Chemical analysis of the chloroform
extract of the aerial parts
of the Algerian plant <i>Pulicaria undulata</i> exhibiting
anti-inflammatory activity resulted in the isolation of 10 new humulene
sesquiterpenoids, <b>1</b>–<b>10</b>, belonging
to the asteriscunolide family of compounds. The structure and relative
configuration have been defined by NMR data, whereas the absolute
configuration has been established by ECD analysis. Compounds <b>1</b>–<b>10</b> include enantiomers of the known
asteriscunolides A–D and tetrahydroasteriscunolide previously
reported from the genera <i>Asteriscus</i> and <i>Nauplius</i>. Compounds <b>1</b> and <b>10</b> showed in vitro anti-inflammatory
activity by inhibiting heat-induced albumin denaturation with IC<sub>50</sub> values of 23.76 and 220.42 μM
