Dithiocarbamate salts: biological activity,preparation, and utility in organic synthesis

The review includes synthetic methodologies of dithiocarbamic acid salts, their S-substituted derivatives, and nano particles (NP's) in their synthesis. This review also deals with the utility of dithiocarbamates in synthesis of: (a) heterocycles, (b) some organic reagents and (c) NP's.     

Crossflow Surfactant-Based Ultrafiltration of Heavy Metals from Waste Streams

Abstract

Five heavy metals (cadmium, lead, copper, nickel, and zinc) in a simulated wastewater, alone and together, were substantially removed by surfactant-based ultrafiltration using natural surfactants such as a derivative of cholesterol (deoxycholic acid) and lecithins. Selective and total removal of metal ions has been achieved by applying an appropriate level of surfactant-to-metal ratio (S/M). The underlying principle is to increase the size of the target metal ions by fixing them to larger surfactant macromolecules so they can be retained by a compatible membrane. Deoxycholic acid exhibited more efficiency in metal removal than did lecithin and sodium dodecyl sulfate. This research showed that transmembrane pressure had a minimal effect on metal removal whereas S/M had a substantial influence. The optimal S/M for considerable metal removal (99.9 + rejection ratio) is around 2.5 and 5 for deoxycholic acid and sodium dodecyl sulfate, respectively. The binding of metals to surfactant in the absence of membrane interferences was also determined by a centrifuge method.     

Synthesis of 9Z,11E-octadecadienoic and 10E,12Z-octadecadienoic acids, the major components of conjugated linoleic acid

Linoleic acid was efficiently converted into the two major components of conjugated linoleic acid, 9Z,11E-octadecadienoic (1a) and 10E,12Z-octadecadienoic acid (1b) using either the superbase (n-butyllithium/potassium tert-butoxide) or by simply refluxing with KOH in 1-butanol. In turn, 1a and 1b were separated from each other using the lipase from Aspergillus niger via stereoselective esterification in 1-butanol. This enzyme has a preference for the 9Z,11E isomer, 1a, and has excellent selectivity. This method has allowed the ready preparation of gram quantities of 1a and 1b in their highly purified forms, which are not readily accessible by current methods.     

Isolation of the diterpenoids, ent-kauran-16alpha-ol and ent-atisan-16alpha-ol, from sunflowers, as oviposition stimulants for the banded sunflower moth, Cochylis hospes

Two diterpenoid alcohols, ent-kauran-16-ol (1) and ent-atisan-16-ol (2), were isolated from pre bloom (R3-R4 stage) sunflower heads as oviposition stimulants for the banded sunflower moth, Cochylis hospes. Fractionation of a sunflower head extract, by normal-phase flash column chromatography, resulted in an early eluting fraction exhibiting significant activity in an egg-laying bioassay. Compounds 1 and 2, along with ent-trachyloban- 19-oic acid (3) and ent-kaur-16-en-19-oic acid (4), were isolated as the major components of this fraction and identified by their NMR and mass spectra. The purified compounds were individually tested for ovipositional activity in dose-response bioassays. In these bioassays, compounds 1 and 2 gave linear dose responses, with increasing numbers of eggs laid as the dosage of either increased. Compounds 3 and 4 failed to stimulate significant egg-laying at any of the dosages tested. A factorial design bioassay, using compounds 1 and 2, showed that 1 was relatively more stimulatory than 2, and that there was no synergistic effect on oviposition when the two compounds were combined.     

Partial Oxidation of Isobutane over Vanadium Phosphorus Oxides

A series of vanadium phosphorus oxides (VPO) were prepared by using dodecyl amine as surfactant and tested for the partial oxidation of isobutane and isobutene. Characterization results showed that their structure and properties depend on the content of dodecyl amine. Catalytic tests showed that relatively high isobutane conversion and desired product selectivity can be achieved over a proper dodecyl amine doping VPO catalyst. It is also found that higher isobutane conversion can be achieved over V⁴⁺-containing phases as compared to V⁵⁺-containing phases, while proper surface V⁵⁺/V⁴⁺ ratio may be propitious to obtain high selectivity to methacrylic acid for the selective oxidation of isobutane. In addition, the content of dodecyl amine in the preparation of the VPO catalysts appears to be more important in determining the surface P/V ratio of the catalysts.     

Monomers for adhesive polymers, 17.a Synthesis,photopolymerization and adhesive properties of polymerizable phosphonic acids bearing urea groups

Four polymerizable phosphonic acids bearing urea groups 4a, 4b, 9a, and 9b as well as the 10-(methacryloyloxy)decylphosphonic acid 10 were synthesized in four to six steps. They were characterized by ¹H, ¹³C, and ³¹P NMR spectroscopy and by high-resolution mass spectroscopy. Contrary to methacrylates 4a and 4b, methacrylamides 9a and 9b were hydrolytically stable in deuterated water/deuterated ethanol solutions. The photopolymerization behavior of acidic monomers 4a, 4b, 9a, 9b, and 10 and their corresponding phosphonates were studied using a differential scanning calorimeter. Homopolymerizations and copolymerizations with N-butyl-N-ethylacrylamide were carried out. The presence of a urea group was found to significantly increase the rate of polymerization. Monomers bearing a phosphonic acid group were more reactive than their corresponding phosphonates. Self-etch adhesives based on monomers 4a, 4b, 9a, and 9b were able to provide a strong bond between a composite and the dental hard tissues (dentin and enamel). The presence of a urea group led to a significant increase in the shear bond strength to both dentin and enamel.     

Helikauranoside A, a New Bioactive Diterpene

A new ent-kaurane glucoside, named helikauranoside A (4), was isolated from the aerial parts of Helianthus annuus L. together with three known ent-kaurane-type diterpenoids: (−)-kaur-16-en-19-oic acid (1), grandifloric acid (2), and paniculoside IV (3). The structure of 4 was determined by using a combination of 1D (¹H-NMR and ¹³C-NMR) and 2D (COSY, HSQC, and HMBC) NMR techniques. Bioactivity spectra of isolated compounds were tested by using the etiolated wheat coleoptile bioassay in aqueous solutions at concentrations ranging from 10⁻³ to 10⁻⁶M. Helikauranoside A (4) was the most active (−84%, 10⁻³M; −56%, 10⁻⁴M). These results suggest that this new compound may be involved in defense mechanisms of H. annuus.     

Intensification of phenolic extraction from yellow European plums by use of conventional,microwave-, and ultrasound-assisted extraction

ABSTRACT

In this study, microwave and ultrasound extraction were selected as process intensification tools to intensify the conventional heat reflux extraction process. Process efficiency was evaluated based on total phenolic content (ascorbic acid, neochlorogenic acid, and chlorogenic acid), scavenging ability of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric (Fe³⁺) free radicals, and process intensification principles and domains. Highest phenolic content and antioxidant activity were achieved using microwave extraction followed by heat reflux and ultrasound extraction. Microwave extraction was selected via decision matrix as a suitable process intensification approach based on results and its ability to satisfy process intensification principles.     

Electrical Aspects of Adsorbing Colloid Flotation. XIX. Viscosity and the Structures of Mixed Micelles

Abstract

Viscosity measurements on mixed surfactant solutions containing the nonionic surfactant Triton X-100 and a number of other cosurfactants (dodecanoic acid, dodecyl amine, sodium dodecylsulfate, dodecyltrimethylammonium chloride, dodecyl alcohol, and sodium dodecylphosphate) indicate the presence of two quite different ‘types of micelles’. Solutions containing an electrically neutral cosurfactant exhibit very large viscosities, indicating the presence of extended micellar structures. Solutions containing a charged cosurfactant exhibit much lower viscosities, indicating that the micelles in these solutions are small spherical or ellipsoidal structures. Evidently coulombic repulsions destabilize the extended structures when charged surfactants are present in the micelles. The effects of pH and ionic strength are consistent with this interpretation.     

Flotation of Cesium Coprecipitated with Nickel Hexacyanoferrate(II) from Aqueous Solutions and Radioactive Waste Simulants

Abstract

The coprecipitate flotation of ¹³⁷Cs from dilute aqueous solutions and simulated radioactive wastes using nickel hexacyanoferrate(II) as a coprecipitant and sodium lauryl sulfate, cetyltrimethylammonium bromide, or dodecyl amine as a collector was extensively investigated to establish the best conditions for cesium removal. Under the optimal conditions, removals exceeding 99% and decontamination factors higher than 110 could be achieved for the radioactive waste simulants. The results are compared with those obtained by conventional removal methods and are discussed in terms of the collector properties and the electrical state of the coprecipitate.     

Synthesis,spectroscopic characterization and DFT studies on the novel indeno-thiazolopyrimidine heterocyclic system

4-Phenyl-2-thioxo-3,4-dihydro-1H-indeno[1,2-d]pyrimidin-5(2H)-one 2, obtained by stirring a mixture of indane-1,3-dione, benzaldehyde and thiourea in acetic acid at room temperature for 12 h, on reaction with chloroacetic acid and 1,2-dibromoethane furnish compounds 3 (or 6) and 4 (or 7), respectively. The regiochemistry of the cyclized products and their structure is established by an elemental analysis, ¹H NMR, ¹³C NMR, IR and mass spectral data. Density functional theory calculations have been carried out for compounds 3 and 4 and their isomers 6 and 7 with Jaguar version 6.5112 using the B3LYP density functional method and LACVP* basis set. ¹H and ¹³C NMR of compounds 3, 4, 6 and 7 have been calculated. 2-Arylidene derivatives of 3 were obtained by two routes and their structure was established by spectral data.     

Electrical Aspects of Adsorbing Colloid Flotation. XVIII. NMR Studies of Sodium Dodecyl Sulfate Sorbed on Al(OD)3

Abstract

Adsorption of dodecyl sulfate on Al(OD)₃ flocs has been studied by means of proton and ¹³C-NMR. Spin-lattice relaxation times (T ₁) of α-CH₂ and the unresolved methylene proton signals were measured in monomer, micellar, and adsorbed forms of the surfactant. These results, together with the spin-spin relaxation times (T ₂) estimated from the line-widths of ¹³C signals, indicate that dodecyl sulfate ions adsorbed on Al(OD)₃ flocs are more constrained in their motions than are micellar dodecyl sulfate ions, and that the binding to the floc is through the sulfate group.     

Synthesis of Ethyl 5 Z ,9 Z ,12 Z -octadecatrienoate (ethyl pinolenate) and Methyl 12 Z ,15 Z -octadecadienoate

Pinolenic acid (5Z,9Z,12Z-octadecatrienoic acid, 1a), one of the most abundant trienoic fatty acids in nature, is very difficult to obtain in quantity in a pure state from the highly complex mixture of unsaturated tall oil fatty acids. For this reason its chemistry has been little studied when compared to linolenic or linoleic acids. A simple synthesis of esters of 1a and of 12Z,15Z-octadecadienoic acid 3 using the one pot double Wittig procedure is described here. The products of double Wittig reactions were purified by argentation chromatography, and their structural purity was established by ¹H-, ¹³C-NMR and 2D-NMR spectroscopies.

Synthesis and Chromatographic Separation of Monomethoxypolyethylene Glycol Modified Insulin

Abstract

Insulin was modified with monomethoxypolyethylene glycol (MPEG)‐succinimidyl succinate and succinimidyl ester of carboxymethyl MPEG. Effects of reaction solvents, initial molar ratio of MPEG derivative to insulin and reaction time on PEGylation of insulin were investigated by 2,4,6‐trinitrobenzenesulfonic acid spectrophotometric assay and sodium dodecyl sulfate‐polyacrylamide gel electrophoresis. Sephadex G75 size exclusion chromatography (SEC), ion exchange chromatography (IEC) and reversed phase‐high performance liquid chromatography (RP‐HPLC) were applied to separate PEGylated insulin. IEC and RP‐HPLC were proved to be efficient tools on separation of different PEGylated insulin species.     

Cyclic ammonium salts of dithiocarbamic acid: stable alternative reagents for the synthesis of S-alkyl carbodithioates from organyl thiocyanates in water

Carbodithioate esters are important functional organosulfur compounds widely used in diverse fields such as pharmaceuticals, agrochemicals and material sciences. Common preparative methods include reaction of alkyl halides, carbon disulfide and bases under both metal-free and metal-catalyzed conditions. However, organyl thiocyanates have not been previously explored, possibly because of their conversion to organyl disulfides under basic conditions. Here, we report an efficient and practical method for the preparation of libraries of carbodithioate esters from organyl thiocyanates by reacting with cyclic amine-based dithiocarbamic acid salts in water. The protocol is found to be applicable in general to various thiocyanates such as benzyl/aroyl methyl/cinnamyl and so on. Other notable features include no by-products such as disulfides, metal- and alkali-free, aqueous conditions, and finally easy and near-quantitative formation of cyclic amine-based dithiocarbamic acid salt as a stable alternative reagent.     

Correlation of hard surface detergency,soil, and surfactant

In the practical detergency range between the 90% soil removal point (the CC-1 concentration) and the point at twice the CC-1 concentration (the CC-2 point), hard surface (steel) detergency (D) is a linear function of micellar solubilization (S) such that D=K₁S+K₂, for glyceryl trioleate, oleic acid, and lauryl alcohol soils. Equations of this form were obtained for glyceryl trioleate systems using polyethenoxyethers of nonyl phenol and tridecyl alcohol, polyoxyethylene sorbitan monolaurate, sodium dodecyl benzene sulphonate, and sodium oleate. It was shown that the constants K₁ and K₂ of the detergency equation possess more than mathematical significance. Analysis of the equations for the 15, 20, and 40 ethylene oxide mole ratio adducts of nonyl phenol with glyceryl trioleate soil revealed that K₁ varied linearily with HLB of the adducts and that the K₂-log interfacial tension function (at the CC-1 point) was linear. Examination of the equations for the 20, 50, and 100 mole ratio adducts of nonyl phenol with oleic acid soil indicated also that K₁ was a function of HLB and that K₂ was a function of interfacial tension (at the CC-1 point). The detergency equations of a single surfactant (sodium dodecyl benzene sulphonate) and three soils (triolein, lauryl alcohol, and oleic acid) indicated K₁ was a function of soil dipole moment, and K₂ was a function of soil surface tension.     

Liquid-Liquid Chromatographic Separation of Neodymium,Samarium, and Gadolinium

Abstract

Neodymium, samarium, and gadolinium were separated by a liquid-liquid chromatographic technique. Sulfuric acid was more effective than hydrochloric or nitric acid as an eluent with di(2-ethylhexyl) phosphoric acid (EHPA) as the stationary phase. Recovery of 45% of the neodymium as >90% Nd₂O₃, 84% of the samarium as>99% Sm₂O₃, and 50% of the gadolinium as>99% Gd₂O₃ was achieved. The degree of separation and the time required for the separation can be varied by changing the concentration of the eluent and the number of stages in the system. A system comprising a primary amine organic extractant and an aqueous eluent containing diethylenetriaminepentaacetic acid (DTPA) was less effective for separating the rare earths.     

Monomers for adhesive polymers, 18. Synthesis,photopolymerization and adhesive properties of polymerizable α-phosphonooxy phosphonic acids

Four polymerizable α-phosphonooxy phosphonic acids 7a, 7b, 9 and 16 were synthesized in seven steps. They were characterized by ¹H, ¹³C and ³¹P NMR spectroscopy and by high-resolution mass spectroscopy. The copolymerization of acidic monomers 7a, 7b, 9 and 16 with 2-hydroxyethyl methacrylate was studied using a differential scanning calorimeter. Due to the presence of two acidic groups, those monomers are significantly more reactive than 10-methacryloyloxydecylphosphonic acid (MDPA) and 10-methacryloyloxydecyl dihydrogen phosphate (MDP). Self-etch adhesives based on monomers 7a, 7b, 9 and 16 were formulated and used to mediate a bond between a dental composite and the dental hard tissues (dentin and enamel). These adhesives exhibit excellent performances and provide significantly higher dentin and enamel shear bond strength than adhesives based on MDP or MDPA.     

Synthesis of imine bond containing insoluble polymeric ligand and its transition metal complexes,structural characterization and catalytic activity on esterification reaction

In this study, synthesis of insoluble polymeric ligand (L) and its transition metal complexes [Cu(L)Cl₂]·2H₂O (1), [Co(L)Cl₂(H₂O)₂] (2) and [Ni(L)Cl₂(H₂O)₂] (3), having the azomethine groups, were synthesized by the condensation reactions of the diamines and dialdehydes. The structural properties were characterized by the analytical and spectroscopic methods using by elemental analysis, Fourier Transform Infrared, Thermo Gravimetric Analysis, Powder X-ray Diffraction, magnetic susceptibility and Inductively Coupled Plasma. The solubilities of the synthesized polymeric materials were also investigated and found as insoluble some organic and inorganic solvents. Additionally, their catalytic performance was carried out for the esterification reaction of acetic acid and butyl acetate. The highest conversion rate is 75.75% by using catalyst 1. The esterification of butanol gave butyl acetate with 100% selectivity.     

Modeling and Performance Study of MEUF of Divalent Metal Ions in Aqueous Streams

Abstract

Modeling of micellar enhanced ultrafiltration (MEUF) was studied for the removal of Ni from aqueous phase by using sodium dodecyl sulphate for micellisation. Localized adsorption equilibrium model was used to predict the bound and unbound counter ions. The retentate concentration was predicted using localized adsorption equilibrium and a material balance model, and the experimental values are in close agreement with less than 1% deviations. Experimental values of the permeate flux were in close agreement with the predicted values obtained by resistances in the series model. An algorithm was developed for the prediction of the retentate concentration.