Interaction of Chelerythrine Choloride in Acid Buffer with Calf-thymus DNA

The binding of chelerythrine （CHE） iminium to calf-thymus （CT） DNA is characterized by hypochromism and bathochromism in the absorption band, enhancement of fluorescence intensity, increase in fluorescence polarization, and the perturbation of the CD spectra of DNA. These changes are characteristic of intercalation. Scatchard plots constructed from fluorescence titration data gave a binding constant of 5.77×10^5 and a binding site size of 3,4 base pairs at 25 ℃. The intercalative interaction is exothermic with a Van＇t Hoff enthalpy of -33.7 kJ/mol. In addition, △G =-32.9 kJ/mol, and △S =-2.9 J/mol/K. The intercalation of CHE into the DNA helix is enthalpy-driven.

Chelerythrine chloride binding of guanosine in aqueous solution

In this work, the interaction between chelerythrine （CHE） and guanosine is studied using UV-vis and fluorescence measurements at various temperatures. The UV-vis spectra show that the increasing guanosine concentrations result in the decreasing absorption intensity and red shift of CHE E absorption band （267 nm）. The fluorescence spectra are fitted to linear analysis, yielding a binding constant of 1.04×10^4 L/tool at 298.15 K of CHE with guanosine. Besides, with △rHm^θ = - 8.26 kJ/mol, △rGm^θ = -22.90 kJ/mol, and △rSm^θ = 49.38 J/（mol K） the interaction should be entropy-driven and exterothermic.

A spectral study of the interaction between chelerythrine chloride and cytidine

To study the possible anticancer mechanisms of chelerythrine (CHE), and its interactions with cytidine were investigated by UV–vis spectrophotometric and spectrofluorimetric measurements and by thermodynamic calculations. The binding of CHE to cytidine could be characterized by the hypochromic and bathochromic effects in the absorption bands, and the quenching of fluorescence intensity. The spectral data were fit by linear analysis, yielding a binding constant of 2.49 × 10(4) L mol(?1)at 25 °C of CHE and cytidine, and a van’t Hoff enthalpy of ?20.02 kJ/mol for the exothermic interaction in the standard state. In addition, with and , the interactions should be entropy-driven.

Stability of Sanguinarine and Chelerythrine in Macleaya cordata (Willd.) R. Br.

[Objectives]To explore the stability of sanguinarine and chelerythrine in Macleaya cordata(Willd.)R.Br.[Methods]The solubility and stability of sanguinarine and chelerythrine in seven solvents were measured by HPLC.Besides,the effects of water quality,light source,oxidant,temperature,and pH on stability were investigated.[Results]The solubility and stability of sanguinarine and chelerythrine in methanol and ethanol are good;the stability of sanguinarine and chelerythrine in distilled water and rainwater is not affected by light and is very stable,but they are unstable in tap water whether they are protected from light or not;oxidants have a great influence on the stability of sanguinarine and chelerythrine;sanguinarine and chelerythrine are stable at room temperature lower than 54℃;sanguinarine is stable in pH 2.5-7.0,while chelerythrine is stable in pH 2.5-8.0.[Conclusions]The good stability of sanguinarine and chelerythrine under specific conditions shows that they have broad development prospects and value.

Simultaneous Quantitative Determination of Nitidine, Chelerythrine and Sanguinarine Using HPTLC from Callus Extract of <i>Zanthoxylum rhetsa</i>

Nitidine, Chelerythrine and Sanguinarine, all these three alkaloids are benzophenanthridine alkaloids. Nitidine was used as an anti-HIV, anti-malarial and anti-cancer. Chelerythrine had anti-cancer and anti-inflammatory activities. Sanguinarine was widely used as an anti-plaquestic and anti-cancer. High performance thin layer chromatography (HPTLC) method was used for simultaneous quantification of Nitidine, Chelerythrine and Sanguinarine in callus extract of Zanthoxylum rhetsa by using Silica gel 60 F254 as stationary phase and ethyl acetate:methanol:water:diethylamine (30:5:2:0.5 v/v) as mobile phase at 280 nm. The linearity concentration range was 5 - 160 μg/band of each alkaloid. The Rf values of Nitidine, Chelerythrine and Sanguinarine were found to be 0.28, 0.49 and 0.73. The limit of detection and limit of quantification were found to be 0.026, 0.088 μg/spot and 0.010 and 0.033 μg/spot, 0.0104 and 0.035 μg/spot respectively for Nitidine, Chelerythrine and Sanguinarine. HPTLC method was developed and validated according to ICH guidelines for simultaneous estimation of Nitidine, Chelerythrine and Sanguinarine and proved to be simple, specific, accurate, robust and rapid.

应对可转移多黏菌素耐药性--饲料添加剂来源的白屈菜红碱具有双重效应

The emergence and spread of the mobile colistin-resistance gene,mcr-1,and its variants pose achallenge to the use of colistin,a last-resort antibiotic used to treat severe infections caused by extensively drug-resistant(XDR)Gram-negative pathogens.Antibiotic adjuvants are a promising strategy to enhance the efficacy of colistin against colistin-resistant pathogens;however,few studies have considered the effects of adjuvants on limiting resistance-gene transmission.We found that chelerythrine(4 mg·L^(-1))derived from Macleaya cordata extract,which is used as an animal feed additive,reduced the minimal inhibitory concentration(MIC)of colistin against an mcr-1 positive Escherichia coli(E.coli)strain by 16-fold(from 2.000 to 0.125 mg·L^(-1)).eliminated approximately 10^(4) colony-forming units(CFUs)of an mcr-1-carrying strain in a murine intestinal infection model,and inhibited the conjugation of an mcr-1-bearing plasmid in vitro(by>100-fold)and in a mouse model(by up to 5-fold).A detailed analysis revealed that chelery-thrine binds to phospholipids on bacterial membranes and increases cytoplasmic membrane fluidity,thereby impairing respiration,disrupting proton motive force(PMF),generating reactive oxygen species(ROS),and decreasing intracellular adenosine triphosphate(ATP)levels,which subsequently downregu-lates mcr-1 and conjugation-associated genes.These dual effects of chelerythrine can expand the use of antibiotic adjuvants and may provide a new strategy for circumventing mobile colistin resistance.

Chelerythrine chloride from Macleaya cordata induces growth inhibition and apoptosis in human gastric cancer BGC-823 cells

This study aimed to investigate the ability of chelerythrine chloride(CHE),the main active ingredient of Macleaya cordata,to induce apoptosis in human gastric cancer BGC-823 cells.The results demonstrate that CHE inhibits cell proliferation in a time-and dose-dependent manner with accompanying S phase arrest.It also induces apoptosis by a mechanism involving a reduction in the mitochondrial mem brane potential,the release of cytochrome c,activation of caspase 3 and cleavage of poly-ADP-ribose polymerase.In addition,CHE-induced apoptosis is accompanied by down-regulation of Bcl-x1 and Bcl-2 proteins with no change in the levels of Bax proteins.Taken together,the results support the development of CHE as a potentially useful anticancer drug for the treatment of gastric cancer.

CRYSTAL AND MOLECULAR STRUCTURE OF 6-METHOXY-5, 6-DIHYDROCHELERYTHRINE

Ⅰ. INTRODUCTION Seven alkaloids were isolated from the roots of Zanthoxylum nitidum by HUANG Zhi-xun et al. The compound C22H21O5N, named 6-methoxy-5, 6-dihydrochelerythrine, was one of the alkaloids. It exhibits medium antitumor activity.We carry out the X-ray structural analysis of the drug in order to study the relation between the molecular structure and its antitumor activities.

蒺藜皂苷对缺血心肌细胞内核转录因子-κB的作用

目的研究蒺藜皂苷对培养大鼠乳鼠心肌细胞H2O2损伤时心肌细胞内蛋白激酶C(PKCε)、细胞外信号调节激酶(ERK1/2)及核转录因子-κB(NF-κB)水平的影响。方法利用培养的Wistar大鼠乳鼠心肌细胞,采用H2O2建立心肌细胞损伤模型,应用PKCε抑制剂Chelerythrine干预后,观察细胞形态学改变,应用流式细胞仪定性检测细胞凋亡率,Western blotting定量检测各组PKCε、ERK1/2及NF-κB水平。结果蒺藜皂苷明显保护受损心肌细胞,降低细胞凋亡率,并且能够升高PKCε、ERK1/2及NF-κB水平;应用Chelerythrine可部分阻断蒺藜皂苷的上述作用。结论蒺藜皂苷对H2O2损伤大鼠心肌细胞具有保护作用,其保护作用机制与PKCε、ERK1/2及NF-κB激活有关。

The Genome of Medicinal Plant Macleaya cordata Provides New Insights into Benzylisoquinoline Alkaloids Metabolism

The overuse of antibiotics in animal agriculture and medicine has caused a series of potential threats to public health. Macleaya cordata is a medicinal plant species from the Papaveraceae family, providing a safe resource for the manufacture of antimicrobial feed additive for livestock. The active constituents from M. cordata are known to include benzylisoquinoline alkaloids （BIAs） such as sanguinarine （SAN） and chelerythrine （CHE）, but their metabolic pathways have yet to be studied in this non-model plant. The active biosynthesis of SAN and CHE in M. cordata was first examined and confirmed by feeding ^13C-labeled tyrosine. To gain further insights, we de novo sequenced the whole genome of M. cordata, the first to be sequenced from the Papaveraceae family. The M. cordata genome covering 378 Mb encodes 22,328 predicted protein-coding genes with 43.5% being transposable elements. As a member of basal eudicot, M. cordata genome lacks the paleohexaploidy event that occurred in almost all eudicots. From the genomics data, a complete set of 16 metabolic genes for SAN and CHE biosynthesis was retrieved, and 14 of their biochemical activities were validated. These genomics and metabolic data show the conserved BIA metabolic pathways in M. cordata and provide the knowledge foundation for future productions of SAN and CHE by crop improvement or microbial pathway reconstruction.