Aromatic Region Research Articles

Mesomorphism and crystal packing of dichotomous compounds; X-ray crystal structure of N-(4-hexyloxybenzylidene)-p-toluidine

The crystal structure of N-(4-hexyloxybenzylidene)-p-toluidine (1) was determined at 150, 273, 295, and 320 K. Compound 1 was studied by differential scanning calorimetry (DSC). According to the DSC analysis, compound 1 exhibits monotropic mesomorphism associated with Cr-Iso-N-S-Cr phase transitions. The crystal packing is built up from alternating loosely packed aliphatic and closely packed aromatic regions, which is typical of enantiotropic mesomorphic compounds. In the closely packed regions, there are two types of weak directional interactions, such as π⋯π stacking interactions and weak C-H O hydrogen bonds, which link the molecules into centrosymmetric dimers. The thermal behavior of compound 1 and its relation to the crystal packing are discussed.

Chemical compositional analysis of soil fulvic acids using Fourier transform ion cyclotron resonance mass spectrometry.

Soil fulvic acids (FAs) are considered to be a highly reactive pool of soil organic matter. The functions of FAs are related to their chemical structures, the details of which are largely unidentified. To better understand them, Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) must be a useful but generally unused tool. The structural properties of the components of five FA samples from a variety of soils were determined using FTICR-MS with negative-mode electrospray ionization. The peaks were assigned to molecular formulae, which were categorized into seven compound groups based on the H/C-O/C van Krevelen diagram. Ramp 13 C cross polarization/magic angle spinning nuclear magnetic resonance (NMR) spectra with phase-adjusted spinning side bands were also recorded to estimate the C composition. From FTICR-MS, molecular formulae were assigned to 1746-2605 peaks across the m/z range of 200-700. Those aligned in the lignin-like, tannin-like, and condensed aromatic regions of the van Krevelen diagram accounted for 49-58%, 4-20%, and 18-39% of the total peak magnitude, respectively. The proportion of the summed peak magnitudes that were detected in the lignin-like and condensed aromatic regions correlated positively to the aromatic C% as estimated by 13 C NMR. From Kendrick mass defect analysis using a carboxyl group, 94 molecular formulae were assigned to condensed aromatic acids, of which the maximum ring number was 4-7, as potential structures. A high proportion of lignin-like formulae and condensed aromatics, including those probably condensed aromatic acids with small ring numbers, as well as the existence of tannin-like formulae, which were generally lacking in soil humic acids, was suggested as a common feature of soil FAs.

X-Ray Diffraction and Thermographic Study of Mesomorphic 4-Acylphenyl 4'-Nonyloxybenzoate CH3C(O)C6H4–OC(O)–C6H4–OC9H19

The structure and thermal properties of mesomorphic phenyl benzoate CH3–C(O)–C6H4–OC(O)–C6H4–OC9H19 (I) were studied by differential scanning calorimetry (DSC) and X-ray diffraction. The crystal packing of I is typical of mesomorphic crystals. It consists of alternating loosely packed aliphatic and closely packed aromatic regions, the latter regions being stabilized by weak directional C–H···π interactions. According to the DSC data, compound I does not form a mesophase upon melting. The latter was observed only upon cooling of the isotropic melt. The lack of enantiotropic mesomorphism in the crystal of I is attributed to the fact that C–H···π non-covalent interactions, which could ensure the structuring of the melt, are broken at the melting point.

Toward high-efficiency photoluminescence emission by fluorination of graphene oxide: Investigations from excitation to emission evolution

Graphene oxide (GO) alters zero bandgap of graphene to achieve photoluminescence (PL), while the low quantum yield (generally: PLQY < 1%) seriously restricts its further development in practical applications. Here we employ two-step fluorination strategy to controllably modify GO, achieving island structure of aromatic regions in continuous phase of fluorine regions. The fluorinated product (FGO) presents a high PLQY of 66%, far exceeding the largest value (21.2%) reported for modifications of GO. We systematically and meticulously investigate fluorine effect of FGO during whole PL evolution. In excitation process, the coexistence of fluorine and aromatic regions in FGO is responsible for new electronic bandgap structure then multitudinous excited electrons produce, thus providing foundation for strong PL. In emission process, Raman measurements show that the weaker electron-phonon interactions in FGO result in slower nonradiative decay. It is attributed to that FGO possesses larger rigidity, as demonstrated by temperature-dependent fluorescence spectra, broadband dielectric measurements, density functional theory calculations and infrared spectra. Interestingly, different types of fluorine-related groups in FGO play different roles. That is, unoriented CF2 and CF3 groups realize passivation of defects, and C–F bonds perpendicular to graphene plane contribute to weakening interlayer interactions, both greatly enhancing PL.

Pharmacophore modelling, QSAR study, molecular docking and insilico ADME prediction of 1,2,3-triazole and pyrazolopyridones as DprE1 inhibitor antitubercular agents

Tuberculosis (TB) is a chronic lung infected airborne disease caused by Mycobacterium tuberculosis (MTB). The development of resistance towards available antitubercular agents leads to the discovery of new drugs for treatment against these resistant bacteria. Decaprenyl phosphoryl-β-D-Ribose 20-epimerase (DprE1) is a vulnerable target for the design of antitubercular agents which are more acting against multidrug resistant bacterial pathogens. DprE1 is an oxidase involved in the synthesis of arabinogalactan. Inhibition of DprE1 leads to blocking off cell wall synthesis, causing the death of the bacteria. A series of 50 DprE1 inhibitors having activity were subjected to 2D, 3D QSAR, Pharmacophore Modeling, Molecular Docking and in silico ADME studies. Prediction of preliminary Pharmacokinetic and the Drug Likeliness profile was performed for these compounds by in silico ADME study. 2D-QSAR and 3D- QSAR models developed by Partial Least Square associated with the Sphere Exclusion method (PLS-SE) and StepWise variable selection method (SW-kNN MFA) based on k- Nearest Neighbor technique are more significant which have cross-validated squared correlation coefficient (q2), coefficient of determination (r2), Fisher ratio (F) values as 0.7499, 0.8917 and 85.04 and the internal (q2 = 0.8198), external (pred_r2 = 0.6109) model validation correctly predicts activity ~ 81% and ~ 61% for the training and test set, respectively. Pharmacophore model was developed with two aromatic regions (Aro), one aliphatic (Ala) and one hydrogen donor (HDr). Docking studies of the selected inhibitors with the active site of DprE1 enzyme showed hydrogen bond interaction with Gly-116, His-131, Arg-118, Thr-117 and Gln-299 residues present at the active site. The results of the present work provide more useful information and important structural insights for designing DprE1 inhibitors with much more enhanced potency.

A novel phenylalanine ammonia-lyase from Pseudozyma antarctica for stereoselective biotransformations of unnatural amino acids

A novel phenylalanine ammonia-lyase of the psychrophilic yeast Pseudozyma antarctica (PzaPAL) was identified by screening microbial genomes against known PAL sequences. PzaPAL has a significantly different substrate binding pocket with an extended loop (26 aa long) connected to the aromatic ring binding region of the active site as compared to the known PALs from eukaryotes. The general properties of recombinant PzaPAL expressed in E. coli were characterized including kinetic features of this novel PAL with l-phenylalanine (S)-1a and further racemic substituted phenylalanines rac-1b-g,k. In most cases, PzaPAL revealed significantly higher turnover numbers than the PAL from Petroselinum crispum (PcPAL). Finally, the biocatalytic performance of PzaPAL and PcPAL was compared in the kinetic resolutions of racemic phenylalanine derivatives (rac-1a-s) by enzymatic ammonia elimination and also in the enantiotope selective ammonia addition reactions to cinnamic acid derivatives (2a-s). The enantiotope selectivity of PzaPAL with o-, m-, p-fluoro-, o-, p-chloro- and o-, m-bromo-substituted cinnamic acids proved to be higher than that of PcPAL.

Synthesis and Antichlamydial Activity of Molecules Based on Dysregulators of Cylindrical Proteases.

Chlamydia trachomatis is the most common sexually transmitted bacterial disease globally and the leading cause of infertility and preventable infectious blindness (trachoma) in the world. Unfortunately, there is no FDA-approved treatment specific for chlamydial infections. We recently reported two sulfonylpyridines that halt the growth of the pathogen. Herein, we present a SAR of the sulfonylpyridine molecule by introducing substituents on the aromatic regions. Biological evaluation studies showed that several analogues can impair the growth of C. trachomatis without affecting host cell viability. The compounds did not kill other bacteria, indicating selectivity for Chlamydia. The compounds presented mild toxicity toward mammalian cell lines. The compounds were found to be nonmutagenic in a Drosophila melanogaster assay and exhibited a promising stability in both plasma and gastric fluid. The presented results indicate this scaffold is a promising starting point for the development of selective antichlamydial drugs.

Composition and emission factors of traffic- emitted intermediate volatility and semi-volatile hydrocarbons (C10–C36) at a street canyon and urban background sites in central London, UK

Abstract Hydrocarbons in both gas and particle phases from C10 to C36 (I/SVOCs) were analysed at sites in central London. Samples were collected from a street canyon, Marylebone Road (MR), a rooftop site (WM) above MR, and a site in the adjacent Regent's Park (RU), north of MR to evaluate the change in composition of I/SVOCs during advection from the traffic to the cleaner atmosphere of the urban background. Groups of compounds identified and quantified in gas and particle phases include C13–C36 n-alkanes and branched alkanes, C12–C25 monocyclic alkanes, C13–C27 bicyclic alkanes and C10–C24 monocyclic aromatics. The similarities found in the aliphatic and aromatic region above C12 in urban air and diesel exhaust demonstrate the impact of diesel-powered vehicles on urban air quality. Diesel exhaust is suggested to be the dominant emission source, while small differences between sites indicate the possibility of other sources which are also discussed. The ambient concentrations of I/SVOCs in the street canyon at MR were highest when the southerly winds brought the traffic emitted pollutants to the sampler. Emission factors (EFs) for all compound groups were estimated from the concentrations at the MR site. Particle-phase n-alkane EFs are broadly similar to those measured elsewhere in the world, despite differences in traffic fleet composition. A comparison between n-alkane EFs estimated from field measurements and those measured from diesel engines in the laboratory suggests a large contribution from vehicles with higher emissions than recent passenger cars to London air.

Recovery and reuse of acid digested amine/epoxy-based composite matrices

Chemical recycling of thermoset composites has been focused largely on recovering high-value carbon fibers with property retention, while recovery and reuse of decomposed polymer matrix residues is generally overlooked, despite the fact that matrix recycling constitutes an essential component of a sustainable approach to the overall problem. Our previous study demonstrated that oxidative acid digestion can be deployed effectively to recover near-virgin quality carbon fibers from amine-cured epoxy composites. In the present study, we investigate the viability of recovery and reuse of the decomposed amine/epoxy residue after acid digestion of the matrix, effectively closing the recycling loop. We find that polymer matrix residues recovered from acid digestion solutions via neutralization and precipitation contain molecular components of the epoxies in which aromatic regions are preserved. The recovered matrix residues are blended into virgin resin formulations and two approaches are evaluate for potential reuse. Approach I utilizes the matrix residue as an accelerator for a virgin anhydride/epoxy formulation that contains no accelerator and thus cannot be self-catalyzed. We discover that adding matrix residue produces catalytic effects on the curing reaction. In general, anhydride/epoxy samples blended and cured with recovered matrix residues are homogenous and exhibit thermal and mechanical properties comparable to specimens cured with a commercial accelerator. Approach II deployed the matrix residue as a filler for virgin anhydride-based epoxies with a commercial accelerator to produce blended formulations. In such cases, blended formulations yielded acceptable retention of thermal and mechanical properties, provided the fraction of matrix residue added did not exceed 10 wt%.

Dynamic Covalent Synthesis of Crystalline Porous Graphitic Frameworks

Summary Porous graphitic framework (PGF) is a two-dimensional (2D) material that has emerging energy applications. An archetype contains stacked 2D layers, the structure of which features a fully annulated aromatic skeleton with embedded heteroatoms and periodic pores. Due to the lack of a rational approach in establishing in-plane order under mild synthetic conditions, the structural integrity of PGF has remained elusive and ultimately limited its material performance. Here, we report the discovery of the unusual dynamic character of the C=N bonds in the aromatic pyrazine ring system under basic aqueous conditions, which enables the successful synthesis of a crystalline porous nitrogenous graphitic framework with remarkable in-plane order, as evidenced by powder X-ray diffraction studies and direct visualization using high-resolution transmission electron microscopy. The crystalline framework displays superior performance as a cathode material for lithium-ion batteries, outperforming the amorphous counterparts in terms of capacity and cycle stability.

Lignin side chain region participates in Cd detoxification related to the cultivar-dependent Cd accumulation in Brassica chinensis L

To investigate the effect of lignin in the cultivar-dependent Cd detoxification of Brassica chinensis L., Cd and lignin contents, lignin composition and laccase genes expressions in low-Cd-accumulating (LAJK) and high-Cd-accumulating (HAJS) cultivars grown under control (CK) and 25 μM Cd-treatment were determined. The results showed that lignin combined about 14 % of total Cd in both LAJK and HAJS. LAC genes were more up-regulated in HAJS than in LAJK, indicating that the LAC genes were involved in the cultivar-dependent lignin functions. Higher β-aryl ether (A) proportion in the lignin side chain region in LAJK than in HAJS were observed, whereas resinol (B) and phenylcoumaran (C) constitute much higher proportions in HAJS than in LAJK. Chemical calculation to estimate Cd affinity associating with lignin side chain region displayed that i) β-aryl ether (A) exhibited major coupling with lignin aromatic region; ii) resinol (B) and phenylcoumaran (C) displayed major participation in complexation with Cd. We therefore conclude that Cd compartmentalization in the secondary cell wall (SCW) by coupling with lignin side chain region is responsible for Cd detoxification related to cultivar-dependent Cd accumulation of Brassica chinensis. This is the first study on lignin composition in relation to Cd retention mechanisms in SCW.

Enantioselective HPLC Analysis to Assist the Chemical Exploration of Chiral Imidazolines.

In the present work, we illustrate the ability of high-performance liquid chromatography (HPLC) analysis to assist the synthesis of chiral imidazolines within our medicinal chemistry programs. In particular, a Chiralpak® IB® column containing cellulose tris(3,5-dimethylphenylcarbamate) immobilized onto a 5 μm silica gel was used for the enantioselective HPLC analysis of chiral imidazolines synthesized in the frame of hit-to-lead explorations and designed for exploring the effect of diverse amide substitutions. Very profitably, reversed-phase (RP) conditions succeeded in resolving the enantiomers in nine out of the 10 investigated enantiomeric pairs, with α values always higher than 1.10 and RS values up to 2.31. All compounds were analysed with 50% (v) water while varying the content of the two organic modifiers acetonitrile and methanol. All the employed eluent systems were buffered with 40 mM ammonium acetate while the apparent pH was fixed at 7.5. Based on the experimental results, the prominent role of π-π stacking interactions between the substituted electron-rich phenyl groups outside of the polymeric selector and the complementary aromatic region in defining analyte retention and stereodiscrimination was identified. The importance of compound polarity in explaining the retention behaviour with the employed RP system was readily evident when a quantitative structure-property relationship study was performed on the retention factor values (k) of the 10 compounds, as computed with a 30% (v) methanol containing mobile phase. Indeed, good Pearson correlation coefficients of retention factors (r - log k1st = −0.93; r - log k2nd = −0.94) were obtained with a water solubility descriptor (Ali-logS). Interestingly, a n-hexane/chloroform/ethanol (88:10:2, v/v/v)-based non-standard mobile phase allowed the almost base-line enantioseparation (α = 1.06; RS = 1.26) of the unique compound undiscriminated under RP conditions.

Structural changes from heating amber and copal as observed by nuclear magnetic resonance spectroscopy.

Structural changes caused by heating of fossilized (amber) and semifossilized (copal) resins have been examined by nuclear magnetic resonance spectroscopy. A set of 28 samples was constituted to include different geographical sources, degrees of maturation, colors, and structural groupings. The onset of structural alterations was determined by observation of the lowest temperature at which spectral changes occurred. Both proton spectra in solution and carbon-13? spectra in the solid state then were recorded of cooled samples after heating for 12 hr at temperature increments, until liquification of the sample began. The spectra of both nuclides exhibit loss of a few peaks, broadening of most peaks, and enhancement of the unsaturated or aromatic region at the expense of saturated resonances. Such changes are irreversible and lead to a harder and less soluble material on cooling. The changes parallel those that occur with maturation of fossil resins or materials that lead to coal.

Synthesis of Substituted Benzothiazepine Compounds with Medicinal Potential

A versatile synthetic approach toward a series of benzothiazepines with medicinal potential (for example, compound 1) that allows incorporation of structural variation at the three aromatic regions of the structure, and at the sulfur atom, was developed. Knoevenagel condensation of indan-1,3-diones with benzaldehydes, yielded 2-benzylidineindan-1,3-diones, which undewent thio-Michael addition and intramolecular imine formation upon reaction with 2-aminothiophenols, to produce the target benzothiazepines. Use of indan-1,3-diones, benzaldehydes or 2-aminothiophenols bearing further substitution enabled production of novel 5,11-dihydro-12H-benzo[b]indeno [1,2-e][1,4]thiazepin-12-one analogs 1 - 14, including compounds bearing substitution at novel positions within the scaffold.

Detection of adulteration in Chinese monofloral honey using 1H nuclear magnetic resonance and chemometrics

Incidents of fraud are emerging on the domestic Chinese honey market, especially where lower value rape honey is mixed with high-value acacia honey. In this study, we use a combination of 1H NMR spectroscopy combined with chemometric techniques to detect and quantify adulteration of acacia honey with cheaper rape honey. The honey 1H NMR spectroscopy was split into three regions i.e. the aliphatic (0.00–3.00 ppm), carbohydrate (3.00–6.00 ppm) and aromatic (6.00–9.50 ppm) regions, to investigate which region provided the best qualitative and quantitative indicators in terms of rape honey adulteration in acacia honey. Results showed that the highest prediction accuracy for rape honey addition is 89.7 % using canonical discriminant analysis (CDA), determined from compounds located in 0.00–6.00 ppm spectral range. Orthogonal projection to latent structures discriminant analysis (OPLS-DA) was used to further discriminate samples of pure acacia honey adulterated with different amounts of rape honey. A partial least squares model (PLS) established a linear fit between the actual and predicted adulterant concentration with an R2 value up to 0.9996. When the content of rape honey added was less than 100 g/kg, the purity of acacia honey could still be estimated using 1H NMR spectroscopy and chemometric methods.

Selective sorption of amines by graphite oxide: Brønsted basicity is the major factor for selectivity

Graphite oxide (GO) exhibits selective sorption of di-butylamine from a mixture of butylamine, di-butylamine and tri-butylamine. The selectivity is attributed to the higher basicity of di-butylamine in comparison to butylamine and tri-butylamine. Reaction of GO with a mixture of hexylamine and cyclohexylamine, two amines of similar basicity but different structures, suggests that in alkylamines, selectivity is predominantly due to the basicity of the amine with structural differences playing almost no role. However, when GO reacts with a mixture of aniline and cyclohexylamine (amines with a large difference in basicity) no selectivity is observed. The π-π interaction between the aromatic amine, aniline, and the aromatic regions of GO causes the sorption of aniline in its non-protonated form as much as cyclohexylamine with a far higher basicity.

Comparison of CHARMM and OPLS-aa forcefield predictions for components in one model asphalt mixture

Molecular dynamics simulations have been widely applied to understand the effect of chemical composition on the major physical and mechanical properties and micro-structure of asphalt. However, the choice of forcefields has been mostly empirical. In this project, two commonly used forcefields, the Chemistry at Harvard Macromolecular Mechanics (CHARMM) forcefield and the Optimized Potentials for Liquid Simulations in all atom version (OPLS-aa) forcefield were evaluated, side by side for simulation of the three main components of one model asphalt mixture to compare the effectiveness of the forcefields. The CHARMM forcefield parameters for two smaller components —including n-docosane and 1,7-dimethylnaphthalene molecules—were obtained using the CGENFF program; the forcefield parameters for an average asphaltene molecule were obtained with the VMD forcefield toolkit and Gaussian quantum calculations. Comparing molecule structures of asphaltene, 1,7-dimethylnaphthalene and n-docosane (n-C22) predicted using the CHARMM forcefield to those from traditional OPLS-aa forcefield, the energy-minimized structures are very similar. At a high temperature such as 300 K and above, slight bending on the aromatic ring regions and the alkane chains was observed for the asphaltene molecule; kinking of the n-docosane molecule chain structure was also observed using both forcefields; and the structure of 1,7-dimethylnaphthalene is consistent at both low and high temperatures. Comparing the properties predicted based on the long-term simulation trajectories, the density, diffusion coefficient and g(r) result of asphaltene, 1,7-dimethylnaphthalene and n-docosane from the CHARMM and Nanoscale Molecular Dynamics (NAMD) program are very close to those from the OPLS-aa forcefield and LAMMPS program. However, the CHARMM forcefield correctly predicted the crystallization of n-docosane at 300 K while the OPLS-aa forcefield did not.

NMR-based metabolic profiling of different yeast fermented apple juices

NMR based metabolic profiling was used to investigate metabolic changes in ciders fermented by yeast species as valuable tool for the identification of metabolites responsible for yeast activities. 1H NMR spectra of apple ciders produced by Saccharomyces cerevisiae EC1118, Torulaspora delbrueckii TD291, Starmerella bacillaris YR21, Hanseniaspora osmophila HO16, Hanseniaspora uvarum Y4M, and Saccharomyces uvarum SU3, revealed to be dominated by glycerol and organic acids signals. The aromatic region showed the presence of low intense signals referred to epicatechin, catechin, chlorogenate, xanthine, uracil, tyrosol, fumarate, histamine, and histidine. The anomeric region showed signals related to xylose, arabinose, glucose, fructose and sucrose. Finally, in the aliphatic region, signals due to amino acids like alanine, aspartate, asparagine, isoleucine and threonine, organic acids like acetate, lactate, malate, pyruvate, quinate, succinate, and alcohols like 2,3 butanediol, ethanol, and glycerol and sterol were detected. Principal component analysis performed considering NMR data from either all spectral regions and only aromatic region revealed the potentiality to discriminate the yeast action. Signals due to glucose, fructose, glycerol, malate, fumarate, tyrosol, histidine, and histamine resulted discriminant for sample differentiation. This study, the first one by NMR, provides preliminary insights on the metabolic differences among yeast species involved in cider production.

SYNTHESIS AND PROPERTIES OF POLYETHYLENE-p-TRIPHENYLBORON ESTER

Triphenyl ester of boric acid was obtained by esterification of boric acid and phenol in o-xylene with water azeotropic distillation, then it was purified by distillation in vacuo. This substance was used as a model compound for the development of a synthesis method for heat-resistant polymers based on polymethylene esters of phenols and boric acid. Reaction of triphenyl ester of boric acid with 1,3,5-trioxane (paraformaldehyde) gave a new boron-containing oligomer – polymethylene-p-triphenyl ester of boric acid. This oligomer was prepared both in the presence of a solvent and without a solvent in the melt of triphenyl ester of boric acid, since at a temperature of 101 °C it completely passes into a liquid state. The polycondensation reaction was carried out in both cases in an acidic medium. The advantage of the second method is obvious, since for the beginning of the polycondensation reaction, three times less catalyst was required than in the reaction using a solvent. The structure of the synthesized oligomer was confirmed by elemental analysis, IR and 1H, 11B NMR spectroscopy. The modification reactions of polymethylene-p-triphenyl ester of boric acid with sulfur curing system, epoxy resin and urotropine were studied. In the IR spectra of modified materials, bands in the aromatic region, in particular those characteristic of disubstituted benzene, are observed to change bands characteristic of tri- and tetrasubstituted benzenes. Thus, the curing of polymethylene-p-triphenyl ester of boric acid occurs in the o-position of the phenyl ring to form three-dimensional structures. The noted curing reactions allow using polymethylene-p-triphenyl boronic acid ester as an independent thermally stable binder and as additives to composite materials.

Structural analysis and mode of action of BMAP-27, a cathelicidin-derived antimicrobial peptide

BMAP-27, a member of cathelicidin family, plays an important role against microorganisms, including bacteria and fungi. BMAP-27 may exert antimicrobial effects through membrane integrity disruption, but the exact molecular mechanism remains unclear. To identify the structural features important for antimicrobial activity and propose a mechanism underlying antibacterial effects, we determined the nuclear magnetic resonance structure of BMAP-27 in a membrane-mimetic environment and investigated its interactions with lipid membranes. BMAP-27 exhibited a long N-terminal α-helix with faces patterned into aromatic and cationic regions, central kink, and short hydrophobic C-terminal helix. While the N-terminal 18-residue peptide (BMAP-18) exerted only antibacterial activity, BMAP-27 showed potent activity against bacteria and cancer cells. Both peptides inhibited bacterial growth, but BMAP-18 showed delayed bactericidal activity and BMAP-27 completely killed bacteria within 20 min. The differences in antimicrobial activities and microbicidal kinetics may be associated with membrane permeabilisation; BMAP-27 rapidly and largely disrupted membrane integrity, whereas BMAP-18 showed low membrane disruption activity. Thus, the N-terminal helix is sufficient to inhibit bacterial growth and the C-terminal helix is involved in membrane permeabilisation for rapid bactericidal and efficient anticancer activities. The structural and functional characterisation of BMAP-27 may encourage the development of novel antimicrobial/anticancer agents.