Introduction
Hexadecyltrimethylammonium chloride, referred to as CTAC, is a cationic surfactant widely used in the field of chemistry for various applications. It is extensively researched for its ability to form micelles in solution, which is fundamental in the study of colloidal and surface chemistry. This property is particularly useful for understanding the mechanisms of solubilization and emulsification processes.
In materials science, Hexadecyltrimethylammonium chloride is employed to synthesize mesoporous materials and to control the morphology of nanostructured substances due to its phase-transfer catalysis capabilities. Additionally, it serves as a template molecule in the formation of various types of nanostructures. Its role in the stabilization and modification of nanoparticles is also a subject of investigation, with implications for the development of novel materials with specific optical, electronic, or catalytic properties.
1. Properties:
Hexadecyl Trimethyl Ammonium Chloride is a cationic surfactant, soluble in water, methanol, and ethanol. It is mainly be used as softener and hair conditioner. It also can be used as softener in waterproof coatings, natural fiber, synthetic fiber, and glass fiber. It has good compatibility with cationic, nonionic and amphoteric surfactants.
Hexadecyl Trimethyl Ammonium Chloride has good chemical stability, heat resistance, light resistance, pressure resistance, resistance to acid and alkali, and it also has excellent properties of permeability, softness, emulsification, anti electrostatic and bactericidal.
2. Usage:
- For shampoo, hair care products, architectural coatings, fabric softener, etc.
- In the petroleum, papermaking, food processing fields, used as bactericidal in cycling cooling water treatment.
- Used as emulsifying silicone oil, hair conditioner emulsifier, fiber softener and antistatic agent, can be used to soften and isolate the paper, corrosion inhibitor in the pickling industry
- Used as a washing adjustment agent (hair rinse agent) and hair conditioner.
3. Safety
Merck’s SDS provide essential information for anyone handling laboratory chemicals, including all of Merck’s dangerous and most non-dangerous products. All laboratory personnel should be fully aware of the potential risks involved and take appropriate safety measures before actually working with the substances. These safety measures include the technical handling of chemicals, the personal safety for people working with them as well as environmental considerations.
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Metabolism of in Pseudomonas Strain Bi
Quaternary ammonium salts, which are widely used synthetic organic chemicals, are ingredients in a variety of consumer products. Because of their widespread application and volume, quaternary ammonium salts occur in wastewaters. Generally, they are adequately removed by biodegradation and adsorption in wastewater treatment plants (7, 18, 21), but reduced concentrations will enter natural ecosystems. Therefore, knowledge of the biodegradability of these chemicals is important in order to assess the selfcleaning function of nature.
Biodegradation of quaternary ammonium salts by microorganisms has been determined in the OECD/EEC screening test (11, 13). However, the results from these simple biodegradation tests do not exclude the formation of recalcitrant intermediates. Degradation pathways of organic compounds are vital proof of total mineralization of the organic compounds. By using pure culture studies, possible recalcitrant intermediates may be identified. Only one article deals with the metabolism of alkyltrimethylammonium salts.
The degradation of decyltrimethylammonium chloride by a xanthomonad is probably initiated by the oxidation of the far end of the alkyl chain (3). However, other results obtained by Dean-Raymond and Alexander (3) suggest the splitting off of trimethylamine. Although alkyltrimethylammonium salts have received little attention, the catabolism of tetramethylammonium salts has been extensively studied. Tetramethylammonium chloride is completely biodegraded by a Pseudomonas sp.
(8). The oxidation of tetramethylammonium chloride proceeds by splitting the C-N bond, resulting in methanal and trimethylamine. This reaction is catalyzed by an NAD(P)Hand O2-dependent monooxygenase. The intermediate, trimethylamine, is either oxidized to trimethylamine-N-oxide (10) or directly converted to methanal and dimethylamine (2, 14). The trimethylamine-N-oxide is demethylated to dimethylamine (9, 15). Dimethylamine, in turn, is oxidized to methanal and methylamine (2). Finally, a primary dehydro-
Genase degrades methylamine, yielding methanal and ammonium (5). The aim of this study is to establish clearly the complete mineralization of alkyltrimethylammonium salts. This paper reports the isolation of a microorganism that grows on alkyltrimethylammonium salts and the metabolism of hexadecyltrimethylammonium chloride determined by simultaneous adaptation studies and enzyme activities in cell extracts.
1. MATERUILS AND METHODS
1. Chemicals.
All quaternary ammonium salts [docosyltrimethylammonium chloride, octadecyltrimethylammonium chloride (Arquad 18), Hexadecyltrimethylammonium chloride (Arquad 16), (dodecyl-tetradecyl)trimethylammonium chloride (Arquad MC), and dodecyltrimethylammonium chloride (Arquad 12)] used were supplied by Akzo Chemicals BV, Deventer, The Netherlands. The biochemicals were obtained from Sigma Chemical Co., St. Louis, Mo. All other chemicals were purchased from Janssen Chimica, Beerse, Belgium.
2. Media
Belgium. Media. The yeast-glucose plates contained, per liter of deionized water, 1 g of yeast extract, 5 g of glucose, and 15 g of agar. The mineral salts medium contained, per liter, 1.55 g of K2HPO4, 0.85 g of NaH2PO4, 0.5 g of NH4Cl, 0.1 g of MgSO4- 7H20, and 0.1 ml of a trace solution described by Visniac and Santer (24). Volatile organic compounds such as methylamines were added through a sterile filter. When a toxic quaternary ammonium salt was used as the growth substrate, silica gel was added to give a final concentration of 16 g/liter.
3. Isolation and maintenance of the microorganisms.
Microorganisms were enriched from activated sludge taken from a domestic sewage plant in a hexadecyltrimethylammonium chloride-limited continuous culture. The microorganisms in this culture were streaked to purity on yeast-glucose agar plates. These isolated strains were maintained on yeastglucose plates. One strain (Bi) was used in further studies.
- Growth of cultures.
Strain Bi was grown in batch culture in 100-ml flasks with 20 ml of the mineral salts medium. The final concentration of the growth substrate was 1 g/liter. The media were inoculated from a yeast-glucose plate and incubated in a stationary fashion at 30°C. Liquid cultures for respiration experiments and enzyme assays were grown in 400 ml of a mineral salts medium in 2-liter Erlenmeyer flasks. The latter were shaken at 200 rpm in an orbital incubator at 30°C. In some experiments, to quantify the formation of trimethylamine, flasks were sealed with rubber stoppers. The specific growth rate was estimated from logarithmically plotted curves of the accumulation of trimethylamine.
5. Preparation of washed cell suspensions and cell extracts.
Prior to harvest of hexadecyltrimethylammonium chloridegrown cells, silica gel was removed by gravitation. Cell suspensions of the liquid culture were harvested by centrifugation at 10,000 x g for 15 min at 4°C, washed with 100 mM phosphate buffer (pH 7.1), and resuspended in the same buffer. Washed cells of strain Bi were disrupted by sonification at 20,000 Hz by using a Vibra cell ultrasonic processor eight times for 10 s each time. Whole cells and cell debris were removed by centrifugation (33,000 x g for 45 min at 4°C). The cell extracts were stored at 4°C.
6. Determination of the oxidation rate.
The endogenous and substrate-dependent oxygen uptake rate of washed cell suspensions was determined in a Biological Oxygen Monitor (Yellow Springs Instruments, Yellow Springs, Ohio). The biological oxygen monitor consisted of a thermostated vessel with a magnetic stirrer.
The vessel was closed by an oxygen electrode to measure the oxygen depletion. After 5 min (necessary to determine the endogenous respiration), the substrate-dependent respiration was measured by injecting 0.1 ml of an 0.1% (wt/vol) substrate solution into the vessel.
2. Analytical methods.
The protein content of the cell extracts was determined by the bicinchoninic acid method (Pierce, Rockford, Wis.). Prior to chemical analysis of trimethylamine in the growth medium, bacteria were removed by centrifugation at 10,000 x g for 15 min. Trimethylamine was estimated in a Varian gas chromatograph, model 3700a, equipped with a flame ionization detector.
The chromatograph was fitted with a stainless steel column (1.8 m by 3 mm) packed with 5% Free Fatty Acid Phase on Chromosorb W (80/100 mesh, acid washed). The flow rate of the carrier gas nitrogen was 20 ml/min. The detector and the injector temperatures were 300 and 250°C, respectively, and the column temperature was 60°C. Hexadecyltrimethylammonium chloride was analyzed colorimetrically. The quaternary ammonium salts form a colored complex with methyl orange. This insoluble complex was extracted from the buffered water phase and bacteria into a 1,2-dichloroethane layer. The concentration of the insoluble complex was measured photometrically at 420 nm (25).
Enzymatic assays
Enzyme assays were carried out at 30°C with freshly prepared extracts. Spectrophotometric assays were performed in a Shimadzu UV 160 spectrophotometer (Shimadzu Corporation, Kyoto, Japan). Isocitrate lyase was assayed as described by Dixon and Kornberg (4). Hexadecanoyl coenzyme A (CoA) synthetase was determined by the formation of hydroxamate (1). Alkanal dehydrogenase was measured spectrophotometrically as an NAD+-linked activity at 340 nm. Assays were carried out in a total volume of 1 ml. The cuvette contained 1.5 ,umol of NAD+, 1.4 ,umol of phosphate buffer (pH 7.1), and 0.33 mg of protein. The reaction was initiated by the addition of 0.24 ,umol of tetradecanal.
Hexadecanoyl-CoA dehydrogenase was assayed by incu_bating 50 ,umol of phosphate buffer (pH 7.6), 0.3 ,umol of Na2EDTA, 0.03 ,umol of 2,6-dichlorophenol indophenol, 1.4 ,umol of phenazine methosulfate, and 0.03 ,mol of hexadecanoyl-CoA. The reduction of 2,6-dichlorophenol indophenol was monitored at 600 nm against a control containing no hexadecanoyl-CoA (26). Monooxygenase assays were performed in gas chromatography vials (1.5 ml) in a total volume of 0.5 ml.
The complete reaction mixture contained 7 ,umol of phosphate buffer (pH 7.1), 0.26 ,umol of NAD(P)H, 0.25 ,umol of hexadecyltrimethylammonium chloride, and 0.34 mg of protein. The vial was sealed and incubated at 30°C in a water bath with shaking at 100 rpm. The activity was determined by measuring the formation of trimethylamine.
3. Results
Isolation, cultivation, and characterization.
. Microorganisms capable of growing on hexadecyltrimethylammonium chloride as the sole carbon and energy source were enriched in a continuous culture inoculated with activated sludge (23). Six strains were isolated from this continuous culture fed with a mineral medium containing 0.5 g of hexadecyltrimethylammonium chloride per liter.
These six bacteria were streaked to purity on yeast-glucose plates. Growth on hexadecyltrimethylammonium chloride of these strains could not be demonstrated in batch cultures containing the medium of the continuous culture because the initial concentration (0.5 g/liter) in the batch culture was toxic to the microorganisms isolated.
To reduce the concentration of hexadecyltrimethylammonium chloride in the water phase, 16 g of silica gel per liter was added to the culture. The medium with silica gel supported the growth of three strains. One of these strains, designated Bi, was studied in detail since it grew rapidly on hexadecyltrimethylammonium chloride. Colonies of strain Bi on yeast-glucose plates were slightly brown. The organisms were mobile gram-negative rods. Strain Bi was also oxidase positive and unable to utilize mannitol, inositol, sorbitol, rhamnose, or saccharose.
These characteristics suggest that the strain was a Pseudomonas sp. Of the quaternary ammonium salts tested (i.e., monoalkyltrimethyl, dialkyldimethyl, and alkylbenzyldimethyldimethyl quatemary ammonium salts) Pseudomonas strain Bi grew only on alkyltrimethylammonium salts. In addition to the monoalkyltrimethylammonium salts, Pseudomonas strain Bi used a wide range of organic compounds as sole sources of carbon and energy, including acetate, ethanol, glucose, hexadecanoate, and hexadecanal. Hexadecyldimethylamine, hexadecylamine, trimethylamine, dimethylamine, and methylamine were no growth substrates.
The batch culture doubling time of Pseudomonas strain Bi on hexadecyltrimethylammonium chloride was approximately 6 h.
Oxidation of possible intermediates of hexadecyltrimethylammonium chloride.
Substrate-dependent oxygen uptake was determined for cells grown on hexadecyltrimethylammonium chloride, hexadecanoate, and acetate (Table 1). Both hexadecyltrimethylammonium chloride- and hexadecanoate-grown Pseudomonas strain Bi cells readily oxidized quaternary ammonium salts. A slight increase of the oxygen consumption rate by acetate-grown Pseudomonas strain Bi was observed upon the addition of hexadecyltrimethylammonium chloride. Hexadecanoate and hexadecanal were immediately and rapidly oxidized by both hexadecyltrimethylammonium chloride- and hexadecanoate-grown cells of Pseudomonas strain Bi. Neither the amines tested nor.
4. Discussion
The biodegradability of alkyltrimethylammonium salts has been demonstrated in OECD/EEC screening tests (11, 13). Furthermore, the biodegradation percentages of alkyltrimethylammonium salts with increasing alkyl chain length obtained in these screening tests also reflect the toxicity of these compounds to microorganisms (13). The toxicity of these salts increases with increasing chain length (3). Attempts to isolate microorganisms on hexadecyltrimethylammonium chloride were unsuccessful because of this toxicity (7, 12).
Recently, van Ginkel and Kolvenbach (23) enriched microorganisms in a continuous culture. In this culture, three strains were present which used hexadecyltrimethylammonium chloride as the sole carbon and energy source. Strain Bi, tentatively identified as a Pseudomonas sp., was studied in detail. Pseudomonas strain Bi makes use of a wide range of alkyltrimethylammonium salts (C12 to C22). This strain is, to the best of our knowledge, the first pure culture reported to use
Hexadecyltrimethylammonium chloride as the sole growth substrate. Growth of microorganisms on hexadecyltrimethylammonium chloride can occur in a chemostat but not in a batch culture, because of high initial concentrations of the growth substrate (7, 12). However, growth on this toxic compound in batch cultures is possible in the presence of silica gel. Silica gel acts as an adsorbent which slowly releases hexadecyltrimethylammonium chloride during the growth of the microorganisms, thus preventing inhibitory concentrations. Pseudomonas strain Bi also grows on hexadecanal and hexadecanoate.
These compounds are oxidized by hexadecyltrimethylammonium chloride-grown cells (Table 1). This indicates that both hexadecanal and hexadecanoate are intermediates in the degradation of hexadecyltrimethylammonium chloride. On the other hand, none of the amines tested could serve as growth substrates for Pseudomonas strain Bi. Furthermore, these amines were not oxidized by hexadecyltrimethylammonium chloride-grown cells. This suggests that amines are not intermediates in the degradation route of hexadecyltrimethylammonium chloride. Finally, the stoichiometric formation of trimethylamine from hexadecyltrimethylammonium chloride clearly shows that Pseudomonas strain Bi is capable only of oxidizing the alkyl chain.
The potential of hexadecanoate- and acetic acid-grown cells to oxidize hexadecyltrimethylammonium chloride demonstrates that the enzymes required for the hexadecyltrimethylammonium chloride metabolism are constitutively expressed. The crucial step in the biodegradation of hexadecyltrimimethylammonium chloride is the removal of the alkyl chain which may be catalyzed by an oxygenase.
Hampton and Zatman (8) have reported investigations of the breakdown of tetramethylammonium chloride by cell extracts to yield methanal and trimethylamine involving an NAD(P)H- and 02-dependent monooxygenase. The direct formation of trimethylamine from hexadecyltrimethylammonium chloride was also dependent on NAD(P)H and molecular oxygen as demonstrated with a cell extract of hexadecyltrimethylammonium
The direct cleavage of the C-N bond of hexadecyltrimethylammonium chloride. The specific activity of hexadecanal dehydrogenase in cell extracts of Pseudomonas strain Bi was measured after growth on hexadecyltrimethylammonium chloride.
Hexadecanoyl-CoA synthetase activity was not detected in cell extracts of hexadecyltrimethylammonium chloride- or hexadecanoate-grown cells probably because of an inadequate enzyme assay. The next enzyme in the degradative pathway, hexadecanoyl-CoA dehydrogenase, was detected. Hexadecanoate has to be progressively changed via 1-oxidation into acetyl-CoA. Therefore, cell extracts were assayed for isocitrate lyase, an essential anaplerotic enzyme, during growth on fatty acids.
The specific activity of isocitrate lyase in hexadecyltrimethylammonium chloride- and acetate-grown cells is high compared with that of the glucose-grown cells. It is assumed from the high specific activity of isocitrate lyase that hexadecyltrimethylammonium chloride is metabolized largely via acetyl-CoA. All data obtained are consistent with the proposed pathway shown in Fig. 3. Accumulation of 9-carboxynonyltrimethylammonium and 7-carboxyheptyltrimethyl ammonium salts during the biodegradation of decyltrimethylammonium chloride was demonstrated by using gas chromatographymass spectrometry (3).
of the far end of decyltrimethylammonium chloride, which contradicts the proposed biodegradation route.
However, respirometric studies described by Dean-Raymond and Alexander (3) are in accordance with our results (19). The initial microbial degradation of methylamines, including tetramethylammonium chloride, always involves the breakage of one of the C-N linkages (8). Additionally, microbial degradation of triethanolamine and nitrilotriacetic acid is also initiated by a C-N cleavage. Both triamines are converted into the respective aldehydes and diamines (20, 27). Quaternary ammonium salts are widely distributed components in many organisms.
It is noteworthy that these naturally occurring quaternary ammonium salts such as betaine, choline, and cametine are metabolized in the same way as synthetic alkyltrimethylammonium salts. Formation of trimethylamine from these naturally occurring compounds has been demonstrated by several authors (6, 16, 17, 22, 28). The potential to mineralize alkyltrimethylammonium salts by the Pseudomonas sp. may have been evolved from betaine-, choline-, and carnitine-degrading microorganisms.
Hexadecyltrimethylammonium chloride is totally mineralized by at least two microorganisms (Fig. 3). It appears that one organism oxidizes the alkyl chain only as far as trimethylamine and that this compound serves as a growth substrate for trimethylamine-degrading bacteria (2, 10, 14). Formation of recalcitrant metabolites which might arise from incomplete biodegradation of alkyltrimethylammonium salts is therefore quite impossible.
Cooperative binding of hexadecyltrimethylammonium chloride and sodium dodecyl sulfate to 5. 5. 5. 5.
5. Cytochrome C And The Resultant Change In Protein Conformation
Abstract
The binding of hexadecyltrimethylammonium chloride (HTAC) and sodium dodecyl sulfate (SDS) to cytochrome c was determined by potentiometric titration and the corresponding changes in protein conformation by circular dichroism (CD). The binding isotherms were biphasic; about 20 surfactant cations or anions were bound to cytochrome c in the first phase. Another 30 or so HTA+ ions were bound in the second phase, which was below the critical micelle concentration of the surfactant, but the binding of dodecyl sulfate ions in the second phase increased sharply near the critical micelle concentration.
The binding of both surfactants was highly cooperative and was endothermic; the data in the first phase fitted the Hill plot. The corresponding change in the secondary structure of cytochrome c was small; the CD spectra in the ultraviolet region showed a moderate increase in the helicity in HTAC solution and some changes in conformation in SDS solution. However, the CD spectra for the Soret band indicated a marked change in the local conformation around the heme.
Question
1. What is hexadecyltrimethylammonium chloride used for?
It has a role as a surfactant. It is a quaternary ammonium salt and an organic chloride salt. It contains a cetyltrimethylammonium ion. Cetyltrimethylammonium compound whose salts and derivatives are used primarily as topical antiseptics.
2. What is Hexadecyltrimethylammonium bromide used for?
The cetrimonium (hexadecyltrimethylammonium) cation is an effective antiseptic agent against bacteria and fungi. It is also one of the main components of some buffers for the extraction of DNA.
3. What is the chemical CTAC used for?
MULTI USE: Cosmetic Grade CTAC Liquid is used as a raw material for your cosmetic brand or DIY use to make products such as facial mask, face and body scrubs, lotions, creams, moisturizers, serums, body butters, hair and skin care and bath products, pressed powders, liquid foundation, mascara, deodorant soap, shampoo …
4. What is CTAB used for?
Today, in addition to its use as a topical antiseptic, CTAB has applications in medicine as an apoptosis-promoting anticancer agent, and in protein electrophoresis, DNA extraction buffer systems, and nanoparticle synthesis.
5. What is CTAC in altered carbon?
The United Nations Colonial Tactical Assault Corps ( Abbr. UNCTAC; CTAC) ( Fr. Corps Colonial de l’Assault Tactique des Nations unies) is a terrestrial army corps of the military of the United Nations Protectorate. It is tasked with immediate responses to acts of terrorism and rebellion on human worlds.
6. Is cetrimonium chloride safe for skin?
It is a colorless to pale yellow liquid in raw material form. The 2012 Cosmetic Ingredient Review report deemed cetrimonium chloride safe in amounts up to 10% when used in rinse-off formulas.