Anionic Detergent Research Articles

Removal of anionic detergents from water and treatment of gray water by micelle–clay composites

Shortage of water has resulted in attempts to purify contaminated water. This study demonstrates removal of anionic detergents from synthetic water, well water, and gray water (GW), and the removal of pathogenic microorganisms from GW. The complex of montmorillonite with micelles of the organic cation, octadecyltrimethylammonium, was expected to yield efficient adsorption of anionic detergents and microorganisms on account of its large surface area, positive charge, and existence of large hydrophobic domains. The removal of anionic detergents, total suspended solids, and bacteria was tested by column filters packed with micelle/montmorillonite complexes mixed with excess sand. Efficient removal of anionic detergents was demonstrated for synthetic water (130 and 30 ppm), well water (from 1.35 to below 0.3 ppm) and from two domestic laundries. A model that considers convection, adsorption, and desorption yielded adequate simulations and predictions for the above kinetics of filtration. GW from showers and sinks included several million of fecal coli per 100 mL, indicating health hazard in using the water without proper treatment. The second column of two in series removed all pathogenic bacteria after the passage of 30 L, whereas activated carbon yielded poor removal. The micelle–clay filter can adequately purify such GW for reuse in irrigation and toilet flushing.

Structural Determinants of Tau Aggregation Inhibitor Potency

Small-molecule Tau aggregation inhibitors are under investigation as potential therapeutic agents against Alzheimer disease. Many such inhibitors have been identified in vitro, but their potency-driving features, and their molecular targets in the Tau aggregation pathway, have resisted identification. Previously we proposed ligand polarizability, a measure of electron delocalization, as a candidate descriptor of inhibitor potency. Here we tested this hypothesis by correlating the ground state polarizabilities of cyanine, phenothiazine, and arylmethine derivatives calculated using ab initio quantum methods with inhibitory potency values determined in the presence of octadecyl sulfate inducer under reducing conditions. A series of rhodanine analogs was analyzed as well using potency values disclosed in the literature. Results showed that polarizability and inhibitory potency directly correlated within all four series. To identify putative binding targets, representative members of the four chemotypes were added to aggregation reactions, where they were found to stabilize soluble, but SDS-resistant Tau species at the expense of filamentous aggregates. Using SDS resistance as a secondary assay, and a library of Tau deletion and missense mutants as targets, interaction with cyanine was localized to the microtubule binding repeat region. Moreover, the SDS-resistant phenotype was completely dependent on the presence of octadecyl sulfate inducer, but not intact PHF6/PH6* hexapeptide motifs, indicating that cyanine interacted with a species in the aggregation pathway prior to nucleus formation. Together the data suggest that flat, highly polarizable ligands inhibit Tau aggregation by interacting with folded species in the aggregation pathway and driving their assembly into soluble but highly stable Tau oligomers.

Histopathological changes of gill, liver and kidney in Caspian kutum exposed to Linear Alkylbenzene Sulfonate

The histopathological effects of Linear Alkylbenzene Sulfonate on the gill, liver and kidney tissues of the Caspian kutum, Rutilus frisii kutum were studied. The fish were exposed to three sublethal concentrations of anionic detergent, Linear Alkylbenzene Sulfonate (LAS) for short term intervals (192 h). Gill, liver and kidney samples were collected after 192 h of exposure to LAS and lesions were analyzed by light microscopy. The histological changes to gills were edema, fusion of lamellae and lamellar aneurism. Some alterations like reduction of the interstitial haematopoietic tissue, tubular shrinkage, degeneration in the epithelial cells of renal tubule and necrosis were observed in the kidney. In the liver tissue, hepatocyte degeneration, congestion and dilation of sinusoid and vacuolar degeneration were seen. It seems that sublethal concentration of LAS may affect sever changes to gill, kidney and liver of R. frisii kutum specimens that leads to malfunction of these organs which cause damage to health of the fish .

N-Dodecyl β-D-maltoside specifically competes with general anesthetics for anesthetic binding sites

We recently demonstrated that the anionic detergent sodium dodecyl sulfate (SDS) specifically interacts with the anesthetic binding site in horse spleen apoferritin, a soluble protein which models anesthetic binding sites in receptors. This raises the possibility of other detergents similarly interacting with and occluding such sites from anesthetics, thereby preventing the proper identification of novel anesthetic binding sites. n-Dodecyl β-D-maltoside (DDM) is a non-ionic detergent commonly used during protein-anesthetic studies because of its mild and non-denaturing properties. In this study, we demonstrate that SDS and DDM occupy anesthetic binding sites in the model proteins human serum albumin (HSA) and horse spleen apoferritin and thereby inhibit the binding of the general anesthetics propofol and isoflurane. DDM specifically interacts with HSA (Kd = 40 μM) with a lower affinity than SDS (Kd = 2 μM). DDM exerts all these effects while not perturbing the native structures of either model protein. Computational calculations corroborated the experimental results by demonstrating that the binding sites for DDM and both anesthetics on the model proteins overlapped. Collectively, our results indicate that DDM and SDS specifically interact with anesthetic binding sites and may thus prevent the identification of novel anesthetic sites. Special precaution should be taken when undertaking and interpreting results from protein-anesthetic investigations utilizing detergents like SDS and DDM.

Metabolism Dependent Chemotaxis of Pseudomonas aeruginosa N1 Towards Anionic Detergent Sodium Dodecyl Sulfate.

Sodium dodecyl sulfate (SDS) is one of the most commonly used detergent, which exhibits excellent biocidal activity against various bacteria and fungi. It is commonly employed in many detergent formulations and is employed for disinfection purposes. It is shown to be toxic to fishes, aquatic animals and is also inhibitory to microbes and cyanobacteria. We had isolated a strain belonging to Pseudomonas aeruginosa N1, from a detergent contaminated pond situated in Varanasi city India, which was able to degrade and metabolize SDS as a source of carbon. In the present investigation, we have studied chemotactic response of this strain towards SDS. The results clearly indicate that this strain showed chemotactic response towards SDS. The nature of chemotaxis was found to be metabolism dependent as glucose grown cells showed a delayed chemotactic response towards SDS. This is first study that reported chemotaxis response for P. aeruginosa towards anionic detergent SDS.

Enhanced recovery of spermatozoa and comprehensive lysis of epithelial cells from sexual assault samples having a low cell counts or aged up to one year

Differential extraction (DE) is the most common method for processing sexual assault samples, allowing for the simultaneous recovery of sperm and epithelial cells from the swab with the separation of sperm cells from epithelial cell DNA by exploiting the differences in the cell membrane susceptibility to detergents. However, sperm cell recovery when using DE is generally 40-50% [1], which can reduce the probability of obtaining a STR profile of the semen contributor, especially if the sample is aged or has a low number of sperm cells. Here, we present a novel buffer, containing SDS and ProK that, when used as an initial incubation buffer, enhances sperm cell recovery to as high as 90%, representing a 200-300% increase over conventional DE buffer. Adjusting the incubation time and temperature provided high, reproducible sperm cell yields. Sample vortexing and replacement of SDS with sodium octyl sulfate (SOS), another sulfate-based anionic detergent, did not provide any further enhancement of the sperm cell recoveries. Furthermore, the one-step buffer provided up to a 300% increase in recovery over the conventional DE buffer when used on samples aged up to one year. STR analysis of samples containing 500 or more sperm cells treated with this buffer showed comparable results (i.e., full STR profiles; 16 of 16 loci) to those obtained using a conventional DE buffer. Finally, when the sample contained only 400 sperm cells (recovered in 100μL volume, then extracted), substantially more STR loci (14 of 16) were generated using the novel buffer in comparison to the conventional DE buffer (4 of 16 loci). This work demonstrates that this buffer may be useful as an alternative for the initial sample incubation step in differential extraction, particularly for aged or samples known to have a low number of sperm cells.

Comparative Study on Cytotoxicity Activity of N-α-Acylarginine Ethyl Ester

Amino-acid derived compounds, for example N-α-lauroylarginine ethyl ester (LAE), N-α-myristoylarginine ethyl ester (MAE) and a 1:1 mixture of N-α-myristoylarginine ethyl ester with monolaurin (MAE + MLN) are examined for their cytotoxicity towards L929-Mouse connective tissue to explore their use as microbicidal agent, in comparison to sodium dodecylsulfate (SDS) as an anionic control detergent. MTT (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cytotoxicity assay method was used to determine IC50 value. Cytotoxicity of MAE is found to be more toxic as compared to LAE, having IC50 value 0.052 mg/ml against 0.68 mg/ml of LAE. But MAE when mixed with monolaurin (1:1), showed less toxicity with IC50 0.89 mg/ml. These results suggest that a combination of MAE and Monolaurin can be a potential candidate for studying its microbicidal properties.

A Comparison of DNA Extraction Methods using Petunia hybrida Tissues

Extraction of DNA from plant tissue is often problematic, as many plants contain high levels of secondary metabolites that can interfere with downstream applications, such as the PCR. Removal of these secondary metabolites usually requires further purification of the DNA using organic solvents or other toxic substances. In this study, we have compared two methods of DNA purification: the cetyltrimethylammonium bromide (CTAB) method that uses the ionic detergent hexadecyltrimethylammonium bromide and chloroform-isoamyl alcohol and the Edwards method that uses the anionic detergent SDS and isopropyl alcohol. Our results show that the Edwards method works better than the CTAB method for extracting DNA from tissues of Petunia hybrida. For six of the eight tissues, the Edwards method yielded more DNA than the CTAB method. In four of the tissues, this difference was statistically significant, and the Edwards method yielded 27-80% more DNA than the CTAB method. Among the different tissues tested, we found that buds, 4 days before anthesis, had the highest DNA concentrations and that buds and reproductive tissue, in general, yielded higher DNA concentrations than other tissues. In addition, DNA extracted using the Edwards method was more consistently PCR-amplified than that of CTAB-extracted DNA. Based on these results, we recommend using the Edwards method to extract DNA from plant tissues and to use buds and reproductive structures for highest DNA yields.

Production of kertinases using chicken feathers as substrate by a novel multifunctional strain of Pseudomonas stutzeri and its dehairing application

Abstract In this study, keratinolytic potential of a Sodium Dodecyl Sulfate (SDS) degrading strain of Pseudomonas stutzeri strain K4 was evaluated. Strain K4 completely metabolized 1% (w/v) chicken feathers after 72 h of incubation with production of 784.2 µg/ml of soluble protein and 42 U/ml of keratinase. Scanning Electron Microscopy (SEM) analysis of chicken feathers indicated damage on the surface of feathers. Activity staining for keratinase showed presence of five keratinases (26–76 kDa) during growth with chicken feathers. Optimum pH and temperature for crude keratinase was found to be pH-8 and 40 °C respectively. Crude keratinase showed activation in presence of metal ions such as Mg2+ (39%), Mn2+ (28%), Na+ (20.8%), solvents such as isopropanol (30.7%), glycerol (28.2%), reducing agents such as β- mercaptoethanol (70%), chelating agents such as EDTA (25.3%) and anionic detergent SDS (37.8%), respectively. Crude keratinases showed high substrate specificity for keratin and chicken feathers, low specificity for collagen and hair, respectively. Dehairing of goat skin by employing crude ketainase preparation (40 U/ml) indicated complete dehairing after 20 h of incubation. Enzymatic dehairing was superior over chemical dehairing, as no damage to skin and hairs were observed. This is the first report of a novel strain of P. stutzeri exhibiting excellent dehairing activity; results indicate that purification of keratinases prior to dehairing was not required.

Cellular prion proteins in humans and cattle but not sheep are characterized by a low-solubility phenotype

A feature of transmissible spongiform encephalopathies is the accumulation of infectious prion proteins (PrP(Sc)), which are formed by the conversion of physiological prion proteins (PrP(C)). As PrP(C), which is modified posttranslationally with various types of glycoproteins, serves as the substrates for PrP(Sc) conversion, various PrP(C) subtypes may play a role in the formation of PrP(Sc) and species-specific transmission; the cattle disease BSE is transmissible naturally to humans, but the sheep disease scrapie is not. To reveal new mechanisms modulating prion conversion, we analyzed the PrP(C) profiles by determining the differential PrP(C) protein solubilities in the anionic and nonionic detergents N-lauroylsarcosine, N-octyl-β-D-glucopyranoside, CHAPS and deoxycholic acid. We compared the resulting solubility profiles of human PrP(C) with the solubility profiles of PrP(C) from sheep and cattle. The PrP(C) subtypes were differentially soluble. However, non-glycosylated PrP(C) from cattle and human was found explicitly in the insoluble fraction, while non-glycosylated ovine PrP(C) was detected in the soluble fraction. These findings indicate the existence of low-solubility PrP(C) phenotypes in cattle and humans.

Klebsiella pneumoniae Peptidoglycan-Associated Lipoprotein and Murein Lipoprotein Contribute to Serum Resistance, Antiphagocytosis, and Proinflammatory Cytokine Stimulation

Peptidoglycan-associated lipoprotein (Pal), murein lipoprotein (LppA), and outer membrane protein A (OmpA) are dominant outer membrane proteins (OMPs) that are released by gram-negative bacteria during sepsis. OMPs are implicated in the maintenance of cell envelope integrity. Here, we characterize the roles of these OMPs in pathogenesis during bacteremia caused by Klebsiella pneumoniae. pal-, lppA-, and ompA-deficient K. pneumoniae strains were constructed using an unmarked deletion method. Serum sensitivity, antiphagocytosis activity, outer membrane permeability, and sensitivity to anionic detergents and antimicrobial polypeptides were determined for these OMP gene deletion mutants. The ability of these OMP gene deletion mutants to induce immune responses was compared with that of the wild-type strain in a bacteremic mouse model. Klebsiella pneumoniae strains deleted for pal or lppA exhibited reduced protection from serum killing and phagocytosis; perturbation to the outer membrane permeability barrier and hypersensitivity to bile salts and sodium dodecyl sulfate. The strain mutated for lppA had reduced ability to activate Toll-like receptor 4. Immunization of mice with the pal or lppA mutant provided protection against infection by the wild-type strain. Our findings indicate that K. pneumoniae Pal and LppA proteins are important in the maintenance of cell integrity, contribute to virulence, and could be used as attenuated vaccines.

ChemInform Abstract: Mild Palladium‐Catalyzed Oxidative Direct ortho‐C—H Acylation of Anilides under Aqueous Conditions.

AbstractThe rate accelerating effect of long chain anionic detergent and trifluoroacetic acid under aqueous conditions is shown.

Dependence of the Product Chain-Length on Detergents for Long-Chain E-Polyprenyl Diphosphate Synthases

Long-chain E-polyprenyl diphosphate synthases (E-PDS) catalyze repetitive addition of isopentenyl diphosphate (IPP) to the growing prenyl chain of an allylic diphosphate. The polyprenyl diphosphate products are required for the biosynthesis of ubiquinones and menaquinones required for electron transport during oxidative phosphorylation to generate ATP. In vitro, the long-chain PDSs require addition of phospholipids or detergents to the assay buffer to enhance product release and maintain efficient turnover. During preliminary assays of product chain-length with anionic, zwitterionic, and nonionic detergents, we discovered considerable variability. Examination of a series of nonionic PEG detergents with several long-chain E-PDSs from different organisms revealed that in vitro incubations with nonaethylene glycol monododecyl ether or Triton X-100 typically gave chain-lengths that corresponded to those of the isoprenoid moieties in respiratory quinones synthesized in vivo. In contrast, incubations in buffer with n-butanol, CHAPS, DMSO, n-octyl-β-glucopyranoside, or β-cyclodextrin or in buffer without detergent typically proceeded more slowly and gave a broad range of chain-lengths.

Comparative Study on Cytotoxicity Activity of N-α-Acylarginine Ethyl Ester

Amino-acid derived compounds, for example N-α-lauroylarginine ethyl ester (LAE), N-α-myristoylarginine ethyl ester (MAE) and a 1:1 mixture of N-α-myristoylarginine ethyl ester with monolaurin (MAE + MLN) are examined for their cytotoxicity towards L929-Mouse connective tissue to explore their use as microbicidal agent, in comparison to sodium dodecylsulfate (SDS) as an anionic control detergent. MTT (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cytotoxicity assay method was used to determine IC50 value. Cytotoxicity of MAE is found to be more toxic as compared to LAE, having IC50 value 0.052 mg/ml against 0.68 mg/ml of LAE. But MAE when mixed with monolaurin (1:1), showed less toxicity with IC50 0.89 mg/ml. These results suggest that a combination of MAE and Monolaurin can be a potential candidate for studying its microbicidal properties.

The Parasitic Contamination of Raw Vegetables Consumed in Zahedan, Iran

Background: Fresh vegetables are an important part of a healthy diet. In recent years there has been an increase in the number of reported cases of food-borne illness regarding fresh vegetables. Objectives: The objective of this study was to evaluate the parasitological contamination of vegetables which are consumed raw and commercialized in Zahedan, Iran. These findings could lead to better practices in handling vegetables to protect against intestinal parasitic infections. Materials and Methods: We studied 96 samples of raw vegetables including Garden cress, Wild Leek, sweet basil, cultivated radish, Dill, Coriander, Parsley, Peppermint and Scallion collected from markets in Zahedan City, Iran between June and August 2012. The study was performed in the Department of Parasitology, Faculty of Medicine, and Zahedan University of Medical Sciences. The vegetables were washed in tap water including an anionic detergent, the washing solution was then centrifuged and the sediments were examined for parasites. Results: The findings of forty three samples (44.8%) of all vegetables were microscopically positive for the presence of pathogenic metazoans, the results of 22 (22.9%) were positive for pathogenic protozoa and the results of 34 (35.4%) were positive for nonpathogenic protozoa species. Conclusions: It may be concluded that parasites are common in vegetables that are frequently eaten raw, and the use of tap water does little to remove them. Regarding the results of this study, the importance of vegetables in the transmission of intestinal parasites is stressed, and it is necessary to improve the sanitary conditions of these kinds of food.

A rapid paper chromatographic method for detection of anionic detergent in milk

A paper chromatographic method for the detection of adulteration of anionic detergent in milk is described. The method is based on the complexing of anionic detergent with methylene blue dye and separation of complex from free dye using simple paper chromatographic method. Since complexing of detergent is with dye, visualization is direct without involvement of subsequent detection of complex. The method is simple and results are available in 10min. The method is sensitive to detect 0.1% (w/v) labolene (laboratory grade detergent) or 0.01% (w/v) sodium dodecylbenzene sulfonate (pure anionic detergent) in milk. The method can be adopted at quality control laboratories in dairies for ascertaining the quality of milk.

Antibacterial efficacy of polypyrrole in textile applications

This paper describes application and evaluation of polypyrrole as an antibacterial polymer. Polypyrrole was produced embedding two doping agents: chloride and dicyclohexyl sulfosuccinate ions. Stability of the antibacterial efficacy of polypyrrole deposited on cotton fabrics was assessed before and after three different kinds of washing (namely, laundering with anionic and non-ionic detergents and dry-cleaning). Polypyrrole showed excellent antibacterial properties (100 % of bacterial reduction) against Escherichia coli for both doping agents. Treated fabrics were further characterised by scanning electron microscopy, energy dispersive X-ray analysis and infrared spectroscopy. The antibacterial efficacy diminished after launderings with anionic and non-ionic detergents because of two different mechanisms: the neutralisation of positive charges under alkali conditions (dedoping), and a partial removal of polypyrrole by abrasion and surfactant action. After dry-cleaning, polypyrrole embedding chloride and dicyclohexyl sulfosuccinate ions still showed excellent antibacterial efficacy. Moreover, scanning electron microscopy investigations were used to intuitively explain the bactericidal mechanism of polypyrrole on Escherichia coli bacteria.

Stability-indicating comparative methods using mekc and lc for determination of olmesartan medoxomil

A stability-indicating method using MEKC was validated for the analysis of olmesartan medoxomil in tablets. Successful separation was achieved using a fused silica capillary (40 cm x 50 µm i.d.); background electrolyte consisted of a combination of 10 mmol L-1 borate buffer and 5 mmol L-1 anionic detergent sodium dodecyl sulfate (95:5; v/v) pH 6.5; hydrodynamic mode at 50 mBar for 5 s; 25 kV separation voltage at 25 ºC; and column temperature 25 ºC with detection at 257 nm. The proposed method, validated following ICH guidelines, was applied to the determination of this antihypertensive with good results compared with an LC method.

Characterization and optimization of a novel protein refolding methodology

Controlling the refolding process of proteins is of considerable theoretical and practical interest [1, 2]. Recently, a simple yet effective method to recover refolded and active proteins has been developed, based on the association of an anionic detergent (the sodium dodecyl sulfate, SDS, known as denaturing agent) with an amphipathic diol solvent [3–5]. More precisely, it has been shown that peculiar solvents can modulate the denaturing properties of SDS and even induce the refolding from a SDS-denatured state. Up to now, this cosolvent effect has been observed on both soluble and bacterial membrane proteins. None to say, it is crucial to have a clear picture of the physicochemical and molecular basis of these refolding processes. To this end, we have used both experimental (intrinsic fluorescence and circular dichroism) and theoretical (molecular dynamics [6]) approaches to help understanding such intricate phenomena including the complex interplay between protein-SDS, protein-solvent and solvent-SDS interactions. In that context, a fundamental investigation has been achieved starting from the study of the detergent/cosolvent couple and then considering the protein/detergent/cosolvent complex. In a first stage, we explore the micellization characteristics of SDS in presence (or absence) of solvents (chain length, one or several alcohols groups, position isomers, ... ). Such a study gives access to the nature and strength of the interactions between the molecules, the system stability as a function of time, and the micelles formation kinetics. Original detergent/solvent pairs can be proposed in order to improve the efficiency of our refolding protocol, as well as to sharpen our understanding of its mechanism, paving the way to the full protein (especially of tricky systems as membrane proteins) characterization.

Time-Resolved Fluorescence Quenching Studies of Sodium Lauryl Ether Sulfate Micelles

Aggregation numbers (NAg) of micelles of the commercial anionic detergent sodium lauryl ether sulfate (SLES), with an average of two ethylene oxide subunits, were determined at 30 and 40o C by the time-resolved fluorescence quenching method with pyrene as the fluorescent probe and the N-hexadecylpyridinium ion as the quencher. The added-salt dependent growth of SLES micelles (γ = 0.11-0.15, where γ is the slope of a plot of log aggregation number vs. log [Yaq] and [Yaq] is the sodium counterion concentration free in the intermicellar aqueous phase) is found to be significantly lower than that of sodium alkyl sulfate micelles (γ ca. 0.25), a difference attributed to the larger headgroup size of SLES. The I1/I3 vibronic intensity ratio and the rate constant for intramicellar quenching of pyrene show that the pyrene solubilization microenvironment and the intramicellar microviscosity are insensitive to micelle size or the presence of added salt.