Bioactive Terpenoids from <i>Salvia plebeia</i>: Structures, NO Inhibitory Activities, and Interactions with iNOS

A phytochemical investigation to obtain new NO inhibitors resulted in the identification of six new (<b>1</b>–<b>6</b>) and four known (<b>7</b>–<b>10</b>) terpenoids from <i>Salvia plebeia</i>. Compounds <b>1</b> and <b>2</b> are new diterpenoids, <b>3</b>–<b>5</b> are new meroditerpenoids, <b>6</b>–<b>9</b> are sesquiterpenoids, and <b>10</b> is a known meroditerpenoid. The structures of these isolates were determined by routine NMR experiments and X-ray diffraction, as well as the electronic circular dichroism spectra. Compounds <b>1</b>–<b>4</b> are diterpenoids carrying an oxygen bridge, and <b>6</b> is a rare copane-type sesquiterpenoid with a bridged tricyclic framework. The isolates inhibited NO generation induced by lipopolysaccharide in BV-2 cells. The possible mechanism of NO inhibition of some bioactive compounds was also investigated using molecular docking, which revealed interactions of bioactive compounds with the iNOS protein

Bioactive Terpenoids from <i>Salvia plebeia</i>: Structures, NO Inhibitory Activities, and Interactions with iNOS

A phytochemical investigation to obtain new NO inhibitors resulted in the identification of six new (<b>1</b>–<b>6</b>) and four known (<b>7</b>–<b>10</b>) terpenoids from <i>Salvia plebeia</i>. Compounds <b>1</b> and <b>2</b> are new diterpenoids, <b>3</b>–<b>5</b> are new meroditerpenoids, <b>6</b>–<b>9</b> are sesquiterpenoids, and <b>10</b> is a known meroditerpenoid. The structures of these isolates were determined by routine NMR experiments and X-ray diffraction, as well as the electronic circular dichroism spectra. Compounds <b>1</b>–<b>4</b> are diterpenoids carrying an oxygen bridge, and <b>6</b> is a rare copane-type sesquiterpenoid with a bridged tricyclic framework. The isolates inhibited NO generation induced by lipopolysaccharide in BV-2 cells. The possible mechanism of NO inhibition of some bioactive compounds was also investigated using molecular docking, which revealed interactions of bioactive compounds with the iNOS protein