihydroxy-δ-cadinol (4), and 3α,6α-dihydroxyspiroax-4-ene (5), have been isolated from cultures of the fungus Phellinus igniarius. Their structures were characterized based on extensive spectroscopic data. In preliminary in vitro assays, compounds 3 and 4 exhibited the vascular-activities against phenylephrine-induced vasoconstriction with the relaxing rates of 11.0 % and 7.0 % at 3 × 10-4 M, respectively.