| Summary: | Nine sesquiterpenes, including eight pentalenenes (<b>1</b>–<b>8</b>) and one bolinane derivative (<b>9</b>), were isolated from the culture broth of a marine-derived actinobacterium <i>Streptomyces qinglanensis</i> 213DD-006. Among them, <b>1</b>, <b>4</b>, <b>7</b>, and <b>9</b> were new compounds. Their planar structures were determined by spectroscopic methods (HRMS, 1D, and 2D NMR), and the absolute configuration was established by biosynthesis consideration and electronic-circular-dichroism (ECD) calculations. All the isolated compounds were screened for their cytotoxicity against six solid and seven blood cancer cell lines. Compounds <b>4</b>–<b>6</b> and <b>8</b> showed a moderate activity against all of the tested solid cell lines, with GI<sub>50</sub> values ranging from 1.97 to 3.46 µM.
|
|---|