scholarly journals Synthesis, Characterization, and BSA-Binding Studies of Novel Sulfonated Zinc-Triazine Complexes

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Nalin Abeydeera ◽  
Inoka C. Perera ◽  
Theshini Perera
Keyword(s):  
Bathochromic Shift ◽  
Binding Constants ◽  
Disodium Salt ◽  
Water Soluble ◽  
Disulfonic Acid ◽  
Binding Studies ◽  
H Nmr ◽  
Acid Sodium Salt ◽  
Vis Spectroscopy ◽  
Chemical Formulas

Four Zn(II) complexes containing a pyridyl triazine core (L1 = 3-(2-pyridyl)-5,6-di(2-furyl)-1,2,4-triazine-5′,5″-disulfonic acid disodium salt and L2 = 3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine-4′,4″-disulfonic acid sodium salt) were synthesized, and their chemical formulas were finalized as [Zn(L1)Cl2]·5H2O·ZnCl2 (1), [Zn(L1)2Cl2]·4H2O·2CH3OH (2), [Zn(L2)Cl2]·3H2O·CH3OH (3), and [Zn(L2)2Cl2] (4). The synthesized complexes are water soluble, making them good candidates for biological applications. All four complexes have been characterized by elemental analysis and 1H NMR, IR, and UV-Vis spectroscopy. The IR stretching frequency of N=N and C=N bonds of complexes 1–4 have shifted to lower frequencies in comparison with free ligands, and a bathochromic shift was observed in UV-Vis spectra of all four complexes. The binding studies of ligands and complexes 1–4 with bovine serum albumin (BSA) resulted binding constants (Kb) of 3.09 × 104 M−1, 12.30 × 104 M−1, and 16.84 × 104 M−1 for ferene, complex 1, and complex 2, respectively, indicating potent serum distribution via albumins.

scholarly journals Synthesis, Characterization, and BSA Binding Studies of Some New Benzamides Related to Schiff Base

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
M. K. Prashanth ◽  
M. Madaiah ◽  
H. D. Revanasiddappa ◽  
K. N. Amruthesh
Keyword(s):  
Schiff Base ◽  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Binding Constants ◽  
Spectral Studies ◽  
Spectroscopic Techniques ◽  
Binding Studies ◽  
Mass Spectral ◽  
H Nmr

Condensation of amine 1 with aldehyde 2 gives Schiff base, N-(4-((benzofuran-2-ylmethylene) amino)phenyl)acetamide 3. Schiff base on N-acylation with different substituted acid chlorides in the presence of triethylamine gives the corresponding benzamides, N-acetyl-N-(4-((benzofuran-2-ylmethylene)amino)phenyl)substitutedbenzamide (NABP) 5a–j. The structures of newly synthesized compounds were characterized by elemental analysis, 1H NMR, 13C NMR FT-IR, and mass spectral studies. Compounds 3 and 5a–j have been screened for their antimicrobial activity using the disc diffusion and minimum inhibitory concentration (MIC) method against the selected bacterial and fungal strain. Compounds 5a, 5e, 5g, and 5h were found to be more active against all tested strains. The antioxidant properties were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radical scavenging methods. Compounds 5i and 5j showed predominant antioxidant activities among the synthesized analogues. The interaction between NABP and bovine serum albumin (BSA) was investigated using fluorescence and ultraviolet spectroscopic techniques at 298 K under imitated physiological conditions. The results revealed that NABP caused the fluorescence quenching of BSA through a static quenching procedure. The binding constants and the number of binding sites were calculated. The binding distance between the donor (BSA) and acceptor (NABP) was determined based on Forster’s theory.

Metallocene-catalyzed olefin polymerizations using triphenylcyclopropenium tetrakis(pentafluorophenyl)borate as the activator

2003 ◽  
Vol 81 (6) ◽  
pp. 758-763 ◽  
Author(s):  
Huiying Li ◽  
Douglas C Neckers
Keyword(s):  
Ethylene Polymerization ◽  
Bathochromic Shift ◽  
Propylene Polymerization ◽  
Styrene Polymerization ◽  
Coordination Polymerization ◽  
Polymerization Mechanism ◽  
H Nmr ◽  
Carbonium Ion ◽  
Vis Spectroscopy ◽  
Olefin Polymerizations

Triphenylcyclopropenium (TPCP) tetrakis(pentafluorophenyl)borate activates bis(cyclopentadienyl)dimethyl titanium resulting in a highly reactive initiating system for the polymerization of styrene. In contrast to triphenylmethyl tetrakis(pentafluorophenyl)borate which is quite active in the absence of the metallocene, TPCP borate shows no activity for styrene polymerization in the absence of bis(cyclopentadienyl)dimethyl titanium. TPCP is the most efficient activator in the carbonium ion – borate class. We propose, based on 1H NMR evidence that reaction of Cp2TiMe2 and TPCP borate leads to the formation of the cationic Ti complex [Cp2TiMe]+B(C6F5)4–. Evidence for the latter is also provided by UV–vis spectroscopy in that we found a bathochromic shift of the Cp2TiMe2 LMCT absorption band from 361 to 482 nm in CH2Cl2 and 487 nm in toluene, respectively. Thermal decomposition of the cationic complex [Cp2TiMe]+B(C6F5)4– leads to less activity. The systems are good catalysts for ethylene polymerization as well, but are less active when using propylene. A conventional Ziegler–Natta coordination polymerization mechanism accounts for ethylene and propylene polymerization while a carbocationic polymerization mechanism is proposed for styrene.Key words: triphenylcyclopropenium tetrakis(pentafluorophenyl)borate, bis(cyclopentadienyl)dimethyl titanium, activator, olefin polymerization.

UV-vis and Binding Studies of Cobalt Tetrasulfophthalocyanine–Thiolate Complexes as Intermediates of the Merox Process

1999 ◽  
Vol 03 (07) ◽  
pp. 654-666 ◽  
Author(s):  
ALI NAVID ◽  
EDUARD M. TYAPOCHKIN ◽  
CHARLES J. ARCHER ◽  
EVGUENII I. KOZLIAK
Keyword(s):  
Charge Transfer ◽  
Charge Transfer Band ◽  
Broad Band ◽  
Spectral Feature ◽  
Binding Constants ◽  
Kinetic Studies ◽  
Binding Studies ◽  
Π Stacking ◽  
Vis Spectroscopy ◽  
Major Factors

Intermediates of the cobalt tetrasulfophthalocyanine ( CoTSPc )-catalyzed thiol autoxidation were studied by UV-vis spectroscopy. All thiolates react with CoTSPc resulting in the formation of 1:1 complexes. Three major factors control both the stability and aggregation of the complexes: thiolate basicity, metal-to-ligand charge transfer (MLCT) and π stacking. Basic thiolates partially reduce C oII TSPc , whereas CoTSPc complexes with low-basicity aliphatic thiolates ( p K a < 4) do not exhibit Co (II) reduction, based on the absence of the characteristic Co (I) charge transfer band at 450 nm. CoTSPc complexes with aliphatic and bulky aromatic thiolates appear to be aggregated in aqueous solutions and are characterized by a broad band at 650 nm. Non-bulky aromatic thiolates of low basicity ( p K a < 6) form unique stable monomeric Co II TSPc complexes. This unique spectral feature can be attributed to π stacking between the phthalocyanine ring and thiolate. Comparison of binding constants shows that the partial reduction of Co (II) significantly contributes to the thiolate binding. A combination of aromatic π stacking and MLCT appears to be responsible for the observed 1000-fold stronger binding of non-basic aromatic thiolates as compared with aliphatic ligands of similar basicity. Kinetic studies confirm the importance of the thiolate binding type for catalysis.

scholarly journals DNA binding properties, histidine interaction and cytotoxicity studies of water soluble ruthenium(ii) terpyridine complexes

2016 ◽  
Vol 45 (11) ◽  
pp. 4633-4646 ◽  
Author(s):  
Dejan Lazić ◽  
Aleksandar Arsenijević ◽  
Ralph Puchta ◽  
Živadin D. Bugarčić ◽  
Ana Rilak
Keyword(s):  
Dna Binding ◽  
Competitive Binding ◽  
Water Soluble ◽  
Binding Studies ◽  
Binding Properties ◽  
Cytotoxicity Studies ◽  
Vis Spectroscopy ◽  
Spectroscopy Studies ◽  
Ct Dna ◽  
Dna Binding Properties

UV-Vis spectroscopy studies, viscosity measurements and competitive binding studies with EB have revealed the ability of the complexes to bind to CT DNA covalently through N7 of guanine residues and non-covalently through intercalation.

Determination of Seven Manufacturing Impurities in FD&C Red No. 40 by Ultra-High-Performance Liquid Chromatography

2020 ◽  
Vol 103 (1) ◽  
pp. 235-243
Author(s):  
Bhakti Petigara Harp ◽  
Marianita Perez-Gonzalez ◽  
Hector M Cordero-Nieves ◽  
Rachel S Pandian ◽  
Bryan K Bowes
Keyword(s):  
Sulfonic Acid ◽  
High Performance ◽  
Hplc Method ◽  
Disodium Salt ◽  
Disulfonic Acid ◽  
Linear Calibration ◽  
Acid Sodium Salt ◽  
Color Additive ◽  
Survey Analyses

Abstract Background: The U.S. Food and Drug Administration batch-certifies color additives to ensure that each lot meets published specifications for coloring food, drugs, and cosmetics. Objective: An ultra-high-performance LC (UHPLC) method was developed to determine seven manufacturing impurities in the monoazo color additive FD&C Red No. 40 (R40). The analytes consist of two intermediates, an impurity originating from one intermediate, a reaction by-product, and three subsidiary colors. The intermediates are 4-amino-5-methoxy-2-methylbenzenesulfonic acid [cresidine-p-sulfonic acid (CSA)] and 6-hydroxy-2-naphthalene sulfonic acid sodium salt (SS). The impurity originating from the intermediate SS is 6,6′-oxybis[2-naphthalenesulfonic acid] disodium salt. The reaction by-product is 4,4′-(diazoamino)bis[5-methoxy-2-methylbenzenesulfonic acid disodium salt. The subsidiary colors are sodium salts of CSA coupled with 2-naphthol-3,6-disulfonic acid, 2-naphthol-6,8-disulfonic acid, or 2-naphthol. Methods: Samples of R40 were dissolved in an ammonium acetate buffer modified to pH 9.2, filtered, and analyzed by UHPLC. Quantitation of the analytes was performed by calibration in the presence of the color additive matrix. Results: UHPLC validation studies showed linear calibration curves (R2 = 0.9999), good recovery (95–121%) and precision (RSDs = 1.0–6.3%), and LOQs ranging from 0.002 to 0.030%. Survey analyses of 31 samples from 11 manufacturers yielded results by the new UHPLC method and a previously used HPLC method that are consistent within experimental error. Conclusions: The new UHPLC method provides faster analysis time, improved separation, and similar sensitivity compared to the HPLC method. Highlights: An UHPLC method was developed and validated to determine seven manufacturing impurities in R40 submitted to the FDA for batch certification.

Photophysical, photochemical and bovine serum albumin binding studies on water-soluble gallium(III) phthalocyanine derivatives

2007 ◽  
Vol 11 (09) ◽  
pp. 635-644 ◽  
Author(s):  
Abimbola Ogunsipe ◽  
Tebello Nyokong ◽  
Mahmut Durmuş
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Binding Constants ◽  
Water Soluble ◽  
Albumin Binding ◽  
Binding Studies ◽  
Amphiphilic Compounds ◽  
Yield Values ◽  
Bovine Serum Albumin Binding

Spectral, photophysical, photochemical and bovine serum albumin binding studies on some gallium(III) derivatives - {1,(4)-(tetrapyridyloxyphthalocyaninato)gallium(III), (α GaPc ); 2,(3)-(tetrapyridyloxyphthalocyaninato)gallium(III), (β GaPc ); and their quaternized derivatives: Q α GaPc and Q β GaPc )} are hereby presented. β-Substituted complexes are more fluorescent, but show lower tendencies to undergo intersystem crossing than the α-substituted, as judged by their fluorescence and triplet quantum yield values. The quaternized derivatives ( QGaPc ) are water-soluble and non-aggregated, which makes them potential photosensitizers of choice for photodynamic therapy applications; these amphiphilic compounds also bind strongly to bovine serum albumin in 1:1 stoichiometries, and with binding constants ( Kb) in the order of 106M−1.

scholarly journals Synthesis, Characterization, and Antimicrobial Activity of Novel Sulfonated Copper-Triazine Complexes

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Supun Katugampala ◽  
Inoka C. Perera ◽  
Chandrika Nanayakkara ◽  
Theshini Perera
Keyword(s):  
Antimicrobial Activity ◽  
Clinical Sample ◽  
Bathochromic Shift ◽  
Inhibition Zone ◽  
Analysis Data ◽  
Positive Control ◽  
Disodium Salt ◽  
Disulfonic Acid ◽  
Elemental Analysis Data ◽  
Empirical Formulas

Metallotriazine complexes possess interesting biological and medicinal properties, and the present study focuses on the synthesis, characterization, and antimicrobial activity of four novel copper-triazine derivatives in search of potent antibacterial and antifungal drug leads. In this study, 3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine-4,4′-disulfonic acid monosodium salt (L1, ferrozine) and 3-(2-pyridyl)-5,6-di(2-furyl)-1,2,4-triazine-5,5′-disulfonic acid disodium salt (L2, ferene) have been used as ligands to study the complexation towards copper(II). The synthesized complexes, [CuCl2(ferrozine)]·7H2O·MeOH (1), [CuCl2(ferrozine)2]·5H2O·MeOH (2), [CuCl2(ferene)]·H2O·MeOH (3), and [CuCl2(ferene)2]·H2O·MeOH (4), have been characterized spectroscopically, and preliminary bioassays have been carried out. FTIR spectroscopic data have shown that N=N and C=N stretching frequencies of complexes have been shifted towards lower frequencies in comparison with that of the ligands, confirming new bond formation between Cu and N, which in turn lowers the strength of N=N and C=N bonds. In addition, a bathochromic shift has been observed for UV-visible spectra of complexes (1), (2), (3), and (4). Furthermore, elemental analysis data have been useful to obtain empirical formulas of these complexes and to establish the purity of each complex. Complexes (1) and (2) have shown antibacterial activity for bothS. aureus(ATCC® 25923) andE. coli(ATCC® 25922) at 1 mg/disc concentration, and ferrozine has shown a larger inhibition zone against the clinical sample ofC. albicansat 1 mg/disc concentration in comparison with the positive control, fluconazole.

Tuning of the Cavity of Water-Soluble Thiacalix[4]arene for the Control of Inclusion Ability Toward Water-Miscible Organic Molecules

2004 ◽  
Vol 69 (5) ◽  
pp. 1080-1096 ◽  
Author(s):  
Noriyoshi Kon ◽  
Nobuhiko Iki ◽  
Yuichiro Sano ◽  
Satoshi Ogawa ◽  
Chizuko Kabuto ◽  
...  
Keyword(s):  
Guest Molecule ◽  
Organic Molecules ◽  
Hydrophobic Effect ◽  
Binding Constants ◽  
Water Soluble ◽  
Main Role ◽  
Diethyl Ketone ◽  
Guest Molecules ◽  
X Ray ◽  
H Nmr

Inclusion abilities of water-soluble thiacalix[4]arenetetrasulfonate (3) and mono-O-carboxymethylated derivatives 5 and 6 toward water-miscible organic molecules such as alcohols, ketones, and nitriles in water were investigated by 1H NMR. The limit chemical shift change of the guest upon inclusion in the host suggested that the hosts regioselectively encapsulate the guests from the side of aliphatic moiety. Large guests such as pentan-1-ol showed folding of the alkyl chain to be included inside the cavity. On the other hand, mono-O-substituted 6 included a guest molecule less deep in the cavity than 3 did. Binding constants (K) of 3 toward guest molecules increased with hydrophobicity of the guest, suggesting that hydrophobic effect plays a main role for the complexation. On the contrary, mono-O-carboxymethyl derivatives 5 and 6 showed the opposite dependency of stability on hydrophobicity; higher affinities toward less hydrophobic guests. Among the guests examined, the smallest entities such as CH3OH and CH3CN were best included in 5 with the highest binding constant ever reported (K > 102 M-1). It was concluded that introduction of the carboxymethyl group into one of the phenolic OH of thiacalix[4]arene led to tuning of the cavity shape for stereospecific inclusion of small guests. The tuning of cavity by the O-alkylation was actually confirmed by X-ray crystal analysis of a complex of 5 with diethyl ketone.

scholarly journals Effect of Net Charge on DNA-Binding, Protein-Binding and Anticancer Properties of Copper(I) Phosphine-Diimine Complexes

2021 ◽  
Author(s):  
Sammar Alsaedi ◽  
Bandar A. Babgi ◽  
Magda H. Abdellatif ◽  
Abdul-Hamid Emwas ◽  
Mariusz Jaremko ◽  
...  
Keyword(s):  
Dna Binding ◽  
Emission Spectra ◽  
Disodium Salt ◽  
Disulfonic Acid ◽  
Anticancer Activities ◽  
Binding Studies ◽  
Net Charge ◽  
Major Mechanism ◽  
Anticancer Properties ◽  
Ct Dna

AbstractThe syntheses of [Cu(PPh3)2(L)]NO3 and [Cu(PPh3)2(L-SO3Na)]NO3 were achieved through the reaction of Cu(PPh3)2NO3 and equimolar amount of the ligands (L = 5,6-diphenyl-3-[2-pyridyl]-1,2,4-triazine; LSO3Na = 5,6-diphenyl-3-[2-pyridyl]-1,2,4-triazine-4,4′-disulfonic acid disodium salt). The complexes were characterized by NMR and IR spectroscopy and mass spectrometry. The compounds exhibit similar absorption and emission spectra, suggesting a similar electronic structure. Ct-DNA binding studies show the strong influence of the net charge as Cu-L (positively charged) is able to bind to ct-DNA while Cu-LSO3Na (negatively charged) is not. The net charge of the complexes affects the thermodynamic and kinetic binding parameters toward human serum albumin. HSA-binding of the complexes was further investigated by molecular docking, revealing different binding sites on the HSA protein as a function of the net charge. The different anticancer activities of the complexes towards ovcar-3 and hope-62 cancer cell lines are suggestive of a role for the overall charge of the complexes. Interaction with the DNA is not the major mechanism for this class of complexes. The overall net charge of the pharmacophore (anticancer agent) should be a key consideration in the design of anticancer metal complexes.

Enantioselective Recognition of Chiral Guests by the Water-Soluble Chiral Keplerate {Mo132} Spherical Capsule with 30 Inner Lactate Ligands

2019 ◽  
Author(s):  
Nancy Watfa ◽  
Weimin Xuan ◽  
Zoe Sinclair ◽  
Robert Pow ◽  
Yousef Abul-Haija ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Chiral Recognition ◽  
Association Constants ◽  
Water Soluble ◽  
Enantioselective Recognition ◽  
H Nmr ◽  
Dosy Nmr ◽  
Spherical Capsule ◽  
Surface Pores ◽  
Guest Chemistry

Investigations of chiral host guest chemistry are important to explore recognition in confined environments. Here, by synthesizing water-soluble chiral porous nanocapsule based on the inorganic metal-oxo Keplerate-type cluster, {Mo<sub>132</sub>} with chiral lactate ligands with the composition [Mo<sub>132</sub>O<sub>372</sub>(H<sub>2</sub>O)<sub>72</sub>(<i>x-</i>Lactate)<sub>30</sub>]<sup>42-</sup> (<i>x</i> = D or L), it was possible to study the interaction with a chiral guest, L/D-carnitine and (<i>R</i>/<i>S</i>)-2-butanol in aqueous solution. The enantioselective recognition was studied by quantitative <sup>1</sup>H NMR and <sup>1</sup>H DOSY NMR which highlighted that the chiral recognition is regulated by two distinct sites. Differences in the association constants (K) of L- and D-carnitine, which, due to their charge, are generally restricted from entering the interior of the host, are observed, indicating that their recognition predominantly occurs at the surface pores of the structure. Conversely, a larger difference in association constants (K<i><sub>S</sub></i>/K<i><sub>R</sub></i> = 3) is observed for recognition within the capsule interior of (<i>R</i>)- and (<i>S</i>)-2-butanol.

Sign in / Sign up

Export Citation Format

Share Document