Green synthesis, in silico modeling, and biological evaluation of N-substituted (Z)-5-arylidene imidazolidine/thiazolidine-2,4-dione/4-thione derivatives catalyzed by Bu SO3H core-shell nanostructures.

In this effort, the immobilization of guanidine-sulfonate on the surface of Fe3O4 MNPs (magnetic nanoparticles) as a novel acid nanocatalyst has been successfully reported for the synthesis of N-substituted (Z)-5-arylidene thiazolidine-2,4-dione and related cyclic derivatives, including rhodanine (RHD) and hydantoin (HYD) via a one-pot multiple-component reaction under green conditions. The products were characterized by SEM, TEM, TGA, EDS, BET techniques, VSM, and FTIR. The novel compounds synthesized using this methodology, designated as series La (1-9), Lb (1-8), and Lc (1-8), were subjected to anticancer screening against A549 and MCF7cell lines via MTT assays. Notably, several compounds (L1a, L2a, L3a, L1b, L2b, L3b, and L4b) exhibited potent antiproliferative activities, with observed IC50 values as low as 1.23 µM and 1.02 µM against MCF-7 cells, thereby outperforming the established anticancer drugs doxorubicin and cisplatin. Molecular docking and dynamics simulations revealed that ligands L1a, L2a, and L3a strongly interact with the protein target 3CD8, with L1a displaying significant hydrophobic and hydrogen bonding interactions and L2a engaging in unique pi-pi stacking with key residues. For protein 2WGJ, ligand L4b exhibited exceptional binding affinity, characterized by robust hydrogen bonding, hydrophobic interactions, and additional stabilizing mechanisms such as water bridges and pi interactions. Hence, N-substituted (Z)-5-arylidene thiazolidine-2,4-dione and its cyclic derivatives may serve as promising candidates for further exploration in the development of new multi-target cancer chemotherapy agents. These findings introduce promising anticancer agents and establish Fe3O4 MNPs as a versatile and environmentally sustainable catalytic platform in drug discovery.

Green synthesis, anti-proliferative evaluation, docking, and MD simulations studies of novel 2-piperazinyl quinoxaline derivatives using hercynite sulfaguanidine-SA as a highly efficient and reusable nanocatalyst.

In this study, the immobilization of sulfaguanidine-SA on the surface of FeAl2O4 (hercynite) MNPs (magnetic nanoparticles) as a novel acid nanocatalyst has been successfully reported for the synthesis of 2-(piperazin-1-yl) quinoxaline derivatives via a one-pot multiple-component reaction under green conditions. The products were characterized by SEM, TEM, TGA, EDS, BET technique, VSM, and FTIR. This series of novel 2-piperazinyl quinoxaline derivatives containing isatin-based thio/semicarbazones and/or Schiff bases of Metformin were evaluated for anticancer activity against both human ovarian and colon-derived tumor cell lines by MTT colorimetric assay. Although most of the investigated hybrid compounds exhibited excellent anti-proliferative activities and high selectivity index (SI) values, the promising compounds N'-[4-(quinoxaline-2-yl)-piperazine-1-yl]methyl-5-chloro-1-H-indole,2,3-dion-3-metformin 4c and N'-[4-(quinoxaline-2-yl)-piperazine-1-yl]methyl-5-bromo-1-H-indole,2,3-dion-3-metformin 4b proved to be the most potent anti-proliferative agents (IC50 values < 1 µM). Molecular docking and dynamics simulation suggest that these hybrid compounds can be wrapped in the catalytic cavity of c-Kit tyrosine kinase receptor and the binding pocket of P-glycoprotein with high scores. Thus, 2-piperazinyl quinoxaline linked isatin-based N-Mannich bases of metformin and/or thio/semicarbazones might be served as suitable candidates for further investigations to develop a new generation of multi-target cancer chemotherapy agents.

Correction to: In silico investigation of the therapeutic and prophylactic potential of medicinal substances bearing guanidine moieties against COVID-19.

[This corrects the article DOI: 10.1007/s11696-022-02528-y.].

In silico investigation of the therapeutic and prophylactic potential of medicinal substances bearing guanidine moieties against COVID-19.

The current viral pandemic, coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), creates health, mental, economic, and other serious challenges that are better to say global crisis. Despite the existence of successful vaccines, the possible mutations which can lead to the born of novel and possibly more dangerous variants of the virus as well as the absence of definitive treatment for this potentially fatal multiple-organ infection in critically ill patients make us keep searching. Theoretically targeting human and viral receptors and enzymes via molecular docking and dynamics simulations can be considered a wise, rational, and efficient way to develop therapeutic agents against COVID-19. In this way, The RNA-dependent RNA polymerase (RdRP), main protease, and spike glycoprotein of SARS-CoV-2 as well as the human angiotensin-converting enzyme 2 receptor and transmembrane serine protease 2 are the most discussed and studied targets that play essential roles in the viral life and infection cycle. In the current in silico investigation, the guanidine functionality containing drugs and medicinal substances such as metformin, famotidine, neuraminidase inhibitors, antimalarial medications, anticancer drug imatinib, CGP compounds, and human serine protease inhibitor camostat were studied against the above-mentioned therapeutic targets and most of them (especially imatinib) have revealed an incredible spectrum of free docking scores and MD results. The current in silico investigation that its novel perspective of view is corroborated by the different experimental and clinical evaluations, confirms that the guanidine moiety can be considered as a missing promising pharmacophore in drug design and development approaches against SARS-CoV-2. Considering the chemical potency of this polyamine group in chemical interaction creation, the observed outcomes in this virtual screening were not surprising. On the other hand, the guanidine functional group has unique physico-chemical properties such as basicity that can make the target cells intracellular pH undesirable for the virus entry, uncoating, and cytosolic lifecycle. According to the obtained results in the current study that are interestingly confirmed by the previously reported efficacy of some the guanidine carrying drugs in COVID-19, guanidine as a potential multi-target anti-SARS-CoV-2 functional scaffold deserves further comprehensive investigations. Supplementary Information: The online version contains supplementary material available at 10.1007/s11696-022-02528-y.

Molecular docking and dynamics studies of Nicotinamide Riboside as a potential multi-target nutraceutical against SARS-CoV-2 entry, replication, and transcription: A new insight.

The highly contagious Coronavirus Disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), which is a newborn infectious member of the dangerous beta-coronaviruses (ß-CoVs) following SARS and MERS-CoVs, can be regarded as the most significant issue afflicting the whole world shortly after December 2019. Considering CoVs as RNA viruses with a single-stranded RNA genome (+ssRNA), the critical viral enzyme RNA dependent RNA polymerase (RdRp) is a promising therapeutic target for the potentially fatal infection COVID-19. Nicotinamide riboside (NR), which is a naturally occurring analogue of Niacin (vitamin B3), is expected to have therapeutic effects on COVID-19 due to its super close structural similarity to the proven RdRp inhibitors. Thus, at the first phase of the current molecular docking and dynamics simulation studies, we targeted SARS-CoV-2 RdRp. On the next phase, SARS-CoV RdRp, human Angiotensin-converting enzyme 2, Inosine-5'-monophosphate dehydrogenase, and the SARS-CoV-2 Structural Glycoproteins Spike, Nonstructural viral protein 3-Chymotrypsin-like protease, and Papain-like protease were targeted using the docking simulation to find other possible antiviral effects of NR serendipitously. In the current study, the resulted scores from molecular docking and dynamics simulations as the primary determinative factor as well as the observed reliable binding modes have demonstrated that Nicotinamide Riboside and its active metabolite NMN can target human ACE2 and IMPDH, along with the viral Spro, Mpro, PLpro, and on top of all, RdRp as a potential competitive inhibitor.

Synthesis and In Silico Investigation of Isatin-Based Schiff Bases as Potential Inhibitors for Promising Targets against SARS-CoV-2.

Despite the significant development in vaccines and therapeutics cocktails, there is no specific treatment available for coronavirus disease 2019 (COVID-19), caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Targeting the main protease (Mpro) of SARS-CoV-2, which possesses a key role in producing the essential viral structural and functional proteins, can be considered an efficient way to control this potentially lethal infection. Recently, some of Michael acceptor-pharmacophore containing inhibitors have been suggested as successful suppressors of the main protease. Here, we synthesized the Isatin-based Schiff bases possessing the structural pattern of a Michael acceptor-like portion employing synthesis procedures. In silico investigation of these compounds was not limited to the main protease. We have also evaluated their possible inhibitory activity against the other identified druggable targets using homology modeling, molecular docking, and molecular dynamics simulations. Our investigations revealed that the dimethyl biguanide carrying Schiff bases of Isatin-derivatives have the best binding mode and interaction energy. The dimethyl biguanide moiety-containing compounds have formed promising interactions with the key amino acid residues Cys145 and HIS41 of Mpro with a binding free energy of -7.6 kcal/mol which was lower than the positive control compound Carmofur (-6.3 kcal/mol). It also leads to the higher affinity and the much inhibitory potential against the SARS-CoV-2 RdRp and Spike glycoproteins, human TMPRSS2, and ACE2 receptors.

Stereoselective synthesis of spirocyclic pyrrolidines/pyrrolizidines/pyrrolothiazolidines using l-proline functionalized manganese ferrite nanorods as a novel heterogeneous catalyst.

An efficient, green, one-pot, and three-component protocol has been reported for the stereoselective synthesis of a new class of spiro thiazolidines. A series of spiro-heterocycle derivatives were produced stereoselectively in high yields by the reaction of 5-arylidene thiazolidine-2,4-diones, isatin, and secondary amino acids in the presence of MnCoCuFe2O4@l-proline (MCCFe2O4@l-proline) magnetic nanorods as a novel nanocatalyst. The synthesized catalyst was fully characterized for thermal stability, magnetic properties, and other physicochemical properties via numerous techniques. It was applied as an efficient and reusable catalyst for the synthesis of endo-isomers of spirocyclic pyrrolidine/pyrrolizidine/pyrrolothiazolidine derivatives in high yield. The regioselectivity and stereochemistry of these heterocyclic spiro-compounds were established by 1H, 13C, HMBC, HSQC, and COSY NMR spectroscopy techniques. The main attractive characteristics of the presented protocol are high yield, high level of diastereoselectivity, and easy recovery of catalyst without significant loss of its catalytic activity.

Cavity-trapped electrons: lithium doped tetracyano-2,6-naphthoquinodimethane (TNAP) systems.

The interesting features in the lithium based electride motived us to explore new species with electride properties. To achieve this goal, the tetracyano-2,6-naphthoquinodimethane (TNAP) species has been used as backbone to investigate systematic addition of lithium atoms to the TNAP backbone (Lin@TNAP (n = 1-4) species) through density functional theory (DFT) simulation. After finding the most stable geometries for each Lin@TNAP (n = 1-4) species by full optimization process, we show their electronic-structural features in this work. In the next step, the properties of electron-density-laplacian (∇2ρ(r)), non-linear-optical (NLO), non-nuclear-attractor (NNA), and electron-localization-function (ELF) have been studied to incorporate the reported Lin@TNAP (n = 1-4) species in two different categories, salt or electride. The obtained outcomes present that the Li1@TNAP and the Li2@TNAP molecules are the lithium-salt. In contrast, the Li3@TNAP and the Li4@TNAP molecules are lithium-based electrides along with the isolated electrons in the molecular structure.

Green Synthesis, Biological Activity Evaluation, and Molecular Docking Studies of Aryl Alkylidene 2, 4-thiazolidinedione and Rhodanine Derivatives as Antimicrobial Agents.

AIMS AND OBJECTIVE: The magic scaffolds rhodanine and thiazolidine are very important heterocyclic compounds in drug design and discovery. Those are important heterocyclic compounds that have attracted a great deal of attention due to the fact that they exhibit a variety of bioactivities including antibacterial, antifungal, antiviral, antimalarial, and anti-inflammatory activities. These agents often exhibit selective toxicity. The goal of this study was molecular docking, green and solvent-free efficient synthesis of a new series of hetero/aromatic substituted rhodanine and thiazolidine analogues and then investigation of their antimicrobial activity. MATERIALS AND METHODS: To a mixture of TZD or rhodanine (1 mmol) in the presence of ionic liquid ChCl/urea, various aldehyde (1 mmol) was added. After completion of the reaction, obtained crude compound was collected by filtration and products were recrystallized from ethanol. The binding-free energy between all synthesized compounds with 3EEJ protein (C. glabrata enzyme) were obtained by molecular docking studies. These compounds were evaluated using microdilution method against (ATCC 6538) and (ATCC 12228) Gram-negative, (ATCC 8739) and (ATCC 9027) as Gram-positive and (ATCC 1012), (ATCC 339), C. (ATCC 1057), (ATCC 503), (ATCC 340) and (ATCC 194) as fungi. RESULTS: All of the acceptable products were determined by 1H NMR, 13C NMR, Mas and FT-IR spectroscopy. The binding-free energy between compounds 10a and 10b with 3EEJ protein were found to be -8.08 kcal/mol and -8.15 kcal/mol, respectively. These compounds having a heteroaromatic ring attached to the TZD or rhodanine core showed excellent antimicrobial activity with MIC values of 0.25-8 µg/mL (compound 10a) and 0.5-16 µg/mL (compound 10b) against the most tested fungi strains, Gram-positive and Gram-negative bacteria. CONCLUSION: A convenient and rapid method has been developed for the synthesis of rhodanine and thiazolidine-2,4-dione (TZD) derivatives as efficient antimicrobial agents using a Deep Eutectic Ionic Liquids (DEILs) choline chloride urea under solvent-free condition. Among the newly synthesized compounds, (Z)-5-((quinoxalin-3-yl) methylene) thiazolidine-2, 4-dione (10a) and (Z)- 5- ((quinoxalin-3-yl) methylene)-2-thioxothiazolidin-one (10b) exerted the promising effect and these compounds can be considered to be further probed as inhibitors of cgDHFR enzyme.

High-efficiency purification of sulforaphane from the broccoli extract by nanostructured SBA-15 silica using solid-phase extraction method.

Sulforaphane, a promising phytochemical, has received much attention in recent decades as a potential anticarcinogenic compound. In this research work, a novel, specific and affordable method has been developed for the separation and purification of natural sulforaphane from broccoli extract using SBA-15 mesoporous silica. SBA-15 was found to be the most efficient in the purification of sulforaphane compared to some of the conventionally used adsorbents and zeolites. The nanoparticles of SBA-15 mesoporous silica were synthesized using the hydrothermal method from natural amorphous silica extracted from rice husk ash with a silica purity of 96%. Structural and morphological analysis of the synthesized SBA-15 mesoporous silica were performed by the XRD, FT-IR, FE-SEM, and BET techniques. The method includes the primary immiscible solvent extraction of autolyzed broccoli sample with dichloromethane, followed by purification of the extract by SBA-15 mesoporous silica using solid-phase extraction (SPE) method. The recovery of the purified sulforaphane from broccoli extract was >98% using SBA-15 mesoporous silica, which is higher compared to that obtained using current purification methods. The highest purity of sulforaphane product was measured 94% based on the results of analytical HPLC chromatograms. Moreover, the effects of different parameters on the sulforaphane purification by using SBA-15 were studied and optimized.

A novel aluminum-sensitive fluorescent chemosensor based on 4-aminoantipyrine: An experimental and theoretical study.

A practical and an efficient Schiff base fluorescent chemosensor, salicylidene-4-aminoantipyrinyl-4-aminophenol (A2) has been synthesized through the condensation procedure of 1-phenyl-2,3-dimethyl-4-(N-2-hydroxybenzylidene)-3-pyrazoline-5-one and 4-aminophenol. Compound A2 has displayed a considerable fluorescence enhancement with high selectivity and sensitivity toward Al3+ ion and exhibited an emission band at 484 nm, which contained a low detection limit (LOD) of 1.06 × 10-7 M. In accordance to the experimental study, DFT, TDDFT calculations, and the enhancement of fluorescence intensity might be attributed to the inhibition of Photoinduced Electron Transfer (PET) along with the Excited-State Intramolecular Proton Transfer (ESIPT). As it has been specified by Job's plot and DFT calculations, the binding stoichiometries of A2 with Al3+ are 1:1, while the association constant (Ka) of Al3+ has been calculated and observed to be 2.67 ×â€¯× 105 M-1. Furthermore, the binding behavior and sensing mechanism of A2 with Al3+ have been confirmed through the experiments of 1H NMR titration.

Design, synthesis, biological assessment and molecular docking studies of new 2-aminoimidazole-quinoxaline hybrids as potential anticancer agents.

In a search for novel antiproliferative agents, a series of quinoxaline derivatives containing 2-aminoimidazole (8a-8x) were designed and synthesized. The structures of synthesized compounds were confirmed by IR, 1H NMR, 13C NMR, Mass Spectroscopy and analyzed using HSQC, COSY, ROESY, HMBC techniques. The anticancer activity of all derivatives were evaluated for colon cancer and breast cancer cell lines by the MTT assay and acridine orange/ethidium bromide double staining method. The anti-cancer effect in human colon cancer (HCT-116) and breast cancer (MCF-7) cell lines exhibited that compounds 8a, 8s, 8t, 8w, 8x appeared as potent antiproliferative agents and especially inhibited the human colon cancer cell proliferation with percentage of inhibition by over 50%. The most active compound was (E)-4-phenyl-1-((quinoxalin-2-ylmethylene)amino)-1H-imidazol-2-amine (8a) with the highest inhibition for MCF-7 (83.3%) and HCT-116 (70%) cell lines after 48 and 24h, respectively. Molecular docking studies of these derivatives within c-kit active site as a validated target might be suggested them as appropriate candidates for further efforts toward more potent anticancer compounds.

A new fluorene-based Schiff-base as fluorescent chemosensor for selective detection of Cr3+ and Al3.

2-((9H-fluoren-2-ylimino) methyl)phenol (F3) was synthesized by condensation reaction of 9H-fluoren-2-amine and 2-hydroxybenzaldehyde in EtOH and characterized by its melting point, 1H-,13C NMR and molecular mass. F3 exhibits a high selectivity for detection of Cr3+ and Al3+ ions as a fluorescent chemosensor and showed a single emission band at 536nm upon excitation at 333nm according to fluorescence emission studies. The addition of Cr3+ and Al3+ make a significant increase in fluorescent intensity at 536nm in CH3CN, while other metal ions have almost no influence on the fluorescence. The fluorescence enhancement was attributed to the inhibited CN isomerization and the obstructed excited state intra-molecular proton transfer (ESIPT) of compound F3. Job's plot and DFT calculations data showed that the binding stoichiometries of F3 with Cr3+ and Al3+ are 2:1. The association constants (Ka) for Cr3+ and Al3+ were calculated and found to be 8.33×104M-1 and 5.44×104M-1, respectively. The detection limits were also calculated for Cr3+ and Al3+ and found to be 2.5×10-7mol/L and 3.1×10-7mol/L, respectively.

Hypothermic activity of acetaminophen; involvement of GABAA receptor, theoretical and experimental studies.

OBJECTIVES: The mechanism of hypothermia action of acetaminophen (APAP) remains unclear even 125 years after its synthesis. Acetaminophen produces hypothermia. The mechanism of this reduction in core body temperature is not clear but evidence shows that it is not dependent on opioid and cannabinoid receptors. Because of strong documents about the roles of GABA and benzodiazepine receptors in hypothemic activity of some drugs such as diazepam, we determined if these receptors also contributes to the hypothermic effect of APAP. MATERIALS AND METHODS: Diazepam (5 mg/kg, IP) was used for induction of hypothermia. Flumazenil (10 mg/kg, IP) or picrotoxin (2 mg/kg, IP) used for reversal of this effect. Rats injected with APAP (100, 200 or 300 mg/kg, IP). Baseline temperature measurements were taken with a digital thermometer via rectum. To evaluate the structural correlation between APAP and benzodiazepine receptor ligands, numerous models are selected and studied at HF/6-31G* level of theory. Relative energies, enthalpies and Gibbs free energies were calculated for all selected drugs. RESULTS: Diazepam induced hypothermia was reversed by flumazenil or picrotoxin. Rats injected with APAP displayed dose- and time-related hypothermia. For combined administration, the hypothermic effect of APAP (200 mg/kg) was strongly reduced by pretreatment with picrotoxin or flumazenil P<0.0001and P<0.01, respectively. Selective structural data, bond length, dihedral angles, and related distance in pharmacophore of APAP and BZDR models were the same. Some significant structural analogues were obtained between these drugs. CONCLUSION: Results suggest hypothermic action of acetaminophen may be mediate by its effect at GABAA benzodiazepine receptor.

Novel coumarin-based fluorescent probe for selective detection of Cu(II).

We report an efficient and convenient method for preparing nitro-3-carboxamide coumarin derivatives, proposed as novel fluorescent chemosensor, through microwave irradiation. This compound can be used as fluorescent probe for Cu(2+) with selectivity over other metal ions in aqueous solution. The fluorescence of 6-nitro-N-[2-(dimethylamino)ethyl]-2-oxo-2H-chromene-3-carboxamide(3) is the highest in the presence of Cu(2+), with stronger excitation at λ=320nm than for the other cations tested.

Quantum dots and ionic liquid-sensitized effect as an efficient and green catalyst for the sensitive determination of glucose.

A novel fluorescence (FL) method using water-soluble CdSe quantum dots (QDs) is proposed for the fluorometric determination of hydrogen peroxide and glucose. Water-soluble CdSe QDs were synthesized by using thioglycolic acid as stabilizer in aqueous solutions. The nanoparticles were structurally and optically characterized by X-ray powder diffraction (XRD), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), UV-Vis absorption spectroscopy, photoluminescence (PL) emission spectroscopy and transmission electron microscope (TEM). Ionic liquid-sensitized effect in aqueous solution was then investigated. In the presence of ionic liquid as catalyst, H2O2 was decomposed into radical that could quench the fluorescence of CdSe QDs more efficiently and rapidly. Then the oxidization of glucose by glucose oxidase was coupled with the fluorescence quenching of CdSe QDs by H2O2 producer with ionic liquid catalyst, which can be used to detect glucose. Therefore, a new FL analysis system was developed for the determination of glucose. Under the optimum conditions, there is a good linear relationship between the relative PL emission intensity and the concentration of glucose in the range of 5.0×10(-7)-1.0×10(-4) M of glucose with a correlation coefficient (R(2)) of 0.9973. The limit of detection of this system was found to be 1.0×10(-7) M. This method is not only simple, sensitive and low cost, but also reliable for practical applications.

New insights into the mechanism of iron-catalyzed cross-coupling reactions.

The mechanism of the iron-catalyzed cross-coupling of alkyl halides with aryl Grignard reagents is studied by a combination of GC monitoring and DFT calculation. Herein, we investigate two possible reaction pathways, the regular oxidative addition (OA) pathway and the atom transfer (AT) pathway that might occur in the rate-limiting step. The computational studies revealed that the AT pathway requires less energy than the regular OA pathway.

The use of imidazolium ionic liquid/copper complex as novel and green catalyst for chemiluminescent detection of folic acid by Mn-doped ZnS nanocrystals.

A novel chemiluminescence (CL) method using water-soluble Mn-doped ZnS quantum dots (QDs) as CL emitter is proposed for the chemiluminometric determination of folic acid in pharmaceutical formulation. Water-soluble Mn-doped ZnS QDs were synthesized by using L-cysteine as stabilizer in aqueous solutions. The nanoparticles were structurally and optically characterized by X-ray powder diffraction (XRD), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), UV-Vis absorption spectroscopy and photoluminescence (PL) emission spectroscopy. The CL of ZnS QDs induced by directly chemical oxidation and its ionic liquid-sensitized effect in aqueous solution were then investigated. It was found that oxidants, especially hydrogen peroxide, could directly oxidize ZnS QDs to produce weak CL emission in basic conditions. In the presence of 1,3-dipropylimidazolium bromide/copper a drastic light emission enhancement is observed, related to a strong interaction between Cu(2+) and the imidazolium ring. Therefore, a new CL analysis system was developed for the determination of folic acid. Under the optimum conditions, there is a good linear relationship between the relative CL intensity and the concentration of folic acid in the range of 1×10(-9)-1×10(-)(6) M of folic acid with a correlation coefficient (R(2)) of 0.9991. The limit of detection of this system was found to be 1×10(-)(10) M. This method is not only simple, sensitive and low cost, but also reliable for practical applications.

Determination of epinephrine in pharmaceutical formulation by an optimized novel luminescence method using CdS quantum dots as sensitizer.

In this article, a novel chemiluminescence method using water-soluble CdS quantum dots (QDs) as sensitizers is proposed for the chemiluminometric determination of epinephrine. The method is based on the quenching effect of epinephrine on the chemiluminescence emission generated by the mixing of CdS quantum dots (QDs) with hydrogen carbonate (HCO3(-)) in the presence of hydrogen peroxide (H2O2) in an alkaline medium. The optimization of variables influencing the chemiluminescence response of the method has been carried out by using experimental design. Under the optimal conditions, there is good linear relationship between the relative chemiluminescence intensity and the concentration of epinephrine over the range of 5 × 10(-9)-1 × 10(-6) molL(-1) with a 3σ detection limit of 5 × 10(-11) molL(-1). The method has been successfully applied to the determination of epinephrine in pharmaceutical formulation and the recovery test was done in human urine.

Immunohistochemical expression of vascular endothelial growth factor and its correlation with tumor grade in breast ductal carcinoma.

Breast cancer is the most common cause of cancer-related death in female, after lung cancer. Angiogenesis is essential for tumor growth and metastasis; therefore, antiangiogenesis strategies for treatment of cancer are currently an issue of interest. The role of vascular endothelial growth factor that assumed to be most potent angiogenesis factor is ambiguous in breast cancer. This study described the correlation between vascular endothelial growth factor expression and tumor grade, to define the breast cancer patients who responder to anti-vascular endothelial growth factor therapy. In this research, 200 cases of histological proved invasive ductal breast carcinomas analyzed for vascular endothelial growth factor expression by immunohistochemical staining via cross-sectional descriptive study. Vascular endothelial growth factor expressed in 72.54% of the breast cancers. The VEGF was more detectable in grade I (78.5%) than grade II (77.4%) and grade III (56.2%). There is a significant correlation between tumor grade and VEGF expression (P<0.05). According to this study, VEGF often expressed in invasive ductal breast carcinomas and inversely correlated with tumor grade. Anti-vascular endothelial growth factor postulated more convenience for tumor progression suppression in low grade tumor than high grade tumor.