Bibenzyls and lignans from Dendrobium devonianum and their immunosuppressive activities

11 phenolic compounds, including two new bibenzyl-phenylpropane hybrids, dendrophenenes A-B (1-2), were isolated from the cultivated Dendrobium devonianum Paxt. Compound 1 is a rare bibenzyl-phenylpropane hybrid with a coumarin core. All structures were elucidated by extensive spectroscopic analysis and chemical transformation. Bioassays on the Con A and LPS-induced proliferation of mouse splenic lymphocytes revealed that compounds 1-3, 5, and 7 were specifically immunosuppressive to T lymphocytes with IC50 values ranging from 0.17 to 7.1 mu M, of which compounds 1 (IC50 = 0.17 mu M) and 3 (IC50 = 1.19 mu M) were potential natural immunosuppressive agents for T lymphocytes with the selectivity indices of 166.5 and 45.6, respectively.

Automated summary

Eleven phenolic compounds, including two new bibenzyl-phenylpropane hybrids, were isolated from cultivated Dendrobium devonianum Paxt. Compound 1, a rare bibenzyl-phenylpropane hybrid with a coumarin core, showed potential as a natural immunosuppressive agent for T lymphocytes.