Novel Host Compounds, 1,1′-Binaphthyl-2,2′-Dihydroxy-5,5′- and 6,6′-Dicarboxylic Acid, which Trap Guest Molecules Tightly in their Inclusion Crystals

The host compounds 1,1’-binaphthyl-2,2′-dihydroxy-5,5′-dicarboxylic acid (1) and 1,1′-binaphthyl-2,2′-dihydroxy-6,6′-dicarboxylic acid (2) have been synthesized, and their inclusion properties have been studied. Inclusion complexes formed by 1 and 2 with volatile guests such as acetone and methanol release the guests only at much higher temperatures than their boiling points. The crystal structures of the inclusion complexes have been determined from single crystal X-ray diffraction data and show different host lattices.     

Instantaneous strain recovery elasticity and endothermic heat change in nylon-6 monofilaments and silicone rubbers

The instantaneous elastic moduli for a nylon-6 monofilament were derived on strain recoveries right after creep, stress relaxation, and rapid elongation,E _c ,E _s andE _e , respectively. It was found that during strain recoveryE _s (>E _e ) andE _e increase monotonically with increasing load,m ₁, on the sample. The extrapolated value of E_s atm ₁=0 g is almost equal to Young's modulus, 4.06 GPa. The value ofE _c also increased with increasingm ₁, and atm ₁=600 g (1.93 t cm^–2) reached about 14 GPa. The endothermic heat change right after creep, stress relaxation or rapid elongation,Q, was negligibly small. For comparison,E _s ,E _c andQ were also investigated for silicone rubber. It was found thatE _s (53.8 M Pa at the draw ratioD=1.2) decreased abruptly atD=1.3. In the range ofD=1.4–1.9,E _s was only 22.6 MPa. In the case of stress relaxation,Q increased with increasingD from 4 J mol^–1 (atD=1.2) to 56 J mol^–1 (atD=1.9). FurthermoreE _c (5.58 MPa atm ₁=133.8 g (429.4 kg cm^–2)) increased gradually with increasing m₁ and attained 16.6 MPa atm ₁=548.4 g (1.76 t cm^–2). In the case of creep,Q was in the range of 0–11.5 J mol^–1 and larger when larger loads,m ₂ were removed during the later stages of creep.Dedicated to Professor Bernhard Wunderlich on the occasion of his 65th birthdayThe author wishes to thank Mr. Keizi Igarashi and Mr. Tetsuya Yasui for helping in the experiments.     

Clinical evaluation of immunoglobulin-E radioimmunoassay kit

An IgE RIA kit (Sandwich method; Dainabott), is used to obtain the following results. (1) Standard curve: Since the range of reproduction rate show 3.16-7.07% (C.V.), the curve become steep. (2) Incubations under controlled situation: Both of the incubations are controlled at 15-30 degrees C for 2 h. (3) Reproducibility test: Coefficients of variation (C.V.) of intra-assay and inter-assay variation are 2.32-3.94% and 2.92-3.92% respectively. (4) Recovery test: A result of the recovery test range between 100.1-101.7%. (5) Dilution test: Multiple dilution effects are observed. (6) Average counts of the serum IgE for the controlled and diseased groups: The average counts of the serum IgE for the controlled group, atopic diseased group, allergic rhinitis group and allergic bronchial asthma are 144.9 +/- 183.2 IU/ml, 1,099.0 +/- 2,782.4 IU/ml, 1,150.9 +/- 2,063.3 IU/ml and 600.7 +/- 686.4 IU/ml respectively. The value of the diseased groups have tendency to show higher averages than the controlled group. Since the controlled and diseased groups show wide distributions of the serum IgE level, there is no significant difference of two variations. However the diseased groups have tendency to show higher ratio of the serum IgE level in blood than the controlled groups. These basic researches are quite meaningful, because they are able to apply for a supplemental diagnosis of the atopic and parasitic disease.     

Vibrational spectra and molecular conformations of 1,5-dichloro- and 1,5-dibromopentanes and 1,6-dichloro-and 1,6-dibromohexanes

The Raman and IR spectra of 1,5-dichloro- and 1,5-dibromopentanes and 1,6-dichloro-and 1,6-dibromohexanes have been measured. The normal coordinates have been calculated for these molecules using a consistent set of force constants and the molecular conformations studied by analysing the spectra with reference to the results of the calculations. In the crystalline solid state, 1,5-dichloropentane assumes the trans-trans-trans-gauche form and 1,5-dibromopentane, 1,6-dichloro- and 1,6-dibromohexanes assume the all-trans form. The normal coordinate treatment with the well-established force field was of great help in determining the whole molecular form of the relatively large chain molecules.     

Mycosamine orientation of amphotericin B controlling interaction with ergosterol: sterol-dependent activity of conformation-restricted derivatives with an amino-carbonyl bridge

Amphotericin B (AmB 1) is known to assemble together and form an ion channel across biomembranes. The antibiotic consists of mycosamine and macrolactone moieties, whose relative geometry is speculated to be determinant for the drug's channel activity and sterol selectivity. To better understand the relationship between the amino-sugar orientation and drug's activity, we prepared conformation-restricted derivatives 2-4, in which the amino and carboxyl groups were bridged together with various lengths of alkyl chains. K+ influx assays across the lipid-bilayer membrane revealed that ergosterol selectivity was markedly different among derivatives; short-bridged derivative 2 almost lost the selectivity, while 3 showed higher ergosterol preference than AmB itself. Monte Carlo conformational analysis of 2-4 based on NOE-derived distances indicated that the amino-sugar moiety of 2 comes close to C41 because of the short bridge, whereas those of 3 and 4 are pointing outward. The mutual orientation of the amino-sugar moiety and macrolide ring is so rigid in derivatives 2 and 3 that these conformations should be unchanged upon complex formation in lipid membranes. These results strongly suggest that the large difference in sterol preference between derivatives 2 and 3 is ascribed to the different orientation of amino-sugar moieties. These findings allowed us to propose a simple model accounting for AmB-sterol interactions, in which hydrogen bonding between 2'-OH of AmB and 3beta-OH of ergosterol plays an important role.     

Quantitative analysis of hyaluronic acid by high-performance liquid chromatography of streptomyces hyaluronidase digests

The separation and quantitative analysis of streptomyces hyaluronidase ( HAase ) degradation products of hyaluronic acid (HA) by high-performance liquid chromatography are described. The substituted 4,5-unsaturated tetrasaccharide and hexasaccharide which result from the digestion of HA are quickly separated on a silica gel (Zorbax SIL) column. The assay of HA is linear between 5 and 250 micrograms of HA. This procedure is suitable for some weakly acidic glycosaminoglycan contaminants having similar properties to those of HA.     

Ni-catalyzed alkylative dimerization of vinyl grignard reagents using alkyl fluorides

Alkyl halides underwent unique cross-coupling reaction with vinylmagnesium chloride in the presence of Ni catalyst to give 2-alkyl-3-butenyl Grignard reagent (1) in high yields. This reaction proceeded efficiently at 25 degrees C in THF using primary and secondary alkyl fluorides. On the other hand, PhCH=CHMgBr gave double alkylative vinyl coupling product 4 in good yield as the sole coupling product. Alkyl fluorides react as the most suitable alkylating reagent in comparison to the corresponding chlorides, bromides, and iodides.     

Multiplex amplified product-length polymorphism analysis of 36 mitochondrial single-nucleotide polymorphisms for haplogrouping of East Asian populations

We present a reliable, rapid, and economical multiplex amplified product-length polymorphism (APLP) method for analyzing the haplogroup-diagnostic mitochondrial single-nucleotide polymorphisms (mtSNPs) in East Asian populations. By examining only 36 haplogroup-specific mtSNPs in the coding region by using four 9-multiplex polymerase chain reaction (PCR) and subsequent electrophoresis, we could safely assign 1815 individuals from 8 populations of Japanese, Korean, Chinese, and Germans to 45 relevant haplogroups. This multiplex APLP analysis of coding-region mtSNPs for haplogrouping is especially useful not only for molecular phylogenetic studies but also for large-scale association studies due to its rapid and economical nature. This is the first panel of mtSNPs in the coding region to be used for haplogrouping of East Asian populations.     

Adsorption mechanism of polylysine on hydroxyapatite and its effect on dissolution properties of hydroxyapatite

Adsorbed amounts of poly-l-lysine (pLys) and bromide ion on hydroxyapatite (HAp) from aqueous solutions of poly-l-lysine hydrobromide, and amounts of calcium and phosphate ions liberated concurrently from HAp during the adsorption of pLys were determined at 25 degrees . The pLys was adsorbed on HAp by the mechanism of ion-exchange between its amino groups and calcium ions of HAp. The released amount of calcium ion increased, therefore, with the adsorbed amount of pLys. On the other hand, the released amount of phosphate ion first decreased and then increased after attaining a minimum with the equilibrium concentration of pLys. The analysis using an equilibrium dialysis method revealed that the released phosphate ions were mainly in the bound state to the amino groups of pLys remaining in the solution, and that the concentrations of calcium and phosphate ions free from both HAp and pLys were restricted by each other under the law of the solubility product of HAp. The first decrease in the released amount of phosphate ion was concluded to be attributed primarily to the increase in the released amount of calcium ion because pLys remaining in the solution was little in this region. When sodium hydroxide was added to the solution, the adsorbed amount of pLys increased and then slightly decreased with the equilibrium pH of the solution due to the increase or decrease of the electrostatic attractive force between the adsorbate and the adsorbent. However, conformational change in pLys around pH 10 seemed to have little effect on the adsorption.     

Characterization of an avidin-bonded column for direct injection in reversed-phase high-performance liquid chromatography

An automatic method for the determination of metabolites of Ropivacaine in urine was set up. It utilizes supported liquid membrane extraction for sample clean-up and enrichment, followed by ion-pair chromatography determination using UV detection. The extraction was very selective with no observed interfering compounds from the urine matrix, permitting simple isocratic chromatographic analysis. The detection limits for spiked urine samples were 2–18 nM for the different compounds. The repeatability was 1–3% (RSD) with an internal standard that was also extracted, and about twice without this standard. A throughput of 3.3 samples per hour was achieved and the liquid membrane was stable for more than a week.