Six new tirucallane-type triterpenoids, named munropenes A–F (1–6), were extracted from the whole plants of Munronia pinnata 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 (1–6) were established using carbon–proton spin-coupling constants (^2,3J_C,H) and inter-proton spin-coupling constants (³J_H,H). Furthermore, the absolute configurations of munropenes A–F (1–6) 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 (1, 2, 4, and 6) inhibited proliferation in the HCT116 cell line with IC₅₀ values of 40.90, 19.13, 17.66, and 32.62 µM, respectively.

Global climate change is reshaping the habitat suitability of medicinal plants, potentially compromising their phytochemical integrity and therapeutic efficacy. Siraitia grosvenorii, an edible medicinal plant in China, has expanded its cultivation area into non-native habitats. Therefore, this study analyzed the suitable cultivation region under different periods in China based on the MaxEnt model, and 59 samples were investigated to explore the interrelationships between chemical constituents and climatic variables through multivariate statistical analysis, which will contribute to meeting the sustainable supply of high-quality S. grosvenorii. We discovered that appropriate habitats cover an area of 58.76 × 10⁴ km², mainly in the southern parts of China. Under future climate conditions, suitable habitats decrease and shift to the northeast along the current habitats. The precipitation levels of the driest month, precipitation seasonality, and temperature seasonality were crucial for its distribution. Furthermore, 11 elements were identified to distinguish samples from different suitable areas through orthogonal partial least squares discriminant analysis. Correlation analysis revealed a strong association between chemical constituents and various climatic factors. This study offers valuable insights into potential S. grosvenorii cultivation areas in China and provides reference indicators for quality evaluation.

Munronia pinnata (Meliaceae), a medicinal plant used in Zhuang traditional medicine, is recognized as a rich source of structurally diverse limonoids. In our continuing investigation of bioactive constituents from Guangxi medicinal plants, four new prieurianin-type limonoids, munropins G–J (1–4), were isolated from their aerial parts. Their structures were determined through comprehensive spectroscopic analysis, including nuclear magnetic resonance and high-resolution mass spectrometry, and further supported by quantum chemical calculations for electronic circular dichroism and statistical probability analysis. Munropins G (1) and H (2) feature an unprecedented C-12 β-D-glucosylated α-methyl-2′-hydroxypentanoate side chain and a C-17 β-substituted furan ring, with 1 being the 7-O-acetyl derivative of 2. Munropins I (3) and J (4) possess a formyl group at C-11, a 3-methyl-2-hydroxypentanoate ester at C-12, and a C-17 γ-hydroxy-α,β-unsaturated γ-lactone unit (21-hydroxy for 3, 23-hydroxy for 4), each existing as an equilibrating mixture of C-21 epimers—a phenomenon observed for the first time within a prieurianin-type framework. The absolute configurations of 1 and 2 were established by quantum chemical electronic circular dichroism calculations, while those of 3 and 4 remain to be assigned. All compounds were evaluated for cytotoxicity against human lung (A549), liver (HepG2), breast (MCF-7), and colon (HCT116) cancer cell lines and for anti-inflammatory activity in lipopolysaccharide-induced RAW 264.7 murine macrophages, but none exhibited significant effects at a concentration of 80 μM. This study expands the chemical diversity of Munronia limonoids and provides new molecular scaffolds for future structure–activity relationship investigations and chemotaxonomic markers for the Meliaceae family.