An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

•66 ent-clerodane diterpenoids, including 52 new compounds, were isolated from Callicarpa arborea.•Their bioactivity against pyroptosis were evaluated, and the typical α,β-unsaturated-γ-hemiacetal lactone ring was a key active segments from SAR analysis.•Compound 1 showed potent inhibitory activity against pyroptosis by blocking NLRP3 inflammasome activation.•Compound 1 treatment markedly reduced infiltration of CD11b+F4/80+ macrophages into lung and protected lung injury in LPS- induced septic mice.

A spiro ent-clerodane homodimer with a rare 6/6/6/6/6-fused pentacyclic scaffold, spiroarborin (1), together with four new monomeric analogues (2-5), were isolated from Callicarpa arborea. Their structures were elucidated by comprehensive spectroscopic data analysis, quantum-chemical calculations, and X-ray diffraction. A plausible biosynthetic pathway of 1 was proposed, and a biomimetic synthesis of its derivative was accomplished. Compound 1 showed a potent inhibitory effect by directly binding to the YEATS domain of the 11-19 leukemia (ENL) protein with an IC50 value of 7.3 μM. This gave a KD value of 5.0 μM, as recorded by a surface plasmon resonance binding assay.

Candida albicans is a ubiquitous clinical fungal pathogen. Prolonged use of the first-line antifungal agent fluconazole (FLC) has intensified fungal resistance and limited its effectiveness for the treatment of fungal infections. The combined administration of drugs has been extensively studied and applied. SWL-1 is a lignin compound derived from the Traditional Chinese Medicine Schisandra chinensis. In this study, we show that SWL-1 reverses resistance to fluconazole in C. albicans when delivered in combination, with a sharp decrease in the IC50 of fluconazole from >200 to 3.74 ± 0.25 μg/ml, and also reverses the fluconazole resistance of C. albicans in vitro, with IC50 from >200 to 5.3 ± 0.3 μg/ml. Moreover, killing kinetics curves confirmed the synergistic effects of fluconazole and SWL-1. Intriguingly, when SWL-1 was administered in combination with fluconazole in a mouse model of systemic infection, the mortality of mice was markedly decreased and fungal colonization of the kidney and lung was reduced. Further mechanistic studies showed that SWL-1 significantly decreased intracellular adenosine 5’-triphosphate (ATP) levels and inhibited the function of the efflux pump responsible for fluconazole resistance of C. albicans. Proteomic analysis of the effects of SWL-1 on C. albicans showed that several enzymes were downregulated in the glycolytic pathway. We speculate that SWL-1 significantly decreased intracellular ATP levels by hindering the glycolysis, and the function of the efflux pump responsible for fluconazole resistance of C. albicans was inhibited, resulting in restoration of fluconazole sensitivity in FLC-resistant C. albicans. This study clarified the effects and mechanism of SWL-1 on C. albicans in vitro and in vivo, providing a novel approach to overcoming fungal resistance.

Fungal drug resistance is a major health threat, and reports of clinical resistance worldwide are becoming increasingly common. In a research program to discover new molecules to help overcome this problem, 14 new lanostane-type triterpenoids, gibbosicolids A-G (2-8) and gibbosic acids I-O (9-15), were isolated from the fruiting bodies of Ganoderma gibbosum, along with seven known triterpenoid derivatives. These compounds featured high levels of oxidation, epimerization, and γ-lactonization. Structures were elucidated by comprehensive spectroscopic analyses and HRMS data. Absolute configurations were assigned based on quantum chemical calculations, including calculated chemical shift with DP4+ analysis, coupling constants, and electronic circular dichroism (ECD) methods. Results show that the calculated NMR with DP4+ analysis could not reliably establish the overall spatial configuration of molecules possessing independent and free-rotational stereoclusters. All these compounds significantly increased the sensitivity of fluconazole (FLC)-resistant C. albicans to FLC. Compounds 2, 5, 9, 12, 16, 17, and 21 exhibited strong antifungal activity against FLC-resistant C. albicans when combined with FLC, with MIC50 values ranging from 3.8 to 8.8 μg/mL.