New Dammarane-Type Triterpenoid Saponins from <i>Panax notoginseng</i> Leaves and Their Nitric Oxide Inhibitory Activities

• Main Authors: Fan Sun, Jingya Ruan, Wei Zhao, Ying Zhang, Guilin Xiang, Jiejing Yan, Mimi Hao, Lijie Wu, Yi Zhang, Tao Wang
• Format: Article
• Language: English
• Published: MDPI AG 2019-12-01
• Series: Molecules
• Subjects: <i>panax notoginseng</i> leaves; dammarane-type triterpenoid saponins; notoginsenosides nl; raw 246.7 cell; anti-inflammatory activity
• Online Access: https://www.mdpi.com/1420-3049/25/1/139

Inflammation is a very common and important pathological process that can cause many diseases. The discovery of anti-inflammatory drugs and the treatment of inflammation are particularly essential. Dammarane-type triterpenoid saponins (PNS) were demonstrated to show anti-inflammatory effects in the leaves of <i>Panax notoginseng</i>. Chromatographies and spectral analysis methods were combined to isolate and identify PNS. Moreover, the nitric oxide (NO) inhibitory activities of all compounds were examined in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. As a result, eleven new dammarane-type triterpenoid saponins, notoginsenosides NL-A₁&#8722;NL-A₄ (<b>1</b>&#8722;<b>4</b>), NL-B₁&#8722;NL-B₃ (<b>5</b>&#8722;<b>7</b>), NL-C₁&#8722;NL-C₃ (<b>8</b>&#8722;<b>10</b>), and NL-D (<b>11</b>) were isolated, and their structures were identified by using various spectrometric techniques and chemical reactions. Among them, compounds <b>4</b> and <b>11</b> were characterized by the malonyl substitution at 3-position. The 3-malonyl substituted dammarane-type terpennoids were first obtained from natural products. In addition, compounds <b>1</b>, <b>2</b>, <b>5</b>, <b>6</b>, and <b>8</b>&#8722;<b>10</b> were found to play an important role in suppressing NO levels at 50 &#956;M, without cytotoxicity. All inhibitory activities were found to be dose-dependent.