Four new pyrrolidone substituted bibenzyls, dusuanlansins A-D (1-4) were isolated from the pseudo bulbs of Pleione bulbocodioides, along with 19 known compounds (5-23). Compounds 1-4 are two pairs of epimers of pyrrolidone substituted bibenzyls, which were separated successfully by a Chiralcel OD-RH C18 column. Their absolute configurations were elucidated by calculated ECD. Biological investigations showed that compounds 5 and 7 exhibited potent anti-inflammatory activities on LPS-stimulated NO production in BV-2 microglial cells, with IC50 values of 2.46 and 3.14μM, respectively.
Keywords: Anti-inflammatory activity; Bibenzyl; ECD; Epimer; Pleione bulbocodioides.
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