Thiazole Groups Research Articles

Influence of side chain structure on the thermal and antimicrobial properties of cationic methacrylic polymers

A novel methacrylic monomer, 2-(((2-(4-methylthiazol-5-yl)ethoxy)carbonyl)oxy)ethyl methacrylate (MTZ), containing in the lateral chain both hydrolytically sensitive carbonate and thiazole groups has been firstly described. Posterior, it was free-radical polymerized and copolymerized with acrylonitrile in anhydrous solution of dimethylsulfoxide, with the purpose of investigate the influence of its chemical and structural characteristics on the antimicrobial activity. Cationic antimicrobial polymers were subsequently obtained by alkylation reaction with methyl and butyl iodide agents. Their thermal behavior was analyzed in all series, modified and unmodified copolymers in terms of glass transition temperature and thermal stability. The antimicrobial activity in solution was tested against Gram-positive Staphylococcus aureus and Staphylococcus epidermidis, Gram-negative Escherichia coli and Pseudomonas aeruginosa bacteria, and Candida parapsilosis yeast and further correlated with their zeta potential. Then, blends of these cationic polymers with commercial polyacrylonitrile as matrix material were prepared and their effectiveness as antimicrobial coating was determined against Gram-negative Escherichia coli bacteria. In addition and due to the presence of the carbonate groups in the copolymer structures, these systems could be further used as antimicrobial releasing coatings in alkaline conditions.

Synthetic modifications in ethyl 2-amino-4-methylthiazole-5-carboxylate: 3D QSAR analysis and antimicrobial study

Ethyl 2-amino-4-methylthiazole-5-carboxylate (1) is a very substantial derivative of the thiazole group. This derivative has been modified and has been synthesized using readily available materials. The structures of synthesized derivatives were confirmed by IR, 1H NMR, 13C NMR, and mass spectral techniques. The newly prepared compounds (5a-k) were studied for their antimicrobial activities against strains of bacteria (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Streptococcus pyogenes) and fungi (Candida albicans, Aspergillus niger, and Aspergillus clavatus) using serial dilution method. Structure-activity relationship was carried out by CoMFA and CoMSIA with the help of 3D-QSAR analysis. As per the database alignment, the CoMFA and CoMSIA models were developed. Information based on these models is useful for structure-activity relationships of the reported molecules.

Synthesis of new antidiabetic agent by complexity between vanadyl (II) sulfate and vitamin B1: Structural, characterization, anti‐DNA damage, structural alterations and antioxidative damage studies

Complexity between thiamine (vitamin B1) and VSO4.xH2O salt with the suggest formula, [VO (vitB1)2] has been synthesized by the chemical reaction in neutralization media pH = 7.5 at 70 °C. The assignments of the elemental analysis, conductivity measurements, FT‐IR, UV–Vis, ESR spectroscopy, thermal analyses (TGA‐DTA) and magnetic moment data visualize the stoichiometry, formula and chelation of the vanadyl (II) complex. The spectroscopic analyses revealed that vitamin B1 reacted with vanadyl (II) ions as a bidentate ligand via hydroxyl ethyl‐oxygen and sulfur of the thiazole group. New vanadyl (II) complex has the protective effect against pancreatic toxicity induced by STZ. The target of this investigation was to assess the enhancement effect of new vanadyl (II)complex in two doses on pancreatic toxicity, oxidative stress, DNA damage and hyperglycemia persuade by STZ. The rats were divided into 7 groups; control group, STZ (diabetic untreated group) (50 mg/kg), STZ plus thiamine (10 mg/Kg) (Low dose), STZ plus thiamine (50 mg/Kg) (High dose), STZ plus VSO4. xH2O (15 mg/kg), STZ + vanadyl (II) complex (10 mg/Kg) (Low dose), STZ+ vanadyl (II) complex (50 mg/Kg) (High dose). Vanadyl (II) complex in high dose afforded a significant decline in MDA level parallel to significant elevation in antioxidant enzymes (SOD, CAT, MPO and XO) in pancreas homogenates. It may be due to the capturing activities of reactive oxygen species by the new complex, which reduces oxidative damage and enhance antioxidant capacities. The novel complex succeeded in the restoration of lipid parameters to its normal levels beside lowering TNF‐α and CRP levels. The new complex also reduces hyperglycemia induced by STZ greatly and improve histological and ultrastructure of pancreas and has a high potency in reducing DNA damage in pancreatic tissues.

Spectroscopic characterization, thermogravimetry, density functional theory and biological studies of some mixed‐ligand complexes of meloxicam and 2,2′‐bipyridine with some transition metals

The mixed‐ligand Mn(II), Fe(III), Ni(II), Cu(II), Zn(II) and Zr(IV) complexes of meloxicam (H2mel) and 2,2′‐bipyridine (Bipy) were prepared and characterized. For all complexes, the analytical and spectroscopic results revealed that H2mel acts in a monobasic bidentate manner through the oxygen of the amide and nitrogen of the thiazole groups, whereas Bipy coordinates through the two nitrogen atoms with slightly distorted octahedral geometry. Thermodynamic parameters (E, ΔS*, ΔH* and ΔG*) were calculated using Coats–Redfern and Horowitz–Metzger methods. The geometries of H2mel and the complexes were carefully studied using density functional theory to predict the properties of materials performed using the hybrid density functional method B3LYP. All studied complexes are soft with respect to H2mel where η varies from 0.096 for Zn(II) complex to 0.067 for Fe(III) complex and σ varies from 10.42 to 14.93 eV, while η and σ for H2mel are 0.14 and 7.14 eV, respectively. The antibacterial activities of the ligands and metal complexes were investigated and the data show that the complexes are active against some bacterial species compared with H2mel.

Crystal structure of (1,3-thia-zole-2-carboxyl-ato-κN)(1,3-thia-zole-2-carb-oxy-lic acid-κN)silver(I).

The linear two-coordinate silver (I) complex [Ag(C4H2NO2S)(C4H3NO2S)] or [Ag(2-Htza)(2-tza)] is reported (2-Htza = 1,3-thia-zole-2-carb-oxy-lic acid). The AgI ion is coordinated by two heterocyclic N atoms from two ligands in a linear configuration, forming a discrete coordination complex. There is an O-H⋯O hydrogen bond between 2-tza- and 2tzaH of adjacent complexes. The hydrogen atom is shared between the two oxygen atoms. This inter-action produces a hydrogen-bonded tape parallel to the [110] direction, which is augmented through inter-molecular C-H⋯O hydrogen-bonding inter-actions between the bound thia-zole groups. There is a further rather long Ag⋯O inter-action [2.8401 (13) Å, compared with a mean of 2.54 (11) Å for 23 structures in the CSD] that assembles these tapes into columns, between which there are C-H⋯π inter-actions, leading to the formation of a three-dimensional supra-molecular architecture.

Total synthesis of micrococcin P1 and thiocillin I enabled by Mo(vi) catalyst.

Thiopeptides are a class of potent antibiotics with promising therapeutic potential. We developed a novel Mo(vi)-oxide/picolinic acid catalyst for the cyclodehydration of cysteine peptides to form thiazoline heterocycles. With this powerful tool in hand, we completed the total syntheses of two representative thiopeptide antibiotics: micrococcin P1 and thiocillin I. These two concise syntheses (15 steps, longest linear sequence) feature a C-H activation strategy to install the trisubstituted pyridine core and thiazole groups. The synthetic material displays promising antimicrobial properties measured against a series of Gram-positive bacteria.

Oxazole and Thiazole Analogs of Sulindac for Cancer Prevention

Aim:Experimental and epidemiological studies and clinical trials suggest that nonsteroidal anti-inflammatory drugs possess antitumor potential. Sulindac, a widely used nonsteroidal anti-inflammatory drug, can prevent adenomatous colorectal polyps and colon cancer, especially in patients with familial adenomatous polyposis. Sulindac sulfide amide (SSA) is an amide-linked sulindac sulfide analog that showed in vivo antitumor activity in a human colon tumor xenograft model.Results/methodology:A new analog series with heterocyclic rings such as oxazole or thiazole at the C-2 position of sulindac was prepared and screened against prostate, colon and breast cancer cell lines to probe the effect of these novel substitutions on the activity of sulindac analogs.Conclusion:In general, replacement of the amide function of SSA analogs had a negative impact on the cell lines tested. A small number of hits incorporating rigid oxazole or thiazole groups in the sulindac scaffold in place of the amide linkage show comparable activity to our lead agent SSA.

Highly refractive thiazole-containing polyimides: a structural property comparison

Highly refractive, thermally stable, and solution processable polyimides (PIs) were synthesized by the introduction of thiazole units, thioether linkages, and phenyl or nitrophenyl groups into the polymer backbones. These PIs were prepared via the polycondensation of two diamine monomers, 5,5′-thiobis(2-amino-4-phenyl-thiazole) (DA-1) or 5,5′-thiobis(2-amino-4-(3-nitrophenyl)thiazole) (DA-2), with various aromatic dianhydrides(a–d). The bulky pendant phenyl or nitrophenyl units as well as the non-coplanar conformations because of ortho-sulfide linkages endowed the resulting PIs with excellent solubility in organic solvents. These PIs showed outstanding thermal stability, with 10% weight loss temperatures exceeding 492 °C under nitrogen and 475 °C in air atmosphere, while their glass transition temperatures were in the range of 239–278 °C. In general, the synergic effects of thiazole groups, phenyl or nitrophenyl substituents, and thioether linkages provided PIs with very high refractive indices of up to 1.7646 at 632.8 nm, along with small birefringences (<0.0085) and high Abbe’s numbers. The structure–property relationships of the analogous PIs containing phenyl or nitrophenyl substituents groups were also studied in detail by comparing the results.

Theoretical study on p-type D-π-A sensitizers with modified π-spacers for dye-sensitized solar cells.

Based on a prototype sensitizer W2, we designed triarylamine-based p-type sensitizers W2-1 to W2-7 that contain modified π-spacers (π'), a π-spacer and two anchors. For W2-1 to W2-4, instead of 2,1,3-benzothiadiazole in W2, thieno[3,4-b]-1,4-dioxin, thiophene, thieno[3,4-c][1,2,5]thiadizole, thiazolo[5,4-d]thiazole are π' and thiophene as π-spacer. For W2-5 to W2-8, π' and π are same, with 2,1,3-benzothiadiazole, thieno[3,4-b]-1,4-dioxin, thieno[3,4-c][1,2,5]thiadiazo, thiazolo[5,4-d]thiazole, respectively, as the π'-spacers. Structure optimization, electronic level and absorption characters were calculated with density functional theory (DFT) and time-dependent DFT (TDDFT) at the CAM-B3LYP/6-311G (d,p). The solvent effect was involved using a polarized continuum model in chloroform. The results showed that the highest occupied molecular orbital and the lowest unoccupied molecular orbital guarantee sufficient hole injection (lower than -0.2 eV), and dye regeneration (lower than -0.2 eV). W2-4 has higher light-harvesting efficiency (LHE) (0.994) and larger overlap with the visible light from 400 nm to 600 nm. Finally, the results suggest that the driving force of hole injection, dye regeneration and charge recombination (ΔGinj, ΔGreg and ΔGCR) of W2-4 are the best, with more negative ΔGinj (-4.33), ΔGreg (-1.74) and more positive ΔGCR (1.92). Replacing 2,1,3-benzothiadiazole with thiazolo[5,4-d]thiazole as π'-spacers is a effective way to improve the performance of the dyes. An introduction of thiazolo[5,4-d]thiazole group can improve the absorption ability and hinder charge recombination. Graphical abstract Absorption spectra of p-type D-π-A sensitizers with modified π-spacers.

Effects of Single Atom N-Substitution in the Molecular Skeleton on Fabricated Film Quality and Memory Device Performance

In this paper, two conjugated organic small molecules, NITP and NITZ, were designed and synthesized. NITZ is just altered by single atom N-substitution from the NITP thiophene group to the thiazole group in the heterocyclic aryl ring of the skeleton. The morphology and intermolecular stacking style of the fabricated nanofilms were analyzed by atomic force microscopy (AFM), grazing-incidence small-angle X-ray scattering (GISAXS), and X-ray diffraction (XRD). It demonstrates that both molecules prefer highly ordered packing after annealing, and the crystallite orientation is even more superior by N-substitution. As a result, both memory devices exhibit ternary memory performance. This study highlights that the thiazole group also constitutes a good candidate for a π-bridge of organic semiconducting molecules, and it really provides a simple and refined strategy for designing multilevel memory materials by single atom substitution.

Synthesis of nanoparticle emulsion collector HNP and its application in microfine chalcopyrite flotation

Hydrophobic polystyrene nanoparticles bearing thiazole groups named HNP were used as collectors to improve recovery of microfine chalcopyrite in flotation. HNP adsorbs onto microfine particles selectively, which were modified hydrophobically to induce flotation effectively. Particle size and scanning electron microscope analysis for HNP show that HNP is a spherical nano particles with small size, uniform distribution and good dispersion. Infrared spectrum analysis for HNP proved that functional monomer 2-mercapto styrene acrylic thiazole was bonded chemically onto styrene. Flotation test results indicate that HNP is the right collector of chalcopyrite. Especially, the recovery of chalcopyrite is higher than 95% in neutral and acid media. FTIR results reveal that the flotation selectivity of collector HNP is due to strong chemical absorption onto chalcopyrite surface. Zeta potential analysis shows that the zeta potential of chalcopyrite decreased more quickly after interaction with HNP with the increase of pulp pH value, confirming that collector HNP is an anionic collector. Scanning electron microscope conform that HNP has good selective adsorption on chalcopyrite.

Kinetic analysis of thermal degradation of NR/EPDM blends with maleic anhydride as compatibilizer: The effect of the reactive accelerators

Thermal characteristic is important to determine the thermal resistance of a polymer. In this work, the thermal characteristics of the NR/EPDM blends was investigated to study the storage and application condition of the blends. The NR/EPDM blends were prepared in the two-roll mill by using MAH as a compatibilizer with several types of accelerators, i.e., MBTS from thiazole group, the combination of MBTS and TMTD from thiuram group, and TBBS from sulphenamide group. This research used the thermogravimetric method with the heating rate of 10, 15, and 20oC/min. The kinetic parameters are calculated by using Coats-Redfern equation. The degradation of NR/EPDM blends occurs in two stages (frst stage at 220-420oC and second stage at 420-520oC). Combination of MBTS and TMTD give higher energy activation (112.236 kJ/mol), followed by MBTS-blend (111.999 kJ/mol), and TBBS-blend (110.856 kJ/mol). Combination of MBTS and TMTD accelerator with MAH as the compatibilizer is the proper choice for NR/EPDM blends to get a good thermal stability.

Ligational, DFT, optical band gap and biological studies on Mn(II), Co(II) and Ni(II) complexes of ethyl and allyl thiosemicarbazides ending by thiazole group

The Mn(II), Co(II), Ni(II) and Cu(II) complexes with two ligands derived from the addition of 2-(2-aminothiazol-5-yl) actahydrazide to ethyl (H2TAET) and allyl (H2TAAT) isothiocynates have been prepared and characterized by way of traditional strategies. The isolated complexes assigned the formulae, [Mn(HTAET)2(H2O)2](2.5H2O), [Co(HTAET)(H2O)3Cl](2H2O), [Ni(HTAET)(H2O)2Cl](4H2O), [Mn(HTAAT)Cl](2.5H2O), [Co(HTAAT)(H2O)Cl](2H2O) and [Ni(HTAAT)(H2O)Cl]. IR data found out that the both ligands behave as monovalent bidentate via (CN)th and deprotonated enolized (CO) group in Mn(II) and Co(II) complexes of (H2TAET) and in all complexes of (H2TAAT) except Mn(II) complex. Mn(II) of (H2TAAT) and Ni(II) of (H2TAET) complexes act as monobasic tridentate (NNO) and subsequently (H2TAET) act as (NNS) tridentate in Cu(II) complex. The data of UV–vis spectra and the magnetic measurements recommended that the octahedral geometry for all complexes of (H2TAET) at the same time as tetrahedral geometry for all complexes of (H2TAAT) except Ni(II) that is square planar was suggested. The bond lengths, bond angles, HOMO, LUMO and dipole second values have been calculated by way of DFT the use of materials studio program to verify the recommended geometries of ligands and their metal complexes. Additionally, the kinetic and thermodynamic parameters for the different thermal degradation steps of the complexes have been decided by way of Coats-Redfern and Horowitz- Metzger techniques. The optical band gap (Eg) of the metal complexes has been calculated. The optical band gap (Eg) measurements confirmed allowed direct electronic transitions for the photon absorption inside the investigated complexes. Moreover, the antimicrobial, antioxidant and antitumor of ligands and their complexes have been evaluated.

Zinc Coordination Polymers Containing Isomeric Forms of p‐(Thiazolyl)benzoic Acid: Blue‐Emitting Materials with a Solvatochromic Response to Water

Two coordination polymers of assorted dimensionality (1D, 2D) have been prepared, namely [Zn3(L2Th)4(OH)2·2(HL2Th)]∞ (1) and [Zn(L5Th)(OAc)]∞ (2), starting from ZnII salts and the isomeric forms of the organic linker p‐(thiazolyl)benzoic acid: p‐(2‐thiazolyl)benzoic acid (HL2Th) and p‐(5‐thiazolyl)benzoic acid (HL5Th). The isomers have been prepared ad hoc, following straightforward Pd‐catalyzed C–C coupling reaction protocols. In 1, the deprotonated ligand is coordinated through its carboxylate group only, with dangling thiazole groups. The –COO– units are bridging adjacent metal centers, thus creating a 1D chain. The Zn3 cluster is made of one six‐coordinate (Oh) and two four‐coordinate (Td) ZnII ions; triple‐bridging µ3‐OH groups are balancing the overall positive charge. The structure of 2 is instead made of Zn2(carboxylate)4 “paddle‐wheel” dimers as the constituting inorganic node. The octahedral metal coordination sphere includes two µ‐(κ‐COO) benzoate spacers, two µ‐(κ‐COO) acetate ions, the thiazole N atoms coming from adjacent building blocks, and a weak Zn···Zn axial interaction. The resulting final assembly is two‐dimensional (2D), where p‐(5‐thiazolyl)benzoate adopts a genuine µ‐[κ(COO):κ(N)] bridging coordination mode. The luminescent properties of both polymers have been analyzed in the solid state; they feature ligand‐centered emissions at λ = 434 nm (1) and λ = 427 nm (2). These electronic transitions fall in the visible region, giving the samples a characteristic blue color under an ordinary UV lamp (excitation at λ = 254 nm). The theoretical analysis of the electronic features of the ligands and related molecular orbitals reveals that the observed transitions are mainly of π→π* nature, involving π orbitals delocalized on both aromatic cycles. A significant (reversible) blueshift of the emission maximum of ca. 60 nm, from the visible to the UV region, has been observed for 1 when suspended in water.

Novel PAMAM dendrimers with porphyrin core as potential photosensitizers for PDT applications

The photophysical properties of meso-substituted tetraphenyl porphyrins with PAMAM branches, and one peripherally-modified derivative with thiazole groups were studied in DMF solution. The singlet states of the compounds were characterized by means of absorption and fluorescence spectroscopies. The triplet state decay kinetics and the triplet–triplet absorption spectra were determined by laser flash photolysis. Triplet state spectra showed intense absorbance with a maximum at around 450nm and other bands in the regions of 300–400 and 500–800nm, for all compounds. The triplet quantum yields (ΦT) and the singlet oxygen quantum yields (ΦΔ) were estimated to be ca. 0.50 and 0.45, respectively. From the present results, it is inferred that the triplet states of these molecules allow an efficient energy transfer to molecular oxygen, which makes them potentially suitable for photodynamic therapy.

Properties, characteristics and application of grinded Malpighia emarginata seeds in the removal of toxic metals from water

Cadmium and copper, which are found in aquatic ecosystems, may be considered toxic and potentially toxic metal species, respectively. These metals tend to accumulate in plants and fish, besides their potential to be transferred to other animals and cause several diseases. Malpighia emarginata grinded seeds were simply prepared and applied as adsorbent in order to remove and assist the safe trace quantification of such elements. Dry biomass was characterized through FTIR, 13C-NMR, SEM, surface area measurements and through elemental analysis. Important structures, which may be involved in metal coordination, such as carboxylic acid, thiazole and amine groups, were identified. Malpighia emarginata seeds had its pHPZC determined (6.0) and the influence of dynamic contact time (kinetic) and pH on adsorption of Cu(II) and Cd(II) was investigated. Adsorption equilibrium was reached in less than 30min, and it had good correlation with the pseudo-second-order kinetic model in Cu(II) and Cd(II). The Ns values were calculated through the modified Langmuir equation (0.103 and 0.098mmolg−1 for Cu(II) and Cd(II), respectively), which showed results similar to those published in other studies. The preconcentration system accomplished enrichment factor of approximately 40-fold in Cu(II) and Cd(II). Such result evidenced that Malpighia emarginata seeds can be a low-cost procedure adopted to remove metallic species from aqueous samples, as well as to assist analytical methodologies in determining Cu(II) and Cd(II) traces.

Contact Active Antimicrobial Coatings Prepared by Polymer Blending.

Herein, contact active antimicrobial films are prepared by simply blending cationic amphiphilic block copolymers with commercial polystyrene (PS). The copolymers are prepared by combining atom transfer radical polymerization and "click chemistry." A variety of copolymers are synthesized, and composed of a PS segment and an antimicrobial block bearing flexible side chain with thiazole and triazole groups, 4-(1-(2-(4-methylthiazol-5-yl)ethyl)-1H-1,2,3-triazol-4-yl) butyl methacrylate (TTBM). The length of the TTBM block is varied as well as the alkylating agent. Different films are prepared from N,N-dimethylformamide solution, containing variable PS-b-PTTBM/PS ratio: from 0 to 100 wt%. Remarkably, the blend films, especially those with 30 and 50 wt% of copolymers, exhibit excellent antimicrobial activities against Gram-positive, Gram-negative bacteria and fungi, even higher than films prepared exclusively from the cationic copolymers. Blends composed of 50 wt% of the copolymers present a more than 99.999% killing efficiency against the studied microorganisms. The better activity found in blends can be due to the higher roughness, which increases the surface area and consequently the contact with the microorganisms. These results demonstrate that the use of blends implies a reduction of the content of antimicrobial agent and also enhances the antimicrobial activity, providing new insights for the better designing of antimicrobial coatings.

Triazolylidene Iridium Complexes for Highly Efficient and Versatile Transfer Hydrogenation of C═O, C═N, and C═C Bonds and for Acceptorless Alcohol Oxidation.

A set of iridium(I) and iridium(III) complexes is reported with triazolylidene ligands that contain pendant benzoxazole, thiazole, and methyl ether groups as potentially chelating donor sites. The bonding mode of these groups was identified by NMR spectroscopy and X-ray structure analysis. The complexes were evaluated as catalyst precursors in transfer hydrogenation and in acceptorless alcohol oxidation. High-valent iridium(III) complexes were identified as the most active precursors for the oxidative alcohol dehydrogenation, while a low-valent iridium(I) complex with a methyl ether functionality was most active in reductive transfer hydrogenation. This catalyst precursor is highly versatile and efficiently hydrogenates ketones, aldehydes, imines, allylic alcohols, and most notably also unpolarized olefins, a notoriously difficult substrate for transfer hydrogenation. Turnover frequencies up to 260 h-1 were recorded for olefin hydrogenation, whereas hydrogen transfer to ketones and aldehydes reached maximum turnover frequencies greater than 2000 h-1. Mechanistic investigations using a combination of isotope labeling experiments, kinetic isotope effect measurements, and Hammett parameter correlations indicate that the turnover-limiting step is hydride transfer from the metal to the substrate in transfer hydrogenation, while in alcohol dehydrogenation, the limiting step is substrate coordination to the metal center.

Secondary Sulfonamides as Effective Lactoperoxidase Inhibitors.

Secondary sulfonamides (4a–8h) incorporating acetoxybenzamide, triacetoxybenzamide, hydroxybenzamide, and trihydroxybenzamide and possessing thiazole, pyrimidine, pyridine, isoxazole and thiadiazole groups were synthesized. Lactoperoxidase (LPO, E.C.1.11.1.7), as a natural antibacterial agent, is a peroxidase enzyme secreted from salivary, mammary, and other mucosal glands. In the present study, the in vitro inhibitory effects of some secondary sulfonamide derivatives (4a–8h) were examined against LPO. The obtained results reveal that secondary sulfonamide derivatives (4a–8h) are effective LPO inhibitors. The Ki values of secondary sulfonamide derivatives (4a–8h) were found in the range of 1.096 × 10−3 to 1203.83 µM against LPO. However, the most effective inhibition was found for N-(sulfathiazole)-3,4,5-triacetoxybenzamide (6a), with Ki values of 1.096 × 10−3 ± 0.471 × 10−3 µM as non-competitive inhibition.

Antimicrobial surfaces obtained from blends of block copolymers synthesized by simultaneous ATRP and click chemistry reactions

A series of amphiphilic block copolymers based on styrene (S) and a monomer bearing both thiazole and triazole groups (MTA) were synthesized by combination of ATRP and click chemistry. In particular, two approaches were followed; the direct ATRP from a PS macroinitiator of the pre-synthesized MTA antimicrobial monomer; and the simultaneous synthesis and polymerization of the MTA through a one-step ‘click chemistry’/ATRP process. Both strategies conduct to well-defined block copolymers with controlled molecular weight and low polydispersity. Subsequent quaternization of the thiazole and triazole groups of MTA units with butyl iodine renders systems with antimicrobial properties. Although these systems presented relatively low antimicrobial activity against bacteria and fungi in aqueous media, the preparation of surfaces functionalized with these copolymers leads to potent antimicrobial surfaces, especially against gram-positive bacteria.