Fast Atom Bombardment Research Articles

Effect of gamma-irradiation on thermal decomposition kinetics, X-ray diffraction pattern and spectral properties of tris(1,2-diaminoethane)nickel(II)sulphate

Tris(1,2-diaminoethane)nickel(II)sulphate was prepared, and characterised by various chemical and spectral techniques. The sample was irradiated with 60Co gamma rays for varying doses. Sulphite ion and ammonia were detected and estimated in the irradiated samples. Non-isothermal decomposition kinetics, X-ray diffraction pattern, Fourier transform infrared spectroscopy, electronic, fast atom bombardment mass spectra, and surface morphology of the complex were studied before and after irradiation. Kinetic parameters were evaluated by integral, differential, and approximation methods. Irradiation enhanced thermal decomposition, lowering thermal and kinetic parameters. The mechanism of decomposition is controlled by R3 function. From X-ray diffraction studies, change in lattice parameters and subsequent changes in unit cell volume and average crystallite size were observed. Both unirradiated and irradiated samples of the complex belong to trigonal crystal system. Decrease in the intensity of the peaks was observed in the infrared spectra of irradiated samples. Electronic spectral studies revealed that the M–L interaction is unaffected by irradiation. Mass spectral studies showed that the fragmentation patterns of the unirradiated and irradiated samples are similar. The additional fragment with m/z 256 found in the irradiated sample is attributed to S8+. Surface morphology of the complex changed upon irradiation.

Down-regulation of MITF, TRP-1, TRP-2, and tyrosinase expressions by compounds isolated from Pruni persicae Flos in murine B16F10 melanoma

Three single compounds were isolated by the fractionation from Pruni persicae Flos, and its chemical structure was analyzed using 1H-, 13C-nuclear magnetic resonance, fast atom bombardment -Mass, and fourier transform infrared spectrometer analyses. The compounds were determined as quercetin 3-O-rhamnoside, kaempferol 3-O-β-neohesperidoside, and kaempferol 3-O-β-d-glucoside. To prove the whitening effect of these compounds, B16F10 melanoma was treated with quercetin-3-O-rhamnoside, kamferol-3-O-β-neohesperidoside or kaemferol-3-O-β-d-glucoside to confirm cell cytotoxicity using 3-[4,5-dimethylthiazol-2yl]-2,5-diphenyl-tetrazolium-bromide assay. As a result, cell cytotoxicity was examined at more than 20% in 20 μg/mL of compounds isolated from Pruni persicae Flos. Tyrosinase activity and melanin production were examined at 10 μg/mL of each compounds. Results showed quercetin-3-O-rhamnoside, kamferol-3-O-β-neohesperidoside or kaemferol-3-O-β-d-glucoside reduced tyrosinase activity in a dose-dependent manner. Moreover, quercetin-3-O-rhamnoside showed reduction of tyrosinase activity by 37.6% at 10 μg/mL of quercetin-3-O-rhamnoside as well as the reduction of melanin contents by 58.8%. In addition, quercetin-3-O-rhamnoside, kamferol-3-O-β-neohesperidoside, and kaemferol-3-O-β-d-glucoside reduced tyrosinase, tyrosinase-related proteins 1, and 2, microphthalmia associated transcription factor expressions, which were related to whitening effect, as well as both of mRNA and protein level of cyclic adenosine monophosphate as upstream signals. More interestingly, quercetin-3-O-rhamnoside strongly reduced both mRNA and protein expressions than other compounds. Therefore, we determined the whitening effect from isolated compound fractionated from Pruni persicae Flos. Moreover, strong whitening activity of quercetin-3-O-rhamnoside was examined, which suggested the potential application of this compound in functional cosmetic development.

Glycosyl glycerides from hydroponic Panax ginseng inhibited NO production in lipopolysaccharide-stimulated RAW264.7 cells

BackgroundAlthough the aerial parts of hydroponic Panax ginseng are reported to contain higher contents of total ginsenosides than those of roots, the isolation and identification of active metabolites from the aerial parts of hydroponic P. ginseng have not been carried out so far. MethodsThe aerial parts of hydroponic P. ginseng were applied on repeated silica gel and octadecylsilane columns to yield four glycosyl glycerides (Compounds 1–4), which were identified based on nuclear magnetic resonance, infrared, fast atom bombardment mass spectrometry, and gas chromatography/mass spectrometry data. Compounds 1–4 were evaluated for inhibition activity on NO production in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Results and conclusionThe glycosyl glycerides were identified to be (2S)-1-O-7(Z),10(Z),13(Z)-hexadecatrienoyl-3-O-β-d-galactopyranosyl-sn-glycerol (1), (2S)-1-O-linolenoyl-3-O-β-d-galactopyranosyl-sn-glycerol (2), (2S)-1-O-linolenoyl-2-O-linolenoyl-3-O-β-d-galactopyranosyl-sn-glycerol (3), and 2(S)-1-O-linoleoyl-2-O-linoleoyl-3-O-β-d-galactopyranosyl-sn-glycerol (4). Compounds 1 and 2 showed moderate inhibition activity on NO production in LPS-stimulated RAW264.7 cells [half maximal inhibitory concentration (IC50): 63.8 ± 6.4μM and 59.4 ± 6.8μM, respectively] without cytotoxicity at concentrations < 100μM, whereas Compounds 3 and 4 showed good inhibition effect (IC50: 7.7 ± 0.6μM and 8.0 ± 0.9μM, respectively) without cytotoxicity at concentrations < 20μM. All isolated compounds showed reduced messenger RNA (mRNA) expression of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α in LPS-induced macrophage cells with strong inhibition of mRNA activity observed for Compounds 3 and 4.

Synthesis, Characterization, and Crystal Structure of Pyridinium Tetrakis{1-trifluoromethyl-3-(1′-pyreno)-1,3-propanedionato}lanthanate(III) Complex

The reaction of 1-trifluoromethyl-3-(1′-pyreno)-1,3-propanedione with lanthanum(III) trichloride in the presence of pyridine leads to halide ligand exchange, yielding a novel pyridinium tetrakis{1-trifluoromethyl-3-(1′-pyreno)-1,3-propanedionato}lanthanate(III) complex with four polycyclic aromatic hydrocarbon moieties. This reaction easily proceeds under mild conditions (25°C, 24 h) producing the complex in a 90% isolated yield. The complex was characterized by infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and positive fast atom bombardment mass spectrometry, and its precise structure was determined by single crystal X-ray diffraction. Ultraviolet-visible spectroscopy, fluorescence spectroscopy, and X-ray analysis demonstrated that the four pyrene moieties were independently oriented.

Acridine Synthesis by the Reaction of 2-(Perfluoroalkyl)aniline with ortho-Alkyl-Substituted Aromatic Grignard Reagent: Mechanistic Studies

The reaction of 2-(perfluoroethyl)aniline and its higher perfluoroalkyl analogues with an arylmagnesium bromide substituted with a methyl or ethyl group at the ortho position furnishes an acridine containing a shorter perfluoroalkyl group at the 9-position and devoid of the methyl or ethyl group of the Grignard reagent. Yields are in the range of 46–93 %. The intermediary of a substituted aza-ortho-xylylene has been postulated for related transformations in the literature previously, but this intermediate product has never been isolated. As part of this work, the labile product E-27 (half-life of 6 h at 23°C) was isolated for the first time and characterized by infrared spectroscopy, electron impact mass spectrometry, fast atom bombardment mass spectrometry, and 1H NMR. Experimental evidence was also obtained regarding the elimination of the ortho-alkyl group of the Grignard reagent during the course of the reaction as an alcohol.

Combined Surface-Activated Bonding (SAB) Technologies for New Approach to Low Temperature Wafer Bonding

Wafer surface activation is of great importance for low temperature wafer bonding process development. However, different surface activation methods are needed for various bonding materials due to their different requirements and mechanisms for low temperature bonding. A challenge of the low temperature wafer bonding technology is to develop compatible surface activation processes for hybrid surfaces (e.g., Cu/polymer adhesive and Cu/SiO2 hybrid surfaces). In this study, we developed surface activation processes for low temperature Cu/dielectric hybrid bonding. We report the results of surface treatment for Cu/adhesive hybrid surface by using Ar plasma and Ar fast atom bombardment, and a combined SAB process for SiO2 hydrophilic bonding. Post-bonding vacuum annealing is employed to develop void-free hydrophilic SiO2 wafer bonding.

Combined Surface-Activated Bonding (SAB) Technologies for New Approach to Low Temperature Wafer Bonding

Surface activating/cleaning is of great importance for low temperature wafer bonding and various surface activating methods have been studied. Fast atom bombardment activation removes oxides and contaminations on bonding surface and it is efficient for room temperature wafer bonding for semiconductors and metals, etc. Plasma activated bonding has been developed for low temperature hydrophilic bonding for silicon and silicon oxide wafers[1] and Au bonding. Formic acid gas treatment reduces Cu oxide to Cu and then the Cu can be bonded at temperature below 200°C [2]. Water vapor-assisted SAB method introduces water vapor onto the FAB activated surfaces at atmospheric pressure, and then homogeneous and heterogeneous bonding of Cu, SiO2, and polyimide can be achieved at 150°C and atmospheric pressure [3]. SAB with a modification using nano-adhesion layer at the interface realized room temperature bonding of polymer films and glass[4]. However, every activating method has its advantages and limitations depending the bonding materials and applications. Thus, there is a need to combine various surface activating methods for novel low temperature wafer bonding approaches development. The objectives of this study are to develop new approach for low temperature wafer bonding by using combined surface-activated bonding (SAB) technologies and to explore the mechanisms of the bonding processes.We used Ar plasma and Ar fast atom bombardment (FAB) to activate the Cu/polymer hybrid surface for removal of Cu native oxide and organic contaminations on Cu surface. X-ray photoelectron spectroscopy (XPS) was used to analyze the chemical composition and state of the activated surfaces. The results show that Ar FAB is more effective for Cu oxides and organic contaminations removal than Ar plasma. The XPS spectra (Figure 1) show that Cu hydroxide, Cu oxides and organic contaminations on Cu surface could be removed by FAB activating for 9 minutes. However, Cu contamination on polymer surface is observed after both Ar plasma and Ar FAB activation.To develop new low temperature bonding approaches, we designed a combined surface-activated bonding system, which consists of two main subsystems: a surface activating subsystem and a wafer bonding subsystem. The surface activating subsystem could employ combined surface activating processes, including oxygen, nitrogen, and fluorine containing plasma, formic acid gas, water vapor and FAB surface treatments. The wafer bonding subsystem could perform wafer alignment and bonding process in ultra high vacuum.In this paper, we report the design and results of a combined surface-activated bonding system that we have constructed to explore the effects of combined surface activating processes on bonding surfaces, and conclude with prospects for the future.

Two novel glycosyl cinnamic and benzoic acids from korean black raspberry (Rubus coreanus) wine

Korean black raspberry (Rubus coreanus) wine was solvent-fractionated with n-hexane, ethyl acetate, and n-butanol and the n-butanol layer was purified by various column chromatographic procedures, including Amberlite XAD-2, Sephadex LH-20, and octadecylsilane resins as well as high performance liquid chromatography. Two novel glycosyl cinnamic and benzoic acids were isolated and their structures were (E)-8-O-β-d-glucopyranosylcinnamic acid (1) and 3′-[O-β-d-glucopyranosyl)(1″→6′)-α-d-psicofuranosyl] benzoate (2) based on the spectroscopic data obtained by high resolution fast-atom bombardment mass spectroscopy and nuclear magnetic resonance analyses.

Fifty years of desorption ionization of nonvolatile compounds

During the past 50 years mass spectrometry has advanced from a small molecule method to one critical to understanding biological processes. The ability to analyze compounds as large as protein complexes did not happen with any single invention, but occurred in steps. Thus, electrospray ionization can be traced to Zeleny (1917) and Dole (1968), but also to Colby and Evans (1973) with the demonstration of electrohydrodynamic ionization of organic compounds. Likewise, matrix-assisted laser desorption/ionization can be traced to early work with laser desorption by Mumma and Vastola (1972), and the importance of a matrix in analysis of nonvolatile compounds can be attributed to Barber et al. with the introduction of fast atom bombardment (1981). Here, we look back over the past 50 years at the development of desorption methods for the analysis of nonvolatile compounds and the associated attempts at understanding the mechanism by which solid or liquid phase compounds are converted to gas-phase ions.

SIMS—A precursor and partner to contemporary mass spectrometry

Significant events driving the development of SIMS over the last 50 years are reviewed. The discussion includes recollections of dynamic and static SIMS from the 1970s, of the emergence of TOF–SIMS during the 1980s and of the incorporation of cluster ion bombardment during most recent times. Advances in theoretical understanding of the sputtering phenomenon and of the ionization process that accompanied these advances are also included. Many early discoveries were focused upon the stimulated desorption of organic and bioorganic molecules, first via static SIMS and next via fast atom bombardment, that were important precursor experiments to modern day mass spectrometry. Today, submicron molecule-specific imaging and molecular depth profiling represent unique aspects of SIMS experiments. Developments that led to the optimization of these modalities are also emphasized in the review. In general, the characteristics of SIMS that make it a contemporary partner to modern day mass spectrometry are highlighted.

Development of a miniaturized multi-turn time-of-flight mass spectrometer with a pulsed fast atom bombardment ion source.

A miniaturized multi-turn time-of-flight (TOF) mass spectrometer with a pulsed fast atom bombardment (FAB) ion source (FAB-MULTUM) has been designed and constructed in order to overcome the drawbacks associated with magnetic sector type instruments utilizing a FAB ion source such as size and weight. This instrument consists of a pulsed FAB ion source, a multi-turn TOF mass spectrometer, a detector, vacuum system, and electronic circuits. The size and weight of the system are less than H520 mm x L580 mm x W230 mm and 45 kg (including vacuum pumps and electronic circuits). The achieved resolving power and mass accuracy of this instrument were > 25000 and about 1 ppm, respectively, which are equivalent to those of magnetic sector type instruments, although the size and weight are much smaller than those of magnetic sector type instruments. The experimental results led us to the conclusion that this instrument enables accurate mass measurements and is a powerful tool for the confirmation of synthesized compounds.

New flavone-di-C-glycosides from the seeds of Egyptian lupin (Lupinus termis)

Raw lupin seeds flour is increasingly used as a food ingredient because of its nutritional and functional values. This study is considered to be the first phytochemical investigation of the flavonoids of the methanol (MeOH) fraction of Lupinus termis seeds. The study led to the isolation of two new di-C-glycoside flavones, apigenin-6-C-β-d-glucopyranosyl-8-C-[β-d-apiofuranosyl-(1→2)]-β-glucopyranoside (1), apigenin-6-C-β-d-glucopyranosyl-8-C-[α-l-rhamnopyranosyl-(1→2)]-β-glucopyranoside (2), together with one known flavone di-C-glycoside, apigenin-7-O-β-d-apiofuranosyl-6,8-di-C-β-glucopyranoside (3). These compounds are considered to have potential functional properties. The isolated compounds may contribute to the yellow color of raw lupin seeds flour-based products. It may also be used as natural yellow color in food or pharmaceutical products and as a dietary supplement product. These rare flavones were purified by using semi-preparative HPLC. The structures of the isolated compounds were elucidated on the basis of extensive spectroscopic methods, 1D and 2D nuclear magnetic resonance techniques, FAB (Fast Atom Bombardment) – mass spectrometry and acid hydrolysis.

Preparation of 1,3‐Diphenylselenophenotetraazaporphyrinato Ruthenium(II) Bis(4‐methylpyridine) by the Reaction of 3,4‐Dicyano‐2,5‐diphenylselenophene and Phthalonitrile: Its Optical and Electrochemical Properties

ABSTRACT2,5‐Diphenylselenophene (2a) was treated with bromine and then copper(I) cyanide to produce 3,4‐dicyano‐2,5‐diphenylselenophene (4). Compound 4 was mixed with phthalonitrile, and the mixture was reacted with ruthenium(III) trichloride and 4‐methylpyridine in the presence of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) in refluxed 2‐ethoxyethanol to give 1,3‐diphenylselenophenotetraazaporphyrinato ruthenium(II) bis(4‐methylpyridine) (6). The structure of 6 was determined by 1H NMR and fast atom bombardment mass spectrometry (FABMS). In the 1H NMR spectrum, the signals of 4‐methylpyridine coordinating to the central ruthenium atom were observed at a higher magnetic field than those of free 4‐methylpyridine itself but at a lower magnetic field than those of phthaocyaninato ruthenium(II) bis(4‐methylpyridine) (7). The 77Se NMR spectrum of 6 showed one singlet peak at δ = 759.5 ppm, which is a lower magnetic field than those of 2a and 4. The Q band absorption of 6 (λmax = 660 nm) lies at a longer wavelength than does that of 7. Oxidation and reduction potentials of 6 were measured with cyclic voltammetry using Ag/AgNO3 as a reference electrode.

Sector instruments for chemical analysis and research

When the last chemical elements were successfully measured by mass spectrometry its use for the characterisation of isotopes declined, but its use for chemical analysis and research grew. This new field of activity was aided by the emergence of commercially manufactured sector mass spectrometers designed for the analysis of oil refinery gases. Although the 1940s saw the use of mass spectrometry dominated by the petroleum industry it also saw many developments in its application to chemical analysis. By the early 1950s heated inlet systems were allowing spectra of all kinds of volatile organic compounds to be obtained. The 1950s saw the development of accurate mass measurement of organic molecules as a means of determining their elemental composition. This led to a demand for higher resolution double focusing instruments. Two types of design competed for this application, each with their perceived advantages and disadvantages. It was another decade, following the application of computers to high throughput accurate mass measurement, before one of these came to dominate. Double focusing sector instruments also enhance the information afforded by “metastable” ions, allowing identification of precursor and product ions. This led to the developments of Collision Induced Decompositions, MIKES and “linked scans”. The mass range demanded of mass spectrometers jumped to new levels with the development of Fast Atom Bombardment (FAB). This led to new sector designs incorporating innovative new magnets. The success of FAB as a soft ionisation technique meant it produced little fragmentation and structural information. This led to a growth in the use of tandem MS/MS instrumentation as a tool for determining structures. This paper recounts these and many other developments which kept magnetic sectors at the centre of major new developments in mass spectrometry for chemical analysis and research for so long.

Synthesis, physicochemical characterization, and biological activity of nanocomplexes of iron(III) of 3(2′-hydroxyphenyl)-5-(4-substituted phenyl) pyrazolines and dithiophosphoric acid

Complexes of iron(III) with dithiophosphoric acid and 3(2′-hydroxy phenyl)-5-(4-substituted phenyl) pyrazolines, [Fe(C6O14O2PS2)2(C15H12N2OX)], and [Fe(C6O14O2PS2)(C15H12N2OX)2], where (C6O14O2PS2H) = dithiophosphoric acid, (C15H13N2OX) = deprotonated 3(2′-hydroxy phenyl)-5-(4-substituted phenyl)pyrazolines (X = H, CH3, OCH3, Cl), have been synthesized. These complexes have been physicochemically characterized by elemental analysis (C, H, N, S, Cl, and Fe), magnetic moment data, thermogravimetric analysis, molar conductance, cyclic voltammetry, and spectral analysis (UV–visible, IR, and Fast atom bombardment mass spectrometry). Scanning electron microscopy, TEM, and PXRD have been carried out for powdered samples, which show nanometric particles of these derivatives. Antibacterial and antifungal potential of free pyrazoline and iron(III) complexes have been evaluated.

Rod shaped oxovanadium(IV) Schiff base complexes: Synthesis, mesomorphism and influence of flexible alkoxy chain lengths

A series of oxovanadium(IV) complexes of bidentate [N,O] donor Schiff-base ligands of the type [VO(L)2], [L=N-(4-n-alkoxysalicylaldimine)-4′-octadecyloxyaniline, n=8, 10, 12, 14, 16 and 18] have been synthesized. The compounds were characterized by elemental analyses, Fourier transform infrared spectroscopy (FTIR), 1H, 13C nuclear magnetic resonance (NMR), ultraviolet–visible spectroscopy (UV–Vis), and fast atom bombardment (FAB) mass spectrometry. The mesomorphic behavior of the compounds was studied by polarized optical microscopy (POM) and differential scanning calorimetry (DSC). The ligands and complexes are all thermally stable exhibiting smectic mesomorphism. The ligands 8-OR to16-OR show SmC phase at ∼113–118°C and an unidentified SmX phase reminiscent of soft crystal at ∼77–91°C whereas the complexes all showed SmA phases. Interestingly the complexes with C10 and C12 alkoxy chain length exhibited additionally SmC phases also. The melting points of the ligands linearly increases whereas mesophase to isotropic transition temperature decreases as a function of increasing carbon chain length of alkoxy arm while no trend was apparently noticeable for the complexes.

Abietane, Labdane, and Pimarane Diterpenoids from the Pulp of Torreya nucifera

Torreya nucifera is an evergreen coniferous tree, widely distributed in Japan, Korea, and People's Republic of China. Its seeds exhibit significant insecticidal activity. The fruits of this evergreen are widely used in folk medicine for the treatment of tapeworm infestation in Korea and to induce abortion in Japan, but most chemical studies of T. nucifera have focused on its leaves and wood. A number of sesquiterpenoids, labdane and abietane diterpenoids, ligans, and flavonoids were identified as active secondary metabolites [1–8]. T. nucifera is a Taxaceae plant endemic to Korea, Japan, and China. In order to compare its constituents with those of Taxus spp. and to understand their taxonomic relationship, we investigated the chemical composition of Torreya nucifera. Five diterpenoids were isolated for the first time from the pulp of the title plant, including one labdane diterpenoid, two abietane diterpenoids, and two pimarane-type diterpenoids. Their structures were established on the basis of 1D and 2D NMR spectrascopic analysis. We report herein the isolation and structure characterization of these diterpenoids and detailed the 1H and 13C NMR data of compounds 1–5. Melting points were measured with an MRK micro-melting point apparatus and were uncorrected. Column chromatographic separations were carried out using silica gel (300–400 mesh, Qingdao Haiyang Chemical Group Corporation, Qingdao, P. R. China). Na2SO4 was the drying agent used in all workup procedures. Solvents and reagents of analytic grade (reagent grade used without further purification) were purchased from commercial sources. TLC was performed on precoated silica gel F254 glass-backed plates without activation. Fractions were monitored by TLC with visualization under UV light (254 and 365 nm) and by dipping the plates into a solution of 10% (v/v) H2SO4 in EtOH followed by heating on a hot plate for 5 min. Analytical HPLC was performed on a Waters 2695 separation module coupled to a 2996 photodiode array detector. Preparative HPLC was carried out on a Waters Delta Prep 3000 instrument coupled to a UV 2487 dual absorbance detector. Analytical HPLC was performed using two Whatman partisil 10 ODS-2 analytical columns (4.6 250 mm) in series. Preparative HPLC was performed using a partisil 10 ODS-2 MAG-20 preparative column (9.4 250 mm). The products were eluted with a 50 min linear gradient of acetonitrile (25 to 100%) in water at a flow rate of 3 mL/min (preparative HPLC). Positive ion fast atom bombardment mass spectra (FAB-MS) was obtained with a Vacuum Generators ZAB-HS instrument. All NMR spectra were recorded on a Varian Unity INOVA 600 or 500 NMR spectrometer equipped with a 5 mm probe at ambient temperature in CDCl3 solution. The 1H and 13C chemical shifts were referenced relative to TMS residue. Typical one-dimensional (1D) 1H and 13C spectra were acquired under standard condition on a Varian Unity INOVA 500/600 spectrometer operating at 499.861/599.913 and 125.690/150.848 MHz, respectively. 1H and 13C chemical shifts are expressed in the scale as parts per million (ppm).

Food Poisonings by Ingestion of Cyprinid Fish

Raw or dried gallbladders of cyprinid fish have long been ingested as a traditional medicine in the Asian countries, particularly in China, for ameliorating visual acuity, rheumatism, and general health; however, sporadic poisoning incidences have occurred after their ingestion. The poisoning causes complex symptoms in patients, including acute renal failure, liver dysfunction, paralysis, and convulsions of limbs. The causative substance for the poisoning was isolated, and its basic properties were examined. The purified toxin revealed a minimum lethal dose of 2.6 mg/20 g in mouse, when injected intraperitoneally. The main symptoms were paralysis and convulsions of the hind legs, along with other neurological signs. Liver biopsy of the euthanized mice clearly exhibited hepatocytes necrosis and infiltration of neutrophils and lymphocytes, suggesting the acute dysfunction of the liver. Blood tests disclosed the characteristics of acute renal failure and liver injury. Infrared (IR) spectrometry, fast atom bombardment (FAB) mass spectrometry, and 1H- and 13C-nuclear magnetic resonance (NMR) analysis indicated, a molecular formula of C27H48O8S, containing a sulfate ester group for the toxin. Thus, we concluded that the structure of carp toxin to be 5α-cyprinol sulfate (5α-cholestane-3α, 7α, 12α, 26, 27-pentol 26-sulfate). This indicated that carp toxin is a nephro- and hepato- toxin, which could be the responsible toxin for carp bile poisoning in humans.

Use of Gram-positive Chemoheterotrophic Bacterium Basillus subtilis В-3157 with HMP-cycle of Carbon Assimilation for Microbiological Synthesis of [2H]riboxine with High Level of Deuterium Enrichment

We studied the growth and biosynthetic properties of a strain of Gram-positive chemoheterotriphic bacterium Bacillus subtilis В-3157 producer of 2 H-labeled purine ribonucleoside riboxine (outcome is 3,9 g/l) in heavy hydrogen (HH) medium with high level of deuterium enrichment (99,8 at.% 2 H2O) with 2 % hydrolysate of deuterated biomass of methylotrophic bacterium Brevibacterium methylicum B-5662 as a source of 2 H-labeled growth substrates, obtained in the minimal М9 growth medium of 98 % 2 Н2О and 2 % ( 2 H)methanol. Isolation of riboxine from liquid culture of riboxine producer strain was carried out by adsorption/resorption on a surface of activated carbon coal, extraction by 0.3 M NH4-formiate buffer (рН = 8.9) with the subsequent crystallization in 80 % of ethanol and column ion exchange chromatography on cation exchanger AG50WX 4, counterbalanced with 0.3 M NH4-formiate with 0.045 M NH4Cl (outcome of riboxine is 3.1 g/l (80 %)). The level of deuterium enrichment of biosynthetically prepared riboxine, analyzed by a method of fast atom bombardment (FAB) mass- spectrometry makes up 5 deuterium atoms with incorporation of 3 deuterium atoms into ribose and 2 deuterium atoms into hypoxantine fragments of the molecule.

Influence of spacer group substituent on mesomorphism in copper complexes of ‘salen’ type Schiff bases bearing long alkoxy arm

Novel four-coordinate copper(II) complexes of the type [CuL], L = N, N′-di-(4-hexadecyloxysalicylidene)-4-substituted(X)l,2-diamino-benzene (X = H, CH3, NO2) were synthesised. The compounds were characterised by elemental analyses, Fourier transform infrared spectroscopy, 1H, 13C nuclear magnetic resonance, ultraviolet–visible spectroscopy and fast atom bombardment mass spectrometry. The liquid crystalline properties were ascertained using polarised optical microscopy, differential scanning calorimetry and powder X-ray diffraction technique. The ligands are non-mesomorphic, but the complexes with methyl (CH3) or no substituent on the aromatic spacer showed rectangular columnar (Colr) mesophase and rectangular plastic columnar (Colrp) phase, respectively. An antiparallel dimeric association of half-disc shaped molecule forming a disc-like arrangement in the mesophase is proposed on the basis of X-ray diffraction study. The complex with nitro (NO2) substituent in the spacer linkage decomposes before melting precluding any mesomorphic study. The density functional theory calculations carried out using Gaussian 09 program at B3LYP level revealed distorted square planar geometry around the metal centre. The natural charges and electronic configuration of the atoms of the complexes and free ligand were evaluated by natural bond orbital analysis.