N-octyl Derivatives Research Articles

Synthesis of new quaternized chitosan Schiff bases and their N-alkyl derivatives as antimicrobial and anti-biofilm retardants in membrane technology

New quaternized salicylidene chitosan Schiff bases (QSCSBs) and their N-octyl derivatives (OQCs) have been synthesized and characterized, aiming to develop innovative antimicrobial and anti-biofilm agents. This research holds immense potential, as these compounds could be utilized as anti-biofouling additives in membrane technology in the future. The synthesis involved the modification of low molecular-weight-chitosan (LMC) through simultaneous Schiff base formation and quaternization processes to create QSCSBs. Subsequently, QSCSBs were catalytically reduced to form quaternized N-benzyl chitosan (QBCs) intermediates, which then underwent nucleophilic substitution reactions affording N-octyl quaternized chitosans (OQCs). Characterization techniques such as elemental, spectral, and microscopic analyses were used to confirm the successful synthesis of these materials. As membrane technology relies on surface charge, QSCSBs and OQCs with large zeta potentials could be used as positively charged additives. Moreover, SEM image revealed the regular distribution of pores and voids across the additives' surfaces raises intriguing questions about their implications for membrane performance. Meanwhile, the superior antibacterial and antibiofilm potential of these materials, particularly QSCSB2 and OQC2, indicate that the utilization of these compounds as anti-biofouling additives in membrane technology could significantly improve the performance and longevity of membranes used in various applications such as water treatment and desalination.

Synthesis of N-Alkyl Enamino Ketones Based on 3-Acyl-4H-polyfluorochromen-4-ones and Their Antimicrobial Activity

New N-substituted enamino ketones were synthesized by directed transformation of 3-acetyl- and 3-benzoyl-5,6,7,8-tetrafluoro-4H-chromen-4-ones by the action of highly basic primary amines as a result of opening of the pyranone ring and deacylation. The synthesizedN-hexyl and N-octyl derivatives were evaluated for fungistatic and bacteriostatic activities.

Synthesis of C-glycosyl phosphonate derivatives of 4-amino-4-deoxy-α-ʟ-arabinose.

The incorporation of basic substituents into the structurally conserved domains of cell wall lipopolysaccharides has been identified as a major mechanism contributing to antimicrobial resistance of Gram-negative pathogenic bacteria. Inhibition of the corresponding enzymatic steps, specifically the transfer of 4-amino-4-deoxy-ʟ-arabinose, would thus restore the activity of cationic antimicrobial peptides and several antimicrobial drugs. C-glycosidically-linked phospholipid derivatives of 4-amino-4-deoxy-ʟ-arabinose have been prepared as hydrolytically stable and chain-shortened analogues of the native undecaprenyl donor. The C-phosphonate unit was installed via a Wittig reaction of benzyl-protected 1,5-arabinonic acid lactone with the lithium salt of dimethyl methylphosphonate followed by an elimination step of the resulting hemiketal, leading to the corresponding exo- and endo-glycal derivatives. The ensuing selective monodemethylation and hydrogenolysis of the benzyl groups and reduction of the 4-azido group gave the α-ʟ-anomeric arabino- and ribo-configured methyl phosphonate esters. In addition, the monomethyl phosphonate glycal intermediates were converted into n-octyl derivatives followed by subsequent selective removal of the methyl phosphonate ester group and hydrogenation to give the octylphosphono derivatives. These intermediates will be of value for their future conversion into transition state analogues as well as for the introduction of various lipid extensions at the anomeric phosphonate moiety.

Synthesis and Properties of a Decacyclene Monoimide and a Naphthalimide Derivative as Three-Dimensional Acceptor-Donor-Acceptor Systems.

A method involving the Diels-Alder (DA) cycloaddition of diacenaphtheno[1,2-b;1',2'-d]thiophenes (DATs) with N-alkylacenaphthylene-5,6-dicarboximides (AIs) was developed to synthesize decacyclene monoimides (DCMIs). The reactions generate the corresponding 1:2 adducts (BAIAs) as major products together with 1:1 adducts (the DCMIs). The molecular structure of BAIAb (N-octyl derivative) was unambiguously assigned as the bis-adduct having an endo,endo spatial disposition of the two acenaphthylene-5,6-dicarboximide moieties by using X-ray crystallographic analysis. Relative to the absorption spectrum of decacyclene triimide (DCTIa, N-2-ethylhexyl derivative), that of the analogous N-2-ethylhexyl-substituted monoadduct, DCMIa, is bathochromically shifted despite the fact that it possesses a less delocalized π-electron system. DCMIa does not fluoresce in various organic solvents, whereas DCTIa emits yellow fluorescence in CH2 Cl2 with a low quantum yield (ΦSN ). Moreover, DCMIa in CDCl3 displays concentration-dependent 1 H NMR spectroscopy behavior, which suggests that it self-aggregates with an association constant (Ka ) of (193±50) m-1 at 20 °C. Despite the presence of four bulky tert-butyl groups in DCMIa, its Ka value for aggregate formation is comparable to that of DCTIa [(495±42) m-1 ], which does not contain tert-butyl substituents. Spectroscopic studies with the bis-adduct BAIAa (N-2-ethylhexyl derivative) show that it displays remarkable solvatofluorochromism corresponding to an emission maximum shift (ΔλEM ) of 100 nm. The results of density functional theory calculations on BAIAc (N-methyl derivative) demonstrate that a considerable spatial separation exists between the HOMO and LUMO coefficient distributions, which indicates that the ground-to-excited state transition of the novel three-dimensional acceptor-donor-acceptor BAIAa system should have intramolecular charge-transfer character.

N,N'-Bis(2-cyclohexylethyl)naphtho[2,3-b:6,7-b']dithiophene Diimides: Effects of Substituents.

Naphtho[2,3-b:6,7-b′]dithiophene-4,5,9,10-tetracarboxylic diimide (NDTI) is a promising electron-deficient building block for n-type organic conductors, and the performance of NDTI-based field-effect transistors (FETs) is largely dependent on the substituents that alter the supramolecular organization in the solid state and, in turn, the intermolecular orbital overlap. For this reason, the rational selection of substituent on imide nitrogen atoms and/or thiophene α-positions is the key to developing superior n-type organic semiconductors. We here report new NDTI derivatives having N-(2-cyclohexylethyl) groups. Despite their one-dimensional packing structures in the solid state regardless of the presence or absence of chlorine groups at the thiophene α-positions, their FETs show promising performance with electron mobilities higher than 0.1 cm2·V−1·s−1 under ambient conditions. We also discuss how the cyclohexylethyl groups affect the packing structure in comparison with analogous n-octyl derivatives having the same number of carbon atoms.

New insights of cyanoacrylate glues in surgical applications. A comparative study of akyl cyanoacrylates.

Event Abstract Back to Event New insights of cyanoacrylate glues in surgical applications. A comparative study of akyl cyanoacrylates. Julio San Román1, Mar Fernandez-Gutierrez1, Gemma Pascual2, Barbara Perez-Kholer2 and Juan M Bellon2 1 Institute of Polymers and CIBER-BBN, Biomaterials, Spain 2 University of Alcala de Henares and CIBER-BBN, Faculty of Medicine, Spain Alkyl cyanoacrylates have been applied since 1965 as self-adhesives for biomedical applications because of their good properties and very fast curing process in physiological conditions, associated to the ionic polymerization catalysed by water. However the stability of the poly(alkyl cyanoacrylate)s after the application in contact with living tissues depends on the chemical structure of the corresponding alkyl cyanoacrylates and poly(alkyl cyanoacrylates) formed by the polymerization reaction, being the reaction of the ethyl derivative faster than butyl, hexyl or longer alkyl segments. In addition, the toxicity of these systems is also associated to the nature of the alkyl residue, being the ethyl cyanoacrylate much more toxic that the butyl, hexyl or longer hydrocarbon substituents. The aim of the present work is the comparative analysis in vitro and in vivo of two commercial akyl cyanoacrylate monomers, Glubran 2 (n-butyl cyanoacrylate) and Ifabond (n-hexyl cyanoacrylate) in comparison with an experimental bioadhesive based on n-octyl cyanoacrylate, different from Dermabond (2-octyl cyanoacrylate) indicated for topical applications in dermal defects. The three systems were tested “in vitro” with different cell lines , and “in vivo” by the fixation of surgical meshes of polypropylene applied to abdominal hernias repair, using rabbits as experimental animal model and a methodology previously validated by the group. Adhesion of the mesh by the application of the three adhesives and comparison with suture, fibrosis and tissue integration as well as inflammation and local effects of the three adhesives were determined after periods post-implantation of 14 , 30 and long term 90 days. In addition the biomechanical properties of the meshes integrated into the abdominal wall of the rabbit were determined according to a well-defined protocol using strips of the integrated meshes prepared from the implants. The results demonstrated that the Glubrand and Ifabond glues give a more inflammatory response than the n-octyl cyanoacrylate after the study of the histological sections of the points of application and the biomechanical behaviour is very good for the octyl derivative even after the 90 days of implantation. The resorption of the polymer generated by the systems is also dependent of the nature of the adhesives, being the n-octyl derivative more stable than the commercial glues. The “in vitro” test based on standard analysis MTT and Alamar Blue, indicate a good tolerance and biocompatibility of the three alkyl cyanoacrylates studied, but it is clear that the viability of n-octyl cyanoacrylate is better than the other commercial glues, Glubrand 2 and Ifabond. A detailed study of the cell behaviour and histological evaluation of the implants will be presented. projects SAF2014-55022-P and MAT2014-51918-C2-1R Keywords: Tissue Engineering, Scaffold, in vivo tissue engineering, bioactive interface Conference: 10th World Biomaterials Congress, Montréal, Canada, 17 May - 22 May, 2016. Presentation Type: Poster Topic: Surface and interfacial characterization Citation: San Román J, Fernandez-Gutierrez M, Pascual G, Perez-Kholer B and Bellon J (2016). New insights of cyanoacrylate glues in surgical applications. A comparative study of akyl cyanoacrylates.. Front. Bioeng. Biotechnol. Conference Abstract: 10th World Biomaterials Congress. doi: 10.3389/conf.FBIOE.2016.01.02828 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 27 Mar 2016; Published Online: 30 Mar 2016. Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Julio San Román Mar Fernandez-Gutierrez Gemma Pascual Barbara Perez-Kholer Juan M Bellon Google Julio San Román Mar Fernandez-Gutierrez Gemma Pascual Barbara Perez-Kholer Juan M Bellon Google Scholar Julio San Román Mar Fernandez-Gutierrez Gemma Pascual Barbara Perez-Kholer Juan M Bellon PubMed Julio San Román Mar Fernandez-Gutierrez Gemma Pascual Barbara Perez-Kholer Juan M Bellon Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Acenaphtho[1,2-j]fluoranthene-4,5-dicarboxyimides: A New Monoimide Showing Self-aggregation in Chloroform

Abstract The title imides possessing a planar acenaphthofluoranthene moiety were prepared by the Diels–Alder reaction of diacenaphtho[1,2-b:1′,2′-d]thiophene and maleic anhydride and subsequent treatment with amines. The reaction with maleimide afforded the corresponding 1:2 adduct displaying intense blue fluorescence in solution. Although the imides crystallize yellow needles, their amorphous solids are red. Concentration-dependent 1H NMR spectra of a N-octyl derivative reveal self-aggregation behavior in CDCl3.

A Smart Supramolecular Hydrogel of Nα-(4-n-Alkyloxybenzoyl)-l-histidine Exhibiting pH-Modulated Properties

Six L-histidine-based amphiphiles, N(alpha)-(4-n-alkyloxybenzoyl)-L-histidine of different hydrocarbon chain lengths, were designed, synthesized, and examined for their ability to gelate water. Four of members of this family of amphiphiles were observed to form thermoreversible hydrogels in a wide range of pH at room temperature. The structural variations were characterized by critical gelation concentration, gelation time, gel melting temperature (T(gs)), rheology, and electron microscopy. Among the amphiphiles, the n-octyl derivative showed better gelation ability in the studied pH range. The amphiphiles were found to have T(gs) higher than body temperature (37 degrees C) showing their stability. Also, relatively higher yield stress (>1000 Pa) values of the hydrogels show their higher strength. The effective gelator molecules self-assemble into fibrous structures. Scanning electron microscopic picture of the hydrogels revealed large ribbons with right-handed twist. Small-angle XRD and circular dichroism spectroscopy were also employed to characterize the hydrogels. It was observed that pi-pi stacking, hydrophobic interaction, amide hydrogen bonding, and solubility factor contribute to the stability and strength of the hydrogels.

An N‐methylpolyvinylpyridinium cationic polymer for capillary coating in electrophoresis of proteins and peptides

A novel cationic polymeric coating is here reported, consisting of a N-methylpolyvinylpyridinium quaternary ion. This coating, combined with an isoelectric, aspartic acid as BGE, offers excellent separations of low- to high-M(r) proteins, of low- to high-pI values, coupled to very high run-to-run repeatability. The importance of a hydrophilic coating is also illustrated, whereas the N-methylpolyvinylpyridinium quaternary ion does not seem to adsorb even a large size protein as human albumin, separations are already distorted in the N-ethyl derivative and totally ruined in the N-octyl derivative, due to its high hydrophobicity.

Synthesis, Biological Activity, and Preliminary Pharmacokinetic Evaluation of Analogues of a Phosphosulfomannan Angiogenesis Inhibitor (PI-88)

The phosphosulfomannan 1 (PI-88) is a mixture of highly sulfated oligosaccharides that is currently undergoing clinical evaluation in cancer patients. As well as its anticancer properties, 1 displays a number of other interesting biological activities. A series of analogues of 1 were synthesized with a single carbon (pentasaccharide) backbone to facilitate structural characterization and interpretation of biological results. In a fashion similar to 1, all compounds were able to inhibit heparanase and to bind tightly to the proangiogenic growth factors FGF-1, FGF-2, and VEGF. The compounds also inhibited the infection of cells and cell-to-cell spread of herpes simplex virus (HSV-1). Preliminary pharmacokinetic data indicated that the compounds displayed different pharmacokinetic behavior compared with 1. Of particular note was the n-octyl derivative, which was cleared 3 times less rapidly than 1 and may provide increased systemic exposure.

Synthesis and glycosidase inhibitory activity of some N-substituted 5a-carba-β-fuco- and β-galactopyranosylamines, and selected derivatives

In the course of chemical modification of α-fucosidase inhibitors of 5a-carba-fucopyranosylamine type, an N-dodecyl derivative of the enantiomer 6-deoxy-5a-carba-β- d-galactopyranosylamine demonstrated very strong inhibition of β-galactosidase and β-glucosidase. This finding led us to synthesize corresponding 6-hydroxy compounds, in order to elucidate structure–activity relationships for inhibitors of this type. Among four N-alkyl-5a-carba-β- d-galactopyranosylamines prepared, the N-octyl derivative could be demonstrated to possess moderate activity toward α- and β-galactosidases, and β-glucosidase.

Carbonic Anhydrase Inhibitors: Aliphatic N-phosphorylated Sulfamates--A Novel Zinc-anchoring Group Leading to Nanomolar Inhibitors

A small library of phosphorylated sulfamates (N-(O-alkylsulfamoyl)-phosphoramidic acids) incorporating long aliphatic chains (C8-C16) has been synthesized and investigated for their interaction with two physiologically relevant carbonic anhydrase (CA) isozymes. These compounds behaved as very potent inhibitors of both isozymes, with inhibition constants in the range of 8.2-16.1 nM against isozyme hCA I, and 5.3-11.9 nM against isozyme hCA II. Activity was optimal for the n-octyl derivative (similarly with that of the corresponding unsubstituted sulfamates) and gradually decreased for the longer chain derivatives. Some of these compounds are much more effective CA inhibitors as compared to the clinically used derivatives acetazolamide, sulfanilamide or topiramate, which are used as standards for the enzymatic determinations. The phosphorylated sulfamate moiety represents a novel zinc-binding group for the design of effective CA inhibitors.

Convenient Synthesis and Evaluation of Enzyme Inhibitory Activity of Several N‐Alkyl‐, N‐Phenylalkyl, and Cyclic Isourea Derivatives of 5a‐Carba‐α‐DL‐fucopyranosylamine.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Convenient synthesis and evaluation of enzyme inhibitory activity of several N-Alkyl-, N-Phenylalkyl, and cyclic isourea derivatives of 5a-Carba-α-dl-fucopyranosylamine

Convenient synthesis and chemical modification of the potent α-l-fucosidase inhibitor, 5a-carba-α-dl-fucopyranosylamine (1), are described. Among seven N-substituted and three cyclic isourea derivatives newly prepared, the N-octyl derivative was found to be the strongest inhibitor of α-l-fucosidase (bovine kidney) more potent (Ki=0.016 μM) than deoxyfuconojirimycin (Ki=0.031 μM) with p-nitrophenyl-α-l-fucopyranoside as the substrate.

Molecular weight properties of asphaltenes calculated from GPC data for octylated asphaltenes

Octylated asphaltenes (OA), and hexane-soluble n-octyl derivatives of asphaltenes, have been used for the determination of more realistic molecular weight averages and molecular weight distributions (MWD) of asphaltenes. Here we report the synthesis and characterization of the Hamaca OA. Both C-13 and elemental analyses show that about five n-octyl groups per 100 carbon atoms are incorporated into Hamaca asphaltenes. When GPC columns are calibrated with monodisperse octylated asphaltene standards (OAS), the M n value obtained for Hamaca OA was equal to the one measured by VPO. From this information, and from the GPC results and the above calibration, the MW range (50 000–300), M n (2250) and M w (6000) values were calculated for the above asphaltenes.

A spectral and electrochemical study of mononuclear manganese(III) complexes of a polybenzimidazolyl ligand

A series of MnIII complexes with stoichiometry [MnLX](Y)2 have been synthesized utilizing an exogenous anionic ligand, X- = OAc, SCN or N3, and the hexadentate ligand N,N,N′,N′-tetrakis[2(benzimidazolyl) methyl-1,2-ethanediamine] and its N-octyl derivative. The vis. spectra of the compounds are in keeping with a pseudo-C4v, symmetry for the MnIII ion, implying that all the pendant arms of the hexadentate ligand do not bind to the MnIII centre. Cyclic voltammetric studies reveal that the E1/2 for the MnIII/MnIV couple shifts to positive values with SCN- as the anionic ligand, implying that this anion stabilizes the MnIII oxidation state, whereas E1/2 data for N3- reveals that the anion destabilizes the MnIII state.

Synthesis of potent β-D-glucocerebrosidase inhibitors: N-alkyl-β-valienamines

Six homologous derivatives ( N-butyl 3a, hexyl 3b, octyl 3c, decyl 3d, tetradecyl 3e and stearyl 3f) of β-valienamine were synthesized. All have been shown to be potent and specific inhibitors of β-glucocerebrosidase, and to have no potency against glucosylceramide synthase (mouse liver microsomes). Among them, the N-octyl derivative possesses the strongest activity (IC 50 3 × 10 −8 M), being almost 10-fold more potent compared to the unsaturated 5a-carba-glucosylceramide 1. Compounds 3b and 3c are also moderate inhibitors of α-glucosidase (Baker's yeast).

Antibacterial activity of N-[2-(dodecanoylmethylamine)ethyl]-alkyl dimethylammonium bromides.

The study contains the results of determination of antibacterial activity of the newly synthesized series of N-[2-(dodecanoylmethylamine)ethyl]-alkyldimethylammonium bromides. The efficiency of the compounds has been characterized towards three species of the genus Clostridium such as Clostridium perfringens, type A, Clostridium bifermentans, Clostridium sporogenes and one strain of the genus Lactobacillus such as Lactobacillus yamanashiensis. The antibacterial activity of the studied compounds has been tested in different time intervals. Out of seven investigated compounds, four compounds exerted the pronounced antibacterial activity on Clostridia (CMIC equals to 0.0039-0.0078 mmol/litre) and three compounds influenced the growth of Lactobacillus yamanashiensis (MIC equals to 0.004-0.006 mmol/litre). The most effective compound was found to be n-octyl derivative. These compounds were more effective towards the tested Clostridia strains than the comparing standard disinfectant such as Ajatin.

Impact of acidic/hydrothermal treatment on pore structural and chromatographic properties of porous silicas : I. The conventional approach

A series of commercial silicas and a laboratory made product were subjected to acidic/hydrothermal treatment with solutions of HCI, HNO 3, H 2SO 4 and HF. The concentration of acid and the temperature and duration of treatment were varied. The specific surface area, content of metal impurities, types and concentration of surface hydroxyl and siloxane groups and crystallinity were determined for native and treated silicas. Only changes in the structural order of the surface could be assessed by means of 19Si cross-polarization magic angle spinning NMR spectrometry and electron diffraction. The native and acid-treated silicas were surface modified to n-octyl derivatives and tested under reversed-phase conditions. A notable improvement in the column plate number and the asymmetry of the peaks was observed, whereas the solute capacity factors remained nearly unchanged. The effect of the conditions of acidic treatment (concentration, temperature and duration) was established by factorial experiments. Acidic/hydrothermal treatment caused a more ordered surface structure with quasi-crystalline domains, which improved the chromatographic mass-transfer kinetics and hence the column performance of acid-treated silicas.

Tonic and phasic block of mammalian sodium currents by charged and neutral n-octyl derivatives.

Annals of the New York Academy of SciencesVolume 625, Issue 1 p. 311-314 Tonic and Phasic Block of Mammalian Sodium Currents by Charged and Neutral n-Octyl Derivativesa A. A. ELLIOTT, A. A. ELLIOTT Department of Anatomy and Physiology The University Dundee DD1 4HN United KingdomSearch for more papers by this authorJ. R. ELLIOTT, J. R. ELLIOTT Department of Anatomy and Physiology The University Dundee DD1 4HN United KingdomSearch for more papers by this author A. A. ELLIOTT, A. A. ELLIOTT Department of Anatomy and Physiology The University Dundee DD1 4HN United KingdomSearch for more papers by this authorJ. R. ELLIOTT, J. R. ELLIOTT Department of Anatomy and Physiology The University Dundee DD1 4HN United KingdomSearch for more papers by this author First published: June 1991 https://doi.org/10.1111/j.1749-6632.1991.tb33858.xCitations: 2 a We gratefully acknowledge financial assistance from the Wellcome Trust and the Medical Research Council of the UK. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume625, Issue1Molecular and Cellular Mechanisms of Alcohol and AnestheticsJune 1991Pages 311-314 RelatedInformation