Two new chemical constituents fromDaphne odoraThunb. var.marginata

Potential inhibitors of microglial activation from the roots of Wikstroemia lichiangensis W. W. Sm

Research on natural inhibitors of microglial overactivation derived from members of the Wikstroemia genus revealed that the extract of W. lichiangensis W. W. Sm. Has a remarkable inhibitory effect on nitric oxide production in overactivated microglia. In the present study, thirty-four compounds, including five undescribed sesquiterpenoids [wiksdauctins A-B (1-2) and wikscarotins A-C (3-5)] and one undescribed lignan [wikstroeminasin A (8)], were isolated from a 95% EtOH extract of W. lichiangensis roots using bio-guided phytochemical research. The structures of the isolated compounds were elucidated using comprehensive spectroscopic analyses. Furthermore, their anti-neuroinflammatory effects were evaluated in lipopolysaccharide-stimulated BV-2 microglia. Seventeen isolated compounds exhibited stronger inhibitory effects than positive control minocycline (IC₅₀ values of 67.08 ± 1.95 μM), with IC₅₀ values ranging from 7.35 ± 2.51 to 64.49 ± 3.38 μM. The findings of this study imply that the isolated compounds might serve as potential therapeutic agents for neurodegenerative diseases.

Rapid screening of diarylpentanoids from Daphne bholua

Fractionation motivated by biological activity screening and NMR characteristic signals analysis led to the isolation of seventeen diarylpentanoids from the whole plant of Daphne bholua Buch.-Ham. ex D. Don, among which nine compounds were undescribed. Their structures and stereochemistry were determined by comprehensive spectroscopic data, J-based configurational analysis, and quantum chemical calculations. The inhibitory potentials of all isolates against acetylcholinesterase were evaluated in vitro and in silico.

Hexahydroazulene-2(1H)-one Sesquiterpenoids with Bridged Cyclobutane, Oxetane, and Tetrahydrofuran Rings from the Stems of Daphne papyracea with α-Glycosidase Inhibitory Activity

Chemical investigation of an alcoholic extract from the stem of Daphne papyracea ("Xuehuagou") led to the isolation of the tetracyclic sesquiterpenoid daphnepapytone A (1), containing a unique caged skeleton with a cyclobutane ring having three tetrasubstituted chirality centers. Also isolated were new guaiane sesquiterpenoids, namely, daphnepapytones B-H (2-8), and one 1,5-diphenylpentanone 2-hydroxy-5-oxo-daphneone (9), together with 26 known compounds. The cyclic metabolites share a 5-isoprenyl-hexahydroazulene-2(1H)-one skeleton with different substitution patterns and a bridged cyclobutane, oxetane, or tetrahydrofuran ring. The planar structures and relative configuration of the new compounds were elucidated on the basis of spectroscopic analysis aided by DFT ¹³C NMR calculations. The absolute configurations of 1-7 were determined by X-ray single-crystal diffraction or TDDFT-ECD calculations. Daphnepapytones A and C (1 and 3), 2-hydroxy-5-oxodaphneone (9), daphnenone (10), daphneone (11), and 3-methyldaphneolone (12) showed α-glycosidase inhibitory activity, with IC₅₀ values of 159.0, 102.3, 139.3, 43.3, 145.0, and 126.1 μM, respectively.

Synthesis of heterocyclic compounds through nucleophilic phosphine catalysis

Nucleophilic phosphine catalysis is a practical and powerful tool for the synthesis of various heterocyclic compounds with the advantages of environmentally friendly, metal-free, and mild reaction conditions. The present report summarizes the construction of four to eight-membered heterocyclic compounds containing nitrogen, oxygen and sulphur atoms through phosphine-catalyzed intramolecular annulations and intermolecular [2+2], [3+2], [4+1], [3+1+1], [5+1], [4+2], [2+2+2], [3+3], [4+3] and [3+2+3] annulations of electron-deficient alkenes, allenes, alkynes and Morita-Baylis-Hillman carbonates.

Effects of an ethyl acetate extract of Daphne altaica stem bark on the cell cycle, apoptosis and expression of PPARγ in Eca‑109 human esophageal carcinoma cells

Daphne altaica Pall. (D. altaica; Thymelaeaceae) has long been used in traditional Kazakh medicine for the treatment of cancer and respiratory diseases. Previous studies have demonstrated the in vitro anticancer effects of D. altaica extract and its constituents in certain cancer cell lines; however, the underlying molecular mechanisms are not completely understooD. The present study aimed to investigate the molecular mechanisms underlying the activity of an ethyl acetate extract of D. altaica (Da‑Ea) by assessing its effects on cell morphology, cell apoptosis, cell cycle progression and the expression levels of peroxisome proliferator‑activated receptor γ (PPARγ) in Eca‑109 cells. Cell morphology was observed under a phase contrast microscope. Cell apoptosis and cell cycle progression were assessed by flow cytometry following Annexin V/propidium iodide (PI) double staining and PI single staining, respectively. The mRNA and protein expression levels of PPARγ were determined by reverse transcription‑quantitative PCR and western blotting, respectively. Compared with the control group, the percentage of apoptotic cells, cell cycle arrest at S phase and apoptotic morphological cell characteristics were increased in Da‑Ea‑treated Eca‑109 cells. Furthermore, Da‑Ea treatment upregulated the mRNA and protein expression levels of PPARγ compared with the control cells. High‑performance liquid chromatography with diode‑array detection indicated that daphnetin‑7‑O‑β‑D‑glucoside, daphnetin, demethyldaphnoretin‑7‑O‑β‑D‑glucopyranoside and genkwanol A were the main constituents of Da‑Ea. Collectively, the results suggested that Da‑Ea displayed antiproliferative activities in Eca‑109 cells by inducing apoptosis and S phase cell cycle arrest, as well as upregulating PPARγ expression levels.

The genus Daphne: A review of its traditional uses, phytochemistry and pharmacology

The genus Daphne belongs to the Thymeleaceae family and contains over 90 species that are distributed in Asia, Europe and parts of North Africa. The species of the genus Daphne are used in the traditional medicine of China, Tibet, Korea, and the Middle East for the treatment of various conditions. A broad range of studies has shown the significant biological potential of these species as sources of biologically and pharmacologically active compounds. Daphne species are a source of several classes of valuable phytochemicals such as coumarins, flavonoids, lignans, steroids and different classes of terpenes. The phytochemical diversity of this genus is demonstrated by over 350 secondary metabolites isolated from various species. The genus possesses a broad spectrum of biological activities including antibacterial, antifungal, antioxidant, analgesic, anti-inflammatory, cytotoxic, antiviral, abortive and haemostatic effects. A variety of bioactive secondary metabolites found in this genus may have potential use in pharmaceutical, cosmetic and food industries. Thus, species belonging to the genus Daphne can be considered an important source both for the treatment of various disorders, due to the presence of a plethora of bioactive constituents with potent bioactivities, and as possible leads in the discovery and synthesis of new medications.

Discovery of Natural Products as Novel and Potent FXR Antagonists by Virtual Screening

Farnesoid X receptor (FXR) is a member of nuclear receptor family involved in multiple physiological processes through regulating specific target genes. The critical role of FXR as a transcriptional regulator makes it a promising target for diverse diseases, especially those related to metabolic disorders such as diabetes and cholestasis. However, the underlying activation mechanism of FXR is still a blur owing to the absence of proper FXR modulators. To identify potential FXR modulators, an in-house natural product database (NPD) containing over 4,000 compounds was screened by structure-based virtual screening strategy and subsequent hit-based similarity searching method. After the yeast two-hybrid (Y2H) assay, six natural products were identified as FXR antagonists which blocked the CDCA-induced SRC-1 association. The IC₅₀ values of compounds 2a, a diterpene bearing polycyclic skeleton, and 3a, named daphneone with chain scaffold, are as low as 1.29 and 1.79 μM, respectively. Compared to the control compound guggulsterone (IC₅₀ = 6.47 μM), compounds 2a and 3a displayed 5- and 3-fold higher antagonistic activities against FXR, respectively. Remarkably, the two representative compounds shared low topological similarities with other reported FXR antagonists. According to the putative binding poses, the molecular basis of these antagonists against FXR was also elucidated in this report.

Diarylpentanol constituents from the aerial part of Stelleropsis tianschanica

Five diarylpentanol derivatives including two new compounds stellerasme A (1), stellerasme B (2) were isolated from the aerial parts of Stelleropsis tianschanica. Their structures were elucidated by various spectroscopic techniques (UV, IR, MS, CD, 1D and 2D NMR). All compounds were evaluated for their cytotoxicity activity against HeLa and KB cell lines, and compound 1 showed selective activities against HeLa cell line with an IC50 value of 7.4 μM.

A new biflavone glucoside from the roots of Stellera chamaejasme

The present study investigated the chemical constituents of the roots of Stellera chamaejasme (Thymelaeaceae). One new biflavone glucoside (1), along with other thirteen known compounds (2-14), was isolated by repeated column chromatographic methods and their structures were elucidated on the basis of spectral analyses. The cytotoxic activities of selected compounds were evaluated against four human cancer cell lines (A549, BEL-7402, HCT-116, and MDA-MB-231) by the SRB assay method. Compound 9 showed remarkable cytotoxicity against BEL-7402 with IC50 value being 0.65 μg·mL(-1); compounds 7, 8, and 12 exhibited significant cytotoxic activity against A549 with IC50 values being 2.38, 1.57, and 2.35 μg·mL(-1), respectively.

Two new compounds with cytotoxic activity on the human melanoma A375-S2 cells from Daphne giraldii callus cells

Four compounds were isolated from Daphne giraldii callus cells, and their structures were characterized as daphnenone (1), daphnolon (2), R-( - )-1-(4'-hydroxyphenyl)-3-hydroxy-5-phenyl-1,5-pentandione (3), and S-(+)-daphneolone-4'-O-β-d-glucoside (4) on the basis of MS, NMR spectrographic analysis, and chemical methods. All of the four compounds possessed C6-C5-C6 carbon skeleton, and among them, 3 and 4 were two new compounds. In activity screening test, compounds 1, 2, 3, and 4 showed different degrees of cytotoxic activity against the tumor cells of human melanoma A375-S2 by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium hydrobromide method, with IC(50) values of 29.8, 51.0, 41.0, and 150.0 μM, respectively. Furthermore, we found the important target which could explain the cytotoxic mechanism of the four compounds by using autodock 4.0, a structure-guided discovery approach, and the important residues CYS532, GLY534, and SER535 of B-Raf kinase have been discovered.

The therapeutic effects of daphnetin in collagen-induced arthritis involve its regulation of Th17 cells

OBJECTIVES

Daphne odora var. marginata (D. marginata), an aiophyllus arbuscular plant, is one of the traditional Chinese medicines used to treat rheumatoid arthritis. This study investigated the therapeutic effects and mechanisms of daphnetin, an active monomer ingredient derived from D. marginata, on collagen-induced arthritis (CIA) in rats.

METHODS

The effects of daphnetin on joint diseases were assessed by hematoxylin and eosin staining and radiographic and transmission electron microscopy. The protein and mRNA expression levels of T helper (Th)1/Th2/Th17-type cytokines in the spleen were determined by flow cytometry and quantitative real-time PCR.

RESULTS

Our results showed that daphnetin significantly reduced paw swelling and was nontoxic in vivo at the tested doses. Synovial hyperplasia, joint destruction and chondrocyte degeneration in CIA rats were suppressed by daphnetin. Daphnetin treatment also reduced the levels of Th1/Th2/Th17 type cytokines in spleen lymphocytes in CIA rats. Moreover, the expression of Foxp3, which can down-regulate the activity of Th17 cells, was significantly increased in the daphnetin-treated groups.

CONCLUSIONS

These results suggest that daphnetin may have therapeutic effects in down-regulating Th17-type responses in CIA rats. The beneficial effects of daphnetin on CIA may be related to its inhibition of Th17 cell priming and activation.

Sesquiterpene lactones from Ixeris sonchifolia Hance and their cytotoxicities on A549 human non-small cell lung cancer cells

A new sesquiterpene lactone glucoside, 11,13-dihydroixerinoside (1), together with the five known sesquiterpene lactones, ixerinoside (2), ixerin Z (3), 11,13alpha-dihydroixerin Z (4), ixerin Z1 (5), and 3-hydroxydehydroleucodin (6), respectively, were isolated from the whole plants of Ixeris sonchifolia Hance. The compounds were identified by spectral analysis and comparison with spectroscopic data reported in the literatures. When the in vitro cytotoxic activities of compounds 1-6 were evaluated against A549 human non-small cell lung cancer cells, all six compounds exhibited cytotoxic activity against A549 cells, with compounds 2, 3, and 6 showing good activities (inhibitory concentration (IC(50) values < 30 microg/ml) that are comparable with well-established chemotherapeutic drug, 5-fluorouracil.