Physicochemical analyses of phase transition and dehydration processes of a new oral 1beta-methylcarbapenem antibiotic agent,CS-834

The characterizations of the anhydrate (A-form), monohydrate (B1-form), and dihydrate (B2-form) of CS-834 were investigated by powder X-ray diffraction, differential scanning calorimetry (DSC), thermogravimetry-differential thermal analysis (TG-DTA), infrared spectroscopy, and Karl Fischer moisture titration. The typical DSC curve of the B2-form showed five endothermic peaks at 35.0, 46.4, 56.2, 99.2, and 190.4 degrees C and an exothermic peak at 123.4 degrees C. In TG-DTA analysis, the three peaks at 35.0, 46.4, and 56.2 degrees C had a total weight loss of 7.3%, corresponding to the release of two water molecules. From morphological observation under thermomicroscopy, the endothermic peak at 99.2 degrees C was attributed to the melting of the dehydrous crystals (B0-form) and the exothermic peak at 123.4 degrees C to the recrystallization to the A-form crystals. The endothermic peak at 190.4 degrees C was due to the melting of the A-form crystals. After incubation for 6.0 h at 35, 50, 60, and 80 degrees C, the powder X-ray diffraction patterns of the B2-form indicated that it was converted into the A-form via the B1-form and B0-form. Thus CS-834 exists in homologous hydrous crystal forms in multiple-phase transformations with the dehydration of two water molecules.     

Hydrogen-bonded charge-transfer complexes of TTF containing a uracil moiety: crystal structures and electronic properties of the hydrogen cyananilate and TCNQ complexes

[structure: see text] A novel TTF-based donor with a uracil moiety, TTF-(1-n-butyluracil-5-yl) (TnbU), was synthesized. Crystal structures of both TnbU and the charge-transfer complex of TnbU-hydrogen cyananilate possess complementary double hydrogen bonds through uracil moieties and pi-stacking dimer structures between TTF skeletons. Furthermore, the TnbU-TCNQ charge-transfer complex shows a high electrical conductivity underlying the partial charge-transfer accompanied by a hydrogen-bonding interaction, which was substantiated in terms of the measurements of the IR, electronic spectra, and conductivity.     

CONFIGURATIONS OF CAROTENOIDS IN THE REACTION CENTER and THE LIGHT-HARVESTING COMPLEX OF Rhodospirillum rubrum. NATURAL SELECTION OF CAROTENOID CONFIGURATIONS BY PIGMENT PROTEIN COMPLEXES

Abstract— Carotenoids extracted from the reaction center (RC), the light-harvesting complex (LH), and the chromatophore membrane of Rhodospirillum rubrum SI were analyzed by high-performance liquid chromatography. The chemical structures and the configurations of major components were determined by means of mass, Raman, electronic absorption and ¹H-NMR spectroscopy. The results indicated: (1) 15- cis -spirilloxanthin is bound to RC; (2) both all-frans-spirilloxanthin and aII-(ran.s-3,4-dihydrospirilloxanthin are bound to LH and (3) 13-cK-spirilloxanthin is additionally present in the chromatophore membrane. The natural selection of the carotenoid configurations, i.e. 15-ris by RC and aW-trans by LH, is discussed in relation to the physiological functions and the photophysical properties of isomeric carotenoids.     

Palladium-catalyzed asymmetric amination and imidation of 2,3-allenyl phosphates

[reaction: see text] Asymmetric amination of 2,3-allenyl phosphates with nitrogen nucleophiles such as amines, hydroxylamines, and imides can be performed efficiently using a combination of zerovalent palladium complexes and SEGPHOS or MeOBIPHEP ligand, affording the corresponding optically active 1-aminated derivatives with enantiomeric excess of up to 97% ee.     

Electroweak interactions at an infinite sublayer quark level. III.CP violation

In a previous paper we proposed the infinite sublayer quark model, in which there exists an infinite number of quarksu and antiquarksu ^c at an infinite sublayer level. By applying the standard model of the electroweak interactions to the weak isospin doublets (u _L ,u _L ^cp ) ^T and (u _L ,u _L ^ct ) ^T , it is shown that there exists only one phase factor, which causesCP violation.     

Regional distributions of manganese,iron, copper,and zinc in the brains of 6-hydroxydopamine-induced parkinsonian rats

Time courses of changes in manganese, iron, copper, and zinc concentrations were examined in regions of the brain of a 6-hydroxydopamine (6-OHDA)-induced rat model of Parkinson’s disease using inductively coupled plasma mass spectrometry (ICP-MS). The concentrations were simultaneously determined in brain section at the level of the substantia nigra 1, 3, 7, 10, 14, and 21 days after the 6-OHDA treatment and compared with those of control rats. The distributions of these elements were obtained for 18 regions of the sagittal section (1-mm thick). The ICP-MS results indicated that Mn, Fe, Cu, and Zn levels of the 6-OHDA-induced parkinsonian brain were observed to increase in all regions that lay along the dopaminergic pathway. In the substantia nigra, the increase in Mn level occurred rapidly from 3 to 7 days and preceded those in the other elements, reaching a plateau in the 6-OHDA brain. Iron and Zn levels increased gradually until 7 days and then increased rapidly from 7 to 10 days. The increase in the copper level was slightly delayed. In other regions, such as the globus pallidus, putamen, and amygdala, the levels of Mn, Fe, Cu, and Zn increased with time after 6-OHDA treatment, although the time courses of their changes were region-specific. These findings contribute to our understanding of the roles of Mn and Fe in the induction of neurological symptoms and progressive loss of dopaminergic neurons in the development of Parkinson’s disease. Manganese may hold the key to disturbing cellular Fe homeostasis and accelerating Fe levels, which play the most important role in the development of Parkinson’s disease.     

Preparation of phthalocyanines with eight benzylchalcogeno substituents from 5,6-dibromo-4,7-diethylbenzo[1,2,3]trichalcogenoles

Benzo[1,2,3]trichalcogenoles with two bromine atoms on the benzene ring, 5,6-dibromo-4,7-diethylbenzo[1,2,3]trichalcogenoles (1a) and (1b) (chalcogen: 1a = S; 1b = Se), were first prepared by treating 2,3,5,6-tetrabromo-1,4-diethylbenzene (TBDEB) with elemental sulfur or amorphous selenium in DBU at 140 degrees C (for 1a) and 100 degrees C (for 1b) for 24 h. The structures of 1a and 1b were verified by NMR spectroscopy, mass spectrometry, and elemental analysis. X-ray crystallographic analysis ultimately showed that the substitution reactions of TBDEB proceeded at the two adjacent bromine atoms. To apply 1a and 1b to construction of phthalocyanine derivatives with sulfur or selenium functional groups, 4,5-bis(benzylchalcogeno)-3,6-diethylphthalonitriles (5a) and (5b) as key intermediates were prepared by way of introduction of alkyl groups (2-cyanoethyl or 4-nitrophenethyl groups) on two chalcogen atoms, substitution of two bromine atoms with nitrile groups, and subsequent exchange of alkyl groups with benzyl groups. Compound 5a was treated with lithium in n-pentanol at 100 degrees C for 1 h to produce 2,3,9,10,16,17,23,24-octakis(benzylthio)-1,4,8,11,15,18,22,25-octaethylphthalocyanine (6a). A similar treatment of 5b in n-hexanol at 100 degrees C for 2 h gave phthalocyanine 6b. The structures of 6a and 6b were determined by (1)H NMR spectroscopy and MALDI-TOFMS. X-ray crystallographic analysis of 6a was also performed. The Q-band absorptions (lambda(max)) for 6a and 6b in UV-vis spectra were observed at 755 nm (log epsilon = 5.1) and 757 nm (log epsilon = 5.1), respectively, and their electrochemical properties were verified by cyclic voltammetry in dichloromethane with Ag/AgNO(3) as a reference electrode. Compounds 6a and 6b were further treated with lithium in THF/NH(3) at -78 degrees C and then with dibutyltin dichloride to produce phthalocyanine derivatives 8a and 8b with four dichalcogenastannole rings by way of octachalcogenate phthalocyanines 7a and 7b.     

Nucleoside analogs. I. A synthesis of 1,3-dihydroxy-2-(6-substituted-9-purinyl)cyclohexane

Biologically active 1,3-dihydroxy-2-(6-substituted-9-purinyl)cyclohexanes (VI-X) were prepared by a reaction between trans-2-amino-1,3-cyclohexanediol (I) and 4,6-dichloro-5-amino-pyrimidine (II), followed by cyclization and nucleophilic substitution. Compounds VI and VII showed a weak inhibitory effect against Xanthomonas oryzae, a pathogenic bacteria of leaf blight of rice plant.     

Synthesis of oligodeoxyribonucleotides containing hydroxymethylphosphonate bonds in the phosphoramidite method and their hybridization properties

A set of diastereomeric TpT phosphoramidite building blocks, 1-f and 1-s, containing an alkaline-labile hydroxymethylphosphonate (HMP) linkage were synthesized. Dodecadeoxynucleotides incorporating the HMP bond were also synthesized by use of each stereochemically pure dimer block under mild conditions in the N-unprotected phosphoramidite method. Moreover, it turned out that HMP-oligonucleotides derived from a fast-eluted dimer block exhibit higher affinity for DNA single and double strands than those containing a slow-eluted one.