Ternary Complex System Research Articles

Supramolecular Glycolipid Based on Host-Enhanced Charge Transfer Interaction

Supramolecular glycolipid has been fabricated based on ternary complex system, which is composed of naphthyl glucosamine (GlcNap), alkyl viologen (RV8), and cucurbit[8]uril (CB[8]). CB[8] plays a key role to connect the other two building blocks together, and the process is driven by host-enhanced charge transfer interaction. Compared with the classic glycolipids, supramolecular glycolipids display redox responsiveness. Supramolecular glycolipids are able to self-assemble in water to form spherical aggregations, such as vesicle like structure. In addition, spherical aggregations can specifically interact with Concanavalin A, indicating that the carbohydrate groups are available on the surfaces of the aggregates.

Spectroscopy and Speciation Studies on the Interactions of Aluminum (III) with Ciprofloxacin and β-Nicotinamide Adenine Dinucleotide Phosphate in Aqueous Solutions

In this study, both experimental and theoretical approaches, including absorption spectra, fluorescence emission spectra, 1H- and 31P-NMR, electrospray ionization mass spectrometry (ESI-MS), pH-potentiometry and theoretical approaches using the BEST & SPE computer programs were applied to study the competitive complexation between ciprofloxacin (CIP) and β-nicotinamide adenine dinucleotide phosphate (NADP) with aluminum (III) in aqueous solutions. Rank annihilation factor analysis (RAFA) was used to analyze the absorption and fluorescence emission spectra of the ligands, the binary complexes and the ternary complexes. It is found, at the μM total concentration level and pH = 7.0, the bidentate mononuclear species [Al(CIP)]2+ and [Al(NADP)] predominate in the aqueous solutions of the Al(III)-CIP and Al(III)-NADP systems, and the two complexes have similar conditional stability constants. However, the pH-potentiometry results show at the mM total concentration level and pH = 7.0, the ternary species [Al(CIP)(HNADP)] predominates in the ternary complex system. Comparing predicted NMR spectra with the experimental NMR results, it can be concluded that for the ternary complex, CIP binds to aluminum ion between the 3-carboxylic and 4-carbonyl groups, while the binding site of oxidized coenzyme II is through the oxygen of phosphate, which is linked to adenosine ribose, instead of pyrophosphate. The results also suggested CIP has the potential to be a probe molecular for the detection of NADP and the Al(III)-NADP complexes under physiological condition.

Dendrimer porphyrin-based self-assembled nano-devices for biomedical applications

Dendrimers have attracting great interests in the design of functional materials. Because the core porphyrin unit in dendrimer porphyrin (DP) is surrounded by large poly(benzyl ether) dendritic wedges with ionic periphery, various functional nano-devices, such as DP-loaded polyion complex micelles, ternary complex system for gene delivery, polymer-metal complex micelle, hollow nanocapsules for combination cancer therapy, DP-immobilized surface for diagnostic tools, have been designed through electrostatic interaction with oppositely charged polymeric materials.

Formulation of ternary complexes of glyburide with hydroxypropyl-β-cyclodextrin and other solubilizing agents and their effect on release behavior of glyburide in aqueous and buffered media at different agitation speeds

Glyburide, a sulfonylurea derivative, widely used as hypoglycaemic agent. In the present study, an attempt has been made to investigate the most effective third component which can be used with hydroxylpropyl-β-cyclodextrin (HPβCd) to form a ternary complex with glyburide in order to enhance its dissolution rate, as well as reduce the amount of HPβCd used for formulating the binary complex with glyburide. Moreover, the objective of this study was also to develop a discriminatory dissolution media in order to discriminate the effect of the different solubilizing agents used for formulating the ternary complex system. Sodium lauryl sulphate, Poloxamer-188, Polyvinylpyrrolidone K-30, lactose and l-arginine were used to formulate ternary system along with HPβCd and glyburide. The ternary system formulated with glyburide:HPβCd:l-arginine in a proportion of 1:1:0.5 has shown the fastest dissolution rate when compared to other solubilizing agents. Unbuffered aqueous media with stirring speed 50 rpm has produced the most discriminatory dissolution profiles. The DSC thermograms and the powder X-ray analysis revealed the decrease in crystallinity of the drug. This was an indication of amorphous solid dispersion or molecular encapsulation of the drug into the cyclodextrin cavity.

Study on the Spectrophotometric Determination of Trace Cadmium after Flotation Separation with Ternary Association Complex System

The paper presents a novel method for the flotation separation of Cd2+ with ternary association complex system prior to the determination by spectrophotometry. The effects of different parameters,such as the dosages of KI and octadecyl trimethyl ammonium chloride (OTMAC),various salts and acidity etc. on the flotation yield of Cd 2+ have been investigated to select the experimental conditions. The possible flotation mechanism of Cd2+ was discussed.The results showed that by controlling pH2.0,in the presence of 1.0g (NH4)2SO4, when the dosage of 0.1 mol•L-1 KI solution was 2.00 mL and 0.01 mol•L-1 OTMAC solution was 2.00 mL respectively, the water-insoluble ternary association complex of (OTMAC)2(CdI4) which produced by Cd 2+ and I-,OTMAC cation (OTMAC+) floated above water phase and liquid-solid phases were formed with clear interface,while Mn2+ , Ni2+ ,Co2+ , Zn2+ and Al 3+ could not be floated,so Cd2+ was floated quantitatively at pH2.0. Thereby, the quantitative separation of Cd2+ from the above metal ions could be achieved.A new method of determination of trace cadmium by flotation separation was established.The proposed method has been successfully applied to the determination of Cd 2+ in the sample of synthetic water and the flotation yield was 97.2%~108.7%.

Study on the Determination of Trace Zinc by Spectrophotometry after Flotation Separation with Ternary Association Complex System

AbstractThe paper presents a novel method for the flotation separation of Zn2+ with ternary association complex system prior to the determination by spectrophotometry. The effects of different parameters, such as the dosages of NH4SCN and dodecyl trimethyl ammonium chloride (DTAC), various salts and acidity etc. on the flotation yield of Zn2+ have been investigated to select the experimental conditions. The possible flotation mechanism of Zn2+ was discussed. The results showed that by controlling pH 4.0, in the presence of 1.0 g NaBr, when the dosage of 0.1 molṁL−1 NH4SCN solution was 2.50 mL and 5.0 × 10−3 molṁL−1 DTAC solution was 2.00 mL respectively, the water‐insoluble ternary association complex of [Zn(SCN)4] (DTAC)2 which produced by Zn2+ and SCN−, DTAC cation (DTAC+) floated above water phase and liquid‐solid phases were formed with clear interface, while K+, Na+, Ca2+, Mg2+, Al3+, Fe2+, Mn2+, Cd2+, Co2+ and Ni2+ could not be floated, so Zn2+ was floated quantitatively at pH 4.0. Thereby, the quantitative separation of Zn2+ from the above metal ions could be achieved. A new method of determination of trace zinc by flotation separation was established. The proposed method has been successfully applied to the determination of Zn2+ in plating waster water, and the results agreed well with AAS method. The recoveries were 93.6%∼106.4%, and the RSD was 1.8%∼2.3%.

Ternary Complexes Comprising Polyphosphoramidate Gene Carriers with Different Types of Charge Groups Improve Transfection Efficiency

To understand the influence of charge groups on transfection mediated by polymer complexes, we have synthesized a series of biodegradable and cationic polyphosphoramidates (PPAs) with an identical backbone but different side chains. Our previous study showed that PPA with a spermidine side chain (PPA-SP) showed high transfection efficiency in culture, whereas PPAs with secondary, tertiary, and quaternary amino groups were significantly less efficient. To investigate whether the coexistence of 1 degrees amino charge groups with 3 degrees and 2 degrees amino charge groups in the DNA/polymer complexes would enhance their transfection efficiency, we evaluated a ternary complex system containing DNA and PPAs with 1 degrees amino groups (PPA-SP) and 3 degrees amino groups (PPA-DMA) and a quaternary complex system containing DNA and PPAs with 1 degrees and 2 degrees and 3 degrees amino groups (PPA-EA/PPA-MEA/PPA-DMA), respectively. Ternary complexes mediated 20 and 160 times higher transfection efficiency in COS-7 cells than complexes of DNA with PPA-SP or PPA-DMA alone, respectively. Similarly, quaternary complexes exhibited 8-fold higher transfection efficiency than PPA-EA/DNA complexes. The mechanism of enhancement in transfection efficiency by the mixture carriers appears to be unrelated to the particle size, zeta potential, or DNA uptake. The titration characterization and the transfection experiments using a proton pump inhibitor suggest that the enhancement effect is unlikely due to the slightly improved buffering capacity of the mixture over PPA-SP. This approach represents a simple strategy of developing polymeric gene carriers and understanding the mechanisms of polymer-mediated gene transfer.

Regulation of the growth hormone receptor/binding protein, insulin-like growth factor ternary complex system in human cirrhosis

Background/Aims: The liver is the central organ of the endocrine growth hormone/insulin-like growth factor I (GH/IGF-I) axis and cirrhosis effects a state of acquired GH resistance. Low IGF-I levels are associated with adverse clinical outcomes in cirrhotic patients and may be pathogenic to the complications of cirrhosis. We examined the impact of cirrhosis on hepatic mRNA and serum protein levels for the GH receptor (GHR)/binding protein (GHBP), IGF-I, IGF binding protein (IGFBP)-3 and the acid-labile subunit (ALS). Methods: Fifty patients with cirrhosis were studied and liver tissue was obtained from 18. Gene expression was assessed by Northern analysis and serum protein levels by immunoassay. Results: In cirrhotic liver GHR mRNA and GH binding to microsomal membranes were decreased by 61 and 56%, respectively. Serum GHBP levels were decreased only in severe disease, not correlating with GHR mRNA or GH binding. Hepatic IGF-I and ALS mRNA were significantly decreased by 84 and 68%, respectively, in parallel with serum protein, suggesting transcriptional regulation. Hepatic IGFBP-3 mRNA was unchanged but low serum IGFBP-3 suggested post-transcriptional regulation. Conclusions: The decreased mRNA and serum levels for the GH-dependent, hepatocyte produced proteins IGF-I and ALS confirm the importance of GH receptor loss to the GH resistance of cirrhosis.

Design of a Visualized Sugar Sensing System Utilizing a Boronic Acid-azopyridine Interaction

The boronic acid-amine (B-N) interaction was applied to the molecular design of a visualized sensing system for saccharides. 3-Nitrophenyl-boronic acid (3b) interacts with the pyridine nitrogen of 4-(4-dimethyl-aminophenyl-azo) pyridine (2) in methanol and changes its color from yellow to orange. Added saccharides form complexes with 3b and enhance the acidity of the boronic acid group. As a result, the B-N interaction becomes stronger and the intensified intramolecular charge-transfer band changes the solution color to red. By combined 1H-NMR and absorption spectroscopic studies, four association constants governing the present ternary complex system have been determined. In case of D-fructose, the 3b·D-fructose complex can interact with 2 240 times more strongly than 3b and the 2·3b complex can associate D-fructose 241 times more strongly than 3b. Clearly, the B-N interaction not only enables the colorimetric saccharide sensing but also enhances the association ability (i.e., sensitivity). Thus, the present paper offers a novel basic concept for molecular design of visualized saccharide sensing systems.

A ternary complex system for the reversed-phase chromatography of chromate

A new ternary complex system was described. At pH 4.8 diphenylcarbazon formed ternary complexes with metal ions (Cr(VI) and V(V)) and hexadecyltrimethyl ammonium bromide (cetyltrimethyl ammonium bromide, CTAB). The ternary complex of chromate was separated from that of vanadate by means of liquid chromatography using a mobile phase of acetonitrile-acetone-water ( 85:5:20, v v ) containing 0.002 M CTAB. The analytical sensitivity of the complex of chromate could be raised further if the medium of the injection solution is transferred in methanol by solid-phase extraction.

Zero-Order and Third-Derivative Spectrophotometric Determination of Iron(III) with 4-(2-Pyridylazo)-Resorcinol in the Presence of N-Hexadecylpyridinium Chloride

Abstract The complex formation reaction between iron(III) and 4-(2-pyridylazo) resorcinol(PAR) in the presence of various water soluble surfactants((N-hexadecylpyridinium chloride (HPC), poly(vinylalcohol)(PVA), sodium dodecylsulfate(SDS), sodium N-lauroylsarcosine(SL)) alone or in combination at weakly acidic media was systematically investigated. An improved and more sensitive spectrophotometric method for the determination of iron was proposed by zero-order and third-derivative spectrophotometry using the PAR-iron(III)-HPC ternary complex system at about pH 5.2. The calibration curve was rectilinear in the ranges of 0 – 15.0 μg iron(III) in a final 10-ml on the zero-order spectrophotometry. Also, upon the third-derivative spectrophotometry, Beer's law was obeyed in the range of 0 – 8.0 μg iron(III)/10 ml by measuring the distance between the absorbance peak(λ1 = 527 nm) and the valley (λ2 = 560 nm). The apparent molar absorptivity was 4.8 × 104 1 mol−1 cm−1 in zero-order spectrophotometry, and 1.36 × 105 mol−1 cm−1 in third-derivative spectrophotometry. The effect of foreign ions was decreased within ½ – ¼-fold in comparison with the method in the presence of PVA without HPC. Especially, the third-derivative spectrophotometric method was sensitive and selective, and made possible to assay mixed sample solution containing iron(III) and copper(II), etc.

Spectrophotometric and spectrofluorimetric determination of the ternary complexes of cadmium(II) and zinc(II) with 2,2′-bipyridine and Rose Bengal Extra

A sensitive and selective ternary complex system has been developed for the determination of cadmium(II) and zinc(II). This system consists of the metal ion, an organic base, 2,2′-bipyridine, and the fluorescein dye Rose Bengal Extra (RBE). The ternary complexes of both cadmium(II) and zinc(II) exhibit a sensitivity or molar absorptivity of 1.03 × 105 and 9.97 × 104 l mol–1 cm–1, respectively. Preliminary studies showed an enhancement of the secondary fluorescence spectra of the bipyridine-RBE complex system for cadmium(II) and zinc(II). This enhancement is the basis of the fluorimetric determination of cadmium(II) and zinc(II). This metal ion-bipyridine-RBE system has a linear fluorescence calibration range from 1.0 × 10–6 to 14.0 × 10–6M(0.06–0.91 p.p.m. ZnII and 0.11–1.54 p.p.m. CdII).

Determination of trace amounts of vanadium: A ternary extraction and photometric method using N-salicylhydroxamic acid and thiocyanate

A new extractive photometric method has been developed for a binary complex of vanadium(V) with salicylhydroxamic acid, a bluish-violet complex at pH 3.0 and a violet ternary complex system with ammonium thiocyanate at pH 0.95, both complex species being extractable into methylisobutylketone. The violet complex absorbs at 540 nm and is stable up to 48 hr at 23–25°. The sensitivity is 0.0061μg V(V) cm−2. The method has been applied for the analysis of ores and alloy steels containing vanadium.

Indirect spectrophotometric determination of sulphide with the ternary complex system Ag(I)—phen—BPR

Trace amounts of sulphide can be determined from its effect on the ternary complex system of Ag +, Bromopyrogallol Red (BPR), and 1,10-phenanthroline (phen). Sulphide in the range 5–120 ng/ml causes a decrease in absorption, that is a linear function of the concentration. Common metal ions such as Na +, K +, Ca 2+, Mg 2+, Al 3+, Mn 2+ and anions such as F −, Cl −, NO − 3, SO 2− 4, CO 2− 3, and PO 3− 4 at the 4 μg/ml level or more do not interfere, but I − or CN − must be absent.

The cyclodextrin-nicotinamide compound as a dehydrogenase model simulating apoenzyme-coenzyme-substrate ternary complex system

The cyclodextrin-dihydronicotinamde had a dihydronicotinamde group at the open side of cyclodextrin cavity, and showed a large rate enhancement in the reduction of substrate upon complexation comparing with NADH.

Spectrophotometric determination of titanium(IV) with haematoxylin and cetyltrimethylammonium bromide

A ternary complex system between titanium(IV), haematoxylin and cetyltrimethylammonium bromide is proposed for the determination of microgram amounts of titanium(IV). The system has a molar absorptivity of 3.5 × 104 l mol–1 cm–1 after half an hour of colour development. Tungsten(VI), aluminium(III), silver(I), lead(II), copper(II), zinc(II) and cadmium(II) do not interfere at a level of 1 mg. Interference from molybdenum(VI), antimony(V), chromium(VI), niobium(V), mercury(II) and manganese(II) at the same level and iron(III) and tin(IV) at a level of 0.5 mg can be eliminated by pre-extraction of the titanium, as the titanium-cupferron complex, into 4-methylpentan-2-one.

The Extraction Spectrophotometric Determination of Iron(III) with Eriochrome Cyanine R and Tridodecylethylammonium Bromide

Abstract A sensitive spectrophotometric procedure for the determination of iron(III) has been developed, utilising the ternary complex system of iron–Eriochrome Cyanin R–Tridodecylethylammonium. The iron–Eriochrome Cyanin R chelate anion was extracted with tridodecylethylammonium bromide in xylene. The extracted species had an absorption maximum at 613 nm in the organic layer. The optimum pH range for the extraction was 5.8–6.5. Beer’s law held for 0.2–2 μg of iron(III) in 5 ml of the organic layer. The molar absorptivity of the extracted species was 1.73×105 cm−1·l mol−1·1 at 613 nm. The composition of the ternary complex was assumed to be (Remark: Graphics omitted.) Lead, mercury, tin, chromium, beryllium, thorium, uranium, nitrate, iodide, thiocyanate, and perchlorate interfered with the determination of iron(III).

Coenzyme B 12-dependent propanediol dehydratase system Ternary complex between apoenzyme, coenzyme, and substrate analog

A dead-end ternary complex was formed between propanediol dehydratase ( dl-1,2-propanediol hydro-lyase, EC 4.2.1.28) apoenzyme, coenzyme B 12, and a substrate analog when a substrate analog such as 1,2-butanediol or styrene glycol was incubated with the apoenzyme and coenzyme B 12 in the presence of potassium ions. The 1,2-diols used did not show any substrate activity, and behaved as weak competitive inhibitors with respect to the substrate. When the true substrate, 1,2-propanediol, was added in excessive amounts to the ternary complex system, the initially bound substrate analog was readily displaced by the substrate and the propanediol dehydratase reaction normally took place. The analog ternary complex was relatively stable to oxygen compared with the holoenzyme, and was much more thermostable than the apoenzyme. Like the holoenzyme and reacting holoenzyme, the ternary complex was photostable under the conditions where free coenzyme B 12 was rapidly photolyzed. The apoenzyme was completely inactivated by incubation with p- chloromercuribenzoate , iodoacetamide, or N- ethylmaleimide , but not with arsenite, suggesting that sulfhydryl groups, but not vicinal ones, are involved at the active site of the enzyme. Treatment with mercaptoethanol or dithiothreitol reversed the inhibition by p- chloromercuribenzoate . In contrast to the mercurial-insensitivity of both the holoenzyme and reacting holoenzyme, the analog ternary complex was considerably sensitive to p- chloromercuribenzoate . Upon Sephadex G-25 gel filtration, dissociation of coenzyme B 12 from the ternary complex occurred more readily than that from the holoenzyme. These results suggest that the apoenzyme-coenzyme-substrate analog ternary complex is a suitable, stable model for the so-called Michaelis complex (intermediate enzyme-substrate complex), and that its structure may be somewhat distorted compared to the holoenzyme and reacting holoenzyme.

Ternary Coordination Complex between Human Serum Albumin, Copper (II), and l-Histidine

Abstract Physicochemical studies of the human serum albumin-Cu(II)-l-histidine (HSA-Cu(II)-l-His) ternary complex at pH 7.5 indicate several interesting features. 1. The dissociation constants of the HSA-Cu(II)-l-His ternary complex and the HSA-Cu(II) binary complex are 1.38 x 10-22 and 6.61 x 10-17, respectively. 2. The absorption spectrum of the ternary complex system has characteristics similar to those of the NH2-terminal peptide (1-24) of bovine serum albumin in the presence of Cu(II) and l-His. The computed spectrum of HSA-Cu(II)-l-His has a λmax at 540 nm, a shift of 15 nm toward red from that of HSA-Cu(II) (λmax = 525 nm). 3. The calculated moles of protons liberated in the formation of HSA-Cu(II)-l-His from HSA and Cu(II)-l-His2 are 0.28. While this may originate from an α-amino group, the number is much less than what would be expected if a peptide nitrogen of HSA were involved in the binding. 4. Cu(II) in the ternary complex is most likely bound to both HSA and l-His. The possible binding mode changes from all nitrogen, as shown in HSA-Cu(II), to either a mixture of nitrogen and oxygen or an additional involvement of imidazole nitrogen. 5. Equilibria, existing in the ternary complex system, suggest that the ternary complex may play an important role in the biological transport of Cu(II).

Spectrophotometric determination of molybdenum with gallein and cetyltrimethylammonium bromide

A ternary complex system between molybdenum, gallein and cetyltrimethylammonium bromide is proposed for the determination of microgram amounts of molybdenum. The complex has an absorbance maximum at 618 nm. The sensitivity of the reaction is 0·0026 µg cm–2 of molybdenum for log [graphic omitted] = 0·001. The development of this method for the determination of molybdenum included a study of the effect of pH, temperature, reagent concentration, rate of complex formation and conformity to Beer's law.