Find in Library

Six new tirucallane-type triterpenoids, named munropenes A–F (<b>1</b>–<b>6</b>), were extracted from the whole plants of <i>Munronia pinnata</i> using a water extraction method. Their chemical structures were determined based on detailed spectroscopic data. The relative configurations of the acyclic structures at C-17 of munropenes A–F (<b>1</b>–<b>6</b>) were established using carbon–proton spin-coupling constants (^2,3<i>J</i>_C,H) and inter-proton spin-coupling constants (³<i>J</i>_H,H). Furthermore, the absolute configurations of munropenes A–F (<b>1</b>–<b>6</b>) were determined through high-performance liquid chromatography (HPLC), single-crystal X-ray diffraction, and electronic circular dichroism (ECD) analyses. The antiproliferative effects of munropenes A–F were evaluated in five tumor cell lines: HCT116, A549, HepG2, MCF7, and MDAMB. Munropenes A, B, D, and F (<b>1</b>, <b>2</b>, <b>4</b>, and <b>6</b>) inhibited proliferation in the HCT116 cell line with IC₅₀ values of 40.90, 19.13, 17.66, and 32.62 µM, respectively.