Fenofibrate Recognition and Gq Protein Coupling Mechanisms of the Human Cannabinoid Receptor CB1.

The G-protein-coupled human cannabinoid receptor 1 (CB1) is a promising therapeutic target for pain management, inflammation, obesity, and substance abuse disorders. The structures of CB1-Gi complexes in synthetic agonist-bound forms have been resolved to date. However, the commercial drug recognition and Gq coupling mechanisms of CB1 remain elusive. Herein, the cryo-electron microscopy (cryo-EM) structure of CB1-Gq complex, in fenofibrate-bound form, at near-atomic resolution, is reported. The structure elucidates the delicate mechanisms of the precise fenofibrate recognition and Gq protein coupling by CB1 and will facilitate future drug discovery and design.

Discovery of Natural Ah Receptor Antagonists from Salvia miltiorrhiza Bunge and Synthesis of Analogs for Tumor Immunotherapy.

IDO/TDO/Kyn/AhR signaling plays a crucial role in regulating innate and adaptive immunity, and targeting Ah receptor (AhR) inhibition can potentially redirect immune cells toward an antitumoral phenotype. Therefore, AhR is an attractive drug target for novel small molecule cancer immunotherapies. In this study, natural products tanshinolic A-D (1-4), the first adducts composed of ortho-naphthoquinone-type tanshinone and phenolic acid featuring a unique 1,4-benzodioxan hemiacetal structure, were isolated and characterized from the roots of Salvia miltiorrhiza Bunge. Luciferase reporter gene assay revealed that these adducts exhibited significant AhR inhibitory activity. A linear strategy was developed to construct a cis-3,4-disubstituted 1,4-benzodioxan hemiacetal structure. Encouragingly, in both in vitro and in vivo experiments, (±)-13e demonstrated the ability to inhibit tumor cell proliferation, promote INF-γ secretion in CD8+ T cells, and inhibit PD-1/PD-L1 signal transduction, which could exert tumor inhibition properties by inhibiting AhR activity, positioning it as a promising candidate for tumor immunotherapy.

The tanshinones from the plant of Salvia miltiorrhiza.

Six undescribed tanshinones, (+)-2-Cl-tanshindiol C (1), (-)-2-Cl-tanshindiol C (2), (+)-tanshinoic acid D (3), (-)-tanshinoic acid D (4), (-)-tanshinoic acid E (5), and (+)-tanshinoic acid E (6), were isolated from the rhizome of Salvia miltiorrhiza Bunge. Their structures were elucidated based on the spectroscopic data (UV, IR, HR-ESI-MS, and NMR). The bioactive assays of all these compounds for the antioxidant activities in cardiomyocytes upon hypoxia stimulation were evaluated. The results suggested that compounds 5 and 6 exhibited good antioxidant activities in cardiomyocytes and the cell survival rates were 46.3% and 57.9% (10-5 mol/L), respectively.

Two dimers generated by lithospermic decarboxylation coupling from Danshen.

To further reveal the active ingredients of Danshen, we systematically studied its chemical components and obtained two new lithospermic acid derivatives (compounds 1 and 2) together with five known phenylpropionic acids (compounds 3-7) from the dried rhizomes of Salvia miltiorrhiza. The structures of the two new compounds were determined by multiple spectral analyses (UV, IR, HR-ESI-MS, NMR, and ECD). In addition, the absolute configurations were established by chiral analysis and calculated and experimental circular dichroism spectra. Biological research indicated that compound 1 could significantly inhibit the proliferation of isoproterenol (ISO)-treated cardiac fibroblasts (AC16 cells), and MMP9 was found to be the most likely target of compound 1. The protein expression and mRNA levels of MMP9 were increased in ISO-induced AC16 cells, which could be reversed by treatment with compound 1. Furthermore, this treatment could alleviate the migration and activation of ISO-induced cardiac fibroblasts.

The phenolic acids from the plant of Salvia miltiorrhiza.

Seven new phenolic acids, 7, 8-epiblechnic acid (1), 8-epiblechnic acid 9-ehthyl-9'-methyl ester (2), 9'-ehyl-isolithospermate (3), 9''-methyl-isolithospermate (4), 9'-ethyl-9''-methyl-isolithospermate (5), 9', 9''-dimethyl-isolithospermate (6), sebesteniod E (7), were isolated from the roots of Salvia miltiorrhiza. Their structures were elucidated by detailed spectroscopic means including UV, IR, HRESIMS, and NMR data spectra. The bioactive assays of compounds 1-7 against neuroprotection activities were determined. The results suggested that compound 4 exhibited a moderate glutamate-induced neuroprotective activity and the cell survival rate was 24.0% (10-5 mol/L), while compound 2 showed weak activity (survival rate: 7.58%, 10-5 mol/L), using PHPB (survival rate: 7.56%, 10-5 mol/L) as positive control.

Three 11,12-seco-tanshinone derivatives from the rhizomes of Salvia miltiorrhiza.

Three new compounds named tanshinoic acid A (1), tanshinoic acid B (2), and tanshinoic acid C (3) were isolated from the rhizomes of Salvia miltiorrhiza, together with two known compounds methyl salvianolate A (4) and methyl salvianolate C (5). Their structures were determined on the basis of spectroscopic data (UV, IR, HRESIMS, 1 D and 2 D NMR). The in vitro assay indicated that 4 and 5 could improve the survived rate of cells on oxygen glucose deprivation (OGD) induced neurons damage model and glutamate-induced neurons damage model at a concentration of 10 µM. [Formula: see text].