Ten jatrophane diterpenoids were isolated from the whole plant Euphorbia peplus Linn. including seven new ones, named euphjatrophanes A-G (labeled compounds 1, 2, 4–8). Their structures were elucidated with a combination of spectroscopic and single-crystal X-ray crystallography, enabling the identification of compounds 3, 9, and 10 as the previously published euphpepluones G, K, and L, respectively. All compounds were evaluated for their bioactivity with flow cytometry in assays of autophagic flux in HM Cherry-GFP-LC3 (human microglia cells stably expressing the tandem monomeric mCherry-GFP-tagged LC3) cells. Euphpepluone K (9) significantly activated autophagic flux, an effect that was verified with confocal analysis. Moreover, cellular assays showed that euphpepluone K (9) induced autophagy and inhibited Tau pathology.

Six new C-20 and one new C-19 quassinoids, named perforalactones F-L (1–7), were isolated from twigs of Harrisonia perforata. Spectroscopic and X-ray crystallographic experiments were conducted to identify their structures. Through oxidative degradation of perforalactone B to perforaqussin A, the biogenetic process from C-25 quassinoid to C-20 via Baeyer–Villiger oxidation was proposed. Furthermore, the study evaluated the anti-Parkinson’s disease potential of these C-20 quassinoids for the first time on 6-OHDA-induced PC12 cells and a Drosophila Parkinson’s disease model of PINK1^B9. Perforalactones G and I (2 and 4) showed a 10–15% increase in cell viability of the model cells at 50 μM, while compounds 2 and 4 (100 μM) significantly improved the climbing ability of PINK1^B9 flies and increased the dopamine level in the brains and ATP content in the thoraces of the flies.

Nine jatrophane diterpenoids were isolated from the whole plant Euphorbia helioscopia, including two new ones, helioscopnins A (1) and B (2). Comprehensive spectroscopic data analysis and ECD calculations elucidated their structures, including absolute configurations. All compounds were evaluated for bioactivity towards autophagic flux by flow cytometry using HM mCherry-GFP-LC3 cells. Compounds 1, 3, 4, 5, 8, and 9 significantly increased autophagic flux. Graphical Abstract

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, characterized by the poorest prognosis, and poses a significant threat to women's health. In this study, we identified two novel prieurianin-type limonoids extracted from Munronia henryi, one of which, named DHL-11, exhibited antitumor activity against TNBC cells. DHL-11 suppressed cell proliferation and migration, induced G2/M cell cycle arrest and apoptosis, and effectively increased the accumulation of reactive oxygen species (ROS) and cellular DNA damage in TNBC cells. Mechanistically, we found that DHL-11 binds to the non-catalytic pocket of IMPDH2 and disrupts the interaction between IMPDH2 and FANCI, leading to the degradation of the IMPDH2 protein. The decrease of IMPDH2 protein reduced guanine synthesis, increased ROS levels, and induced DNA damage. DHL-11 significantly inhibited the growth of breast cancer patient-derived organoids with high IMPDH2 expression. Furthermore, DHL-11 inhibited the growth and metastasis of TNBC xenografts in vivo with favorable biosafety profiles. Our findings highlight the potential of DHL-11 as a novel IMPDH2 degrader for the treatment of IMPDH2-positive TNBC.