Antioxidative and DNA Protective Effects of Bacillomycin D-Like Lipopeptides Produced by B38 Strain

In the present study, we evaluated the antioxidant and the scavenging ability of C14, C15 and C16 bacillomycin D-like lipopeptides produced by B38 strain. They all displayed strong reducing power activity, hydroxyl and superoxide anion radicals scavenging activities and inhibition of lipid peroxidation. In addition, they were found to protect plasmid DNA damage from hydroxyl radical oxidation. Data suggested that their antioxidant potency can be attributed to the hydrophobic and aromatic side-chain groups of their amino acids as well as to the aliphatic chain of their beta amino fatty acids. Note that the hydrocarbon chain length did not interfere with the antioxidant power. Overall, such bacillomycin D lipopeptides which exhibit antioxidant and radical scavenging activities may be useful for cosmetic, therapeutic or pharmaceutical purposes in order to delay or prevent oxidative deterioration of manufactured products.     

High-resolution infrared study of the 2ν3 (A1, E) and ν1 + ν3 (E) bands of NF3

The 2ν₃ overtone (A₁, E) and the ν₁ + ν₃ (E) combination bands of the oblate symmetric top ¹⁴NF₃ were studied by FTIR spectroscopy with a resolution of 2.5 × 10⁻³ cm⁻¹. Nearly 500 lines up to K_max/J_max = 30/43 were observed for the weak A₁ component reaching the v₃ = 2⁰ substate (1803.1302 cm⁻¹), the majority of which corresponded to reinforced K = 3p-type transitions. For the strong E component reaching the v₃ = 2^±2 substate (1810.4239 cm⁻¹), about 3550 transitions were assigned up to K_max/J_max = 65/69, favoring a clear observation of the ℓ(4, −2) and ℓ(4, 4) splittings within the kℓ = −2 and +4 sublevels, respectively. The two v₃ = 2 substates are linked by the ℓ(2, 2)- and ℓ(2, −1)-type interactions, providing severe crossings, respectively, at K′ = 6 and near K′ = 24 on the v₃ = 2⁺² side. A model working in the D-reduction and including all these ℓ-type interactions could reproduce together 3695 nonzero weighted experimental data (NZW) through 33 free parameters with a standard deviation of σ = 0.357 × 10⁻³  cm⁻¹. As for the ν₁ + ν₃ (E) combination band, about 3690 lines were assigned up to K_max/J_max = 45/55. Its v₁ = v₃ = 1 upper state (1931.577 5 cm⁻¹) was treated using the same model recently applied to the v₃ = 1 (E, 907.5413 cm⁻¹) state. It yielded 21 free parameters through 3282 NZW experimental data, adjusted with σ = 0.344 × 10⁻³  cm⁻¹ in the D-reduction. For the two excited states, the small and unobserved ℓ(0, 6) interaction was tested as useless. To confirm the adequacy of the vibrationally isolated models used, some other reductions of the Hamiltonian were tried. For the v₃ = 2 state, the D-, L-, and LD-reductions led to similar σ’s, while the Q one was not successful. For the v₁ = v₃ = 1 state, the D- and Q-reductions gave comparable σ’s, while the QD-reduction was not as good. The corresponding unitary equivalence relations are generally more nicely fulfilled for the v₃ = 2 state than for the v₁ = v₃ = 1 state. The three derivable anharmonicity constants in cm⁻¹ are x₃₃ = −4.1528, g₃₃ = +1.8235 and x₁₃ = −7.9652.     

GC–MS analysis of phytoconstituents present in methanolic extract of Actinidia deliciosa L. fruits and its antioxidant activity

Kiwi fruit (KF) (Actinidia deliciosa L.) are members of the Actinidia genus (Family Actinidiaceae). Previously these plants have confirm anti-diabetic, anti-oxidant, anti-inflammatory, antifungal, anticarcinogenic, hepatoprotective, anti-microbial etc. properties. The therapeutic efficacy of complex phytoconstituents found in fruit extracts has piqued the interest of pharmaceutical companies and academics alike. Methanolic extract of kiwi fruit (MEKF) was analyzed by gas chromatography-mass spectroscopy and yielded positive results signaling towards identification and characterization of therapeutic claims of this species in the traditional system. The antioxidant activity of MEKF was determined by the most suitable DPPH method. The most significant constituents found in MEKF are 2-cyclohexylpiperidine (0.58%), phenol, 2,4-bis(1,1-dimethylethyl)- (0.13%), 1,6-anhydro- β-d-glucopyranose (0.52%), dodecanoic acid (0.32%), 2-heptenoic acid, trimethylsilyl ester (2.84%), Tetradecanoic acid (1.87%), Neophytadiene (2.81%), Hexahydro farnesyl acetone (1.72%), Neophytadiene (0.97%), n-hexadecanoic acid (19.00%), Ethyl hexadecanoate (7.21%), Linoleic acid ethyl ester (0.23%), Phytol (4.74%), α-linolenic acid (16.73%), Ethyl (9z,12z)-9,12-octadecadienoate (2.92%), Octadecanoic acid (4.76%), Octadecanoic acid, 17-methyl-, methyl ester (1.68%), Phytol, acetate (0.15%), 2-Methylhexacosane (0.97%), Ethyl 9,12,15-octadecatrienoate (0.81%), Tetracontane (1.45%), α-tocospiro A (0.15%), α-tocospiro B (0.19%), 3.β-Acetoxystigmasta-4,6,22-triene (0.24%), Octacosane, 1-iodo (0.43%), 4,6-cholestadien-3.β-ol, benzoate (2.14%), γ.-Sitosterol (4.40%), and Tigogenin (2.32%). The found results in the analysis of the antioxidant activity of MEKF showed significant free radical scavenging capacity against DPPH-generated free radicals due to the presence of alkaloids, glycoside, terpenoids, vitamins, and some other reported compounds. In the pharmaceutical industry, GC-MS reports will be useful for identifying a wide range of phytoconstituents in polyherbal extracts and standardizing of plant materials.     

On a decoupled algorithm for solving a finite element problem for the approximation of viscoelastic fluid flow

Summary. The aim of this work is to study a decoupled algorithm of a fixed point for solving a finite element (FE) problem for the approximation of viscoelastic fluid flow obeying an Oldroyd B differential model. The interest for this algorithm lies in its applications to numerical simulation and in the cost of computing. Furthermore it is easy to bring this algorithm into play. The unknowns are the viscoelastic part of the extra stress tensor, the velocity and the pressure. We suppose that the solution is sufficiently smooth and small. The approximation of stress, velocity and pressure are resp. discontinuous, continuous, continuous FE. Upwinding needed for convection of , is made by discontinuous FE. The method consists to solve alternatively a transport equation for the stress, and a Stokes like problem for velocity and pressure. Previously, results of existence of the solution for the approximate problem and error bounds have been obtained using fixed point techniques with coupled algorithm. In this paper we show that the mapping of the decoupled fixed point algorithm is locally (in a neighbourhood of ) contracting and we obtain existence, unicity (locally) of the solution of the approximate problem and error bounds. Received July 29, 1994 / Revised version received March 13, 1995     

On the Spectrum of the Weighted p-Biharmonic Operator with Weight

In this work we give a non decreasing sequence of positive eigenvalues of the weighted p-biharmonic operator with weight and with Navier boundary conditions, then we study the simplicity and the isolation of the first positive eigenvalue. Finally, we study the one dimensional case.     

Effect of organic modifier and temperature on the resolution of betamethasone and dexamethasone using a porous graphitic carbon column: application to their identification and confirmation in human urine by LC-ESI-MS/MS

The effects of temperature, organic modifier and the type of acid on the retention factor, the resolution and peak shape of betamethasone and dexamethasone are described. The study is performed using narrow bore porous graphitic carbon (PGC) columns online with diode-array detector (DAD) and ESI MS/MS. The results show that temperature affects the retention behaviour of the two compounds and ACN yields the best separation while no effect is obtained by changing the type of organic acid. The developed method is applied for the confirmation of dexamethasone and betamethasone in human urine.     

The Optical Spectrum of Au2+

The electronic structure of the Au₂⁺ cation is essential for understanding its catalytic activity. We present the optical spectrum of mass-selected Au₂⁺ measured via photodissociation spectroscopy. Two vibrationally resolved band systems are observed in the 290–450 nm range (at ca. 440 and ca. 325 nm), which both exhibit rather irregular structure indicative of strong vibronic and spin-orbit coupling. The experimental spectra are compared to high-level quantum-chemical calculations at the CASSCF-MRCI level including spin-orbit coupling. The results demonstrate that the understanding of the electronic structure of this simple, seemingly H₂⁺-like diatomic molecular ion strictly requires multireference and relativistic treatment including spin-orbit effects. The calculations reveal that multiple electronic states contribute to each respective band system. It is shown that popular DFT methods completely fail to describe the complex vibronic pattern of this fundamental diatomic cation.     

Triggering of the Antibacterial Activity of <Emphasis Type="Italic">Bacillus subtilis</Emphasis> B38 Strain against Methicillin-Resistant <Emphasis Type="Italic">Staphylococcus aureus</Emphasis>

When cultured in minimal growth medium, the B38 strain of Bacillus subtilis did not exhibit any antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) clinical isolate. Coculturing B38 strain with viable MRSA cells weakly increased antibacterial activity production (20 AU/ml). Addition of dead MRSA cells in a B38 culture, increased by 8-fold the B. subtilis strain antibacterial activity reaching 160 AU/ml against MRSA strain. This antibacterial activity recovered from cell-free supernatants was stimulated by an autoinducing compound which is sensitive to the action of proteinase K suggesting a proteinaceous nature. This compound was heat-stable till 80 °C and showed a molecular mass around 20 kDa as determined by SDS-PAGE. These results suggest that the production of antibacterial compounds by B38 strain is dependent on the amount of the autoinducing compound.