Yan-Xiang Wang

CD36 is a co-receptor for hepatitis C virus E1 protein attachment.

The cluster of differentiation 36 (CD36) is a membrane protein related to lipid metabolism. We show that HCV infection in vitro increased CD36 expression in either surface or soluble form. HCV attachment was facilitated through a direct interaction between CD36 and HCV E1 protein, causing enhanced entry and replication. The HCV co-receptor effect of CD36 was independent of that of SR-BI. CD36 monoclonal antibodies neutralized the effect of CD36 and reduced HCV replication. CD36 inhibitor sulfo-N-succinimidyl oleate (SSO), which directly bound CD36 but not SR-BI, significantly interrupted HCV entry, and therefore inhibited HCV replication. SSO’s antiviral effect was seen only in HCV but not in other viruses. SSO in combination with known anti-HCV drugs showed additional inhibition against HCV. SSO was considerably safe in mice. Conclusively, CD36 interacts with HCV E1 and might be a co-receptor specific for HCV entry; thus, CD36 could be a potential drug target against HCV.

N-substituted benzyl matrinic acid derivatives inhibit hepatitis C virus (HCV) replication through down-regulating host heat-stress cognate 70 (Hsc70) expression.

Heat-stress cognate 70 (Hsc70) is a host factor that helps hepatitis C virus (HCV) to complete its life cycle in infected hepatocytes. Using Hsc70 as a target for HCV inhibition, a series of novel N-substituted benzyl matrinic/sophoridinic acid derivatives was synthesized and evaluated for their anti-HCV activity in vitro. Among these analogues, compound 7c possessing N-p-methylbenzyl afforded an appealing ability to inhibit HCV replication with SI value over 53. Furthermore, it showed a good oral pharmacokinetic profile with area-under-curve (AUC) of 13.4 µM·h, and a considerably good safety in oral administration in mice (LD50>1000 mg/kg). As 7c suppresses HCV replication via an action mode distinctly different from that of the marketed anti-HCV drugs, it has been selected as a new mechanism anti-HCV candidate for further investigation, with an advantage of no or decreased chance to induce drug-resistant mutations.

Design, synthesis and biological evaluation of monobactams as antibacterial agents against gram-negative bacteria.

A series of monobactam derivatives were prepared and evaluated for their antibacterial activities against susceptible and resistant Gram-negative strains, taking Aztreonam and BAL30072 as the leads. Six conjugates (12a-f) bearing PIH-like siderophore moieties were created to enhance the bactericidal activities against Gram-negative bacteria based on Trojan Horse strategy, and all of them displayed potencies against susceptible Gram-negative strains with MICxa0≤xa08xa0μg/mL. SAR revealed that the polar substituents on the oxime side chain were beneficial for activities against resistant Gram-negative bacteria. Compounds 19c and 33a-b exhibited the promising potencies against ESBLs-producing E.xa0coli and Klebsiella pneumoniae with MICs ranging from 2xa0μg/mL to 8xa0μg/mL. These results offered powerful information for further strategic optimization in search of the antibacterial candidates against MDR Gram-negative bacteria.

Synthesis, Biological Evaluation, and Autophagy Mechanism of 12N-Substituted Sophoridinamines as Novel Anticancer Agents

A series of 12N-substituted sophoridinamine derivatives were synthesized and evaluated for their cytotoxic activities in human HepG2 hepatoma cells. Structure-activity relationship revealed that introduction of a suitable arylidene or arylethyl at the N-end could greatly enhance antiproliferation potency. Among them, compound 6b possessing a N-trimethoxyphenyl methylene exhibited potent antiproliferation effect against three human tumor cell lines including HepG2, leukemia (K562), and breast cancer (HMLE), with IC50 between 0.55 and 1.7 μM. The underlying mechanism of 6b against tumor cells is to block autophagic flux, mainly through neutralizing lysosomal acidity. Our results indicated that compound 6b is a potent lysosomal deacidification agent and is accordingly able to block autophagic flux and inhibit tumor cell growth.

Synthesis and structure−activity relationship of 8-substituted protoberberine derivatives as a novel class of antitubercular agents

BackgroundThe emergence of multi-drug resistant tuberculosis (MDR-TB) has heightened the need for new chemical classes and innovative strategies to tackle TB infections. It is urgent to discover new classes of molecules without cross-resistance with currently used antimycobacterial drugs.ResultsEighteen new 8-substituted protoberberine derivatives were synthesized and evaluated for their anti-mycobacterial activities against Mycobacterium tuberculosis (M. tuberculosis) strain H37Rv. Among them, compound 7g was the most effective antitubercular agent with minimum inhibitory concentration (MIC) of 0.5 μg/mL. Moreover, it also afforded a potent antitubercular effect against clinically isolated MDR strains of M. tuberculosis with MICs ranging from 0.25 to 1.0 μg/mL, suggesting a novel mode of action.ConclusionsThe structure−activity relationship (SAR) analysis revealed that introduction of a substituent at the 8-position in pseudoprotoberberine, especially an n-decyl, could significantly enhance the anti-TB activity. We consider 8-n-decylberberines to be a novel family of anti-tubercular agents with an advantage of inhibiting MDR strains of M. tuberculosis.

Synthesis and Identification of Novel Berberine Derivatives as Potent Inhibitors against TNF-α-Induced NF-κB Activation

Twenty-three new berberine (BBR) analogues defined on substituents of ring D were synthesized and evaluated for their activity for suppression of tumor necrosis factor (TNF)-α-induced nuclear factor (NF)-κB activation. Structure–activity relationship (SAR) analysis indicated that suitable tertiary/quaternary carbon substitutions at the 9-position or rigid fragment at position 10 might be beneficial for enhancing their anti-inflammatory potency. Among them, compounds 2d, 2e, 2i and 2j exhibited satisfactory inhibitory potency against NF-κB activation, with an inhibitory rate of around 90% (5 μM), much better than BBR. A preliminary mechanism study revealed that all of them could inhibit TNF-α-induced NF-κB activation via impairing IκB kinase (IKK) phosphorylation as well as cytokines interleukin (IL)-6 and IL-8 induced by TNF-α. Therefore, the results provided powerful information on further structural modifications and development of BBR derivatives into a new class of anti-inflammatory candidates for the treatment of inflammatory diseases.

Synthesis and biological evaluation of tricyclic matrinic derivatives as a class of novel anti-HCV agents

Background12N-benzyl matrinic acid analogues had been identified to be a novel scaffold of anti-HCV agents with a specific mechanism, and the representative compound 1 demonstrated a moderate anti-HCV activity. The intensive structure–activity relationship of this kind of compounds is explored so as to obtain anti-HCV candidates with good druglike nature.ResultsTaking compound 1 as the lead, 32 compounds (of which 27 were novel) with diverse structures on the 11-side chain, including methyl matrinate, matrinol, matrinic butane, (Z)-methyl Δβγ-matrinic crotonate derivatives were synthesized and evaluated for their anti-HCV activities. Among all the compounds, matrinol 7a demonstrated potential potency with a greatly improved SI value of 136. Pharmacokinetic studies of 7a showed the potential for oral administration that would allow further in vivo safety studies. The free hydroxyl arm in 7a made it possible to prepare pro-drugs for the potential in the treatment of HCV infection.Conclusions27 novel 12N-substituted matrinol derivatives were prepared. The SAR study indicated that the introduction of electron-donating substitutions on the benzene ring was helpful for the anti-HCV activity, and the unsaturated 11-side chain might not be favorable for the activity. This study provided powerful information on further strategic optimization and development of this kind of compounds into a novel family of anti-HCV agents. Graphical abstractMatrinol derivatives as a class of novel anti-HCV agents

Evolution of matrinic ethanol derivatives as anti-HCV agents from matrine skeleton

Twenty-two novel 12N-substituted matrinic ethanol derivatives were synthesized and evaluated for their antiviral activities against HCV taking compound 1 as the lead. The SAR study indicated that the shortening of the 11-butyl chain to ethyl chain did not affect the activity significantly. Out of the target compounds, matrinic ethanol 6a demonstrated a potential anti-HCV effect with an EC50 value of 3.2μM and a SI value of 96.6. The free hydroxyl arm in 6a made it possible as a parent structure to prepare pro-drug for the potential application in HCV treatment. This study provided powerful information on further strategic optimization and development of this kind of compounds into a novel family of anti-HCV agents.

A Retrospective Study of the Efficacy and Toxicity of Irinotecan in Combination with Nedaplatin versus Irinotecan in Combination with Cisplatin as Salvage Treatment in Refractory or Relapsed Small Cell Lung Cancer

BACKGROUND AND OBJECTIVEnAt present no standard second-line combination has been established for recurrent small cell lung cancer (SCLC). Therefore we evaluate the efficacy and safety of irinotecan in combination with nedaplatin/cisplatin against refractory or relapsed small cell lung cancer.nnnMETHODSnIn this retrospective study, we analyzed the data of 1,140 patients who diagnosed small cell lung cancer at our hospital from April 2009 to April 2012. Of all the patients, 34 patients were treated with irinotecan and nedaplatin (irinotecan 60 mg/m2 on days 1, 8 nedaplatin 85 mg/m2 day 1, every 3 weeks) , and 20 patients were treated with irinotecan and cisplatin (irinotecan 60 mg/m2 on days 1, 8 cisplatin 75 mg/m2 day 1, every 3 weeks) as the second-line treatment. Prognostic factors of overall survival (OS) were estimated by Kaplan-Meier and Coxs Regression-proportional hazards model.nnnRESULTSnOf all the 54 eligible patients, median progression free survival (PFS) was 4.9 months, and median OS was 13.3 months. Median PFS was 5.4 months for irinotecan plus nedaplatin (IN) and 4.9 months for irinotecan plus cisplatin (IC), respectively (P=0.465). Median OS was 14.3 months and 13.3 months, respectively (P=0.704). In multivariate analysis, ECOG PS, number of metastases and cycles of chemotherapy were independent prognostic factors. The toxicities were mild, while toxicity profile was slightly different for each of the arms: hematologic toxicity was higher in IN group, and diarrhea was higher in IC group.nnnCONCLUSIONSnIrinotecan plus platinum is effective and tolerable for refractory and relapsed small cell lung cancer. Irinotecan plus nedaplatin is non-inferior to irinotecan plus cisplatin in terms of efficacy and safety.

Synthesis and Evolution of Berberine Derivatives as a New Class of Antiviral Agents against Enterovirus 71 through the MEK/ERK Pathway and Autophagy

Taking berberine (BBR) as the lead, 23 new BBR derivatives were synthesized and examined for their antiviral activities against four different genotype enterovirus 71 (EV71) strains with a cytopathic effect (CPE) assay. Structure-activity relationship (SAR) studies indicated that introduction of a suitable substituent at the 9-position might be beneficial for potency. Among them, compound 2d exhibited most potent activities with IC50 values of 7.12–14.8 μM, similar to that of BBR. The effect of 2d was further confirmed in a dose-dependent manner both in RNA and protein level. The mechanism revealed that 2d could inhibit the activation of MEK/ERK signaling pathway. Meanwhile, it could suppress the EV71-induced autophagy by activating AKT and inhibiting the phosphorylation of JNK and PI3KIII proteins. We consider BBR derivatives to be a new family of anti-EV71 agents through targeting host components, with an advantage of broad-spectrum anti-EV71 potency.