Rho激酶抑制剂DL0805-0对大鼠离体胸主动脉的舒张作用及机制研究

目的探讨Rho激酶抑制剂DL0805-0对离体大鼠胸主动脉的舒张作用及作用机制。方法采用大鼠胸主动脉环张力测定法,观察DL0805-0对内皮完整或剔除的大鼠胸主动脉环的影响。应用法舒地尔、左旋硝基精氨酸甲醋(LNAME)、亚甲蓝、吲哚美辛、四乙胺(TEA)、格列本脲和4-氨基吡啶(4-AP)等工具药,研究DL0805-0舒张血管的作用机制。结果 DL0805-0能剂量依赖性的舒张KCl(60 mmol·L-1)和NE(0.1μmol·L-1)预收缩的大鼠胸主动脉环。LNAME可明显抑制DL0805-0对NE收缩血管的舒张作用,而亚甲蓝和吲哚美辛无明显影响。TEA可明显抑制DL0805-0对NE收缩血管的舒张作用,而格列本脲和4-AP无明显影响。DL0805-0能够明显抑制NE在无钙K-H液中引起的血管收缩和复钙诱导的外钙依赖性血管收缩。结论 DL0805-0具有明显的舒张血管作用,其作用可能依赖于血管内皮功能,另外开放血管平滑肌细胞上钙激活的钾离子通道以及阻滞钙离子通道可能也是作用机制之一。

Esculin alleviates acute kidney injury and inflammation induced by LPS in mice and its possible mechanism

Acute kidney injury(AKI)is a common clinical serious illness.Esculin(ES)is a coumarin compound of traditional Chinese medicine Cortex Fraxini.Our previous study has found that ES protects against inflammation and renal damage in diabetic rats.In the present study,we aimed to investigate the effects and the possible mechanism of ES against lipopolysaccharides(LPS)-induced AKI in mice.Renal morphology was observed by H&E staining.Renal function was evaluated by blood urea nitrogen(BUN)level and creatinine content in serum.Inflammatory factor levels were measured by ELISA assay.The inflammatory proteins were analyzed by RT-PCR and Western blotting analysis.The results showed that ES alleviated LPS-induced pathological injury and renal dysfunction,and decreased BUN level and creatinine content in serum.In addition,ES significantly reduced the release of pro-inflammatory factors,including IL-1β,IL-6 and TNF-α,chemokine MCP-1 and cell adhesion molecule ICAM-1.Furthermore,the expressions of inflammatory pathway proteins P2 X7,HMGB1,TLR4 and MyD88 both at the mRNA and protein levels were all down-regulated by ES in the kidney tissue of LPS-challenged mice.These results suggested ES protected against LPS-induced AKI through inhibiting P2 X7 expression and HMGB1/TLR4 inflammatory pathway.

Rapid and sensitive HPLC-MS/MS method for quantitative determination of isochlorogenic acid B in rat plasma and its application in pharmacokinetic study

A sensitive LC-ESI-MS/MS method for determination of isochlorogenic acid B in rat plasma was developed and validated in the present study. Plasma samples were prepared by a simple protein precipitation with methanol containing resveratrol as internal standard (IS). The chromatographic separation was performed on a Zorbax SB-Cjg column (3.5 pm, 2.1 mmx 100 mm, Agilent, USA) at a flow rate of 0.2 mL/min using methanol/water containing 0.1% formic acid (v/v) as mobile phase. The detection was performed on a triple quadrupole tandem mass spectrometer equipped with Electronic Spray Ion by selected reaction monitoring (SRM) of the transitions at m/z 515.3->352.9 for isochlorogenic acid B and m/z 227.1-143.1 for IS, respectively. The calibration curve of the method was linear over the range of 5-2500 ng/mL (r^2= 0.9982). The intra- and inter-day precisions (R.S.D.%) were less than 12.46%, and the accuracy (R.E.%) was within ±5.80%. Isochlorogenic acid B was sufficiently stable under all relevant analytical conditions. The validated method was successfully applied to the plasma pharmacokinetic studies of isochlorogenic acid B in rats. It was found that isochlorogenic acid B had non-linear pharmacokinetic characteristics in rats within the dosage ranges from 5 to 20 mg/kg.

Determination of deferasirox particle size distribution via laser diffraction and its application in establishing a correlation between particle size and drug dissolution in vitro

Deferasirox is the first-line drug for iron overload due to thalassemia in adults and pediatric patients. It is classified as a type II compound in the Biopharmaceutics Classification System, and thus the particle size of its active pharmaceutical ingredient(API) should be strictly controlled during the manufacturing process. In the present study, laser diffraction was adopted to measure the particle size distribution of deferasirox API. We also developed and validated an accurate and convenient method by investigating important optical parameters and sample dispersing conditions. The relative standard deviation values, namely, d(0.1), d(0.5), d(0.9), and d(4,3), measured via methodology validation and actual sample measurement were < 3%. The dissolution curves of several batches of dispersible tablets prepared using deferasirox with different particle sizes were compared in the four dissolved media to investigate the influence of particle size on drug dissolution in vitro. Results indicated that the particle size distribution of deferasirox API significantly affected the release of its dispersible tablet.

The synthesis and antibacterial activity evaluation of oxazolidinone-deferasirox conjugates

We reported herein the synthesis and antibacterial activity evaluation of two oxazolidinone-deferasirox conjugates with different linkers that were designed based on the“Trojan horse”strategy.The conjugates could combine with Fe^(3+)ions as the deferasirox.However,both conjugates were inactive against tested bacteria,including S.aureus,E.coli,A.baumannii,and P.aeruginosa.The results suggested that the synthesized iron chelator deferasirox was not suitable as a siderophore of the bacteria to transport the antibiotic,or the coupling linker of the synthesized conjugates could not be hydrolyzed to release the oxazolidinone in the cytoplasm.Therefore,the design and synthesis of oxazolidinone-deferasirox conjugates need further exploration.

Biocatalytic bis-C-alkylation of phenolics using one-pot cascades with promiscuous C-glycosyltransferase and prenyltransferase

C-glycosylation and C-prenylation are two important C-C-bond forming reactions for preparation,diversification and structural modification of natural/unnatural products with pharmacological activities.Here,we described unprecedented enzymatic cascades to C-glycosylate/prenylate different acyl resorcinol derivatives in stepwise,one-pot reactions by combining two promiscuous enzymes,MiCGT,a C-glycosyltransferase,and AtaPT,a prenyltransferase.Five novel bis-C-alkylated products were obtained and structurally identified by MS and NMR spectroscopic data as well as comparison with the literature.This study provided a potential synthetic strategy for synthesizing structurally novel and diverse compounds bearing both C-glycosyl and C-prenyl moieties by a two-step,enzymatic bis-C-alkylation.

Three new compounds from endophytic fungus Periconia sp.F-31

Three new compounds(1–3), including a chlorine-containing dihydroisocoumarin pericochlorosin A(1), a chlorinated phenol pericochlorosin B(2) and a decalin derivative pericoannosin G(3), were isolated from endophytic fungus Periconia sp. F-31 of the medicinal plant Annona muricata. The structures and absolute configurations were elucidated by extensive spectroscopic methods and calculated electronic circular dichroism analysis. Compound 2 displayed potent anti-HIV activity with IC50 value of 2.2 μM.