Conventional Cetyltrimethylammonium Bromide Research Articles

Gemini Surfactant-Directed Facile Pillaring of Two-Dimensional Zeolites with Enhanced Catalytic Activity in Friedel–Crafts Alkylation

We report an efficient procedure for the synthesis of pillared MWW zeolites (MCM-36) via integrating intercalation and hydrolysis of tetraethyl orthosilicate (TEOS) into one step. Specifically, two specially selected surfactants with more hydrophilicity instead of the conventional swelling agent cetyltrimethylammonium bromide (CTAB) were employed to increase the interlayer wetting ability and water content. The resultant intercalation and hydrolysis of TEOS occur concurrently in a confined interlayer microenvironment with enriched interlayer water and basic hexamethyleneimine (HMI). It is found that the wetting ability of swelling surfactants has a profound effect on pillarization efficiency, resulting in the different degrees of order of the layered structure, pore-size distribution, and accessibility of the acid sites of MCM-36. MCM-36 prepared using a gemini-type surfactant as a swelling agent shows a highly long-range ordered structure and enhanced catalytic activity for alkylation of benzene with benzyl alcohol compared to the one produced using conventional CTAB as a swelling agent.

High Quality of Bacterial DNA Extraction from Corbicula fluminea Tissue in Kelantan

Corbicula fluminea served as a popular traditional food in Kelantan, Malaysia. This clam is highly consumed by the local people from the last decade. However, there is lack of the study that obtain high quality of bacterial metagenome deoxyribonucleic acid (DNA) extraction from C. fluminea. Improper DNA extraction protocol always fails to extract a high integrity of bacterial DNA bands. This study compares the effectiveness and efficiency of conventional cetyltrimethylammonium bromide (CTAB) protocol, a commercial kit and modified CTAB protocol for bacterial DNA extraction from the soft tissue surface of raw C. fluminea. The instruments used to examine the quality of the extracted bacterial DNA were DeNovix DS-11 spectrophotometer, gel electrophoresis machine and UV transilluminator. The results showed that the bacterial DNA extracted from modified CTAB protocol the highest purity and integrity with the A₂₆₀/A₂₈₀ ratio of 1.92 ± 0.01 as well as the DNA band with minimum smear. This conclude that modified CTAB protocol is the best among the three extraction protocols for the bacterial extraction from the C. fluminea.

Rapid and efficient method of genomic dna extraction from sweet sorghum [<em>Sorghum bicolor</em> (L.)] using leaf tissue

Extraction of genomic DNA from plant leaf tissue is a basic requirement for molecular biology experiment as well as in plant breeding for crop improvement. The purity of DNA is affected by varying level of polyphenols, polysaccharides and secondary metabolites with are associated with DNA at the time of extraction. A variety of DNA extraction methods and kits are available, however they are costly, low yield and time consuming. Here, we describe a simple and efficient method of DNA extraction from sorghum leaf. The present study is based on conventional cetyl trimethyl ammonium bromide (CTAB) method with four major modifications to isolate genomic DNA from seven different accessions of sorghum and the yield of DNA was varied from1550.2 ngµl-1 to 1910.5ngµl-1 in 100 µl final volume of TE buffer. The purity of DNA sample was found to be varied from 1.53 to 2.16 based on the absorbance at A260 and A280 ratio. This method is very simple as it not requires liquid nitrogen or magnetic beads to grind the leaf sample which is mostly unavailable to some undergraduate laboratories.

Extraction of high-quality genomic DNA from different plant orders applying a modified CTAB-based method

BackgroundReliable measurement of DNA concentration and purity is important for almost all molecular genetics studies. Different plant species have varying levels of polysaccharides, polyphenols, and other secondary metabolites which combine with nucleic acids during DNA isolation and further affect the quality of the extracted DNA. The current extraction protocol is based upon the conventional cetyl trimethylammonium bromide (CTAB) method with further modifications for the extraction of DNA from variable plant seeds and crops belonging to seven different orders. The principle modifications currently employed for DNA extraction involved the use of higher CTAB concentration and higher levels of 2-β-mercaptoethanol. Additionally, higher concentrations of sodium chloride and potassium acetate were added simultaneously with absolute ice cold isopropanol for the precipitation of DNA free from polysaccharides.Results and conclusionThe prescribed modifications in the present method establish a quick and efficient standardized protocol for DNA extraction from different plant orders. The current extraction protocol, therefore, can be of great value for molecular analysis involving large numbers of different plant samples from different orders. These modifications consistently produced pure and high-quality DNA suitable for further molecular analysis. Successful PCR amplification with random amplified polymorphic DNA primer, NPTII gene, and the complete digestion of the isolated DNA with the HindIII restriction enzyme validated the quality of the isolated DNA. Moreover, it reflects the efficiency of the protocol and proves its suitability for further applications for the assessment of food safety, detection of genetically modified (GM) crops, and conservation of biodiversity.

Rapid, simple and potentially universal method for DNA extraction from Opuntia spp. fresh cladode tissues suitable for PCR amplification.

In Opuntia spp., the cladode tissues contain many polysaccharides and secondary metabolites that interfere with obtaining high-quality deoxyribonucleic acid (DNA), using currently available methods. To circumvent this problem, three commercial kits, three modified versions of the conventional cetyltrimethylammonium bromide method (CTAB) method and one combined method were tested in Opuntia ficus-indica, O. robusta, O. dillenii and O. elata species. We obtained a rapid and simple protocol that allows the extraction of DNA from all the tested species with good DNA yield and purity, namely, the combined method. With this method (DNeasy® Plant Mini Kit combined with the CTAB method), DNA yields from 13.2 ± 7.8 to 15.9 ± 11.3µgg-1 of fresh tissue were obtained in the four Opuntia species. The purity, evaluated by the ratio A260/A280 ratio, ranged from 1.67 ± 0.12 to 2.01 ± 0.25, revealing low levels of problematic metabolites. The extracted DNA quality was confirmed by amplifying a set of nuclear microsatellites obtained for the genus. Reliable reproducible bands and electropherogram profiles were obtained. The combined method has potential to be universal for good-quality DNA extraction in cacti, particularly in the Opuntia genus and other difficult-to-extract species.

Modulatory Functionalization of Gold Nanorods Using Supramolecular Assemblies.

Supramolecular-assembly-mediated functionalization of gold nanorods (GNRs) has been developed by reversible phase transfer between water and oils, which offers a facile method for fabricating robust GNRs with surface-charge tunability. In this regard, trimethylammonium (TMA) GNRs were initially prepared from conventional cetyltrimethylammonium bromide (CTAB) GNRs by means of a ligand-exchange reaction in the presence of an excess amount of TMA ligands. To further expand their functionality and potential applications, electrostatic assemblies of positively charged TMA-GNRs with negatively charged oleate ions were prepared. These assemblies (OA-GNRs) can undergo facile phase transfer from water to hexane. Interestingly, the reversible electrostatic assembly between the TMA and OA ions fabricated onto GNRs can be easily disrupted by treatment with HCl, which removes the OA ions from the GNRs to re-form the TMA-GNRs, which can be made soluble in aqueous media again. In addition, OA-GNRs can be further used for the synthesis of negatively charged GNRs such as 11-mercaptoundecanoic acid (MUA) GNRs, which are hard to prepare directly from CTAB-GNRs. This versatile method for phase transfer and functionalization on GNRs is expected to broaden the scope of their applications in sensing, biomedical imaging, photothermal therapies, and drug delivery systems.

Dipeptide Glycyl-Glycine (Gly-Gly)–Ninhydrin Reaction: Effect of Alkanediyl-α,ω-bis(dimethylcetylammonium bromide) (16-s-16, s = 4, 5, 6) Gemini Surfactants on the Reaction Rate

AbstractThe present work concerns with the effect of alkanediyl-α,ω-bis(dimethylcetylammonium bromide) gemini surfactants on the reaction rate of ninhydrin with glycyl-glycine. The spectra showed peaks at 400 nm and 570 nm in aqueous and aqueous–micellar media indicating the formation of the same product. Under pseudo-first-order conditions of excess ninhydrin, the reaction followed an irreversible first- and fractional-order kinetics with respect to [Gly-Gly] and [ninhydrin]. Also, the rate constants (kψ) increases and leveling-off regions are found with [geminis] (akin to conventional cetyltrimethylammonium bromide, CTAB), a third-region of increasing kψ is observed at higher [geminis]. The kinetic data in gemini micellar medium have been examined with the pseudo-phase model.

Effect of Alkanediyl‐α,ω‐Type Cationic Dimeric (Gemini) Surfactants on the Reaction Rate of Ninhydrin with [Cu(II)‐Gly‐Tyr]+ Complex

AbstractThe effect of gemini (16‐s‐16, s = 4, 5, 6) surfactants on the reaction rate of ninhydrin with [Cu(II)‐Gly‐Tyr]+ complex was determined using a spectrophotometric technique. The ninhydrin concentration was kept in excess in order to maintain pseudo‐first‐order conditions. The reaction followed irreversible first‐ and fractional‐order kinetics with respect to [Cu(II)‐Gly‐Tyr]+ and [ninhydrin], respectively. It is found that gemini surfactants effectively catalyze the reaction. The rate constants (kψ) first increase and then become relatively constant with increasing gemini surfactant concentration similar to conventional cetyltrimethylammonium bromide. At higher gemini surfactant concentration a third region of increasing kψ is observed. The unusual third region is ascribed to changes in micellar morphology. The kinetic data has been analyzed using a micellar pseudo‐phase model.

High-quality RNA extraction from small cardamom tissues rich in polysaccharides and polyphenols

Due to the presence of a diverse array of metabolites, no standard method of RNA isolation is available for plants. We noted that polysaccharide and polyphenol contents of cardamom tissues critically hinder the RNA extraction procedure. Hence, we attempted several methods for obtaining intact mRNA and small RNA from various cardamom tissues. It was found that protocols involving a combination of commercial kits and conventional CTAB (cetyl trimethylammonium bromide) methods yielded RNA with good purity, higher yield, and good integrity. The total RNA isolated through this approach was found to be amenable for transcriptome and small RNA analysis through next-generation sequencing platforms.

Interaction of Metal–Dipeptide Complex with Ninhydrin in the Absence and Presence of Conventional CTAB Surfactant

The present work is aimed at studying the interaction between copper-glycyltyrosine [(Cu(II)-Gly-Tyr)]+ and ninhydrin in water and in micelles formed by cetyltrimethylammonium bromide (CTAB) using spectrophometric measurements at 80°C and pH 5.0. The order of reaction remains the same in the two systems, that is, first- and fractional-order kinetics with respect to [Cu(II)-Gly-Tyr]+ and [ninhydrin], respectively, in the excess of ninhydrin over [Cu(II)-Gly-Tyr]+. It was observed that the product formed is same in both the media. The reaction is catalyzed by CTAB, and the maximum rate enhancement is about three fold. Quantitative kinetic analysis of kψ–[CTAB] data was explained in terms of pseudo-phase of the micelles (assuming the association/incorporation of both the reactants at the micellar surface).

Interaction between dipeptide (glycyl-phenylalanine) and ninhydrin: Role of CTAB and gemini (16-s-16, s = 4, 5, 6) surfactant micelles

The kinetics of interaction of dipeptide glycylphenylalanine (Gly-Phe) with ninhydrin have been studied by following the reaction spectrophotometrically at 70°C and a particular pH 5.0 in the absence and presence of conventional cetyltrimethylammonium bromide (CTAB) and gemini (alkanediyl-α,ω-bis(dimethylhexadecylammonium bromide)) surfactants. The rate shows first- and fractional-order dependence on [Gly-Phe] and [ninhydrin], respectively. The surfactants were found to catalyse the reaction. Furthermore, whereas the typical rate constant (kΨ) increase and leveling-off regions are observed with geminis, just like as seen with conventional surfactants, the former produced a third region of increasing kΨ at higher concentrations. A kinetic rate law consistent with experimental results has been derived on the basis of the proposed mechanism.

Automated DNA extraction from genetically modified maize using aminosilane-modified bacterial magnetic particles

A novel, automated system, PNE-1080, equipped with eight automated pestle units and a spectrophotometer was developed for genomic DNA extraction from maize using aminosilane-modified bacterial magnetic particles (BMPs). The use of aminosilane-modified BMPs allowed highly accurate DNA recovery. The (A(260)-A(320)):(A(280)-A(320)) ratio of the extracted DNA was 1.9+/-0.1. The DNA quality was sufficiently pure for PCR analysis. The PNE-1080 offered rapid assay completion (30 min) with high accuracy. Furthermore, the results of real-time PCR confirmed that our proposed method permitted the accurate determination of genetically modified DNA composition and correlated well with results obtained by conventional cetyltrimethylammonium bromide (CTAB)-based methods.

Synthesis of MCM-41 with a Phosphonium Template

Cetyltrimethyl phosphonium bromide was successfully used as a template in the synthesis of MCM-41. The material was characterized by small-angle X-ray diffraction, transmission electron microscopy, nitrogen adsorption, and 2 9 Si, 1 3 C, and 3 1 P solid-state NMR spectroscopy. These results were compared with those of MCM-41 prepared with the conventional cetyltrimethylammonium bromide surfactant showing that the material is highly ordered. Interestingly, the materials showed a temporary hydrothermal stability induced by residual P 2 O 5 produced by the calcination. NMR measurements on the reaction mixture showed that 3 1 P can be used as an excellent probe for in situ investigation of the formation mechanism.