Fast Atom Bombardment Research Articles

Characterization of DHDP, a novel aldose reductase inhibitor isolated from Lysimachia christinae

The aldose reductase (AR) inhibitory effect of Lysimachia christinae was investigated as a functional food ingredient and a new AR inhibitor, DHDP, was isolated from L. christinae, guided by an affinity-based ultrafiltration-HPLC assay. The chemical structure of DHDP was determined to be 1,5-di-hydroxy-1,5-di-[(E)-3-(4-hydroxyphenyl)-2-propenoic]-3-pentanonyl ester by one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR), fast atom bombardment ionization mass spectrometry (FAB-MS), and ultraviolet (UV) and (IR) infrared spectroscopy. In addition, the AR inhibitory activity and mechanism of DHDP were characterized. In vitro and in silico results demonstrated that DHDP binds to the AR active site rapidly, blocking it and competitively preventing substrate access and product formation (IC50, 194.67μM; Ki, 29.68μM). Ex vivo experiments indicated that DHDP can penetrate the eye lens and successfully inhibit AR under hyperglycemic conditions, thus preventing the accumulation of sorbitol and subsequent osmotic stress.

Total Synthesis and Pharmacological Investigation of Cordyheptapeptide A.

The present investigation reports the synthesis of a phenylalanine-rich N-methylated cyclopeptide, cordyheptapeptide A (8), previously isolated from the insect pathogenic fungus Cordyceps sp. BCC 1788, accomplished through the coupling of N-methylated tetrapeptide and tripeptide fragments followed by cyclization of the linear heptapeptide unit. Structure elucidation of the newly synthesized cyclopolypeptide was performed by means of FT-IR, 1H-NMR, 13C-NMR, and fast atom bombardment mass spectrometry (FABMS), and screened for its antibacterial, antidermatophytic, and cytotoxic potential. According to the antimicrobial activity results, the newly synthesized N-Methylated cyclopeptide exhibited potent antibacterial activity against Gram-negative bacteria Pseudomonas aeruginosa and Klebsiella pneumoniae and antifungal activity against dermatophytes Trichophyton mentagrophytes and Microsporum audouinii at a concentration of 6 μg/mL, in comparison to the reference drugs, gatifloxacin and griseofulvin. In addition, cyclopolypeptide 8 displayed suitable levels of cytotoxicity against Dalton’s lymphoma ascites (DLA) and Ehrlich’s ascites carcinoma (EAC) cell lines.

Synthesis and characterization of oxime-modified phenylimido vanadium(V) isopropoxide and their hydrolytic study

Heteroleptic complexes of the type [V(NPh)(O i Pr)3-n {(ONC)(CH3)(C4H3O-2)} n ] {where n = 1 (1), 2 (2) and 3 (3)} were synthesized by the reactions of [V(NPh)(O i Pr)3] (A) with 2-acetylfuryl oxime in different molar ratios in anhydrous benzene. All these new derivatives have been characterized by elemental analyses, Fourier transform infrared spectroscopy, nuclear magnetic resonance (1H, 13C {1H}), 51V) and fast atom bombardment mass spectral studies. Spectral studies appear to be indicating mono-dentate and bi-dentate mode of attachment of the oximato moieties in the solution and solid state, respectively. Fast atom bombardment mass study of one of the representative derivative, [V(NPh){(ONC)(CH3)(C4H3O-2)}3] (3) suggests the monomeric nature of all these complexes. Thermogravimetric curve of [V(NPh){(ONC)(CH3)(C4H3O-2)}3] (3) shows large thermal events. Hydrolysis of [V(NPh)(O i Pr)3] (A) and [V(NPh){(ONC)(CH3)(C4H3O-2)}3] (3) in moist propan-2-ol medium yielded vanadia, (a) and (b), respectively. However, hydrolysis of [V(NPh)(O i Pr)3] (A) in n-hexane medium using calculated amount of water yielded hybrid material, (vn).The presence of (V = NPh) group in (vn) is confirmed by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectral studies as well as by the thermogravimetric study. The X-ray diffraction patterns of vanadia, (a) and (b) indicate formation of orthorhombic phase and the scanning electron microscope images of (a) and (b) show rod like morphology of the crystallites. Absorption spectra of vanadia, (a) and (b) indicate energy band gaps of 2.62 and 2.43 eV, respectively. Heteroleptic complexes of the type [V(NPh)(O i Pr)3-n {(ONC)(CH3)(C4H3O-2)} n ] {where n = 1, 2 and 3} were synthesized by the reactions of [V(NPh)(O i Pr)3] with 2-acetylfuryl oxime. Hydrolysis of [V(NPh)(O i Pr)3] and [V(NPh){(ONC)(CH3)(C4H3O-2)}3] in moist propan-2-ol medium yielded vanadia in orthorhombic phase, whereas, hydrolysis of [V(NPh)(O i Pr)3] in n-hexane medium yielded hybrid material containing (V = NPh) linkages.

Low-temperature direct heterogeneous bonding of polyether ether ketone and platinum

Direct heterogeneous bonding between polyether ether ketone (PEEK) and Pt was realized at the temperatures lower than 150°C. In order to create sufficient bondability to diverse materials, the surface was modified by vacuum ultraviolet (VUV) irradiation, which formed hydrate bridges. For comparison, direct bonding between surfaces atomically cleaned via Ar fast atom bombardment (FAB) was conducted in a vacuum. The VUV irradiation was found to be effective for creating an ultrathin hydrate bridge layer from the residual water molecules in the chamber. Tight bonds were formed through dehydration of the hydrate bridges by heating at 150°C, which also contributed to enhancing interdiffusion across the interface. The VUV-modified surfaces showed bondability as good as that of the FAB-treated surfaces, and the VUV-modified samples had shear strengths at the same level as those of FAB-treated surfaces. This technology will be of practical use in the packaging of lightweight, flexible biomedical devices.

Synthesis, Characterization, Antimicrobial and Antiproliferative Activity Evaluation of Cu(II), Co(II), Zn(II), Ni(II) and Pt(II) Complexes with Isoniazid-Derived Compound.

Hydrazone complexes of Cu(II), Co(II), Zn(II), Ni(II) and Pt(II) with N-isonicotinoyl-N′-(3-metoxy-2 hydroxybenzaldehyde)-hydrazone (HL) were synthesized and characterized by different physico-chemical techniques including elemental and thermal analysis, magnetic susceptibility measurements, molar electric conductivity, as well as IR (infrared), 1H-NMR and 13C-NMR (hydrogen and carbon nuclear magnetic resonance, UV-Vis (ultraviolet-visible), FAB (fast atom bombardment), EPR (electron paramagnetic resonance), and mass spectroscopies. The crystal structure of ligand was determined by single crystal X-ray diffraction studies. Spectral data showed that hydrazone behaves as an ONO tridentate ligand through the azomethine nitrogen, phenolate and keto oxygen atoms. For the copper(II) complexes, metal–ligand bonding parameters were evaluated from the EPR spectra. These parameters indicate the presence of in-plane π bonding. In addition, the f values of complexes 1–4 indicate small distortion from planarity. The effect of these complexes on proliferation of human breast cancer (MCF-7 and SKBR-3), human melanoma (A375), lung adenocarcinoma cells (NCI-H1573) and their antibacterial activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus and Candida albicans strains were studied and compared with those of free ligand. The ligand and complexes 1–3 showed significant antimicrobial activity against the Gram-positive bacteria Staphylococcus aureus and Candida albicans in comparison to the control drugs. The complexes 2–4 could be potential antitumor agents, leading to a significant improvement of the cytotoxic activity when compared with HL.

Melanogenesis inhibition activity of floralginsenoside A from Panax ginseng berry

BackgroundPanax ginseng is a traditional herb used for medicinal purposes in eastern Asia. P. ginseng contains various ginsenosides with pharmacological effects. In this study, floralginsenoside A (FGA), ginsenoside Rd (GRD), and ginsenoside Re (GRE) were purified from P. ginseng berry. MethodsChemical structures of FGA, GRD, and GRE were determined based on spectroscopic methods, including fast atom bombardment mass spectroscopy, ID-nuclear magnetic resonance, and infrared spectroscopy. Inhibitory activities of these compounds on melanogenesis were studied by measuring the expression of protein and melanin content in the melan-a cell line. This inhibitory activity was confirmed by observing pigmentation and tyrosinase activities of zebrafish. ResultsGRD, GRE, and FGA were not cytotoxic at concentrations less than 20μM, 80μM, and 160μM in melan-a cells, respectively. GRD, GRE, and FGA inhibited melanin biosynthesis in melan-a cells by 15.2%, 22.9%, and 23.9% at 20μM, 80μM, and 160μM, respectively. FGA was observed to display the most potent inhibitory effect. In addition, FGA decreased microphthalmia-associated transcription factor protein expression in a dose-dependent manner. Moreover, FGA induced extracellular signal-regulated kinase phosphorylation level in melan-a cells. In addition, melanin pigment content and tyrosinase activity in zebrafish treated with FGA at160μM were reduced. ConclusionFGA showed the most potent inhibition of melanogenesis in both in vitro and in vivo studies. This study suggests that FGA purified from P. ginseng may be an effective melanogenesis inhibitor.

Highly Active and Non‐corrosive Catalytic Systems for the Coupling Reactions of Ethylene Oxide and CO2

Lithium halide‐based molten salts (LiX‐[BMIm]Br) synthesized from the reactions of lithium halides (LiX, X = Cl or Br) with 1‐butyl‐3‐methylimidazolium bromide ([BMIm]Br), and their catalytic performances and corrosivities were tested for the coupling reactions of ethylene oxide with carbon dioxide to produce ethylene carbonate. The activity of a molten salt was influenced with the change of halide ion. At a fixed molar amount of LiX, the activity of LiX‐[BMIm]Br increased with increasing molar ratio of LiX/[BMIm]Br up to 1–1.25, and then decreased thereafter. Fast atom bombardment mass spectral analysis of LiBr‐[BMIm]Br, obtained by dissolving LiBr in [BMIm]Br in a 1:1 molar ratio, implies that [Li a X a +1]− are active species for the carboxylation of ethylene oxide with LiX‐[BMIm]Br. The corrosion test toward carbon steel coupons demonstrates that all the Cl‐containing molten salts are corrosive, whereas the salts without containing Cl− are non‐corrosive under the carboxylation condition.

Multianalyte profiling of per- and polyfluoroalkyl substances (PFASs) in liquid commercial products

The chemical properties of poly- and perfluoroalkyl substances (PFASs) make them widespread for use in a number of industrial and commercial products to confer water and oil-repellency characteristics and to reduce surface tension e.g. in aqueous film-forming foams (AFFFs). Some PFASs, especially perfluoroctane sulfonate, and several perfluoroalkyl carboxylic acids, are known to cause significant human and environmental negative impact. Our knowledge on the content of PFASs in products remains scarce due to limited information available, thus impeding any precise assessment of human exposure and environmental release upon use. This study aimed at analyzing a wide variety of liquid products (n = 194) likely to contain PFASs, including impregnating agents, lubricants, cleansers, polishes, AFFFs and other industrial products. By means of LC- and GC-MS/MS analytical techniques, 24 PFASs (from 41 targeted PFASs) were detected and quantified in 55% of samples. PFAS quantification and profiling was found to be consumer product specific. PFASs were mostly detected in AFFF (90%) and impregnating agents (60%) with mainly ionic and neutral species, respectively. In particular, the fluorotelomer alcohols 6:2, 8:2 and 10:2 FTOHs were detected in 40–50% of impregnating agents. Further investigation by Fast Atom Bombardment Mass Spectrometry (FAB-MS) on a set of AFFF samples allowed the characterization of 8 different PFAS classes as major components in these formulations. Results demonstrated that numerous and diversified PFAS are currently used in specific commercial products, implying significant human exposure and environmental release that necessitate further research concerning their toxicological impact.

ISOLATION AND CHARACTERIZATION OF N-HEPTACOSANYL OLEATE FROM THE WHOLE AERIAL PARTS OF CENTELLA ASIATICA LINN.

ABSTRACTVarious studies have already been performed involving the whole aerial parts of Centella asiatica (L.) (Umbelliferae), commonly known as gotu kola orjalbrahmi, and thus, the present investigation has been carried out for the phytochemical study of an ethanolic extract of the aerial parts of C. asiatica.To perform this activity, the drug (1.5 kg) was exhaustively extracted in 95% ethanol using Soxhlet apparatus. The column chromatography wasperformed then for isolating the various phytoconstituents using the solvents of increasing polarity from petroleum ether to methanol. The isolatedcompounds were structurally elucidated using various spectral data analysis, i.e. infrared,1H nuclear magnetic resonance (NMR),13C NMR, and positiveion fast atom bombardment mass spectrometry. One of the isolated compounds was characterized as n-heptacosanyl oleate.Keywords: Whole aerial parts, Centella asiatica, Soxhlet, Column, Heptacosanyl oleate.

Lipopolysaccharide로 유도된 Raw264.7 cell에서 Rhododendron mucronulatum Turcz. Flower으로부터 분리한 myricetin에 의한 염증 억제효과

As a research of inflammation inhibitory activity using natural resource, the inflammation inhibitory activity by purified active compound from Rhododendron mucronulatum flower was experimented. Rhododendron mucronulatum flower components were purified and separated with Sephadex LH-20 and MCI gel CHP-20 column chromatography, Purified compound was confirmed as myricetin by 1HNMR, 13C-NMR and Fast atom bombardment (FAB)-Mass spectrum to have inhibition activity on inflammatory factors secreted by Raw 264.7 cells in response to lipopolysaccharide stimulation. Myricetin inhibited nitric oxide (NO) expression in a concentration dependent manner, approximately 40% inhibition was observed at a concentration of 50 μM. The inhibition effect of myricetin on inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 protein expression was 20% and 80%, respectively, at a concentration of 25 μM. Myricetin also inhibited expression of the inflammatory cytokines, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and prostaglandin E2 (PGE2) in a concentration dependent manner; a concentration of 50 μM, 70%, 80%, 80% and 95% inhibition was observed, respectively. Therefore myricetin isolated from Rhododendron mucronulatum flowers is expected to have an anti-inflammatory effect in Raw 264.7 cell induced by lipopolysaccharides. The results can be expected myricetin from Rhododendron mucronulatum flower to use as functional resource for anti-inflammatory activity.

Antioxidant compounds produced by Pseudocercospora sp. ESL 02, an endophytic fungus isolated from Elaeocarpus sylvestris

ObjectiveTo isolate endophytic fungi from Elaeocarpus sylvestris (E. sylvestris) and to isolate antioxidant compounds from a potential source fungus. MethodsEndophytic fungi were isolated from fresh leaves and stems of E. sylvestris and identified based on DNA analysis. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was used to evaluate the antioxidant activity of the fungi. The potential antioxidant fungus was further studied to isolate antioxidant compounds. The isolated compounds were identified by melting point analysis, optical rotation, spectral analysis using a UV spectrophotometer, high resolution fast atom bombardment mass spectrometry, X-ray crystallography analysis, 1H nuclear magnetic resonance analysis and 13C nuclear magnetic resonance analysis. The isolated compounds were evaluated with DPPH radical scavenging, reducing power, and β-carotene bleaching assays. ResultsSeven endophytic fungi were successfully isolated from E. sylvestris and identified as Pestalotiopsis sp. EST 01, Pestalotiopsis sp. EST 02, Diaporthales sp. EST 03, Meyerozyma sp. EST 04, Diaporthales sp. EST 05, Pestalotiopsis sp. ESL 01, and Pseudocercospora sp. ESL 02. Of the seven fungi, Pseudocercospora sp. ESL 02 had the highest antioxidant activity [IC50 = (30.54 ± 0.88) μg/mL]. From that fungus, two compounds identified as terreic acid (1) and 6-methylsalicylic acid (2) were isolated with an IC50 of DPPH radical scavenging activity of (0.22 ± 0.02) mmol/L and (3.87 ± 0.27) mmol/L, respectively. The compounds also had good activities from the reducing power and β-carotene bleaching assays. ConclusionsThe Pseudocercospora sp. ESL 02 fungus isolated from E. sylvestris looks promising as a novel source of terreic acid.

Design, synthesis, characterization and biological studies of copper(II) complexes with 2‐aminobenzimidazole derivatives as biomimetic agents

Four novel copper(II) complexes of 2‐aminobenzimidazole derivatives (obtained from the Knoevenagel condensation of acetylacetone (obtained from acetylacetone and halogen‐substituted benzaldehydes) and 2‐aminobenzimidazole) were synthesized. They were characterized using elemental analysis, molar conductance measurements, and fast atom bombardment mass, Fourier transform infrared, NMR, UV–visible and electron paramagnetic resonance spectroscopies. On the basis of the spectral studies, a distorted square planar geometry was assigned for all the complexes. The antibacterial screening of the ligands and their complexes revealed that all the complexes had higher activities than the free ligands. Superoxide dismutase and antioxidant activities of the copper complexes were also studied. The shifts in ΔEp, E1/2, Ipc and Ipa values were explored for the interaction of the complexes with calf thymus DNA using the electrochemical technique.

Influence of TCNQ acceptor on optical and electrical properties of tetrasubstituted allenes films fabricated by vacuum thermal evaporation

In this work, the synthesis and characterization of organic semiconductors formed from allenes and TCNQ salts are reported. These materials have been utilized to prepare thin films by thermal evaporation at high temperature. The chemical structure and morphology of the deposited films were analyzed by IR spectroscopy, fast atomic bombardment mass and scanning electron microscopy. The optical band gap of these semiconductors films was evaluated from optical absorption measurements. Theoretical calculations (DFT with dispersion forces analysis included) were carried out in order to simulate molecular interaction and to establish the nature of the bonds between both fragments. This has resulted in finding some intermolecular and some intramolecular hydrogen bonds and their formation is discussed. Finally the direct current electrical properties of the glass/ITO/allene-TCNQ/Ag sandwich structures were also investigated. The conductivity behaviour of these materials was achieved by means of electrical measurements; the materials show semiconductor characteristics and all the conductivity values are found around 10−8–101 Ω−1 cm−1.

Anti-inflammatory Constituents from the Aerial Parts of Iris minutiaurea

Phytochemical investigation of the methanol extract of the aerial parts of Iris minutiaurea (Iridaceae) using column chromatography led to the isolation of a new xanthone glycoside, 1-hydroxy-3,5-dimethoxy-xanthone-6-O-β-D-glucoside (1), together with one known flavonoid glycoside (2). The structure of this new compound was elucidated by analysis of spectroscopic, including 1D (1H, 13C), 2D NMR (COSY, HMQC, HMBC), and high resolution fast atom bombardment mass spectrometric (HR-FAB-MS) data and enzyme hydrolysis. We found that compounds 1 and 2 significantly suppressed production of NO, and pro-inflammatory cytokine in LPS-induced RAW264.7 cells. These results suggest that compound 1 and 2 have anti-inflammatory activity related with production of TNF-α, IL-6, IL-1β, and NO in macrophages, and then compound 1 were more efficient than compound 2 in lowering the level of proinflammatory cytokine.

Mass-spektrometriya s bombardirovkoy bystrymi atomami v ustanovlenii putey biosinteza purinovogo ribonukleozida [2N]inozina

Mass-spektrometriya s bombardirovkoy bystrymi atomami v ustanovlenii putey biosinteza purinovogo ribonukleozida [2N]inozina

Alternative mass reference standards for direct analysis in real time mass spectrometry.

Mass spectra were acquired with the Direct Analysis in Real Time (DART®) ion source for an amine-terminated polyether used as positive-ion mass reference standards and for several fluorinated materials commonly used as negative-ion reference standards for mass spectrometry. A commercial time-of-flight mass spectrometer equipped with a DART ion source was used for all measurements. Mass reference standards deposited onto the sealed end of a glass melting point tube were suspended in the DART gas stream for analysis. A polyetheramine (Jeffamine® M-600) produced intense peaks corresponding to protonated molecules. Perfluorotributylamine (PFTBA), and perfluorotripentylamine, gave useful reference spectra for different m/z ranges. DART mass spectra of Ultramark 1621® resembled those previously reported for Fast Atom Bombardment (FAB) and Electrospray Ionization (ESI). Fomblin®Y, a fluorinated ether, was the most useful negative-ion reference standard of the materials tested. The material is commercially available, inexpensive, and provides reference peaks covering the m/z range 85 to >3000. Jeffamine-M600 was found to be a convenient alternative to polyethers such as polyethylene glycol (PEG) for DART positive-ion mass calibration. Fomblin Y was suitable for use as a negative-ion reference standard. Copyright © 2016 John Wiley & Sons, Ltd.

Inhibitory Activity against Helicobacter pylori of Isolated Compounds from Pinus koraiensis Siebold et Zucc Leaves

A phenol substance was extracted from Pinus koraiensis Siebold et Zucc leaf extracts and its biological efficacy was measured. The highest content of the phenol substance contained in Pinus koraiensis Siebold et Zucc leaves was 13.5 mg/g, which was obtained when it was extracted with 80% ethanol. At a concentration of 200 mg/mL, the phenolic substances extracted with 80% ethanol and water showed antimicrobial activities against Helicobacter pylori, producing clear zones of 10 and 12 mm diameter, respectively. Pinus koraiensis Siebold et Zucc. leaf extracts were separated using a Sephadex LH-20 column and 4 fractions were obtained (fractions A-D). Fractions C and D showed the greatest inhibitory activity against Helicobacter pylori producing 10.1 and 12.3 mm clear zones, respectively. These two fractions were purified using a Sephadex LH-20 and MCI-gel column (H2O→100% ethanol). Purified compounds A and B were identified as syringic acid and compound C was identified as p-coumaric acid based on 1 H-nuclear magnetic resonance (NMR), 13 C-NMR, and fast atom bombardment mass spectrometry spectra. When two or more purified compounds were mixed, a synergistic effect of anti-Helicobacter pylori activity was evident. This result indicates that extracts of Pinus koraiensis Siebold et Zucc leaves could be considered a functional food because of their high antimicrobial properties.

ChemInform Abstract: Two New Taxane‐Glycosides from the Needles of Taxus canadensis.

AbstractTwo new taxane‐glycosides are isolated from the methanolic extract of the needles of T.canadensis.Their structures are evaluated by 1D and 2D NMR data analysis and high‐resolution fast atom bombardment mass spectroscopy.

Hyperoside and rutin of Nelumbo nucifera induce mitochondrial apoptosis through a caspase-dependent mechanism in HT-29 human colon cancer cells.

The present study demonstrates the mechanism of 2 flavonol glycosides, hyperoside and rutin, in the induction of apoptosis in HT-29 human colon cancer cells through the bioactivity-guided fractionation and isolation method. The chemical structure of hyperoside and rutin, isolated from the roots of Nelumbo nucifera, were established using extensive 1- and 2-dimensional nuclear magnetic resonance experiments and absolute high resolution fast-atom bombardment mass spectrometry, ultraviolet-visible and Fourier transform infrared spectroscopy spectral analytical methods. The treatment of HT-29 colon cancer cells with hyperoside and rutin significantly decreased cell viability in a dose-dependent manner. The concomitant activation of the mitochondria-dependent apoptotic pathway of hyperoside and rutin occurred via modulation of Bcl-2-associated X protein and B-cell lymphoma 2 expression, resulting in the activation of cleaved caspases-3, -8 and -9 and cleaved poly-(ADP-ribose) polymerase. The findings of the present study indicate that hyperoside and rutin induce apoptosis in HT-29 human colon cancer cells, and that this phenomenon is mediated via the death receptor-mediated and mitochondria-mediated apoptotic pathways. These results suggest that hyperoside and rutin may be useful in the development of a colon cancer therapy protocol.

ChemInform Abstract: Synthesis of Novel Spiro[indol‐2,2′‐pyrroles] Using Isocyanide‐Based Multicomponent Reaction.

AbstractAn efficient and facile method for the synthesis of novel spiro[indole‐2,2′‐pyrroles] (IV) from N‐methyl‐3‐isatin imines, alkyl isocyanide, and dialkyl acetylenedicarboxylate is achieved by [3 + 2] cycloaddition reaction.