Biosynthesis and metabolism of abscisic acid and related compounds

This review describes research on the chemistry (biosynthesis, metabolism and synthetic analogs) of a plant hormone, abscisic acid (ABA), covering 1970 to 2002 with 123 references     

Determination of traces of gallium and indium in ores by electrothermal-atomization atomic absorption spectrometry with matrix modifications

Methods were developed for the determination of gallium and indium in complex ores by electrothermal-atomization atomic absorption Spectrometry using matrix modifications. Nickel and nickel-ammonium sulfate as matrix modifier has enhanced the absorption signals for gallium and indium, respectively, eliminating the matrix interferences to allow their solutions in nitric acid to be used as calibration standards. No matrix separations are necessary. Results are quoted for a variety of black ore samples (Kuroko). The RSDs are 7.0% for gallium and 5.3% for indium at their 10 g/g levels, and the inverse sensitivities are 20 pg of gallium and 38 pg of indium for respective 1% absorption.     

Synthesis,structure revision,and absolute configuration of (+)-didemniserinolipid B,a serinol marine natural product from a tunicate Didemnum sp

[structure: see text] En route to proving the absolute and relative stereochemistry, through synthesis, of (+)-didemniserinolipid B (1), the first natural serinolipid isolated from a tunicate Didemnum sp., it was discovered that the isolated natural product was in fact the 31-sulfate configured 8R,9R,10R,13S,30S. This structural reassignment was only possible after the development of a microwave-assisted method for the sulfation of unreactive hydroxyl groups.     

Preparation of ternary platinum(II) complexes with N-(omega-phenylalkyl)-1,2-ethanediamine and 2,2'-dipyridine and the effect of the methylene chain length of the N-(omega-phenylalkyl)-1,2-ethanediamine in the complexes on intermolecular interactions with various arylsulfonates

A series of ternary complexes comprised of platinum(II), 2,2'-dipyridine, and N-(omega-phenylalkyl)-1,2-ethanediamine was prepared by varying the number (n) of methylene chain carbons between the phenyl group and one of the amino groups of 1,2-ethanediamine. NMR measurements indicated that intramolecular stacking occurred for n=1 and intermolecular stacking occurred for n=3 for several of the aryl sulfonates.     

Catalytic Reduction of Molecular Dinitrogen to Ammonia and Hydrazine Using Vanadium Complexes

Newly designed and prepared vanadium complexes bearing anionic pyrrole‐based PNP‐type pincer and aryloxy ligands were found to work as effective catalysts for the direct conversion of molecular dinitrogen into ammonia and hydrazine under mild reaction conditions. This is the first successful example of vanadium‐catalyzed dinitrogen reduction under mild reaction conditions.     

Dispersion of acid-treated carbon nanofibers into gel matrices prepared by the sol-gel method

1-Naphthol has been used as an in-situ fluorescent probe to characterize the dispersibility of carbon nanofibers (CNFs) into the sol-gel matrix of silicon alkoxide. The ion-pair fluorescence of 1-naphthol was found in the gel dispersing acid-treated CNFs instead of 1Lb fluorescence, which was preferred in the low polar gel matrix. This indicates that 1-naphthol easily interacts with oxidized groups present on the surface of the acid-treated CNFs due to the high dispersibility of the CNFs into the gel matrix. The oxidized groups on the CNF surface are useful for preventing self-assembly and/or aggregation of the CNFs in the gel matrix.     

X-ray structure of the delta-cyclodextrin complex with cycloundecanone

The crystal structure of the delta-cyclodextrin complex with cycloundecanone shows a channel-type structure consisting of head-to-head dimer units that include four guest molecules.     

Direct measurement of mass fragmentograms for eluents from a micro-liquid chromatograph using an improved nebulizing interface

An improved vacuum nebulizing interface with a very short counter nozzle was developed for direct coupling of a micro-LC and a quadrupole MS with CI-chamber. With the LC-MS system using the nebulizing interface, it became possible to take mass fragmentograms for various less volatile compounds such as glutamic acid, steroids, aromatic amines and chlorine-containing insecticides.