Chiral Assemblies of Planar and Achiral meta-Arylene Ethynylene Macrocycles Induced by Saccharide Recognition.

We created chiral assemblies of planar and achiral macrocycles by saccharide recognition. To achieve this, we synthesized stackable meta-arylene ethynylene macrocycles consisting of pyridine-acetylene-phenol and pyridine-acetylene-aniline units. 1H NMR, absorption, and fluorescence emission spectroscopy indicated that these macrocycles formed 1:1 and 2:1 complexes with lipophilic alkyl glycosides. The 2:1 complex of the pyridine-acetylene-phenol macrocycle showed induced circular dichroism (ICD) bands, meaning that two achiral macrocycles are arranged in an asymmetrically twisted manner. CD spectroscopy revealed that the helical sense was affected by the chirality of guest saccharides. On the other hand, strong CD bands were observed after solid-liquid extraction of native saccharides into lipophilic solvents using the pyridine-acetylene-aniline macrocycle.

Saccharide Recognition by a Three-Arm-Shaped Host Having Preorganized Three-Dimensional Hydrogen-Bonding Sites.

Generally, cage-shaped hosts for saccharides can bind strongly to guest molecules because of the three-dimensional preorganized hydrogen-bonding sites. However, the preparation of cage molecules is often difficult because of the low yield of the macrocyclization step. Here, we report a three-arm-shaped molecule possessing pyridine-acetylene-phenol units as a new kind of host having a preorganized three-dimensional hydrogen-bonding site. This three-arm-shaped host was readily prepared compared to a cage-shaped analogue. This host associated with lipophilic glycosides to form chiral complexes, and the association constants were sufficiently high as to be comparable to those of the cage-shaped analogue. Furthermore, this host extracted native monosaccharides into a lipophilic solvent.

Preferential Recognition and Extraction to Pentoses over Hexoses by a D6h-Symmetrical Ethynylphenol Macrocycle with Six Inner Phenolic Hydroxy Groups.

A macrocycle consisting of six ethynylphenol units was developed as a host architecture for saccharides. The rigid framework of the macrocycle suppressed the intramolecular hydrogen-bonding between adjacent phenolic hydroxy groups and recognized saccharides by intermolecular hydrogen-bonding within the hole. The well-defined hydrogen-bonding sites enabled the size-selective guest recognition and showed preference to pentoses over hexoses.

Observation of Circularly Polarized Luminescence of the Excimer from Two Perylene Cores in the Form of [4]Rotaxane.

A perylene-based [4]rotaxane was synthesized by the Sonogashira coupling of the 2:2 inclusion complex consisting of two alkynylperylenes and two γ-cyclodextrins with terphenyl-type stopper molecules. The [4]rotaxane showed orange emission attributable to the spatially restricted alkynylperylene excimer with a high fluorescence quantum yield of Φf =0.15. The excimer emission was circularly polarized as a result of the asymmetrically twisted perylene pair under the influence of chirality of γ-cyclodextrin. The glum value of the excimer emission was determined to be -2.1×10-2 at 573 nm, as large as those of the corresponding known pyrene-based series. This is the first example, in which circularly polarized luminescence was clearly observed from the excimer of a pair of perylene cores.

Nonplanar Macrocycle Consisting of Four Pyridine and Phenol Units Connected with Acetylene Bonds Displaying Preferential Binding to Maltoside over Monosaccharides.

A nonplanar macrocycle consisting of four pyridine-acetylene-phenol units was developed as a host for saccharide guest molecules. The macrocycle was found to strongly associate with a lipophilic maltose derivative, with an association constant of 107 M-1, over monosaccharide derivatives, for which much smaller association constants were determined, ranging from 103 M-1 to 104 M-1. The macrocycle was found to adopt a boat-like conformation, encapsulating ß-d-maltoside in a twisted manner through approximately seven intermolecular hydrogen bonds.

Spontaneous Helix Formation of " meta"-Ethynylphenol Oligomers by Sequential Intramolecular Hydrogen Bonding inside the Cavities.

Phenol-based oligomers linked with acetylenes at their meta positions, " meta"-ethynylphenol oligomers, were developed as a synthetic helical foldamer. The architecturally simple oligomers spontaneously formed helical higher-order structures by sequential intramolecular hydrogen bonds through the multiple phenolic hydroxy groups inside the cavities. The hydrogen bonds forced C-C≡C-C bond angles to largely bend toward the inside. Addition of chiral amines caused the helices to be chiral by electrostatic interactions between the resulting chiral ammonium cations and the phenolate anions.

D3h -Symmetrical Shape-Persistent Macrocycles Consisting of Pyridine-Acetylene-Phenol Conjugates as an Efficient Host Architecture for Saccharide Recognition.

Hexagonal shape-persistent macrocycles (SPMs) consisting of three pyridine and three phenol rings linked with acetylene bonds were developed as a preorganized host for saccharide recognition by push-pull-type hydrogen bonding. Three tert-butyl or 2,4,6-triisopropylphenyl substituents were introduced on the host to suppress self-aggregation by steric hindrance. In spite of the simple architecture, association constants Ka of the host with alkyl glycoside guests reached the order of 106 m-1 on the basis of UV/Vis titration experiments. This glycoside recognition was much stronger than that in the cases of acyclic equivalent hosts because of the entropic advantage brought by preorganization of the hydrogen-bonding sites. Solid-liquid extraction and liquid-liquid transport through a liquid membrane were demonstrated by using native saccharides, and much preference to mannose was observed.

Native Mannose-Dominant Extraction by Pyridine-Phenol Alternating Oligomers Having an Extremely Efficient Repeating Motif of Hydrogen-Bonding Acceptors and Donors.

Pyridine-phenol alternating oligomers in which pyridine and phenol moieties are alternatingly linked through acetylene bonds at the 2,6-positions of the aromatic rings were designed and synthesized. The pyridine nitrogen atom and the neighboring phenolic hydroxyl group were oriented so that they do not form an intramolecular hydrogen bond but cooperatively act as hydrogen-bonding acceptor and donor in a push-pull fashion for the hydroxyl group of saccharides. The longer oligomer strongly bound to lipophilic glycosides in 1,2-dichloroethane, and association constants approached 10(8) M(-1) . Moreover, the oligomer extracted native saccharides from a solid phase to apolar organic solvents up to the extent of an equal amount of the oligomer and showed mannose-dominant extraction among naturally abundant hexoses. The oligomer bound to native saccharides even in 20 % DMSO-containing 1,2-dichloroethane and exhibited association constants of greater than 10 M(-1) for D-mannose and D-glucose.

Water-Soluble Rotaxane-Type Porphyrin Dyes as a Highly Membrane-Permeable and Durable Photosensitizer Suitable for Photodynamic Therapy.

Porphyrins have emerged as highly effective photosensitizers in the field of photodynamic therapy (PDT) because of their high singlet oxygen generation efficiency. However, most porphyrin derivatives do not have adequate water solubility and cell membrane permeability suitable for use in PDT. In addition, they frequently suffer from low durability under photoirradiation. Here, we propose rotaxane-type photosensitizers, in which a porphyrin axle is irreversibly encapsulated within cyclodextrins (CDs), to overcome the drawbacks of porphyrins for PDT. The rotaxane-type photosensitizers were synthesized in high yields by employing a cooperative capture strategy. The CD derivatives worked as a transparent shell to impart a porphyrin axle not only with water solubility but also with photostability. These rotaxanes showed higher cell membrane permeability and photoinduced cytotoxic abilities than talaporfin sodium, presently used as a clinical photosensitizer. The rotaxane-based photosensitizer could have potential for being ideal PDT drugs.

Concentration- and time-dependent eccentric changes in circular dichroism of saccharide-linked ethynylpyridine oligomer with copper(II) ions.

We studied the preparation and circular dichroism (CD) behavior of 2,6-pyridylene ethynylene octameric oligomer linked to a ß-d-glucoside moiety with a C20-alkylene chain. The addition of Cu(OTf)(2) salt led to a remarkable enhancement of the first CD band of the oligomer, and an unexpected concentration and time dependency were observed. For example, when 1.0 × 10(-3) M of Cu(OTf)(2) was added to a 1,2-dichloroethane solution of the oligomer (5.0 × 10(-4) M, unit concentration), the CD band appeared in the positive at first and gradually inverted into the negative with time.

Freshly isolated retinal capillaries to determine efflux transporter function at the inner BRB.

Since it has been known that in vitro cell lines for analyzing drug transport at the inner blood-retinal barrier (BRB) do not completely retain several in vivo functions, new ex vivo/in vitro methods to evaluate drug transport across the inner BRB help us understand the role of this barrier in maintaining the homeostasis of vision and regulating drug distribution to the retina. To expand the limitations of existing in vitro approaches, we established a protocol to isolate fresh rat retinal capillaries as ex vivo model of the inner BRB. Fresh retinal capillaries were prepared by applying serial filtration steps and using density gradient centrifugation. We performed mRNA and protein analyses by reverse transcription-polymerase chain reaction and immunostaining that indicated expression of marker proteins such as facilitative glucose transporter 1 and claudin-5 in freshly isolated rat retinal capillaries. We also used fluorescent transporter substrates to characterize functional activity of organic anion transporter (Oat) 3, P-glycoprotein (P-gp), breast cancer resistance protein (Bcrp), and multidrug resistance-associated protein (Mrp) 4 in isolated retinal capillaries. Capillary luminal accumulation of fluorescent substrates of P-glycoprotein and Bcrp was decreased in the presence of transporter inhibitors. Moreover, luminal accumulation of the Oat3 and Mrp4 substrate, 8-(2-[fluoresceinyl]aminoethylthio) adenosine-3',5'-cyclic monophosphate (8-[fluo]-cAMP), was reduced by substrates/inhibitors of Oat3 and Mrp4. In conclusion, our study shows that freshly isolated retinal capillaries retain marker protein expression and transporter functional activity. It is suggested that isolated retinal capillaries are a useful tool to study transport across the inner BRB. Using freshly isolated retinal capillaries, we anticipate applying this approach to determine the role of transporters at the inner BRB during pathophysiological states of the eye and evaluate the drug delivery to the retina.

A Pyridine-Acetylene-Aniline Oligomer: Saccharide Recognition and Influence of this Recognition Array on the Activity as Acylation Catalyst.

In order to create new functions of foldamer-type hosts, various kinds of recognition arrays are expected to be developed. Here, a pyridine-acetylene-aniline unit is presented as a new class of a saccharide recognition array. The conformational stabilities of this array were analyzed by DFT calculation, and suggested that a pyridine-acetylene-aniline oligomer tends to form a helical structure. An oligomer of this array was synthesized, and its association for octyl ß-D-glucopyranoside was confirmed by 1 H NMR measurements. UV/Vis, circular dichroism, and fluorescence titration experiments revealed its high affinity for octyl glycosides in apolar solvents (Ka =104 to 105  M-1 ). This oligomer was relatively stable under basic conditions, and therefore this array was expected to be applied to the derivatization of saccharides. A 4-(dialkylamino)pyridine attached pyridine-acetylene-aniline oligomer proved to catalyze the acylation of the octyl glucoside.

Single-nucleotide polymorphism analysis of the multidrug resistance protein 3 gene for the detection of clinical progression in Japanese patients with primary biliary cirrhosis.

UNLABELLED: Primary biliary cirrhosis (PBC) is a multifactorial disease in which genetic factors rather than environmental factors may predominantly contribute to the pathogenesis. In order to identify the genetic determinants of the disease severity and progression of PBC, we examined an association of seven tag single-nucleotide polymorphisms (SNPs) in the multidrug resistance protein 3 (MDR3/ABCB4) gene in 148 Japanese PBC patients and 150 age- and sex-matched healthy control subjects. SNPs were detected via polymerase chain reaction (PCR) restriction fragment length polymorphism and PCR direct DNA sequencing methods. Subsequently, haplotypes were constructed from three tag SNPs (rs31658, rs31672, and rs1149222) that were significantly associated with progression of PBC. Logistic regression analyses revealed that a Hap 2 haplotype and its homozygous diplotype, Hap 2/Hap 2, in MDR3 were closely associated with the susceptibility to jaundice-type progression of PBC [P = 0.004, odds ratio (OR) 3.93, 95% confidence interval (CI) 1.56-9.90 and P = 0.0003, OR 17.73, 95% CI 3.77-83.42, respectively]. Conversely, another haplotype, Hap 1, and its homozygous diplotype, Hap 1/Hap 1, were associated with the insusceptibility to the progression to late-stage PBC (P = 0.021, OR 0.55, 95% CI 0.33-0.91 and P = 0.011, OR 0.24, 95% CI 0.08-0.71, respectively). CONCLUSION: The present study is the first report of an association of MDR3 haplotypes and diplotypes with progression of PBC. The Hap 2/Hap 2 diplotype in MDR3 could therefore be potentially applied to DNA-based diagnosis in Japanese patients with PBC as a strong genetic biomarker for predicting the progression and prognosis of PBC.

Enantioselective Solid-Liquid Extraction of Native Saccharides with Chiral BINOL-Based Pyridine-Phenol Type Macrocycles.

A chiral 1,1'-bi-2-naphthol (BINOL)-containing pyridine-acetylene-phenol macrocycle and a pyridine-BINOL alternating macrocycle were developed for enantioselective recognition of saccharides. In solid-liquid extraction of native saccharides, these macrocycles selectively extracted one enantiomer from each of a racemic mixture of d/l-fructose, d/l-glucose, and d/l-mannose into a lipophilic solvent. This is the first example in which native saccharides, especially such important hexoses, were enantioselectively extracted with artificial host molecules.

Genetic polymorphisms of OCT-1 confer susceptibility to severe progression of primary biliary cirrhosis in Japanese patients.

BACKGROUND: To identify the genetic factors involved in the pathogenesis of primary biliary cirrhosis (PBC), we focused on the organic cation transporter 1 (OCT1/SLC22A1), which is closely associated with phosphatidylcholine synthesis in hepatocytes. METHODS: We selected four (rs683369, rs2282143, rs622342 and rs1443844) OCT-1 single nucleotide polymorphisms (SNPs), and genotyped these SNPs using the TaqMan probe method in 275 Japanese PBC patients and 194 gender-matched, healthy volunteers as controls. RESULTS: The Chi-square test revealed that the rs683369 variant allele (G) was associated with insusceptibility to PBC development [P = 0.009, odds ratio (OR) 0.60, 95 % confidence interval (CI) 0.40-0.88] in an allele model, and that the rs683369 variant allele (G) was associated with jaundice-type progression in a minor allele dominant genotype model (P = 0.032, OR 3.10, 95 % CI 1.05-9.14). The OCT-1 rs2282143 variant (T) and rs622342 variant (C) were also associated with jaundice-type progression in a minor allele recessive genotype model (P = 0.0002, OR 10.58, 95 % CI 2.36-47.54, and P = 0.006, OR 7.84, 95 % CI 1.39-44.36, respectively). Furthermore, the association of OCT-1 rs683369 and rs622342 with susceptibility to jaundice-type progression was confirmed by a replication study with a distinct set of PBC patients who underwent liver transplantation. CONCLUSIONS: The present study is the first report on the association of OCT-1 genetic polymorphisms with the overall development and jaundice-type progression of PBC.

Association of ITPA polymorphism with outcomes of peginterferon-α plus ribavirin combination therapy.

AIM: To analyzed the association between inosine triphosphatase (ITPA) (rs1127354) genotypes and sustained virological response (SVR) rates in peginterferon (Peg-IFN)α + ribavirin (RBV) treatment. METHODS: Patients who underwent Peg-IFNα + RBV combination therapy were enrolled (n = 120) and they had no history of other IFN-based treatments. Variation in hemoglobin levels during therapy, cumulative reduction of RBV dose, frequency of treatment withdrawal, and SVR rates were investigated in each ITPA genotype. RESULTS: In patients with ITPA CC genotype, hemoglobin decline was significantly greater and the percentage of patients in whom total RBV dose was < 60% of standard and/or treatment was withdrawn was significantly higher compared with CA/AA genotype. However, SVR rates were equivalent between CC and CA/AA genotypes, and within a subset of patients with Interleukin 28B (IL28B) (rs8099917) TT genotype, SVR rates tended to be higher in patients with ITPA CC genotype, although the difference was not significant. CONCLUSION: ITPA CC genotype was a disadvantageous factor for Peg-IFNα + RBV treatment in relation to completion rates and RBV dose. However, CC genotype was not inferior to CA/AA genotype for SVR rates. When full-length treatment is accomplished, it is plausible that more SVR is achieved in patients with ITPA CC variant, especially in a background of IL28B TT genotype.