A mild procedure for the oxidative cleavage of substituted indoles catalyzed by plant cell cultures

We have developed a novel procedure for the oxidative cleavage of indole carbon double bonds in the presence of H₂O₂ using plant cell cultures as a catalytic system. The oxidative procedure has some advantages, such as mild reactions, good yields, easy work-up and safety.     

Effect of anisotropy on acoustoelastic birefringence in wood

The ultrasonic velocity of shear waves propagating through radial direction of a wood plate specimen, transversely to the loading direction, was measured. By rotating an ultrasonic sensor, the oscillation direction of the shear waves was varied with respect to the wood plate axis and loading direction. The relationship between shear wave velocity and oscillation direction was examined to discuss the effect of anisotropy on the acoustoelastic birefringence in wood. The results obtained were summarized as follows. When the oscillation direction of the shear wave corresponded to the tangential direction of the wood specimen regardless of the stress direction, shear wave velocity decreased markedly and the relationship between shear wave velocity and rotation angle tended to become discontinuous. That is, when the shear waves oscillated in the anisotropic axis of the wood, the shear wave velocity peaked unlike in the case of oscillation in the stress direction. In an isotropic material (acrylic, aluminum 5052), on the contrary, when the shear waves oscillated in the stress direction of the specimen, the shear wave velocity peaked regardless of the main-axis direction of the specimen. On the basis of the discussion of these results, the ultrasonic shear wave propagating in wood under stress is confirmed to be polarized in the anisotropic axis of the wood.     

Preparation of petaloid microspheres of basic magnesium carbonate

The synthesis of basic magnesium carbonate was examined under ultrasonic irradiation and was performed by the soda ash method using magnesium sulfate and sodium carbonate as starting materials. The particulate product was evaluated using SEM observations. Ultrasonic irradiation in the preparation of basic magnesium carbonate was found to give fine petaloid microspheres of about 3 mum in primary particle size.     

Simultaneous determination of NG‐monomethyl‐l‐arginine,NG,NG‐dimethyl‐l‐arginine,NG,NG′‐dimethyl‐l‐arginine,and l‐arginine using monolithic silica disk‐packed spin columns and a monolithic silica column

We have developed and validated a high‐performance liquid chromatography method that uses monolithic silica disk‐packed spin columns and a monolithic silica column for the simultaneous determination of N^G‐monomethyl‐l ‐arginine, N^G,N^G‐dimethyl‐l ‐arginine, and N^G,N^G′‐dimethyl‐l ‐arginine in human plasma. For solid‐phase extraction, our method employs a centrifugal spin column packed with monolithic silica bonded to propyl benzenesulfonic acid as a cation exchanger. After pretreatment, the methylated arginines are converted to fluorescent derivatives with 4‐fluoro‐7‐nitro‐2,1,3‐benzoxadiazole, and then the derivatives are separated on a monolithic silica column. l ‐Arginine concentration was also determined in diluted samples. Standard calibration curves revealed that the assay was linear in the concentration range 0.2–1.0 μM for methylated arginines and 40–200 μM for l ‐arginine. Linear regression of the calibration curve yielded equations with correlation coefficients of 0.999 (r²). The sensitivity was satisfactory, with a limit of detection ranging from 3.75 to 9.0 fmol for all four compounds. The RSDs were 4.3–4.8% (intraday) and 3.0–6.8% (interday). When this method was applied to samples from six healthy donors, the detected concentrations of N^G‐monomethyl‐l ‐arginine, N^G,N^G‐dimethyl‐l ‐arginine, N^G,N^G′‐dimethyl‐l ‐arginine and l ‐arginine were 0.05 ± 0.01, 0.41 ± 0.07, 0.59 ± 0.11, and 83.8 ± 30.43 μM (n = 6), respectively.     

Chemical composition of sediments from marine shallow-water hydrothermal mounds in Wakamiko submarine crater revealed by multiple prompt gamma-ray analysis

Multiple prompt gamma-ray analysis (MPGA), a new radionuclide quantification method with high energy resolution, was applied to sediments from a marine shallow-water hydrothermal mound. Surface sediments around mounds were collected from the Wakamiko submarine crater located in Kagoshima Bay, southwest Japan, where the hydrothermal system was different from those at other marine shallow-water hydrothermal mounds. All samples were desalted and MPGA measurements were performed for 4,500?s (real time). Event data were obtained using eight Canberra-Eurisys CLOVER Ge detectors. The size of the list data that included all multiple events was from 1.19 to 19.2?GB. We could obtain concentrations of ³²S, ⁵⁵Mn, ⁷⁵As, ¹⁵⁷Gd, ³⁹K, ¹⁴⁹Sm, ⁵⁶Fe, and ⁸⁵Rb with high sensitivity by MPGA. Furthermore, ³²S, ⁸⁵Rb, and ⁵⁵Mn have characteristic concentrations only at a mound, not at control sampling sites, suggesting that sediments were sulfurated by magmatic fluids at this mound.     

Stereospecific,photochemical rearrangement of 1,1′-spirobiindene and 1,1′-spirobi[benzindene]S

The photochemical rearrangement, of optically active 3,3′-di-t-butyl-1,1?spirobiindene and ?1,1′-spirobi[benzindene]s afforded, respectively, 5,7-di-t-butylbenzo[c]fluorene and its dibenzo derivatives with high stereospecificity.     

FTIR Spectral Study of Intramolecular Hydrogen Bonding in Thromboxane A2 Receptor Antagonist S-145 and Related Compounds. Part 4

Abstract

An N-methylated compound of S-145, (±)-(5Z)-7-[3-endo-[N-methyl)phenylsulphonyl)amino]bicyclo [2.2.1]hept-2-exo-yl]heptenoic acid 1, its chain analogue 12-[N-methyl(phenylsulphonyl)amino]dodecanoic acid 3, (±)-(5Z)-7-[3-endo-(benzoylamino)bicyclo[2.2.1]hept-2-exo-yl] heptenoic acid 5 and related compounds were synthesized in order to study the formation of a new class of intramolecular hydrogen bond IX (cis-CO₂H…O = Y). Their FTIR spectra were measured in dilute CCl₄ solution and subjected to curve analysis in order to separate overlapping absorption bands. For compounds 1,3 and 5, the intramolecular hydrogen bonds of the IX type involving 14-, 17- and 14-membered rings were found between a carboxyl group, which takes a cis-structure IV, and an oxygen atom of a sulphonyl or benzoylamino group, respectively. The C[dbnd]O stretching vibration bands of these carboxyl groups shifted to lower wavenumbers (ca. 19 cm^?1). The direction of these shifts was contrary to that found for α-keto and α-alkoxycarboxylic acids in which carboxyl groups take a trans-structure III due to the formation of intramolecular hydrogen bonds I and II, respectively.     

Effect of spiroconjugation on the UV and CD spectra of 1,1′-spirobiindene

U.v. and c.d. spectra of 1,1′-spirobiindene were theoretically explained based on the composite molecule method. The effect of spiroconjugation was shown to appear markedly in the ¹L_a region of indene, making a large splitting of this band, as was expected from PE spectra.     

Thermodynamic Study on Vesicle Formation and Adsorption of Decyltrimethylammonium Decyl Sulfate

The surface tension of an aqueous solution of decyltrimethylammonium decyl sulfate (DeTADeS) was measured as a function of temperature T at various molalities &mcirc; under atmospheric pressure. DeTADeS has been found to form equilibrium multilamellar vesicles (MLV) spontaneously. The surface density, the entropies of adsorption, and the entropy of vesicle formation are evaluated. The mechanism of formation of equilibrium vesicles is investigated from the standpoint of thermodynamics and from the comparison of the results with those of the micelle-forming systems. From the relatively small change of the surface density Gamma;(H) on T at a given &mcirc;, the adsorbed film is implied to be tightly packed due to the strong electrostatic attraction between the polar headgroups. The energy change associated with adsorption from the vesicular state per mole of surfactant Delta(V)(H)u is positive in the entire temperature range; thus, the curved bilayer in MLV is energetically more favorable than the planar adsorbed film. From the negative values of the entropy of vesicle formation Delta(W)(V)s, it is concluded that vesicle formation is driven by enthalpy whereas micelle formation is mostly entropy driven. Copyright 2001 Academic Press.