Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 26
Filter
1.
Adv Pharm Bull ; 12(3): 419-422, 2022 May.
Article in English | MEDLINE | ID: mdl-35935058

ABSTRACT

Cytokines, as protein biomarkers, have essential functions in the diagnosis, identification, and healing of a broad range of syndromes. For the specific and accurate monitoring of immune conditions, which change rapidly throughout the duration of disease, sophisticated sensors for detecting cytokines are essential and will assist in clinical testing and studies of various diseases. The present manuscript briefly discusses fundamental principles applied to the development of tools for cytokine detection and new biomarker development. The latest developments in the technologies for highly sensitive and multiplexed cytokine quantification, with current detection capabilities across a broad, vibrant array, are also discussed. Finally, nanomaterial-based cytokine sensors, currently considered new approaches, are presented from the perspective of optimizing the sensitivity and multiplexity of cytokine detection.

2.
Mol Biol Rep ; 49(7): 6659-6691, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35253073

ABSTRACT

Parasitic diseases have a serious impact on the world in terms of health and economics and are responsible for worldwide mortality and morbidity. The present review features the hybrid targeting involving three main enzymes for the treatment of different parasitic diseases. The enzymes Dihydrofolate reductase, thymidylate synthase, and Serine hydroxy methyltransferase play an essential role in the folate pathway. The present review focuses on these enzymes, which can be targeted against several diseases. It shed light on the past, present, and future of these targets, and it can be assessed that these targets can play a significant role against several infectious diseases. For combating viral and protozoal infectious diseases, these targets in combination should be addressed.


Subject(s)
Communicable Diseases , Tetrahydrofolate Dehydrogenase , Humans , Methyltransferases , Serine , Tetrahydrofolate Dehydrogenase/genetics , Tetrahydrofolate Dehydrogenase/metabolism , Thymidylate Synthase/genetics , Thymidylate Synthase/metabolism
3.
Heliyon ; 8(1): e08809, 2022 Jan.
Article in English | MEDLINE | ID: mdl-35111986

ABSTRACT

The vehicular industry is looking for continuous challenges to develop the sustainability of its manufacturing, maintenance processes, and vehicle emissions due to marketability, environmental, economic, and policy concerns. The present study focuses on the impact of these processes on the environment. In Pakistan, most of the auto-body refinishing processes are carried out in an open atmosphere. The shades of Azadirachta indica (Neem Tree) are generally used for the outdoor practice of scrapping, grinding, and painting in auto-body refinishing shops of Pakistan. Azadirachta indica leaves were selected as bio-indicator. For the present work, 26 affected sites and 10 control sites were selected from Karachi city, which is the financial hub and biggest city of Pakistan. Concentrations of different metals (Fe, Co, Cd, Cr, Cu, Mn, Mo, Ni, Pb, and Zn) were determined by atomic absorption spectrophotometer. A geographic information system (GIS) is used to present the variation in concentrations within Karachi city. The only positive correlation was observed in Pb and Mn (0.750). Principal component analysis (PCA) is applied to identify the anthropogenic effect between auto-body refinishing areas and control areas. Almost all analyzed metals show higher concentration at affected sites but Pb (87.14 mg/kg), Mn (46.47 mg/kg) and Fe (146.95 mg/kg) were leading the values, as compared to their concentration at control sites, Pb (48.83 mg/kg), Mn (15.23 mg/kg) and Fe (43.07 mg/kg). All analyzed metals are frequently present in different color pigments, whereas Pb, Mn, and Fe may also come from other sources, like the anti-knocking agent, vehicular exhaust, and scraping of car surface.

4.
J Biomol Struct Dyn ; 40(17): 7680-7692, 2022 10.
Article in English | MEDLINE | ID: mdl-33779506

ABSTRACT

Reverse transcriptase is the most therapeutic target for the discovery of novel, potent, and non-toxic new anti-retroviral drugs. In the present work, various docking software such as Sybyl Surflex-Dock, OpenEye FRED, and Hermes GOLD were evaluated for their efficiency to reproduce known cognate inhibitors' conformations. Three metrics were used and compared to assess the performance of the applied scoring functions, i.e. enrichment factor, receiver operating characteristic (ROC) curves, and Bedroc analysis. Twelve different scoring functions of three softwares were used to assess their ability to rank the cognate ligand within the active site of its proteins. The extensive virtual screening task was performed on eight crystal structures, and the performance of docking and scoring was assessed by their ability to efficiently detect known active compounds enriched in the top-ranked of the list among a randomly selected dataset of the ten thousand compounds of the NCI database. The effectiveness of post-docking relaxation in Surflex was also evaluated. The top 20, 50, and 100 compounds were selected based on consensus scoring functions from all 48 proteins with different ligand complexes. Further, the shortlisted leads were subjected to ADMET via using Discovery Studio. The results further implicate the importance of various statistical tools that should be followed before large-scale virtual screening for the drug discovery process. In silico results demonstrating the experiment was successful. The study of the research covers the combinatorial in silico techniques such as benchmarking of the softwares and scoring functions, statistical tools applied for screening and different conformations of HIV-RT crystal structures for virtual screening with rigid and flexible molecular docking and molecular dynamics simulation approach. This study reveals a clear roadmap to identify novel scaffolds against HIV-RT for antiretroviral therapy, thus providing the remedial solutions of HIV related infections and other diseases caused by malfunctioning of the target protein.Communicated by Ramaswamy H. Sarma.


Subject(s)
Molecular Dynamics Simulation , Software , Ligands , Molecular Docking Simulation , Proteins/chemistry , RNA-Directed DNA Polymerase
5.
Bioorg Chem ; 115: 105209, 2021 10.
Article in English | MEDLINE | ID: mdl-34364054

ABSTRACT

A series of semicarbazone, thiosemicarbazone, thiazole, and oxazole derivatives were designed, synthesized, and examined for monoamine oxidase inhibition using two isoforms, i.e., MAO-A and MAO-B. Among all the analogues, 3c and 3j possessed substantial activity against MAO-A with IC50 values of 5.619 ± 1.04 µM and 0.5781 ± 0.1674 µM, respectively. Whereas 3d and 3j were active against monoamine oxidase B with the IC50 values of 9.952 ± 1.831 µM and 3.5 ± 0.7 µM, respectively. Other derivatives active against MAO-B were 3c and 3g with the IC50 values of 17.67 ± 5.6 µM and 37.18 ± 2.485 µM. Moreover, molecular docking studies were achieved for the most potent compound (3j) contrary to human MAO-A and MAO-B. Kinetic studies were also performed for the most potent analogue to evaluate its mode of interaction with MAO-A and MAO-B.


Subject(s)
Molecular Docking Simulation , Monoamine Oxidase Inhibitors/pharmacology , Monoamine Oxidase/metabolism , Oxazoles/pharmacology , Semicarbazones/pharmacology , Thiazoles/pharmacology , Thiosemicarbazones/pharmacology , Dose-Response Relationship, Drug , Humans , Kinetics , Molecular Structure , Monoamine Oxidase Inhibitors/chemical synthesis , Monoamine Oxidase Inhibitors/chemistry , Oxazoles/chemistry , Semicarbazones/chemistry , Structure-Activity Relationship , Thiazoles/chemistry , Thiosemicarbazones/chemistry
7.
J Chromatogr Sci ; 59(10): 923-927, 2021 Oct 29.
Article in English | MEDLINE | ID: mdl-33621328

ABSTRACT

A simple, accurate and precise RP-HPLC method was developed for the simultaneous determination of chloroquine, pyrimethamine and cetirizine hydrochloride concentrations in bulk drug and human serum. The assay was performed using a mobile phase of methanol: water (70:30) at pH of 2.8 ± 0.05 on the Purospher C-18 column with UV detection at 230 nm and rosuvastatin used as an internal standard. The retention times observed for chloroquine, pyrimethamine and cetirizine hydrochloride were 3.5, 2.5 and 5.5 minutes, respectively. The method was found to be specific for the assayed drugs showing a linear response in the concentration range of 1-100 µg mL-1 with coefficients of determination values of (r = 0.999). The method was developed and validated according to ICH guidelines. The method was used to monitor the serum samples and was found to be sensitive for therapeutic purposes, showing the potential to be a useful tool for routine analysis in laboratories.


Subject(s)
Cetirizine , Pyrimethamine , Chloroquine , Chromatography, High Pressure Liquid , Humans , Reproducibility of Results
8.
Eur J Pharmacol ; 890: 173746, 2021 Jan 05.
Article in English | MEDLINE | ID: mdl-33221318

ABSTRACT

Since the discovery of the yellow fever virus in 1901, thus far, two hundred nineteen viral species are recognized as human pathogens. Each year, the number of viruses causing infections in humans increases, triggering epidemics and pandemics, such as the current COVID-19 pandemic. Pointing to bats as the natural host, in 2019, a genome highly identical to a bat coronavirus (COVID-19) spread all over the world, and the World Health Organization (WHO) officially confirmed it as a pandemic. The virus mainly spreads through the respiratory tract, uses angiotensin-converting enzyme 2 (ACE2) as a receptor, and is characterized by symptoms of fever, cough, and fatigue. Antivirals and vaccines have provided improvements in some cases, but the discovery of a new and diverse variety of viruses with outbreaks has posed a challenge in timely treatments for medical scientists. Currently, few specific antiviral strategies are being used, and many of the effective antiviral drugs and reported active molecules are under vital exploration. In this review, with the details of viral diseases, we summarize the current attempts in drug development, epidemiology, and the latest treatments and scientific advancements to combat the COVID-19 epidemic. Moreover, we discuss ways to reduce epidemics and pandemics in the near future.


Subject(s)
Virus Diseases/therapy , Animals , Antiviral Agents/therapeutic use , Computer Simulation , Drug Development , History, 18th Century , History, 19th Century , History, 20th Century , History, 21st Century , Humans , Pandemics , Viral Vaccines , Virus Diseases/epidemiology , Virus Diseases/history
9.
Curr Comput Aided Drug Des ; 16(5): 583-598, 2020.
Article in English | MEDLINE | ID: mdl-31453790

ABSTRACT

BACKGROUND: Human African trypanosomiasis is a fatal disease prevalent in approximately 36 sub-Saharan countries. Emerging reports of drug resistance in Trypanosoma brucei are a serious cause of concern as only limited drugs are available for the treatment of the disease. Pteridine reductase is an enzyme of Trypanosoma brucei. METHODS: It plays a critical role in the pterin metabolic pathway that is absolutely essential for its survival in the human host. The success of finding a potent inhibitor in structure-based drug design lies within the ability of computational tools to efficiently and accurately dock a ligand into the binding cavity of the target protein. Here we report the computational characterization of Trypanosoma brucei pteridine reductase (Tb-PR) active-site using twenty-four high-resolution co-crystal structures with various drugs. Structurally, the Tb-PR active site can be grouped in two clusters; one with high Root Mean Square Deviation (RMSD) of atomic positions and another with low RMSD of atomic positions. These clusters provide fresh insight for rational drug design against Tb-PR. Henceforth, the effect of several factors on docking accuracy, including ligand and protein flexibility were analyzed using Fred. RESULTS: The online server was used to analyze the side chain flexibility and four proteins were selected on the basis of results. The proteins were subjected to small-scale virtual screening using 85 compounds, and statistics were calculated using Bedroc and roc curves. The enrichment factor was also calculated for the proteins and scoring functions. The best scoring function was used to understand the ligand protein interactions with top common compounds of four proteins. In addition, we made a 3D structural comparison between the active site of Tb-PR and Leishmania major pteridine reductase (Lm- PR). We described key structural differences between Tb-PR and Lm-PR that can be exploited for rational drug design against these two human parasites. CONCLUSION: The results indicated that relying just on re-docking and cross-docking experiments for virtual screening of libraries isn't enough and results might be misleading. Hence it has been suggested that small scale virtual screening should be performed prior to large scale screening.


Subject(s)
Drug Discovery/methods , Enzyme Inhibitors , Molecular Docking Simulation , Oxidoreductases/chemistry , Trypanosoma brucei brucei/enzymology , Catalytic Domain , Drug Design , Humans , Structure-Activity Relationship
10.
Article in English | MEDLINE | ID: mdl-31135268

ABSTRACT

Cancer diseases are widely recognised as an important medical problem and killing millions of people in a year. Chemotherapeutic drugs are successful against cancer in many cases and different compounds, including the analogues of natural substances, may be used for anticancer agents. Nucleoside analogues also have become a necessity for the treatment of cancer diseases. Nucleoside, nucleotide and base analogues have been utilised for decades for the treatment of viral pathogens, neoplasms and in anticancer chemotherapy. This review focuses on the different types of nucleosides and their potential role as anticancer agents. It also discusses the nucleoside analogues approved by FDA and in process of approval. The effect of the substitution on the nucleoside analogues and their pharmacological role is also discussed in the review. Owing to the advances in computational chemistry, it concludes with the future advancement and possible outcome of the nucleoside analogues. Also, it depicts the development of heterocyclic nucleoside analogues, explores the QSAR of the synthesised compounds and discusses the 3 D QSAR pharmacophore modelling in order to examine their potential anti-cancer activities.


Subject(s)
Antineoplastic Agents/pharmacology , Nucleosides/pharmacology , Purines/chemistry , Pyrimidines/chemistry , Antineoplastic Agents/chemistry , Dioxolanes/chemistry , Drug Approval , Drug Screening Assays, Antitumor , Humans , Models, Molecular , Molecular Structure , Nucleosides/chemistry , Quantitative Structure-Activity Relationship , United States , United States Food and Drug Administration
11.
Eur J Med Chem ; 166: 502-513, 2019 Mar 15.
Article in English | MEDLINE | ID: mdl-30739829

ABSTRACT

The peroxisome proliferator-activated receptors (PPAR-α, PPAR-ß/δ, and PPAR-γ) are members of the nuclear receptor super-family, acting as ligand-inducible transcription factors and play crucial roles in glucose and lipid metabolism. These are a well-known receptor for diabetic therapy, not only influence the cardiovascular systems but are also expressed in many human solid tumors. For atherosclerosis, inflammation, and hypertension, the PPARs are considered as important therapeutic targets. Furthermore, it has been suggested that careful designing of partial agonists for PPARs, may show improvement with the side effects and also increase the therapeutic value for different diseases as cancer, inflammation and cardiovascular etc. This review summaries structural features of PPAR receptors, illustrates the method of PPAR modulator design, then analyzes recent dual- and pan-agonist with different therapeutic outcomes of the receptor to be used as a target for drugs in future. The advances in PPARs antagonists, their classification and structure-activity relationship are also summarized.


Subject(s)
Peroxisome Proliferator-Activated Receptors/metabolism , Animals , Disease , Drug Discovery , Humans , Ligands , Peroxisome Proliferator-Activated Receptors/chemistry
12.
Curr Comput Aided Drug Des ; 15(2): 167-181, 2019.
Article in English | MEDLINE | ID: mdl-29769007

ABSTRACT

BACKGROUND: QSAR models as PLS, GFA, and 3D were developed for a series of matriptase inhibitors using 35 piperidyl-cyclohexylurea compounds. The training and test sets were divided into a set of 28 and 8 compounds, respectively and the pki values of each compound were used in the analysis. METHODS: Docking and alignment methodologies were used to develop models in 3D QSAR. The best models among all were selected on the basis of regression statistics as r2, predictive r2 and Friedman Lack of fit measure. Hydrogen donors and rotatable bonds were found to be positively correlated properties for this target. The models were validated and used for the prediction of new compounds. Based on the predictions of 3D-QSAR model, 17 new compounds were prepared and their activities were predicted and compared with the active compound. Prediction of activities was performed for these 18 compounds using consensus results of all models. ADMET was also performed for the best-chosen compound and compared with the known active. RESULTS AND CONCLUSION: The developed model was able to validate the obtained results and can be successfully used to predict new potential and active compounds.


Subject(s)
Piperidines/chemistry , Piperidines/pharmacology , Serine Endopeptidases/chemistry , Serine Proteinase Inhibitors/chemistry , Serine Proteinase Inhibitors/pharmacology , Drug Design , Ligands , Models, Molecular , Molecular Docking Simulation , Quantitative Structure-Activity Relationship
13.
Chem Biol Drug Des ; 92(6): 1954-1962, 2018 12.
Article in English | MEDLINE | ID: mdl-30022596

ABSTRACT

Two series of metronidazole derivatives (ester derivatives and ether derivatives) were prepared reacting metronidazole and its acetic acid oxidized form with menthol, thymol, carvacrol, and eugenol. Both series of compounds were tested in vitro against two strains of Helicobacter pylori (the ATCC 26695 and P12), and one strain of Clostridium (Clostridium perfringens). Most of the prepared compounds showed biological activity against the targeted bacteria. Compound 11 was highly active against all tested bacterial strains, especially against P12 with IC50 0.0011 µM/ml. Compound 6 was highly active against C. perfringens with MIC 0.0094 nM/ml. Viability test was conducted for compound 11 to test its selectivity for normal human fetal lung fibroblasts (MRC5), and it was found to be non-toxic with IC50 more than 50 µM/ml.


Subject(s)
Anti-Bacterial Agents/chemistry , Eugenol/chemistry , Metronidazole/analogs & derivatives , Monoterpenes/chemistry , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/pharmacology , Cell Line , Cell Survival/drug effects , Clostridium perfringens/drug effects , Helicobacter pylori/drug effects , Humans , Metronidazole/chemical synthesis , Metronidazole/pharmacology , Microbial Sensitivity Tests
14.
Chem Biol Drug Des ; 90(5): 679-689, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28371417

ABSTRACT

A series of phosphonated carbocyclic 2'-oxa-3'-aza-nucleosides were synthesized via 1,3 dipolar cycloaddition and evaluated for their in vitro antiproliferative activity against the growth of cancer cell lines (MCF-7, A2780, HCT116) and normal non-transformed fibroblast (MRC5) using MTT assay. Synthesized compounds exhibited antiproliferative activity in the micromolar range. Compounds 11b showed the highest activity against MCF-7 cells (IC50 of 0.2344 µm). Cell cycle analysis was performed for compound 11b on MCF7 cells showing arrest of cells in the S phase. Molecular docking of synthesized compounds confirmed high affinity of these compounds to two different receptors for anticancer nucleosides on dCK, namely the 1P5Z and 2ZIA, showing scores higher than the cognate ligand for all tested compounds. All synthesized compounds were evaluated according to the Lipinski, Veber, and Opera rules, and all of them passed the evaluation showing excellent features, superior to reference drugs. In addition, ADME for all the synthesized compounds was predicted through a theoretical kinetic study using the discovery studio 3.1 software.


Subject(s)
Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Neoplasms/drug therapy , Organophosphonates/chemistry , Organophosphonates/pharmacology , Antineoplastic Agents/chemical synthesis , Aza Compounds/chemical synthesis , Aza Compounds/chemistry , Aza Compounds/pharmacology , Cell Cycle Checkpoints/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Humans , MCF-7 Cells , Molecular Docking Simulation , Neoplasms/metabolism , Neoplasms/pathology , Nucleosides/chemical synthesis , Nucleosides/chemistry , Nucleosides/pharmacology , Organophosphonates/chemical synthesis
15.
J Mol Graph Model ; 73: 74-93, 2017 05.
Article in English | MEDLINE | ID: mdl-28242581

ABSTRACT

Towards the design of new class of podophyllotoxin to target topoisomerase II and tubulin as substantial target in cancer therapy, a series of isoxazolidine podophyllotoxin derivatives were designed. Topoisomerase in complex with etoposide and four ß-tubulin in complex with zampanolide, taxol, vinblastine or colchicine were used as targets using GOLD5.2.2 as a docking module. The revealed key structural features of the highest fitness into tubulin domain have been explained as follows: (1) trans orientation of the lactone (ring D) with 5a-ß, 8a-α configuration; (2) dioxolane in ring A; (3) free rotation of ring E; (4) α (R) or ß (S) configuration has equal fitness in position 5; (5) 4'-OMe; (6) phosphoramide linkage; (7) ethylene bridge between the phosphate and isoxazolidine ring; (8) benzyl moiety at N2-position of isoxazolidine ring; and (9) position 5 of isoxazolidine ring accommodated with 6-bromo-9H-purine, 2-amino-6H-purin-6-one, or N-(2-oxopyrimidin-4-yl) acetamide. All of these structural features are applicable for compounds to fit properly into topoisomerase II, except (1) ß (S) configuration has a higher score fitness than α (R) in position 5; (2) 4'-OH; and (3) position 5 of isoxazolidine ring accommodated better with 6-bromo-9H-purine, 2-amino-6H-purin-6-one or 7H-purin-6-amine. Computational ADMET and toxicity studies were in consensus with the docking results. Compounds holding ethylene bridge between phosphate and benzyl moiety at N2-position of isoxazolidine ring have the optimal pharmacokinetic properties and were calculated to be non-toxic. The predicted solubility profile for most of 4'-OMe containing compounds was good. This accomplished our aim in identifying promising new hits as antitumor agent with improved activity and less toxicity.


Subject(s)
DNA Topoisomerases, Type II/metabolism , Oxazoles/pharmacology , Podophyllotoxin/pharmacology , Topoisomerase II Inhibitors/pharmacology , Tubulin Modulators/pharmacology , Animals , Clinical Trials as Topic , Drug Design , Mice , Molecular Conformation , Molecular Docking Simulation , Oxazoles/chemistry , Podophyllotoxin/chemistry , Rats , Topoisomerase II Inhibitors/chemistry , Tubulin Modulators/chemistry , Vinblastine/chemistry , Vinblastine/pharmacology
16.
J Drug Target ; 23(1): 52-8, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25148611

ABSTRACT

The work presented here describes the fabrication of a novel drug delivery system, which consists of gold nanorods and doxorubicin, with the attachment of thioctic acid and folic acid, for the targeted release of drug to cancer cells. Doxorubicin, the potent anticancer drug, is widely used to treat various cancers. Gold nanorods were functionalized chemically to generate active groups for the attachment of drug molecules and subsequently attached to folic acid. The resulting nanostructure was characterized by UV-visible-NIR spectrophotometry, TEM techniques, zeta potential measurement and subsequently used to target folate receptor-expressing cancers cells for the delivery of doxorubicin. We generated a release profile for the release of doxorubicin from the nanostructures in KB cells using single-molecule fluorescence intensity images and fluorescence lifetime images. The results indicated that the nanorods were able to enter the target cells because of the attachment of folic acid and used as a carriers for the targeted delivery of doxorubicin.


Subject(s)
Antineoplastic Agents/administration & dosage , Doxorubicin/administration & dosage , Drug Delivery Systems/methods , Drug Liberation , Gold/chemistry , Nanotubes/chemistry , Antineoplastic Agents/chemistry , Antineoplastic Agents/metabolism , Doxorubicin/chemistry , Doxorubicin/metabolism , Folic Acid/chemistry , Folic Acid/metabolism , Folic Acid Transporters/metabolism , Gold/metabolism , Humans , KB Cells , Neoplasms/metabolism , Optical Imaging , Spectrum Analysis , Thioctic Acid/chemistry
17.
J AOAC Int ; 96(1): 56-9, 2013.
Article in English | MEDLINE | ID: mdl-23513958

ABSTRACT

The objective of this research was to develop and validate a rapid, economical, and sensitive HPLC method for quantitative determination of gliquidone, pioglitazone hydrochloride, and atorvastatin in tablets and serum. Due to drug combination of these formulations, there has been a need for a reliable quantitative method to determine these drugs in commercial samples and human serum. The chromatographic separation was carried out at ambient temperature with a mobile phase consisting of methanol-water (90 + 10, v/v), with pH adjusted to 3.50 with phosphoric acid. The pump was operated at a flow rate of 1 mL/min, and all analytes were detected at 235 nm. The method was linear over the concentration range of 5-50 microg/mL for all the drugs. The LOD of gliquidone, pioglitazone hydrochloride, and atorvastatin was 0.30, 1.30, and 0.57 microg/mL and LOQ was 0.98, 4.28, and 1.90 microg/mL, respectively. The proposed method was successfully applied to the determination of these drugs in commercial tablets and human serum. The established method was validated with respect to specificity, linearity, precision, accuracy, and ruggedness.


Subject(s)
Chromatography, High Pressure Liquid/methods , Heptanoic Acids/analysis , Pyrroles/analysis , Sulfonylurea Compounds/analysis , Thiazolidinediones/analysis , Atorvastatin , Humans , Pioglitazone , Tablets
18.
J Chromatogr Sci ; 50(6): 531-7, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22532591

ABSTRACT

This paper describes tryptophan (TRP) estimation in raw human plasma and rat brain by reversed-phase high-performance liquid chromatography (RP-HPLC). Estimation was carried out on a Purospher STAR C18 column using water-acetonitrile (90:10 v/v, at pH 2.7) mixture at a rate of 1.5 mL/min as mobile phase. Eluents were monitored at 273 nm by an ultraviolet detector. The method was linear (R(2) > 0.999), precise (intra-day and inter-day precision <2%) in the range of 0.25-20 µg/mL. The detection and quantification limits were 0.0144 µg/mL and 0.0437 µg/mL, respectively. In human plasma, Day 1 and Day 2 precision were 0.054-2.29% and 1.66-3.7%; whereas precisions in rat brain were 1.23-2.3% and 0.677-4.2%, respectively. The method was applied to study TRP level in human smokers and in arthritic rat brain. An efficient RP-HPLC method was developed for TRP determination that worked for clinical and research purposes.


Subject(s)
Brain Chemistry , Chromatography, High Pressure Liquid/methods , Tryptophan/analysis , Animals , Chromatography, Reverse-Phase/methods , Female , Humans , Male , Rats , Rats, Sprague-Dawley , Tryptophan/blood
19.
Eur J Med Chem ; 46(5): 1857-60, 2011 May.
Article in English | MEDLINE | ID: mdl-21411194

ABSTRACT

In this paper, we have presented the demonstration of gold nanoparticles (Au NPs) functionalized with an anticancer drug, doxorubicin. Doxorubicin was assembled on gold via amino group. The reaction proceeded under mild acidic conditions. Au NPs could not be adsorbed on doxorubicin in alkaline solution because amino group was not protonated. However, under acidic conditions, protonation created a positively charged amino group thus adsorption was easier. The interaction between Au colloids and doxorubicin is believed to be electrostatic. High-resolution TEM was used for visualization of nanoparticles, which were found to retain their average size and shape. The method, demonstrated that doxorubicin could be attached to Au NPs in a controlled manner. Our research laid the foundation of a linking methodology through which hybrid multi drug and receptor labeled NPs could be created, which might serve as an alternative design for nanosized drug-delivery systems.


Subject(s)
Antineoplastic Agents/chemical synthesis , Doxorubicin/chemical synthesis , Gold/chemistry , Metal Nanoparticles/chemistry , Organometallic Compounds/chemical synthesis , Adsorption , Antineoplastic Agents/chemistry , Doxorubicin/chemistry , Drug Delivery Systems , Hydrogen-Ion Concentration , Molecular Conformation , Organometallic Compounds/chemistry , Particle Size , Surface Properties
20.
J Chromatogr Sci ; 49(2): 114-7, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21223635

ABSTRACT

In the present study, a reverse-phase high performance liquid chromatography method was developed, validated and applied for the simultaneous determination of gliquidone, pioglitazone hydrochloride and verapamil in tablets and human serum. Chromatographic separation was achieved on a C18 column (5 µm, 25 × 0.46 cm) with a mobile phase consisting of methanol-water-acetonitrile (80:10:10 v/v/v) with a flow rate of 0.7 mL/min and pH adjusted to 3.50 with phosphoric acid at 230 nm. Glibenclamide was used as internal standard. The experimentally derived limit of detection and limit of quantitation were determined to be 0.24, 0.93, 0.40, and 0.80, 3.11, 1.36 µg/mL for gliquidone, pioglitazone, and verapamil, respectively. There were no interfering peaks due to the excipients present in the pharmaceutical tablets. Thus, the proposed method is simple and suitable for the simultaneous analysis of active ingredients in dosage forms and human serum.


Subject(s)
Chromatography, High Pressure Liquid/methods , Chromatography, Reverse-Phase/methods , Sulfonylurea Compounds/blood , Thiazolidinediones/blood , Verapamil/blood , Glyburide/analysis , Glyburide/chemistry , Humans , Linear Models , Pioglitazone , Reproducibility of Results , Sensitivity and Specificity , Sulfonylurea Compounds/chemistry , Tablets/chemistry , Thiazolidinediones/chemistry , Verapamil/chemistry
SELECTION OF CITATIONS
SEARCH DETAIL
...