Antimicrobial activity of new bicyclic lactones with three or four methyl groups obtained both synthetically and biosynthetically

Ten new derivatives of isophorone were obtained through a five-step synthesis. Among the products were several unsaturated, bicyclic lactones with three or four methyl groups. These lactones were used as the substrates for biotransformation mediated by selected fungal strains (Fusarium species, Syncephalastrum racemosum, Cunninghamella japonica, Penicillium species, Absidia species, and Pleurotus ostreatus). Four new hydroxylactones were obtained as a result of biotransformation. Because the unsaturated lactone with four methyl groups was a diastereoisomeric mixture, a structural analysis was conducted. The hydroxylactones were also included in this analysis. Both the unsaturated lactones and hydroxylactones were examined for their antimicrobial activity. It was found that some of these compounds exhibited growth inhibition against pathogenic strains of bacteria (Staphylococcus aureus, Pseudomonas fluorescens), yeasts (Candida albicans) and filamentous fungi (Alternaria sp., Penicillium sp.). All obtained compounds were also subjected to scent analysis.     

Chiral induction in cyclopentyl-derived 1,3-meso-diesters: enantioselective hydrolyses with electric eel acetylcholinesterase

Eight 1,3-meso-diesters derived from a common cyclopentyl backbone were exposed to the hydrolase enzyme acetylcholinesterase from Electrophorus electricus. All eight compounds were hydrolyzed by the enzyme. The overall enantioselectivities were quite high, and the resulting e.e.s were generally >90%. The absolute configurations of the product monoesters were determined through stereochemical correlation. These data revealed that the preferred site for enzymatic hydrolysis in seven of the substrates was the pro-S ester function, with pro-R cleavage detected in the eighth.     

pH- and concentration-induced micelle-to-vesicle transitions in pyrrolidone-based Gemini surfactants

The self-assembly of novel Gemini surfactants with pyrrolidone head groups, N,N′-dialkyl-N,N′-di(ethyl-2-pyrrolidone) ethylenediamine (Di-C _n P, where n?=?6, 8, 10, 12), was studied systematically by employing UV–vis spectroscopy, fluorescence spectroscopy, NMR, dynamic light scattering (DLS), and cryo-transmission electronic microscopy (cryo-TEM) measurements. pH-induced spherical micelle-to-vesicle transitions (MVTs) were observed in all diluted Di-C _n P aqueous solutions. Spherical micelles were formed when solution pHs were below 7.0, in which Di-C _n Ps were 1:2 or 1:1 type cationic surfactants, whereas vesicles were formed instead at higher pHs, e.g., pH?=?11.0, when Di-C _n Ps were nonionic type. Apart from the pH-induced MVTs, concentration-induced MVTs were also observed in the protonated Di-C _n P aqueous solutions due to counterion binding, indicating the presence of a second critical vesicle concentration (cvc) for ionic type Di-C _n P. Furthermore, the cvc is decreased linearly with the number of carbon atoms n in the hydrophobic tail, following the well-known Stauff–Klevens rule, in the given protonation states.     

Thermodynamics of fluorinated derivatives of carbosilane dendrimers of high generations

The temperature dependences of the heat capacities of fluorinated derivatives of carbosilane dendrimers of high (4.5 and 7.5) generations were studied by adiabatic vacuum calorimetry in the range from 6 to 340 K for the first time. The standard thermodynamic characteristics of devitrification were estimated. The experimental results were used to calculate the standard thermodynamic functions C _p °(T), H°(T)?H°(0), S°(T)?S°(0), and G°(T)-H°(0) over the range from T??0 to 340 K and standard entropies of formation of dendrimers at T = 298.15 K. The low-temperature (T ?? 50 K) heat capacity was analyzed by using Debye??s heat capacity theory of solids and the multifractal model. The values of fractal dimensionality D were determined, and some conclusions about topology of the studied structures were made. The standard thermodynamic characteristics of the studied fluorinated derivatives of carbosilane dendrimers were compared.     

Enantioselective synthesis of d- and l-α-methylcysteine with hydantoinase

A scalable and cost-effective synthesis of d- and l-α-methylcysteine is described. A key step is d-selective cyclization of N-carbamoyl S-tert-butyl-d,l-α-methylcysteine catalyzed by hydantoinase. d-5-tert-Butylthiomethyl-5-methylhydantoin and N-carbamoyl S-tert-butyl-l-α-methylcysteine were obtained with excellent yield and optical purity, and these compounds were easily separated by filtration. After hydrolysis and cleavage of the tert-butyl group, d- and l-α-methylcysteine hydrochloride were obtained.     

Vibrational analysis of n-butyl, n-pentyl,and n-hexyl fluorides

Infrared spectra were obtained for n-butyl, n-pentyl, and n-hexyl fluorides in the liquid and solid states, and liquid-state Raman spectra were obtained for the first two of these. Normal coordinate calculations were carried out and twenty force constants of the C-CH₂F group were refined to provide the best fit for the 114 assigned frequencies of trans-n-propyl, gauche-n-propyl, TT-n-butyl, and TG-n-butyl fluorides. The resulting force constants were used to calculate the frequencies of the GT- and GG conformations of n-butyl fluoride and the two conformations for each of n-pentyl and n-hexyl fluoride that have coplanar carbon chains. The presence of all four conformers of n-butyl fluoride in the liquid state is indicated, but only the TG-conformer is present in the solid. The existence of the two conformations of n-pentyl and n-hexyl fluorides for which calculations were made is supported by comparison of the observed and calculated frequencies. Additional conformations seem to be present. The simplest solid-state spectrum is due only to the conformer that has a coplanar chain of carbons and the fluorine atom in the gauche position. Previous tentative conclusions about the relation between C-F stretching frequency and configuration have been revised.     

Inactivation of mildew in rough rice and wheat by gamma irradiation

Rough rice and wheat were irradiated by gamma ray (⁶⁰Co) with different doses and the mildew inactivation efficacy was investigated after 0, 6 and 12 month storage. Five genera of mildew in rough rice and wheat were detected, including Alternaria, Fusarium, Aspergillus, Penicillium and Rhizopus. For Aspergillus, four genera of mold were detected, including Aspergillus Kawachii, Aspergillus glaucus, Aspergillus niger, Aspergillus flavus. Detection rates of the five genera of mildew and four genera of Aspergillus were all reduced with increasing dose after 0, 6 and 12 months storage. The detection rates of the other four genera of mildew had no significant change during storage.     

The phenolic contents,antioxidant and anticholinesterase activity of section Amaracus (Gled.) Vogel and Anatolicon Ietsw. of Origanum L. species

Origanum boissieri Ietsw., O. saccatum P.H.Davis, O. solymicum P.H.Davis and O. ayliniae Dirmenci & T.Yazıcı belonging to sect. Amaracus (Gled.) Vogel, O. sipyleum L. and O. hypericifolium O.Schwarz & P.H.Davis belonging to sect. Anatolicon Ietsw. were analyzed for their chemical composition of essential oil and phenolic components. The essential oil compositions were analysed by using GC-MS and GC-FID. The phenolic contents of the chloroform, acetone, and methanol extracts were analyzed using LC-MS/MS. Antioxidant activities of the extracts were investigated by using three methods; DPPH free radical scavenging activity, β-carotene linoleic acid assays and CUPRAC assays. The essential oil compositions of the section Amaracus were found to be as carvacrol type (O. ayliniae, O. boissieri) and p-cymene type (O. saccatum, O. solymicum). In the section of Anatolicon, while O. sipyleum was found as γ-terpinene type, O. hypericifolium was carvacrol type. In the extracts, the most abundant components were determined as flavonoids, coumaric acids and derivatives. Especially rosmarinic acid and penduletin were detected in high amounts. Among the studied species, extracts of O. ayliniae showed quite good activity for all methods. The extracts from all species showed remarkable antioxidant activity. Inhibition capability of the extracts against acetyl and butyrylcholinesterase enzymes (AChE and BChE) were determined. The extracts were found as inactive against AChE. The moderate inhibition capacity observed against BChE.     

Sesquiterpenoids, alantolactone analogues, and seco-guaiene from the roots of Inula helenium

Three new sesquiterpenoids, a new unusual dimeric eudesmanolide, bialantolactone, a new nor-eudesmanolide, trinoralantolactone, and a new seco-guaiene, 7S,1(10)Z-4,5-seco-guaia-1(10),11-diene-4,5-dioxo, together with 13 known sesquiterpenoids, were isolated from the roots of Inula helenium. Their structures were elucidated by comprehensive spectroscopic analyses. The absolute configurations of bialantolactone and 7S,1(10)Z-4,5-seco-guaia-1(10),11-diene-4,5-dioxo were defined via the experimental and computational optical rotation and CD data. The plausible biosynthetic pathways to bialantolactone and 7S,1(10)Z-4,5-seco-guaia-1(10),11-diene-4,5-dioxo are discussed. 16 compounds were evaluated for their anti-bacterial activities against six bacteria.     

Profiling of Volatile Compounds and Associated Gene Expression in Two Anthurium Cultivars and Their F1 Hybrid Progenies

Anthurium is an important ornamental crop in the world market and its floral scent can enhance its ornamental value. To date, studies of the components and formation mechanism of the floral scent of Anthurium are relatively few. In this study, the scent profiles of two Anthurium varieties were measured by gas chromatograph-mass spectrometer (GC-MS). There were 32 volatile organic compounds (VOCs) identified in Anthurium ‘Mystral’, and the most abundant compound was eucalyptol (57.5%). Extremely small amounts of VOCs were detected in Anthurium ‘Alabama’. Compared with A. ‘Alabama’, most genes related to floral scent synthesis exhibited a higher expression in A. ‘Mystral’, including AaDXS, AaDXR, AaMDS, AaHDS, AaTPS, AaDAHPS, AaADT2, AaPAL1, and AaPAL2. In order to produce new varieties of Anthurium with fragrance, 454 progenies of two crossbred combinations of A. ‘Mystral’ and A. ‘Alabama’ were obtained. Four F1 generation plants with different floral scent intensities were selected for further study. The major components of floral scent in the progenies were similar to that of the parental A. ‘Mystral’ plant. The expression patterns of genes related to floral scent synthesis were consistent with the relative contents of different types of VOCs. This study revealed the profiles of volatile compounds and associated gene expression in two Anthurium cultivars and their F1 hybrids, which provided a basis for the floral scent inheritance of Anthurium andraeanum.     

Chemical effect on L X-ray fluorescence cross-sections of Hg,Pb and Bi compounds

Chemical effect on the photon induced L X-ray fluorescence cross-sections (σ_Lα, σ_Lβ and σ_Lγ) for Hg, Pb and Bi compounds were investigated. The samples were excited by gamma rays with energy 59.5 keV from ²⁴¹Am radioisotope source. L X-rays emitted by samples were counted by a Si(Li) detector with resolution 160 eV at 5.9 keV. We observed chemical effect on the photon induced L X-ray fluorescence cross-sections (σ_Lα, σ_Lβ and σ_Lγ) for Hg, Pb and Bi compounds. Our values were compared with calculated theoretical values.     

Variation of the L X-ray fluorescence cross-sections, intensity ratios and fluorescence yields of Sm and Eu in halogen compounds

The chemical effect on the L_i (i=ι, α, β, β₁, β₂, γ) X-ray fluorescence cross-sections, the L X-ray intensity ratios and the average L shell fluorescence yields of Sm and Eu binary compounds with halogen (F, Cl and Br) were investigated. The samples were excited by 59.543 keV photons emitted from an Am-241 radioisotope source. X-rays emitted from the samples were counted by means of a Si(Li) detector, which has a resolution 155 eV at 5.9 keV. The experimental values were compared with the calculated theoretical values     

Calixarene coated gold nanoparticles as a novel therapeutic agent

In the current study, gold nanoparticles (AuC6NPs and AuC8NPs) were prepared through sodium borohydride reduction method by using Calix[6]rene and Calix[8]rene as a stabilizing agents. The synthesized AuNPs were screened for cytotoxic, phytotoxic, antifungal and antibacterial activities. The fabricated AuNPs were characterized by UV–visible spectroscopy, atomic force microscopy (AFM) and FTIR spectroscopy. Antibacterial activities of the AuNPs were tested against E. coli and S. aureus. The AuC6NPs were found to be effective against the growth of gram positive bacteria and inhibited the growth of S. aureus. AuC6NPs interact with bacterial cell and damaged cell membrane. Roughness of the bacterial surface and membrane rupture can be clearly observed by AFM images. The AuNPs possess insignificant antifungal activity against Aspergillus niger and Candida albicans. Moreover, AuC8NPs have significant phytotoxicity and moderate cytotoxicity.     

Synthesis, structure and physical properties of layered semiconductors MCuFCh (M=Sr, Eu, Ch=S, Se)

Effects of open shell cations on magnetic, optical and carrier transport properties were examined for layered wide bandgap semiconductors MCuFCh (M=Sr, Eu, Ch=S, Se). Single-phase MCuFCh powder and ceramic samples were synthesized by solid-state reactions. The crystal structures refined by the Rietveld analyzes revealed that all the materials have the space group P4/nmm, indicating that the samples have the same crystal structure as that of layered oxychalcogenides LaCuOCh, and cation vacancies of several percent were present for Cu⁺ and Eu²⁺ sites in EuCuFCh. Thermopower measurements revealed that both SrCuFCh and EuCuFCh were p-type semiconductors. Degenerate conduction was observed for EuCuFCh with conductivities >1 S cm⁻¹, whereas SrCuFCh exhibited thermally activated behavior. The optical band gaps of SrCuFS and SrCuFSe estimated were approximately 3.0 and 2.7 eV, respectively, and those of EuCuFCh were ∼2 eV. Temperature dependence of magnetic susceptibilities of EuCuFCh followed the Curie-Weiss law down to 5 K and the samples did not show any transition to a magnetic ordering phase.     

Antibacterial activity of N-quaternary chitosan derivatives: Synthesis, characterization and structure activity relationship (SAR) investigations

Quaternary N-(2-(N,N,N-tri-alkyl ammoniumyl and 2-pyridiniumyl) acetyl) derivatives of chitosan polymer, chitooligomer, and glucosamine (monomer) were synthesized for the purpose of investigating the structure activity relationship (SAR) for the antibacterial effect. Novel methods were used in the synthesis. The final chitosan and chitooligomer derivatives could thus be obtained in two steps without prior protection of the hydroxyl groups. However, in order to obtain chitosan derivatives with the bulky N,N-dimethyl-N-dodecyl- and N,N-dimethyl-N-butyl side chains three steps were needed, starting from 3,6-O-di-tert-butyldimethylsilyl chitosan (3,6-O-di-TBDMS chitosan) as the key intermediate. The quaternary ammoniumyl acetyl derivatives of glucosamine were synthesized from glucosamine or tetra-O-acetylglucosamine. N,N,N-trimethyl chitosan (TMC) was used as reference compound for investigation of antibacterial activity. Clinical Laboratory Standard Institute (CLSI) protocols were used to determine MIC and MLC for activity against clinically important Gram-positive strains Staphylococcus aureus (ATCC 25923), and S. aureus (MRSA) (ATCC 43300), and Gram-negative strains of Escherichia coli (ATCC 25922), P. aeriginosa (ATCC 27853) and Enterococcus facialis (ATCC 29212). The MIC values for the compounds ranged from 8 to ?8192 mg/L. In general the N-(2-(N,N-dimethyl-N-dodecyl ammoniumyl) acetyl) derivatives of chitooligomer and glucosamine monomer were more active against bacteria than derivatives with shorter alkyl chains. In contrast the N-(2-(N,N-dimethyl-N-dodecyl ammoniumyl) acetyl) derivatives of chitosan were less active than derivatives with N-(2-N,N,N-trimetylammoniumyl) acetyl or N-(2-(N-pyridiniumyl) acetyl) quaternary moiety. N,N,N-trimethyl chitosan (TMC) was the most active compound in this study.     

A novel structural class of photoswitchable oligonucleotide

Directed Michaelis-Arbuzov reactions of support-bound internucleotide O-benzyl- or O-methyl-phosphite triesters with meta-phenylazobenzylamine or alkane-/glycol-linked α,ω-diamines were effected in the presence of iodine. The corresponding tritylated phosphoramidate-linked 11-mers were fully deprotected and released from the support under standard conditions and the fast- and slow-diastereoisomers of both the E- and the Z-meta-phenylazobenzyl-appended oligomers were readily resolved by RP-HPLC. The primary amine-functionalised oligonucleotides were either purified, detritylated and then finally treated with N-hydroxysuccinimidyl carboxylic acid ester derivatives of photoswitchable moieties (Route A) or first derivatised and then subsequently purified and detritylated (Route B). This latter route enabled resolution of fast- and slow-isomers of the trityl-on oligomers bearing novel photoswitchable azopyridine or 9-alkoxyanthracene moieties using RP-HPLC, following which the pure diastereoisomers were detritylated and characterised by MALDI-MS.     

Application of Biginelli reaction to the synthesis of ferrocenylpyrimidones and [3]-ferrocenophane-containing pyrimido[4,5-d]pyrimidinediones

A series of ferrocene-containing mono- and bis-dihydropyrimidines (DHP’s) were prepared by boric acid mediated three-component Biginelli reactions of formyl- and 1,1′-diformylferrocene, 1,3-dioxo-components and urea. A few further transformations including hydrogenolysis of a benzyl 4-ferrocenyl-DHP-5-carboxylate were also performed. Novel cis-fused saturated pyrimido[4,5-d]pyrimidine-2,7(1H,3H)-diones incorporating [3]-ferrocenophane moiety were constructed by means of iron(III)-catalyzed Biginelli-like condensations of 1,1′-diformylferrocene with urea and in situ generated methyl ketone-derived silyl enol ethers. The structures of the new compounds were established by IR and NMR spectroscopy, including HMQC, HMBC and DEPT measurements.     

Detection of S-palmitoylated Proteins in Mouse Heart Tissue Based on Different Precipitation Methods

The acyl-biotinyl exchange (ABE) is widely used for detection of S-palmitoylated proteins by replacing palmitic acid with biotin, which is a common method for detecting S-palmitoylated proteins. In this study, the effects of acetone precipitation and methanol-chloroform precipitation on the detection of S-palmitoylation proteins in acyl-biotin exchange method were compared, and the S-palmitoylated proteins in mouse cardiac tissue were analyzed. First, N-ethylmaleimide (NEM) was used to block free sulfhydryls within protein molecules. Then, biotinylation reagent (HPDP-Biotin) was used to label the newly produced cysteine thiols that were resulted from treatment by hydroxylamine (HA) in mouse heart tissue. During the ABE reaction, excess unreacted NEM, HA and HPDP-Biotin were removed by precipitation of the proteins. Then, the S-palmitoylated proteins from heart tissue were labeled with ABE reaction based on different precipitation methods, and the S-palmitoylated proteins labeled with biotin were enriched by streptavidin agarose beads. The enriched proteins were analyzed by mass spectrometry, and 50 S-palmitoylated proteins were identified. Specifically, 23 S-palmitoylated proteins were identified in acetone precipitation assay group, and 37 S-palmitoylated proteins in the methanol-chloroform precipitation assay group were identified. 10 palmitoylated proteins were identified in both groups. The results showed that the combination of different precipitation methods could be helpful for the identification of palmitoylated proteins.     

Synthesis of substituted salicylamines and dihydro-2H-1,3-benzoxazines

Phenols were converted to their magnesium salts with the MgCl₂-Et₃N base system and subsequently reacted with Eschenmoser's salt, affording N,N-dimethyl substituted benzylamines in high to excellent yields. A series of mono N-substituted benzylamines were prepared in one-pot syntheses by ortho-formylation of phenols to corresponding salicylaldehydes, which in turn reacted with amines to imines. The imines were subsequently reduced to mono N-substituted benzylamines. Some of these benzylamines were further converted, without work-up, to mono N-substituted dihydro-2H-1,3-benzoxazines.