Interaction of procainamide hydrochloride(PAH) with human serum albumin(HSA) is of great significance in understanding the pharmacokinetic and pharmacodynamic mechanisms of the drug. Multi-spectroscopic techniques wer...Interaction of procainamide hydrochloride(PAH) with human serum albumin(HSA) is of great significance in understanding the pharmacokinetic and pharmacodynamic mechanisms of the drug. Multi-spectroscopic techniques were used to investigate the binding mode of PAH to HSA and results revealed the presence of static type of quenching mechanism. The number of binding sites, binding constants and thermodynamic parameters were calculated. The results showed a spontaneous binding of PAH to HSA and hydrophobic interactions played a major role. In addition, the distance between PAH and the Trp–214 was estimated employing the F?rster's theory. Site marker competitive experiments indicated that the binding of PAH to HSA primarily took place in subdomain IIA(Sudlow's site I). The influence of interference of some common metal ions on the binding of PAH to HSA was studied. Synchronous fluorescence spectra(SFS), 3D fluorescence spectra and circular dichroism(CD) results indicated the conformational changes in the structure of HSA.展开更多
The presence of excess glucose in blood is regarded as a sweet hurt for patients with diabetes.Human serum albumin(HSA)is the most abundant protein in human plasma,which undergoes severe non-enzymatic glycation with g...The presence of excess glucose in blood is regarded as a sweet hurt for patients with diabetes.Human serum albumin(HSA)is the most abundant protein in human plasma,which undergoes severe non-enzymatic glycation with glucose in patients with diabetes;this modifies the structure and function of HSA.Furthermore,the advanced glycation end products produced by glycated HSA can cause pathological damage to the human body through various signaling pathways,eventually leading to complications of diabetes.Many potential glycation sites on HSA have different degrees of sensitivity to glucose concentration.This review provides a comprehensive assessment of the in vivo glycation sites of HSA;it also discusses the effects of glycation on the structure and function of HSA.Moreover,it addresses the relationship between HSA glycation and diabetes complications.Finally,it focuses on the value of non-enzymatic glycation of HSA in diabetes-related clinical applications.展开更多
A simple and sensitive fluorescence detection of domperidone by ultra fast liquid chromatographic method was developed and validated in human serum. For the evaluation of new drug delivery systems, conducting of pharm...A simple and sensitive fluorescence detection of domperidone by ultra fast liquid chromatographic method was developed and validated in human serum. For the evaluation of new drug delivery systems, conducting of pharmacokinetic studies in human volunteers is essential for approval to marketing after preclinical evaluation in animal models. The present method consists of protein precipitation, extraction of analytes from human serum into dichloromethane and separation using reversed-phase C<sub>18</sub> column. Propranolol hydrochloride was used as an internal standard and the eluent was monitored by fluorescence detector at excitation 282 and emission 328 nm. The mobile phase used was 62:38 ratio of 10 mM phosphate buffer pH adjusted to 3.1 with OPA and methanol at a flow rate of 1 mL·min<sup>-1</sup>. The method was evaluated for assay, LLOD, LLOQ, recovery and stability studies. The retention times for domperidone and propranolol hydrochloride were found to be 6.36 and 7.94 minutes respectively. The intraday and inter-day coefficient of variation and percent error values of assay method were less than 5%;mean recovery was more than 96% for each analyte and the method was found to be precise, accurate and specific during study. The method was successfully applied for pharmacokinetic study of immediate and controlled release bioadhesive hot melt extruded buccal patches of domperidone after buccal administration to healthy human volunteers. The C<sub>max</sub>, T<sub>max</sub>, and AUC<sub>0–24 </sub>of domperidone from immediate and controlled release buccal patches were found to be 129.7 ng·mL<sup>-1</sup>, 1.5 h, 455.1 ng·h·mL<sup>-1</sup> and 145.7 ng·mL<sup>-1</sup>, 5.25 h, 911.0 ng·h·mL<sup>-1</sup> respectively. A simple, sensitive and reliable method for the fluorescence determination of domperidone in human serum by UFLC method was developed and validated.展开更多
UV-VIS spectroscopic investigations of interaction of bovine and human serum albumin with selected chalcones (1) and their cyclic chalcone analogues: (E)-2-(4’-X-benzylidene-1-tetralones (3), benzosuberones (4) with ...UV-VIS spectroscopic investigations of interaction of bovine and human serum albumin with selected chalcones (1) and their cyclic chalcone analogues: (E)-2-(4’-X-benzylidene-1-tetralones (3), benzosuberones (4) with dimethylamino and methoxy substituents and (E)-2-(2’,4’-dimethox- ybenzylidene)-1-indanone (2) were performed in polar respiration medium. Absorption maxima of the tested compounds were investigated in the presence of bovine and human serum albumin at the 0, 10, 30 and 60 minute timepoints of the interaction. The absorbance of all studied compounds in the presence of proteins decreased after one hour of the reaction. Molecule 4a showed the strongest and fastest kinet initial interaction with both albumins.展开更多
The interaction mechanism between human serum albumin(HSA) and 1-phenyl-3(fluorenone-2-yl)-5-(9-ethylcarbazole-3-yl)-2- pyrazoline(PFEP) was investigated by fluorescence and absorption titration techniques in combinat...The interaction mechanism between human serum albumin(HSA) and 1-phenyl-3(fluorenone-2-yl)-5-(9-ethylcarbazole-3-yl)-2- pyrazoline(PFEP) was investigated by fluorescence and absorption titration techniques in combination with molecular modeling method.Stern-Volmer plots at different temperatures proved that PFEP could quench the intrinsic fluorescence of HSA attributed to a static quenching procedure.The association constants were calculated in the range of 1×10~5-8×10~5mol^(-1) at different pH condition...展开更多
BACKGROUND Preoperative evaluation of future remnant liver reserves is important for safe hepatectomy.If the remnant is small,preoperative portal vein embolization(PVE)is useful.Liver volume analysis has been the prim...BACKGROUND Preoperative evaluation of future remnant liver reserves is important for safe hepatectomy.If the remnant is small,preoperative portal vein embolization(PVE)is useful.Liver volume analysis has been the primary method of preoperative evaluation,although functional examination may be more accurate.We have used the functional evaluation liver using the indocyanine green plasma clearance rate(KICG)and 99mTc-galactosyl human serum albumin single-photon emission computed tomography(99mTc-GSA SPECT)for safe hepatectomy.AIM To analyze the safety of our institution’s system for evaluating the remnant liver reserve.METHODS We retrospectively reviewed the records of 23 patients who underwent preoperative PVE.Two types of remnant liver KICG were defined as follows:Anatomical volume remnant KICG(a-rem-KICG),determined as the remnant liver anatomical volume rate×KICG;and functional volume remnant KICG(frem-KICG),determined as the remnant liver functional volume rate based on 99mTc-GSA SPECT×KICG.If either of the remnant liver KICGs were>0.05,a hepatectomy was performed.Perioperative factors were analyzed.We defined the marginal group as patients with a-rem-KICG of<0.05 and a f-rem-KICG of>0.05 and compared the postoperative outcomes between the marginal and not marginal(both a-rem-KICG and f-rem-KICG>0.05)groups.RESULTS All 23 patients underwent planned hepatectomies.Right hepatectomy,right trisectionectomy and left trisectionectomy were in 16,6 and 1 cases,respectively.The mean of blood loss and operative time were 576 mL and 474 min,respectively.The increased amount of frem-KICG was significantly larger than that of a-rem-KICG after PVE(0.034 vs 0.012,P=0.0273).The not marginal and marginal groups had 17(73.9%)and 6(26.1%)patients,respectively.The complications of Clavian-Dindo classification grade II or higher and post-hepatectomy liver failure were observed in six(26.1%)and one(grade A,4.3%)patient,respectively.The 90-d mortality was zero.The marginal group had no significant difference in postoperative outcomes(prothrombin time/international normalised ratio,total bilirubin,complication,post-hepatectomy liver failure,hospital stay,90-d,and mortality)compared with the not-marginal group.CONCLUSION Functional evaluation of the remnant liver enabled safe hepatectomy and may extend the indication for hepatectomy after PVE treatment.展开更多
The electrochemical behavior of duloxetine HCl (DXT.HCl) at a carbon paste electrode (CPE) was achieved by cyclic voltammetry and a mechanism of its oxidation was reported and illustrated. A sensitive linear sweep and...The electrochemical behavior of duloxetine HCl (DXT.HCl) at a carbon paste electrode (CPE) was achieved by cyclic voltammetry and a mechanism of its oxidation was reported and illustrated. A sensitive linear sweep and square-wave adsorptive anodic stripping voltammetry methods were described for trace determination of DXT.HCl. Introduction: DXT.HCl, N-methyl-3-(nap-thalen-1- yloxy)-3-(thiophene-2-yl) propan-1-amine hydrochloride is a selective serotonin-norepinephrine reuptake inhibitor (SNRI) originally developed as an antidepressant and is currently recommended for maintenance treatment of major depressive disorder. Methods: Electrochemical behavior was studied using cyclic voltammetric method, and the analytical application was studied using linear sweep and square wave voltammetric methods. Solution pH has been measured by pH meter. Results: The process on the surface of carbon paste electrode was found to be irreversible and diffusion-controlled. The number of proton and electron transferred were calculated. Possible reaction mechanism taking place on the surface of electrode was proposed. Calibration plot constructed using square wave voltammetric technique was used for quantitative analysis in pharmaceutical and human serum samples. Limit of detection (LOD) and limit of quantification (LOQ) were calculated. Conclusions: In the present work, we described the electrochemical behavior of DXT.HCl drug. Two precise linear sweep and square wave adsorptive anodic stripping voltammetry methods have been described for its trace quantitation in pharmaceutical formulation and human serum. The method shows the development of a sensor for selective and sensitive determination of DXT.HCl.展开更多
The interaction between captopril, an inhibitor of angiotensin converting enzyme and human serum albumin, a principal plasma protein in the liver has been investigated in vitro under a simulated physiological conditio...The interaction between captopril, an inhibitor of angiotensin converting enzyme and human serum albumin, a principal plasma protein in the liver has been investigated in vitro under a simulated physiological condition by UV-vis spectrophotometry and fluorescence spectrometry. The intrinsic fluorescence intensity of human serum albumin was strongly quenched by captopril. The binding constants and the number of binding sites can be calculated from the data obtained from fluorescence quenching experiments. The negative value of ΔG0 reveals that the binding process is a spontaneous process. According to the van’t Hoff equation, the standard enthalpy change (ΔH0) and standard entropy change (ΔS0) for the reaction were calculated to be 35.98 KJ●mol-1 and 221.25 J●mol-1 K. It indicated that the hydrophobic interactions play a main role in the binding of captopril to human serum albumin. In addition, the distance between captopril (acceptor) and tryptophan residues of human serum albumin (donor) was estimated to be 1.05 nm according to the F?rster’s resonance energy transfer theory. The results obtained herein will be of biological significance in pharmacology and clinical medicine.展开更多
Thermal denaturation and stability of two commercially available preparations of Human Serum Albumin (HSA), differing in their advertised level of purity, were investigated by differential scanning calorimetry (DSC). ...Thermal denaturation and stability of two commercially available preparations of Human Serum Albumin (HSA), differing in their advertised level of purity, were investigated by differential scanning calorimetry (DSC). These protein samples were 99% pure HSA (termed HSA<sub>99</sub>) and 96% pure HSA (termed HSA<sub>96</sub>). According to the supplier, the 3% difference in purity between HSA<sub>96</sub> and HSA<sub>99</sub> is primarily attributed to the presence of globulins and fatty acids. Our primary aim was to investigate the utility of DSC in discerning changes in HSA that occur when the protein is specifically adducted, and determine how adduct formation manifests itself in HSA denaturation curves, or thermograms, measured by DSC. Effects of site specific covalent attachment of biotin (the adduct) on the thermodynamic stability of HSA were investigated. Each of the HSA preparations was modified by biotinylation targeting a single site, or multiple sites on the protein structure. Thermograms of both modified and unmodified HSA samples successfully demonstrated the ability of DSC to clearly discern the two HSA preparations and the presence or absence of covalent modifications. DSC thermogram analysis also provided thermodynamic characterization of the different HSA samples of the study, which provided insight into how the two forms of HSA respond to covalent modification with biotin. Consistent with published studies [1] HSA<sub>96</sub>, the preparation with contaminants that contain globulins and fatty acids seems to be comprised of two forms, HSA<sub>96-L</sub> and HSA<sub>96-H</sub>, with HSA<sub>96-L</sub> more stable than HSA<sub>99</sub>. The effect of multisite biotinylation is to stabilize HSA<sub>96-L</sub> and destabilize HSA<sub>96-H</sub>. Thermodynamic analysis suggests that the binding of ligands comprising the fatty acid and globulin-like contaminant contributes approximately 6.7 kcal/mol to the stability HSA<sub>96-L</sub>.展开更多
AIM: To evaluate the usefulness of the functional hepatic resection rate(FHRR) calculated using 3D computed tomography(CT)/^(99m)Tc-galactosyl-human serum albumin(GSA) single-photon emission computed tomography(SPECT)...AIM: To evaluate the usefulness of the functional hepatic resection rate(FHRR) calculated using 3D computed tomography(CT)/^(99m)Tc-galactosyl-human serum albumin(GSA) single-photon emission computed tomography(SPECT) fusion imaging for surgical decision making. METHODS: We enrolled 57 patients who underwent bi- or trisectionectomy at our institution between October 2013 and March 2015. Of these, 26 patients presented with hepatocellular carcinoma, 12 with hilar cholangiocarcinoma, six with intrahepatic cholangiocarcinoma, four with liver metastasis, and nine with other diseases. All patients preoperatively underwent three-phase dynamic multidetector CT and ^(99m)Tc-GSA scintigraphy. We compared the parenchymal hepatic resection rate(PHRR) with the FHRR, which was defined as the resection volume counts per total liver volume counts on 3D CT/^(99m)Tc-GSA SPECT fusion images.RESULTS: In total, 50 patients underwent bisectionectomy and seven underwent trisectionectomy.Biliary reconstruction was performed in 15 patients, including hepatopancreatoduodenectomy in two. FHRR and PHRR were 38.6 ± 19.9 and 44.5 ± 16.0, respectively; FHRR was strongly correlated with PHRR. The regression coefficient for FHRR on PHRR was 1.16(P < 0.0001). The ratio of FHRR to PHRR for patients with preoperative therapies(transcatheter arterial chemoembolization, radiation, radiofrequency ablation, etc.), large tumors with a volume of > 1000 m L, and/or macroscopic vascular invasion was significantly smaller than that for patients without these factors(0.73 ± 0.19 vs 0.82 ± 0.18, P < 0.05). Postoperative hyperbilirubinemia was observed in six patients. Major morbidities(Clavien-Dindo grade ≥ 3) occurred in 17 patients(29.8%). There was no case of surgeryrelated death.CONCLUSION: Our results suggest that FHRR is an important deciding factor for major hepatectomy, because FHRR and PHRR may be discrepant owing to insufficient hepatic inflow and congestion in patients with preoperative therapies, macroscopic vascular invasion, and/or a tumor volume of > 1000 m L.展开更多
Human serum albumin(HSA) is a plasma protein responsible for the binding and transport of fatty acids and a variety of exogenous chemicals such as drugs and environmental pollutants.Such binding plays a crucial role i...Human serum albumin(HSA) is a plasma protein responsible for the binding and transport of fatty acids and a variety of exogenous chemicals such as drugs and environmental pollutants.Such binding plays a crucial role in determining the ADME(absorption,distribution,metabolism,and excretion) and bioavailability of the pollutants.The binding interaction between HSA and acetic acid(C2),octanoic acid(C8) and dodecanoic acid(C12) has been investigated by the combination of site-specific fluorescent probe,tryptophan intrinsic fluorescence and tyrosine electrochemistry.For the study of the fatty acid interaction with the two drug-binding sites on HSA,two fluorescent probes,dansylamide and dansyl-L-proline were employed in the displacement measurements.Intrinsic fluorescence of tryptophan in HSA was monitored upon addition of the fatty acids into HSA.Electrocatalyzed response of the tyrosine residues in HSA by a redox mediator was used to investigate the binding interaction.Qualitatively,observations from these three approaches were very similar.HSA did not show any change in the fluorescence and electrochemical experiments after mixing with C2,suggesting there is no significant interaction with the short-chain fatty acid.For C8,the measured signal dropped in a single-exponential mode,indicating an independent and non-cooperative binding.The calculated association constant and binding ratio were 3.1×106 L/mol and 1 with drug binding Site I,1.1×107 L/mol and 1 with Site II,and 7.0×104 L/mol and 4 with the tryptophan site,respectively.The measurements with C12 displayed multiple phases of fluorescence change,suggesting cooperativity and allosteric effect of the C12 binding.These results correlate well with those obtained by the established methods,and validate the new approach as a viable tool to study the interactions of environmental pollutants with biological molecules.展开更多
It is well known that the safety and efficacy profile of an inhaled cortocosteroid(ICS) is influenced by the pharmacokinetic properties and associated pharmacodynamic effects of the drug. Freely circulating,protein un...It is well known that the safety and efficacy profile of an inhaled cortocosteroid(ICS) is influenced by the pharmacokinetic properties and associated pharmacodynamic effects of the drug. Freely circulating,protein unbound, and active ICS can cause systemic adverse effects. Therefore, a detailed investigation of drug-protein interaction could be of great interest to understand the pharmacokinetic behaviour of corticosteroids and for the design of new analogues with effective pharmacological properties. In the present work, the interaction between some corticosteroids and human serum albumin(HSA) has been studied by spectroscopic approaches. UV–Vis spectroscopy confirmed that all the investigated corticosteroids can bind to HSA forming a protein-drug complex. The intrinsic fluorescence of HSA was quenched by all the investigated drugs, which was rationalized in terms of a static quenching mechanism. The thermodynamic parameters determined by the Van't Hoff analysis of the binding constants(negative ΔH and ΔS values) clearly indicate thathydrogen bonds and van der Waals forces play a major role in the binding process between albumin and betamethasone, flunisolide and prednisolone, while hydrophobic forces may play a major role in stabilizing albumin-triamcinolone complexes.展开更多
The antioxidant ability of capsules containing oats avenanthramides on human body was evaluated in present study.Healthy people were randomized to supplementation with oats-derived avenanthramides capsules or placebo ...The antioxidant ability of capsules containing oats avenanthramides on human body was evaluated in present study.Healthy people were randomized to supplementation with oats-derived avenanthramides capsules or placebo for 1 mon.Plasma lipid peroxides and antioxidant status were measured.For 8 capsules (containing 3.12 mg avenanthramides) groups,the levels of serum superoxide dismutase (SOD) and reduced glutathione hormone (GSH) were significantly increased by 8.4 and 17.9%,respectively (P<0.05),and malondialdehyde (MDA) level significantly decreased by 28.1%.The total cholesterol (TC),triglyceride (TG),and low density lipoprotein cholesterol (LDL-C) levels were lowered by 11.1,28.1,and 15.1%,respectively (P<0.05).The high density blood lipoprotein cholesterol (HDL-C) levels in the same treat was increased by 13.2%.Based on our research,it can be concluded that oats extract containing avenanthramides possessed a high antioxidative activity on humans.It indicated that oat avenanthramides could be used to prevent hyperlipemic and angiocardiopathy.展开更多
Five tryptophan analogues with a hydrophobic indole ring and an amino group on each molecule were used as functional ligands of mixed-mode resins for human serum albumin(HSA) purification. Their adsorption performance...Five tryptophan analogues with a hydrophobic indole ring and an amino group on each molecule were used as functional ligands of mixed-mode resins for human serum albumin(HSA) purification. Their adsorption performance was evaluated and the effects of p H and salt addition on HSA adsorption were studied. The resins prepared showed typical p H-dependent adsorption and the highest adsorption capacity and affinity were found at pH 5.0for all the resins tested. The saturated adsorption capacity was 138.02 mg·g^(-1)with the tryptaminefunctionalized resin, which significantly decreased at p H below 4.0 due to electrostatic repulsion between ligands and HSA. Moreover, the addition of Na Cl or(NH_4)_2SO_4in media reduced HSA adsorption capacity, although the two salts showed different affecting profiles. The tryptamine-functionalized resin showed the best salt-tolerant performance, and its high adsorption capacity was maintained under high salt concentrations. In addition, the five resins prepared showed good adsorption selectivity for recombinant HSA from Pichia pastoris broth. Molecular docking results between tryptamine and HSA indicated that tryptamine was favorable to bind on Site II(indole-binding site) of HSA.展开更多
Flavonoids are structurally diverse and the most ubiquitous groups of polyphenols distributed in the various plants,which possess intensive biological activities.In this study,the interaction mechanisms between four f...Flavonoids are structurally diverse and the most ubiquitous groups of polyphenols distributed in the various plants,which possess intensive biological activities.In this study,the interaction mechanisms between four flavonoids containing one glucose unit with similar molecular weight isolated from the Tibetan medicinal herb Pyrethrum tatsienense,namely.apigenin-7-O-β-D-glucoside(1),luteolin-7-O-β-D-glucoside(2).quercetin-7-O-β-D-glucoside(3).quercetin-3-O-β-D-glycoside(4).and human serum albumin(HSA),were investigated by fluorescence.UV-vis absorbance,circular dichroism,and molecular modeling.The effects of biological metal ions Mg^(2+),Zn^(2+),and Cu^(2+) on the binding affinity between flavonoids and HSA were further examined.Structure-activity relationships of four flavonoids binding to HSA were discussed in depth and some meaningful conclusions have been drawn by the experiment data and theoretical simulation.In addition,an interesting phenomenon was observed that the microenvironment of the binding site I in HSA has hardly changed in the presence of 4 differentiating from the other three flavonoids on the basis of conformation investigations.展开更多
文摘Interaction of procainamide hydrochloride(PAH) with human serum albumin(HSA) is of great significance in understanding the pharmacokinetic and pharmacodynamic mechanisms of the drug. Multi-spectroscopic techniques were used to investigate the binding mode of PAH to HSA and results revealed the presence of static type of quenching mechanism. The number of binding sites, binding constants and thermodynamic parameters were calculated. The results showed a spontaneous binding of PAH to HSA and hydrophobic interactions played a major role. In addition, the distance between PAH and the Trp–214 was estimated employing the F?rster's theory. Site marker competitive experiments indicated that the binding of PAH to HSA primarily took place in subdomain IIA(Sudlow's site I). The influence of interference of some common metal ions on the binding of PAH to HSA was studied. Synchronous fluorescence spectra(SFS), 3D fluorescence spectra and circular dichroism(CD) results indicated the conformational changes in the structure of HSA.
基金Supported by the National Natural Science Foundation of China,No.81870593Natural Science Foundation of Shandong Province of China,No.ZR2020MH106and Medical Health Science and Technology Project of Shandong Province,No.202003060400.
文摘The presence of excess glucose in blood is regarded as a sweet hurt for patients with diabetes.Human serum albumin(HSA)is the most abundant protein in human plasma,which undergoes severe non-enzymatic glycation with glucose in patients with diabetes;this modifies the structure and function of HSA.Furthermore,the advanced glycation end products produced by glycated HSA can cause pathological damage to the human body through various signaling pathways,eventually leading to complications of diabetes.Many potential glycation sites on HSA have different degrees of sensitivity to glucose concentration.This review provides a comprehensive assessment of the in vivo glycation sites of HSA;it also discusses the effects of glycation on the structure and function of HSA.Moreover,it addresses the relationship between HSA glycation and diabetes complications.Finally,it focuses on the value of non-enzymatic glycation of HSA in diabetes-related clinical applications.
文摘A simple and sensitive fluorescence detection of domperidone by ultra fast liquid chromatographic method was developed and validated in human serum. For the evaluation of new drug delivery systems, conducting of pharmacokinetic studies in human volunteers is essential for approval to marketing after preclinical evaluation in animal models. The present method consists of protein precipitation, extraction of analytes from human serum into dichloromethane and separation using reversed-phase C<sub>18</sub> column. Propranolol hydrochloride was used as an internal standard and the eluent was monitored by fluorescence detector at excitation 282 and emission 328 nm. The mobile phase used was 62:38 ratio of 10 mM phosphate buffer pH adjusted to 3.1 with OPA and methanol at a flow rate of 1 mL·min<sup>-1</sup>. The method was evaluated for assay, LLOD, LLOQ, recovery and stability studies. The retention times for domperidone and propranolol hydrochloride were found to be 6.36 and 7.94 minutes respectively. The intraday and inter-day coefficient of variation and percent error values of assay method were less than 5%;mean recovery was more than 96% for each analyte and the method was found to be precise, accurate and specific during study. The method was successfully applied for pharmacokinetic study of immediate and controlled release bioadhesive hot melt extruded buccal patches of domperidone after buccal administration to healthy human volunteers. The C<sub>max</sub>, T<sub>max</sub>, and AUC<sub>0–24 </sub>of domperidone from immediate and controlled release buccal patches were found to be 129.7 ng·mL<sup>-1</sup>, 1.5 h, 455.1 ng·h·mL<sup>-1</sup> and 145.7 ng·mL<sup>-1</sup>, 5.25 h, 911.0 ng·h·mL<sup>-1</sup> respectively. A simple, sensitive and reliable method for the fluorescence determination of domperidone in human serum by UFLC method was developed and validated.
基金thanks to the Austrian grant(ASO)SK-06/07-14/2007the Faculty of Mediccine Research Fund(University of Pécs)AOK-KA-213/20.
文摘UV-VIS spectroscopic investigations of interaction of bovine and human serum albumin with selected chalcones (1) and their cyclic chalcone analogues: (E)-2-(4’-X-benzylidene-1-tetralones (3), benzosuberones (4) with dimethylamino and methoxy substituents and (E)-2-(2’,4’-dimethox- ybenzylidene)-1-indanone (2) were performed in polar respiration medium. Absorption maxima of the tested compounds were investigated in the presence of bovine and human serum albumin at the 0, 10, 30 and 60 minute timepoints of the interaction. The absorbance of all studied compounds in the presence of proteins decreased after one hour of the reaction. Molecule 4a showed the strongest and fastest kinet initial interaction with both albumins.
基金supported by the National Natural Science Foundation of China(No.20875059)
文摘The interaction mechanism between human serum albumin(HSA) and 1-phenyl-3(fluorenone-2-yl)-5-(9-ethylcarbazole-3-yl)-2- pyrazoline(PFEP) was investigated by fluorescence and absorption titration techniques in combination with molecular modeling method.Stern-Volmer plots at different temperatures proved that PFEP could quench the intrinsic fluorescence of HSA attributed to a static quenching procedure.The association constants were calculated in the range of 1×10~5-8×10~5mol^(-1) at different pH condition...
文摘BACKGROUND Preoperative evaluation of future remnant liver reserves is important for safe hepatectomy.If the remnant is small,preoperative portal vein embolization(PVE)is useful.Liver volume analysis has been the primary method of preoperative evaluation,although functional examination may be more accurate.We have used the functional evaluation liver using the indocyanine green plasma clearance rate(KICG)and 99mTc-galactosyl human serum albumin single-photon emission computed tomography(99mTc-GSA SPECT)for safe hepatectomy.AIM To analyze the safety of our institution’s system for evaluating the remnant liver reserve.METHODS We retrospectively reviewed the records of 23 patients who underwent preoperative PVE.Two types of remnant liver KICG were defined as follows:Anatomical volume remnant KICG(a-rem-KICG),determined as the remnant liver anatomical volume rate×KICG;and functional volume remnant KICG(frem-KICG),determined as the remnant liver functional volume rate based on 99mTc-GSA SPECT×KICG.If either of the remnant liver KICGs were>0.05,a hepatectomy was performed.Perioperative factors were analyzed.We defined the marginal group as patients with a-rem-KICG of<0.05 and a f-rem-KICG of>0.05 and compared the postoperative outcomes between the marginal and not marginal(both a-rem-KICG and f-rem-KICG>0.05)groups.RESULTS All 23 patients underwent planned hepatectomies.Right hepatectomy,right trisectionectomy and left trisectionectomy were in 16,6 and 1 cases,respectively.The mean of blood loss and operative time were 576 mL and 474 min,respectively.The increased amount of frem-KICG was significantly larger than that of a-rem-KICG after PVE(0.034 vs 0.012,P=0.0273).The not marginal and marginal groups had 17(73.9%)and 6(26.1%)patients,respectively.The complications of Clavian-Dindo classification grade II or higher and post-hepatectomy liver failure were observed in six(26.1%)and one(grade A,4.3%)patient,respectively.The 90-d mortality was zero.The marginal group had no significant difference in postoperative outcomes(prothrombin time/international normalised ratio,total bilirubin,complication,post-hepatectomy liver failure,hospital stay,90-d,and mortality)compared with the not-marginal group.CONCLUSION Functional evaluation of the remnant liver enabled safe hepatectomy and may extend the indication for hepatectomy after PVE treatment.
文摘The electrochemical behavior of duloxetine HCl (DXT.HCl) at a carbon paste electrode (CPE) was achieved by cyclic voltammetry and a mechanism of its oxidation was reported and illustrated. A sensitive linear sweep and square-wave adsorptive anodic stripping voltammetry methods were described for trace determination of DXT.HCl. Introduction: DXT.HCl, N-methyl-3-(nap-thalen-1- yloxy)-3-(thiophene-2-yl) propan-1-amine hydrochloride is a selective serotonin-norepinephrine reuptake inhibitor (SNRI) originally developed as an antidepressant and is currently recommended for maintenance treatment of major depressive disorder. Methods: Electrochemical behavior was studied using cyclic voltammetric method, and the analytical application was studied using linear sweep and square wave voltammetric methods. Solution pH has been measured by pH meter. Results: The process on the surface of carbon paste electrode was found to be irreversible and diffusion-controlled. The number of proton and electron transferred were calculated. Possible reaction mechanism taking place on the surface of electrode was proposed. Calibration plot constructed using square wave voltammetric technique was used for quantitative analysis in pharmaceutical and human serum samples. Limit of detection (LOD) and limit of quantification (LOQ) were calculated. Conclusions: In the present work, we described the electrochemical behavior of DXT.HCl drug. Two precise linear sweep and square wave adsorptive anodic stripping voltammetry methods have been described for its trace quantitation in pharmaceutical formulation and human serum. The method shows the development of a sensor for selective and sensitive determination of DXT.HCl.
基金the National Key Technology R&D Program of China(No.2008BAJ08B13)for financially supporting this work.
文摘The interaction between captopril, an inhibitor of angiotensin converting enzyme and human serum albumin, a principal plasma protein in the liver has been investigated in vitro under a simulated physiological condition by UV-vis spectrophotometry and fluorescence spectrometry. The intrinsic fluorescence intensity of human serum albumin was strongly quenched by captopril. The binding constants and the number of binding sites can be calculated from the data obtained from fluorescence quenching experiments. The negative value of ΔG0 reveals that the binding process is a spontaneous process. According to the van’t Hoff equation, the standard enthalpy change (ΔH0) and standard entropy change (ΔS0) for the reaction were calculated to be 35.98 KJ●mol-1 and 221.25 J●mol-1 K. It indicated that the hydrophobic interactions play a main role in the binding of captopril to human serum albumin. In addition, the distance between captopril (acceptor) and tryptophan residues of human serum albumin (donor) was estimated to be 1.05 nm according to the F?rster’s resonance energy transfer theory. The results obtained herein will be of biological significance in pharmacology and clinical medicine.
文摘Thermal denaturation and stability of two commercially available preparations of Human Serum Albumin (HSA), differing in their advertised level of purity, were investigated by differential scanning calorimetry (DSC). These protein samples were 99% pure HSA (termed HSA<sub>99</sub>) and 96% pure HSA (termed HSA<sub>96</sub>). According to the supplier, the 3% difference in purity between HSA<sub>96</sub> and HSA<sub>99</sub> is primarily attributed to the presence of globulins and fatty acids. Our primary aim was to investigate the utility of DSC in discerning changes in HSA that occur when the protein is specifically adducted, and determine how adduct formation manifests itself in HSA denaturation curves, or thermograms, measured by DSC. Effects of site specific covalent attachment of biotin (the adduct) on the thermodynamic stability of HSA were investigated. Each of the HSA preparations was modified by biotinylation targeting a single site, or multiple sites on the protein structure. Thermograms of both modified and unmodified HSA samples successfully demonstrated the ability of DSC to clearly discern the two HSA preparations and the presence or absence of covalent modifications. DSC thermogram analysis also provided thermodynamic characterization of the different HSA samples of the study, which provided insight into how the two forms of HSA respond to covalent modification with biotin. Consistent with published studies [1] HSA<sub>96</sub>, the preparation with contaminants that contain globulins and fatty acids seems to be comprised of two forms, HSA<sub>96-L</sub> and HSA<sub>96-H</sub>, with HSA<sub>96-L</sub> more stable than HSA<sub>99</sub>. The effect of multisite biotinylation is to stabilize HSA<sub>96-L</sub> and destabilize HSA<sub>96-H</sub>. Thermodynamic analysis suggests that the binding of ligands comprising the fatty acid and globulin-like contaminant contributes approximately 6.7 kcal/mol to the stability HSA<sub>96-L</sub>.
文摘AIM: To evaluate the usefulness of the functional hepatic resection rate(FHRR) calculated using 3D computed tomography(CT)/^(99m)Tc-galactosyl-human serum albumin(GSA) single-photon emission computed tomography(SPECT) fusion imaging for surgical decision making. METHODS: We enrolled 57 patients who underwent bi- or trisectionectomy at our institution between October 2013 and March 2015. Of these, 26 patients presented with hepatocellular carcinoma, 12 with hilar cholangiocarcinoma, six with intrahepatic cholangiocarcinoma, four with liver metastasis, and nine with other diseases. All patients preoperatively underwent three-phase dynamic multidetector CT and ^(99m)Tc-GSA scintigraphy. We compared the parenchymal hepatic resection rate(PHRR) with the FHRR, which was defined as the resection volume counts per total liver volume counts on 3D CT/^(99m)Tc-GSA SPECT fusion images.RESULTS: In total, 50 patients underwent bisectionectomy and seven underwent trisectionectomy.Biliary reconstruction was performed in 15 patients, including hepatopancreatoduodenectomy in two. FHRR and PHRR were 38.6 ± 19.9 and 44.5 ± 16.0, respectively; FHRR was strongly correlated with PHRR. The regression coefficient for FHRR on PHRR was 1.16(P < 0.0001). The ratio of FHRR to PHRR for patients with preoperative therapies(transcatheter arterial chemoembolization, radiation, radiofrequency ablation, etc.), large tumors with a volume of > 1000 m L, and/or macroscopic vascular invasion was significantly smaller than that for patients without these factors(0.73 ± 0.19 vs 0.82 ± 0.18, P < 0.05). Postoperative hyperbilirubinemia was observed in six patients. Major morbidities(Clavien-Dindo grade ≥ 3) occurred in 17 patients(29.8%). There was no case of surgeryrelated death.CONCLUSION: Our results suggest that FHRR is an important deciding factor for major hepatectomy, because FHRR and PHRR may be discrepant owing to insufficient hepatic inflow and congestion in patients with preoperative therapies, macroscopic vascular invasion, and/or a tumor volume of > 1000 m L.
基金supported by the National Basic Re-search Program of China (No. 2006CB403303)the Knowledge Innovation Program of the Chinese Academy of Sciences (No. KZCX2-YW-420-1)the National Natural Science Foundation of China (No. 20890112)
文摘Human serum albumin(HSA) is a plasma protein responsible for the binding and transport of fatty acids and a variety of exogenous chemicals such as drugs and environmental pollutants.Such binding plays a crucial role in determining the ADME(absorption,distribution,metabolism,and excretion) and bioavailability of the pollutants.The binding interaction between HSA and acetic acid(C2),octanoic acid(C8) and dodecanoic acid(C12) has been investigated by the combination of site-specific fluorescent probe,tryptophan intrinsic fluorescence and tyrosine electrochemistry.For the study of the fatty acid interaction with the two drug-binding sites on HSA,two fluorescent probes,dansylamide and dansyl-L-proline were employed in the displacement measurements.Intrinsic fluorescence of tryptophan in HSA was monitored upon addition of the fatty acids into HSA.Electrocatalyzed response of the tyrosine residues in HSA by a redox mediator was used to investigate the binding interaction.Qualitatively,observations from these three approaches were very similar.HSA did not show any change in the fluorescence and electrochemical experiments after mixing with C2,suggesting there is no significant interaction with the short-chain fatty acid.For C8,the measured signal dropped in a single-exponential mode,indicating an independent and non-cooperative binding.The calculated association constant and binding ratio were 3.1×106 L/mol and 1 with drug binding Site I,1.1×107 L/mol and 1 with Site II,and 7.0×104 L/mol and 4 with the tryptophan site,respectively.The measurements with C12 displayed multiple phases of fluorescence change,suggesting cooperativity and allosteric effect of the C12 binding.These results correlate well with those obtained by the established methods,and validate the new approach as a viable tool to study the interactions of environmental pollutants with biological molecules.
基金supported by a grant from the University of Torino(Ricerca Locale ex-60%,Bando 2015)
文摘It is well known that the safety and efficacy profile of an inhaled cortocosteroid(ICS) is influenced by the pharmacokinetic properties and associated pharmacodynamic effects of the drug. Freely circulating,protein unbound, and active ICS can cause systemic adverse effects. Therefore, a detailed investigation of drug-protein interaction could be of great interest to understand the pharmacokinetic behaviour of corticosteroids and for the design of new analogues with effective pharmacological properties. In the present work, the interaction between some corticosteroids and human serum albumin(HSA) has been studied by spectroscopic approaches. UV–Vis spectroscopy confirmed that all the investigated corticosteroids can bind to HSA forming a protein-drug complex. The intrinsic fluorescence of HSA was quenched by all the investigated drugs, which was rationalized in terms of a static quenching mechanism. The thermodynamic parameters determined by the Van't Hoff analysis of the binding constants(negative ΔH and ΔS values) clearly indicate thathydrogen bonds and van der Waals forces play a major role in the binding process between albumin and betamethasone, flunisolide and prednisolone, while hydrophobic forces may play a major role in stabilizing albumin-triamcinolone complexes.
基金supported by the Talent Fund of Chinese Academy of Agricultural Sciences,Chinathe Technology Transformation Fund,the Ministry of Sciences and Technology,China
文摘The antioxidant ability of capsules containing oats avenanthramides on human body was evaluated in present study.Healthy people were randomized to supplementation with oats-derived avenanthramides capsules or placebo for 1 mon.Plasma lipid peroxides and antioxidant status were measured.For 8 capsules (containing 3.12 mg avenanthramides) groups,the levels of serum superoxide dismutase (SOD) and reduced glutathione hormone (GSH) were significantly increased by 8.4 and 17.9%,respectively (P<0.05),and malondialdehyde (MDA) level significantly decreased by 28.1%.The total cholesterol (TC),triglyceride (TG),and low density lipoprotein cholesterol (LDL-C) levels were lowered by 11.1,28.1,and 15.1%,respectively (P<0.05).The high density blood lipoprotein cholesterol (HDL-C) levels in the same treat was increased by 13.2%.Based on our research,it can be concluded that oats extract containing avenanthramides possessed a high antioxidative activity on humans.It indicated that oat avenanthramides could be used to prevent hyperlipemic and angiocardiopathy.
基金Supported by the National Natural Science Foundation of China(21476198,21576233)the International Science&Technology Cooperation Program of China(2015DFG42070)
文摘Five tryptophan analogues with a hydrophobic indole ring and an amino group on each molecule were used as functional ligands of mixed-mode resins for human serum albumin(HSA) purification. Their adsorption performance was evaluated and the effects of p H and salt addition on HSA adsorption were studied. The resins prepared showed typical p H-dependent adsorption and the highest adsorption capacity and affinity were found at pH 5.0for all the resins tested. The saturated adsorption capacity was 138.02 mg·g^(-1)with the tryptaminefunctionalized resin, which significantly decreased at p H below 4.0 due to electrostatic repulsion between ligands and HSA. Moreover, the addition of Na Cl or(NH_4)_2SO_4in media reduced HSA adsorption capacity, although the two salts showed different affecting profiles. The tryptamine-functionalized resin showed the best salt-tolerant performance, and its high adsorption capacity was maintained under high salt concentrations. In addition, the five resins prepared showed good adsorption selectivity for recombinant HSA from Pichia pastoris broth. Molecular docking results between tryptamine and HSA indicated that tryptamine was favorable to bind on Site II(indole-binding site) of HSA.
基金financially supported by the National Natural Science Foundation of China(30960530)
文摘Flavonoids are structurally diverse and the most ubiquitous groups of polyphenols distributed in the various plants,which possess intensive biological activities.In this study,the interaction mechanisms between four flavonoids containing one glucose unit with similar molecular weight isolated from the Tibetan medicinal herb Pyrethrum tatsienense,namely.apigenin-7-O-β-D-glucoside(1),luteolin-7-O-β-D-glucoside(2).quercetin-7-O-β-D-glucoside(3).quercetin-3-O-β-D-glycoside(4).and human serum albumin(HSA),were investigated by fluorescence.UV-vis absorbance,circular dichroism,and molecular modeling.The effects of biological metal ions Mg^(2+),Zn^(2+),and Cu^(2+) on the binding affinity between flavonoids and HSA were further examined.Structure-activity relationships of four flavonoids binding to HSA were discussed in depth and some meaningful conclusions have been drawn by the experiment data and theoretical simulation.In addition,an interesting phenomenon was observed that the microenvironment of the binding site I in HSA has hardly changed in the presence of 4 differentiating from the other three flavonoids on the basis of conformation investigations.
