Novel Bis-Artemisinin-Phloroglucinol hybrid molecules with dual anticancer and immunomodulatory Activities: Synthesis and evaluation.

Bis-(10-deoxydihydroartemisinin)-phloroglucinol (9), has been synthesized in a one-step reaction and has demonstrated strong inhibition to cancer cell proliferation and immunosuppressive activity. The structure modification of the compound reduced its cytotoxicity, and among the analogs, bis-(10-deoxydihydroartemisinin)-phloroglucinol phenyl decanoate (16) showed significant reduction of ear swelling in a mouse model for DNFB-induced delayed-type hypersensitivity without observable toxicity in a dose-dependent manner.

Dihydroartemisinin-ursodeoxycholic acid conjugate is a potential treatment agent for inflammatory bowel disease.

BACKGROUND: A novel artemisinin derivative, dihydroartemisinin-ursodeoxycholic acid conjugate (4), was found to exhibit strong immunosuppressive activity. Various methods were used to evaluate the immunosuppressive activity and mechanism of action of the compound to explore its potential applications. METHODS: T cell proliferation, mixed lymphocyte reaction (MLR), and Th1/Th17 differentiation assays were used to evaluate the immunosuppressive activity of the compound. Differentially expressed genes from RNA sequencing were analysed with Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, while enriched signalling pathways were further validated by western blotting (WB). In vivo efficacy was validated with delayed-type hypersensitivity (DTH) mouse models and dextran sodium sulphate (DSS)-induced inflammatory bowel disease (IBD) mouse model. RESULTS: Compound 4 inhibited concanavalin A -induced mouse splenic T cell proliferation (IC50 = 15 nM) and anti-CD3/CD28-induced human primary T cell proliferation (IC50 = 30 nM) while also reducing the secretion of hIFN-γ. Compound 4 exhibited similar inhibitory activity in MLR assay. Compound 4 dose-dependently inhibited human Th1/Th17 differentiation. The KEGG pathway enrichment analysis indicated that the genes related to T cell activation signalling pathways PI3K-AKT, MAPK, and NF-κB were significantly enriched. WB confirmed that compound 4 inhibited the AKT/MAPK and NF-κB signalling pathways. Compound 4 dose-dependently inhibited ear and foot pad swelling in DTH mouse models. In the DSS-induced IBD mouse model, compound 4 significantly decreased the disease activity index and colon density, and inhibited splenomegaly of the mice. CONCLUSION: The in vitro and in vivo results indicated that compound 4 has the potential to be developed into an anti-IBD drug.

Study on the structure-activity relationship of dihydroartemisinin derivatives: Discovery, synthesis, and biological evaluation of dihydroartemisinin-bile acid conjugates as potential anticancer agents.

A series of dihydroartemisinin derivatives was synthesized, and their anti-proliferation activity against cancer cells was evaluated. Structure-activity relationship studies led to the discovery of dihydroartemisinin-bile acid conjugates that exhibit broad-spectrum anti-proliferation activities. Among them, the dihydroartemisinin-ursodeoxycholic acid conjugate (49) was the most potent, with IC50 values between 0.04 and 0.96 µM when tested to determine its inhibitory properties against 15 various cancer cell lines. In vivo experiments showed that compound 49 effectively suppressed tumor growth in an A549 cell xenograft model at the dosage of 10 mg/kg body weight and in Lewis lung cancer cell transplant model at the dosage of 12 mg/kg body weight.

Synthesis and in vitro antibacterial activity of new aminothiazole-oximepiperidone cephalosporins.

Four new aminothiazole-oximepiperidone cephalosporins (10a-10d) were synthesized, with their in vitro antibacterial activities against hospital isolated Gram-negative bacteria assessed. The results showed that compounds 10a-10d effectively inhibit a variety of Gram-negative bacteria. Compound 10a was the most potent compound, with comparable activity as ceftazidime. The combination of compound 10a and Avibactam was very active against almost all bacteria tested, which including multidrug resistant K. pneumoniae and A. baumannii. Compared to Avycaz, this combination is more potent against ESBL producing K. pneumoniae. Thus, the combination of 10a and Avibactam is of interest for further studies.

Studies on the stereoselective synthesis and immunosuppressive activity of dihydroartemisinin-O-glycoside derivatives.

Eight new dihydroartemisinin-O-glycosides were synthesized with their relative configurations were determined based on NMR spectrum. In vitro immunosuppressive assay showed that 10α-dihydroartemisinin-ß-O-d-mannoside (19a) demonstrate 88% inhibition towards T cells proliferation and 98% reduction in IFN-γ levels in cell media. These results suggest that dihydroartemisinin-O-glycoside as a potential lead for further in vivo evaluation.

A new potent immunosuppressive isoflavanonol from Campylotropis hirtella.

Four new flavonoids were isolated from Campylotropis hirtella and these are a chromone and a 2H-chromene, an isoflavone and an isoflavanonol. The structures of these compounds were elucidated by extensive spectroscopic measurements. All of the compounds were assessed for immunosuppressive activity. Compound 4 showed very strong T lymphocyte suppression activity (IC50: 0.13 µM) and potent B lymphocyte suppression activity (IC50: 0.26 µM). Due to its potent immunosuppressive activity and lower cytotoxicity, further structure-activity studies will be pursued on this compound.

Deaggregators inhibit TNF-α-induced leukocyte adhesion in vitro by breaking up hydrophobic lipophilic interactions.

AIM: Deaggregators (deAgrs) are nontoxic organic molecules that possess the ability to deaggregate simple aggregates formed by hydrophobic lipophilic interactions (HLI). Since HLI-driven organic molecule aggregates may induce leukocyte adhesion, we investigated the influence of deAgrs on TNF-α-mediated leukocyte adhesion in vitro. METHODS: For adhesion studies, vascular endothelial cells or smooth muscle cells monolayers were treated with TNF-α (10 µg/L) and deAgrs for 24 h, followed by addition of monocytes or neutrophils suspension. The non-adherent leukocytes were rinsed, and the number of attached leukocytes was measured using an ELISA plate reader. Simultaneously, fluorescence probes Np-12 and Np-Ch were used to measure the deaggregating efficiencies of these deAgrs. RESULTS: Among the nine deAgrs tested,eight significantly reduced the cell adhesion rates with the order of efficiencies: 260 > 160 > 568 > ZPMOP > R68 > 640 > TB6PMOP > CNS, but TBHQ had no effect. The deAgrs for deaggregating an aggregated probe (Np-12 or Np-Ch) exhibited a similar order of efficiencies: 260 > 160 > 568 > ZPMOP > R68 > 640 > TB6PMOP > CNS > 12-AA > 11-AA > TBHQ. Spearman correlation coefficient analyses indicated that the adherent rates of leukocytes to endothelial cells or smooth muscle cells treated with deAgrs had significantly negative correlation to their deaggregating abilities. CONCLUSION: DeAgrs effectively inhibit TNF-α-mediated leukocyte adhesion in vitro by breaking up hydrophobic lipophilic interactions, thus may be further tested for blocking atherogenesis.

New flavonoids from Campylotropis hirtella with immunosuppressive activity.

In an effort to identify natural compounds with immunosuppressive activity, nine new flavonoids, including one isoflav-3-ene derivative (1), one coumaronochromone (2), two isoflavanones (3, 4), one isoflavone derivative (6), one isoflavone (7), three flavonols (8, 9, 10), as well as one known compound, hydroisoflavone C (5), were isolated from the roots of Campylotropis hirtella. The structures of these compounds were elucidated by extensive spectroscopic measurements. All of the compounds were assessed for immunosuppressive activity. Among the isolates, compound 2 showed good inhibitory activity against mitogen-induced splenocyte proliferation with an IC50 of 0.28 µM and relatively low cytotoxicity.

Ethyl cyanoacetate: a new cyanating agent for the palladium-catalyzed cyanation of aryl halides.

A new Pd-catalyzed cyanation reaction has been discovered using ethyl cyanoacetate as the cyanating reagent. A variety of electron-rich and electron-deficient aryl halides were efficiently converted into their corresponding nitriles in good to excellent yields.

A convenient and efficient one-pot conversion of peimisine into cyclopamine.

A convenient and efficient one-pot synthesis of cyclopamine from peimisine is described. The key steps involve one-pot hydrazination and subsequent Bamford-Stevens reaction. The mild reaction conditions, high overall yield as well as an easy purification indicate this process can potentially be used for the scale-up preparation of cyclopamine.

Flavonoids from the roots of Campylotropis hirtella.

Eight new flavonoids, including three pterocarpene derivatives, hirtellanines C-E, two flavanones, hirtellanines F and G, three isoflavanones, hirtellanines H-J, as well as four known compounds were isolated from the roots of Campylotropis hirtella. The structures of the new compounds were elucidated by spectroscopic analyses, including 2D-NMR techniques. Pharmacological investigation indicated that the new compounds, particularly hirtellanines D and G, possessed potent immunosuppressive activities and low relative cytotoxicities.

[Determination of two bio-active compounds in Campylotropis hirtella (Franch.) Schindl. using reversed-phase high performance liquid chromatography].

A method of reversed-phase high performance liquid chromatography (RP-HPLC) using diode array detection (DAD) was developed for the quantitative determination of 3'-geranyl-5,7,4'-trihydroxyisoflavone (compound 1) and 8,9-dihydroxy-1-methoxy-[6',6'-dimethylpyrano(2',3': 2,3)]pterocarpene (compound 2) in Campylotropis hirtella. The separation and quantification were achieved using an Agilent Zorbax SB-C18 column (250 mm x 4.6 mm, 5 microm), and mobile phases of acetonitrile and 0. 1% formic acid with gradient elution at a flow rate of 1.0 mL/min and 30 degrees C. The calibration curves for compounds 1 and 2 were linear in the ranges of 4.4-13.2 microg and 0.428-1.284 microg, respectively. The recoveries were 99.65% and 99.11% with the relative standard deviations of 1.83% and 2.59% (n=5), respectively. This RP-HPLC-DAD method is rather simple, accurate and convenient. It can be used for the quantitative determination of the active flavonoids in Campylotropis hirtella (Franch.) Schindl.

Isoflavonoids from the roots of Campylotropis hirtella.

From the dried roots of Campylotropis hirtella (Franch.) Schindl., five novel isoflavonoids, 3( S)-7,2',4'-trihydroxy-5,5'-dimethoxy-6-(3-methylbut-2-enyl)-isoflavan ( 1), 3( S)-2',4'-dihydroxy-5,5'-dimethoxy-(6'',6''-dimethylpyrano)-(2'',3'':7,6)-isoflavan ( 2), 3( R)-5,4'-dihydroxy-2'-methoxy-3'-(3-methylbut-2-enyl)-(6'',6''-dimethylpyrano)-(7,6 : 2'',3'')-isoflavanone ( 3), 3( R)-5,4'-dihydroxy-2'-methoxy-(6'',6''-dimethylpyrano)-(7,6: 2'',3'')-isoflavanone ( 4), and 3( R)-5,4'-dihydroxy-7,2'-dimethoxy-6-geranylisoflavanone ( 5) were isolated. The structures of the compounds were elucidated on the basis of spectroscopic analysis. All isolates exhibited good immunosuppressive activities on mitogen-induced splenocyte proliferation, and their cytotoxicity on splenic lymphocytes was also tested.

Geranylated flavonoids from the roots of Campylotropis hirtella and their immunosuppressive activities.

In an effort to identify new immunosuppressive agents from natural sources, 12 new geranylated flavonoids, 5,7,4'-trihydroxy-3'-[7-hydroxy-3,7-dimethyl-2(E)-octenyl]isoflavone (1), a racemate of 5,7,2',4'-tetrahydroxy-3'-[7-hydroxy-3,7-dimethyl-2(E)-octenyl]isoflavanone (2), 2''(S)-5,7-dihydroxy-[2''-methyl-2''-(4-methyl-3-pentenyl)pyrano]-5'',6'':3',4'-isoflavone (3), (2''S,3''R,4''S)-5,7,3'',4''-tetrahydroxy[2''-methyl-2''-(4-methyl-3-pentenyl)pyrano]-5'',6'':3',4'-isoflavone (4), a racemate of 3'-geranyl-5,7,2',4'-tetrahydroxyisoflavanone (5), a racemate of 3'-geranyl-4'-methoxy-5,7,2'-trihydroxyisoflavanone (6), 3'-geranyl-5,7,4',5'-tetrahydroxyisoflavone (8), 3'-geranyl-5,7,2',5'-tetrahydroxyisoflavone (9), 3'-geranyl-4'-methoxy-5,7,2'-trihydroxyisoflavone (10), 2(R),3(R)-3'-geranyl-2,3-trans-5,7,4'-trihydroxyflavonol (12), (2R,3R)-6-methyl-3'-geranyl-2,3-trans-5,7,4'-trihydroxyflavonol (13), and 5,7-dihydroxy-4'-O-geranylisoflavone (14), were isolated from the roots of Campylotropis hirtella (Franch.) Schindl. together with three previously described flavonoids. Their structures were elucidated by spectroscopic measurements, including two-dimensional nuclear magnetic resonance (NMR) techniques. The immunosuppressive effects of these compounds were assessed using mitogen-induced splenocyte proliferation, and the cytotoxicity of the compounds was also examined. The IC50 values of the compounds were found to be in the range of 1.49-61.23 microM for T lymphocyte suppression and 1.16-73.07 microM for B lymphocyte suppression. An analysis of their structure-activity relationships revealed that an isoflavonoid carbon skeleton with a C10 substituent at the C3' position was necessary for the activity. As many of the compounds exhibited good immunosuppressive activities, they may be promising as novel immunosuppressive agents.

[Determination of jervine and veratramine in Veratrum plants using high performance liquid chromatography coupled with evaporative light scattering detection].

A method of reversed-phase high performance liquid chromatography (HPLC) coupled with evaporative light scattering detection (ELSD) was developed for the determination of jervine and veratramine in veratrum plants. The extraction method of total active alkaloids from the raw material was also established. The separation and quantification were achieved using a Kromasil C8column (250 mm x 4.6 mm, 5 microm), and a mobile phase of acetonitrile and 0.1% trifluoroacetic acid with the following gradient elution: 20% acetonitrile at the first 5 mm, 20%-40% acetonitrile at the 5-30 mm, 40%-20% acetonitrile at the 30-40 mm, 20% acetonitrile at the 40-45 mm with a flow rate of 0.8 mL/min; column temperature of 35 t and monitored by an ELSD detector with the drift tube of 98 t and the nitrogen flow rate of 2.2 L/min. The calibration curves for jervine and veratramine were linear over the ranges of 42.05-980 mg/L and 43.52-1020 mg/L, respectively. The recoveries were 99.2% and 101.4% with relative standard deviations of 1.7% and 2.1% (n=6), respectively. The limits of detection for jervine and veratramine in raw material were 18.37 mg/kg and 21.50 mg/kg, respectively, with 3 times of the signal to noise ratio. This HPLC-ELSD method is rapid, simple, accurate and convenient. It can be used as one of the direct and reliable means for quantitative determination of the active alkaloids in veratrum plants.

A new diterpenoid from Fritillaria anhuiensis.

The aim of this study was to look for the chemical constituents of the bulbs of Fritillaria anhuiensis S. C. Chen et S. E. Yin. The bulbs of Fritillaria anhuiensis were extracted with 95% EtOH at reflux. Isolation and purification were performed by silica gel column chromatography. Structures of pure compounds were established on the basis of spectral analysis. Three compounds were obtained and identified as 12,15-epoxy-8(17), 13-labdadien-19-ol (1), ent-3beta-acetoxy-kauran-16beta, 17-diol (2), ent-kaurane-3beta, 16beta, 17-triol (3). Compound 1 is a new labdane-type diterpenoid. Compounds 2 and 3 were obtained from Fritillaria anhuiensis for the first time.

Deaggregation behavior of the phenol gemini derivatives.

The phenol gemini compounds were synthesized by rebuilding the substituents and lateral chain on the phenyl ring. Two parts of the molecules were connected by a spacer of hydrocarbon chain via ester groups. The deaggregation behaviors of target molecules were investigated by studying coaggregation behaviors, evaluating the deaggregating abilities in terms of fluorescence measurements, the measurements of their aggregation number and the effects on restraining the cell adhesion. In present cases, all of these experiments give the same results; that is, in these molecules, the longer branched methyl hydrocarbon chain and the combination of methoxy with hydroxyl groups on the phenyl ring possess the higher deaggregating abilities in the studied situation. The molecules with two hydrocarbon chains, i.e., the phenol gemini compounds, are more effective to deaggregate the aggregated probes than the molecules with one hydrocarbon chain. To find an effective deaggregator might be helpful to design the medicine for the cure of arteriosclerosis.