35060-08-3

A synthetic transmembrane receptor that is capable of transmitting binding information across a lipid bilayer membrane is reported. The binding event is based on aggregation of the receptor triggered by copper(II) complexation to ethylenediamine functionalities. By labelling the receptor with fluorescent dansyl groups, the copper(II) binding event could be monitored by measuring the extent of fluorescence quenching. Comparing the receptor with a control receptor lacking the transmembrane linkage revealed that the transmembrane receptor binds copper(II) ions more tightly than the non-spanning control receptor at low copper(II) concentrations. Since the intrinsic binding to copper(II) is the same for both receptors, this effect was attributed to synergy between the connected interior and exterior binding sides of the transmembrane receptor. Thus, this is the first reported artificial signalling event in which binding of a messenger on one side of the membrane leads to a cooperative binding event on the opposite side of the membrane, resembling biological signalling systems and helping us to get a better understanding of the requirements for more effective artificial signalling systems.

The dansyl fluorophore ligated to gold nanoparticles via imidazole and amine groups affords conjugates capable of detecting micromolar concentrations of the chemical warfare agent sulfur mustard by a fluorescence switching 'ON' displacement assay. The Royal Society of Chemistry.

A new homogeneous competitive assay of ligand affinities was proposed based on quenching the fluorescence of tryptophan/tyrosine residues in a protein via Frster-resonance-energy-transfer using a fluorescent reference ligand as the acceptor. Under excitation around 280 nm, the fluorescence of a protein or a bound acceptor was monitored upon competitive binding against a nonfluorescent candidate ligand. Chemometrics for deriving the binding ratio of the acceptor with either fluorescence signal was discussed; the dissociation constant (K d) of a nonfluorescent candidate ligand was calculated from its concentration to displace 50% binding of the acceptor. N-biotinyl-N′-(1- naphthyl)-ethylenediamine (BNEDA) and N-biotinyl-N′-dansyl-ethylenediamine (BDEDA) were used as the reference ligands and acceptors to streptavidin to test this new homogeneous competitive assay. Upon binding of an acceptor to streptavidin, there were the quench of streptavidin fluorescence at 340 nm and the characteristic fluorescence at 430 nm for BNEDA or at 525 nm for BDEDA. Kd of BNEDA and BDEDA was obtained via competitive binding against biotin. By quantifying BNEDA fluorescence, Kd of each tested nonfluorescent biotin derivative was consistent with that by quantifying streptavidin fluorescence using BNEDA or BDEDA as the acceptor. The overall coefficients of variation were about 10%. Therefore, this homogeneous competitive assay was effective and promising to high-throughput-screening.

A copolymerizable fluorescent monomer N-[2-[[[5-(N,N-dimethylamino)-1-naphthalenyl]sulfonyl]-amino]ethyl]-2- propenamide (DANSAEP) was synthesized, which exhibits dual fluorescence due to the twisted intramolecular charge transfer in the excited state. The emission maximum λem shifts from 463.3 nm in n-hexane to 530.0 nm in water, showing solvent polarity dependence. The relations between λem and the conventional solvent polarity parameters ET(30) or Z are linear, dividing solvents into protic and aprotic groups. Kamlet's linear solvation energy relationship gives a good description for λem as a solvent polarity scale. The increment of dipole moment Δμ at the excited state was estimated as 5.09 D with the solvatochromic analysis.

Monoconjugated and multiply conjugated oligonucleotides were efficiently synthesized by starting from mono-thiohexyl- or tetra-thiohexyl-oligonucleotides and treatment with acrylamide derivatives (carbohydrates, ferrocene, biotin, fluorescent dyes, deoxyc

Two new dyes consisting of an aromatic amine donor and dansyl acceptor were synthesized, where the intramolecular donor and acceptor are connected by Diels-Alder dynamic covalent bonds. These new dyes display a switchable fluorescence resonance energy transfer through reversible formation and cleavage of Diels-Alder bonds. Single crystal X-ray diffraction revealed that Diels-Alder bonds are longer and weaker than normal single bonds. Dynamic covalent properties enable the mutual conversion of the two dyes by maleimide exchanges, where a new higher energy transfer efficiency system can be constructed.

The dansyl derivatives of N-(monoaminoalkyl)- and N-(polyaminoalkyl)acetamides were synthesized and unequivocally characterized. TLC of the dansyl derivatives obtained from human urine indicated the presence of N-[3-[(4-aminobutyl)amino]propyl]acetamide (N1-acetylspermidine), N-[4-[(3-aminopropyl)amino]butyl]acetamide (N8-acetylspermidine), and N-(4-aminobutyl)acetamide (N-acetylputrescine) in appreciable amounts. The dansyl derivatives of N1-acetylspermidine, N8-acetylspermidine, and N-acetylputrescine were isolated and purified using various chromatographic methods. The mass spectra of these compounds were similar to those of authentic samples, which confirmed the identity of these compounds and established the presence of N8-acetylspermidine as well as N1-acetylspermidine and N-acetylputrescine in human urine.

We report that multifunctional polymer nanoparticles approximately the size of a large protein can be 'purified', on the basis of peptide affinity just as antibodies, using an affinity chromatography strategy. The selection process takes advantage of the thermoresponsiveness of the nanoparticles allowing 'catch and release' of the target peptide by adjusting the temperature. Purified particles show much stronger affinity (Kdapp ≈ nM) and a narrower affinity distribution than the average of particles before purification (Kdapp > μM) at room temperature but can release the peptide just by changing the temperature. We anticipate this affinity selection will be general and become an integral step for the preparation of "plastic antibodies" with near-homogeneous and tailored affinity for target biomacromolecules.

The deuterium isotope effects on the volume phase transition of a typical temperature-sensitive polymer gel (poly(N-isopropylacrylamide) (PNIPAM) gel) and the phase separation of the linear polymer (PNIPAM) have been investigated. For the comparison between the bulk change and the microenvironment change, the deuterium isotope effects of PNIPAM gel and linear PNIPAM solution have also been investigated by using a fluorescence probe. Both the transition temperature of the polymer gel and the phase separation temperature of the linear polymer in heavy water are about 0.7 ?°C higher than those in water. However, the deuterium isotope effects on the difference of the transition temperatures in the heating process and the cooling process in the microenvironments of PNIPAM gel and linear PNIPAM solution are not observed.

The binding of copper(II) ions to membrane-bound synthetic receptors has been investigated. Complexation fitted a 4:1 receptor: copper(II) model, and the observed binding constants are significantly enhanced at the membrane relative to solution; these effects can be explained by the lower polarity of the membrane-water interface and the concentrating effect of the membrane, with no observed contribution from receptor preorganization. The stoichiometry of the complex formed is very sensitive to the concentration of the receptor in the membrane, and at low concentrations, binding is reduced relative to solution controls. This implies that by increasing or decreasing the number of receptors in their membranes, cells can finely tune biological responses such as chemotaxis that depend on the size of the receptor-ligand clusters formed.

Functionalized oligonucleotides (ONs) are widely applied as target binding molecules for biosensing and regulators for gene expression. Numerous efforts have been focused on developing facile methods for preparing these useful ONs carrying diverse modifications. Herein, we present a general method for postsynthetic modification of ONs via oxidative amination of 4-thio-2′-deoxyuridine (4SdU). 4SdU-containing ON can be derived by both alkyl and aromatic amines. Using this approach, ONs are successfully attached with alkyne/azide, biotin and dansylamide moieties, and these as-prepared ONs possess the expected biorthogonal reactivity, streptavidin affinity and fluorescent property, respectively. Furthermore, we also directly install fluorophores to the ON nucleobase based on oxidative amination of 4SdU, and these fluorophores exhibit distinct luminescence behaviors before and after conjugation. We believe our method will be a versatile strategy for constructing various functionalized ONs used in a wide range of nucleic acid applications.

Yeast-derived β-glucan particles (GPs) are a class of microcarriers under development for the delivery of drugs and imaging agents to immune-system cells for theranostic approaches. However, the encapsulation of hydrophilic imaging agents in the porous GPs is challenging. Here, we show that the unique coordination chemistry of FeIII-based macrocyclic T1 MRI contrast agents permits facile encapsulation in GPs. Remarkably, GPs labeled with the simple FeIII complexes are stable under physiologically relevant conditions, despite the absence of amphiphilic groups. In contrast to the free FeIII coordination complex, the labeled FeIII-GPs have lowered T1 relaxivity and act as a silenced form of the contrast agent. Addition of a fluorescent tag to the FeIII complex produces a bimodal agent to further enable tracking of the nanoparticles and to monitor release. Treatment of the iron-labeled GPs with a maltol chelator or with mildly acidic conditions releases the intact iron complex and restores enhanced T1 relaxation of the water protons.

We report the development of environmentally responsive fluorescent polymers. The reversible temperature-induced phase transition of copolymers composed of N-isopropylacrylamide and a fluorescent monomer based on the fluorescein (FL), coumarin (CO), rhodamine (RH), or dansyl (DA) skeleton was used as a molecular switch to control the fluorescence intensity. The poly(N-isopropylacrylamide) (PNIPAAm) chain showed an expanded coil conformation below the lower critical solution temperature (LCST) due to hydration, but it changed to a globular form above the LCST due to dehydration. Through the combination of a polarity-sensitive fluorophore with PNIPAAm, the synthetic fluorescent polymer displayed a response to external temperature, with the fluorescence strength dramatically changing close to the LCST. Additionally, the P(NIPAAm-co-FL) and P(NIPAAm-co-CO) polymers, containing fluorescein and coumarin groups, respectively, exhibited pH responsiveness. The environmental responsiveness of the reported polymers is derived directly from the PNIPAAm and fluorophore structures, thus allowing for the cellular uptake of the fluorescence copolymer by RAW264.7 cells to be temperature-controlled. Cellular uptake was suppressed below the LCST but enhanced above the LCST. Furthermore, the cellular uptake of both P(NIPAAm-co-CO) and P(NIPAAm-co-RH) conjugated with a fusogenic lipid, namely, L-α-phosphatidylethanolamine, dioleoyl (DOPE), was enhanced. Such lipid-conjugated fluorescence probes are expected to be useful as physiological indicators for intracellular imaging. (Chemical Equation Presented).

A Dansyl functionalized fluorescent probe (DFFP) has been intended, synthesized, and well-characterized (NMR, IR, Mass, SEM, SCXRD), capable of sensing trace amounts of water contaminant in hygroscopic deuterated solvents by changing colour under UV irradiation. A distinct bathochromic shift in emission spectra of probe DFFP and the visual colour change (Green to Yellow) under UV lamp are the key evidence of the presence of water contaminant. To prove the potentiality of the probe while detecting the remnant water, we did some experimental studies along with exhaustive theoretical evaluation. DFT (Energy optimization and other calculations) helped in better understanding the sensing mechanism and the mode of interactions among probe-water-solvent. Total electron density mapped over Electrostatic Potential Surface and calculation of ESP charges helped in locating more electron-dense regions in the ground state. The involvement of TD-DFT studies helped in finding the possible electronic transitions and corresponding absorption bands. Moreover, the probe is capable of sensing ethanolic water vapour in the gaseous phase. Due to high fluorescence and being nontoxic to cells, probe DFFP could be used as a potential cell imaging dye. It has been employed in a human cancer cell line (A549), and fluorescent confocal microscopic images were obtained.

Acyl glucuronides are common metabolites of carboxylic acid-containing compounds. Since acyl glucuronides sometimes show high reactivity, they are considered to be involved in drug toxicity. Therefore, it is important to evaluate the risk posed by acyl glucuronides in the development of safe drugs; however, there are no suitable evaluation methods for the early stages of drug discovery. We aimed to develop a trapping reagent that detects reactive acyl glucuronides to assess their risk. We designed a diamine-structured trapping reagent, Dap-Dan, and compared its trapping ability with the reported one that has an amino group, and results showed that Dap-Dan showed higher accuracy. In the trapping assay with 17 medicines containing a carboxylic acid, Dap-Dan trapped acyl glucuronides that had a higher risk of toxicity. In conclusion, Dap-Dan can be useful for evaluating the risk of reactive acyl glucuronides.

A series of dansyl-based fluorescent probes bearing linear alkyl-1,n-diamine chains of different length (DA1.n, n = 2–8, 10, 12) was characterized in terms of the absorptive and emissive features in solvents of different polarity and hydrogen bond donor/hydrogen bond acceptor character. The probes show solvent-dependent absorption, a feature that is uncommon among dansyl derivatives. The dual emission of DA1.n probes is strong in non-aqueous solvents and is influenced by the chain length and interactions with the solvent. Solvent effects on the spectral parameters were rationalized on the basis of the Kamlet-Taft and Catalán solvatochromic models, in order to quantify the degree of polarity-driven and hydrogen bonding interactions. A comparative discussion of the results predicted by the two models was made. In ground state, the DA1.n probes act as hydrogen bond acceptors. In excited state, hydrogen bonding is less favoured, the solute-solvent interactions being governed by the increasing polarity of the solvent that results in a large bathochromic shift of the emission. A comparison was made with the spectral features previously reported for the corresponding series of bis-dansyl fluorescent probes (2DA1.n).

Heterocyclic compounds of Formula (I) and pharmaceutically acceptable salt thereof are disclosed. The use of such heterocyclic compounds and pharmaceutically acceptable salt thereof for the treatment of cancers, and more particularly cancers sensitive to mitochondrial activity inhibition and increased reactive oxygen species (ROS) levels, is also disclosed. Such cancers include acute myeloid leukemia (AML), preferably AML characterized by certain features, such as high level of expression of one or more Homeobox (HOX)-network genes, high and/or low expression of specific genes, the presence of one or more cytogenetic or molecular risk factors such as intermediate cytogenetic risk, Normal Karyotype (A/K), mutated NPM1, mutated CEBPA, mutated FLT3, mutated DNMT3A, mutated TET2, mutated IDH1, mutated IDH2, mutated RUNX1, mutated WT1, mutated SRSF2, intermediate cytogenetic risk with abnormal karyotype (intern(abnK)), trisomy 8 (+8) and/or abnormal chromosome (5/7), and/or a high leukemic stem cell (LSC) frequency.

Inspired by nature, supramolecular nanoparticles based on complementary nucleobase interactions have aroused wide interest. In our study, two kinds of fluorophores were conjugated at the end of nucleobase containing homopolymers, which can be used to conf

A series of strained alkynes, based on the 2,2′-dihydroxy-1,1′-biaryl structure, were prepared in a short sequence from readily-available starting materials. These compounds can be readily converted into further derivatives including examples containing fluorescent groups with potential for use as labelling reagents. The alkynes are able to react in cycloadditions with a range of azides without the requirement for a copper catalyst, in clean reactions with no observable side reactions.

Human tissue transglutaminase (hTG2) is a multifunctional enzyme. It is primarily known for its calcium-dependent transamidation activity that leads to formation of an isopeptide bond between glutamine and lysine residues found on the surface of proteins, but it is also a GTP binding protein. Overexpression and unregulated hTG2 activity have been associated with numerous human diseases, including cancer stem cell survival and metastatic phenotype. Herein, we present a series of targeted covalent inhibitors (TCIs) based on our previously reported Cbz-Lys scaffold. From this structure-activity relationship (SAR) study, novel irreversible inhibitors were identified that block the transamidation activity of hTG2 and allosterically abolish its GTP binding ability with a high degree of selectivity and efficiency (kinact/KI > 105 M-1 min-1). One optimized inhibitor (VA4) was also shown to inhibit epidermal cancer stem cell invasion with an EC50 of 3.9 μM, representing a significant improvement over our previously reported "hit" NC9.

Described is a composition comprising one or more active ingredients coated, dispersed, or dissolved with a mucoadhesive polymer. Although subject to multiple uses, the composition, in some embodiments, is usable for treating rhinosinusitis.

It has recently emerged that the succinimide linkage of a maleimide thiol addition product is fragile, which is a major issue in fields where thiol functionalisation needs to be robust. Herein we deliver a strategy that generates selective cysteine thiol

DNA can be oxidatively cleaved by copper complexes of the ATCUN peptide (amino terminal Cu(II)- and Ni(II)-binding motif). In order to investigate the fate of the metal ion throughout this process, we have exploited quenching/dequenching effects of conjugated fluorophores.

Cell binding agent-drug conjugates comprising hydrophilic linkers, and methods of using such linkers and conjugates are provided.

Herein we present the synthesis of fluorescent 2-acetylbenzeneboronic acids that undergo B-N promoted conjugation with lysozyme and N-(2-aminoethyl) folic acid (EDA-FA), generating conjugates that are selectively recognized and internalized by cancer cell

Water-soluble nanoparticles molecularly imprinted against naphthyl derivatives could bind the templates with high affinity and excellent selectivity among structural analogues in aqueous solution. Fluorescent dansyl groups installed during template polyme

Stabilized Wittig olefination holds great potential as a bioconjugation reaction. We demonstrate that the reaction of stabilized phosphorus ylides (or phosphonium salts) with aryl aldehydes is sufficiently robust to be used for live cell affinity isolation and fluorescence tagging of a protein, FKBP12.

In this manuscript, we describe the synthesis of new trans-N-sulfonamide platinum complexes and their antiproliferative activity (GI50, μM) in human solid tumors cells. The structure activity relationships (SAR), with different new synthesized

A series of novel coumarin-benzimidazole hybrids, 3-(1H-benzo[d]imidazol-2- yl)-7-(substituted amino)-2H-chromen-2-one derivatives of biological interest were synthesized. Six out of the newly synthesized compounds were screened for in vitro antitumor act

An object of the present invention is to provide a reagent for protein analysis that has still greater 1) rapidity and 2) high operability, that can be detected with 3) high sensitivity, and that can be detected using 4) a gel imager that carries out excitation with visible light or a detecting device having a highly versatile UV light source (UV transilluminator), and a method for protein analysis. The present invention relates to a composition for analysis of a protein, the composition containing a compound represented by Formula I or a salt thereof; when the composition is applied to a support containing a separated protein, staining and fixation of the protein being carried out thereby, and no destaining of the support after application being required.

A UV-vis, steady-state, and time-resolved fluorescence 2D 1H NOESY NMR spectroscopic and rheological study of new poly(acrylate)s 3% randomly substituted with either N-(2-aminoethyl)-, N-(6-aminohexyl)-, or N-(12-aminododecyl)-5-dansyl-sulfonamide to give the substituted polymers PAADSen, PAADShn, and PAADSddn, respectively, is reported. Their dansyl substituent aggregation and complexation by β-cyclodextrin, βCD, and its covalently linked dimer N,N′-bis(6A-deoxy-6 A-β-cyclodextrin)urea, 66βCD2ur, is also reported. The βCD complexation of the dansyl substituents is characterized by apparent complexation constants, K = 89, 105, and 55 dm3 mol -1 for PAADSen, PAADShn, and PAADSddn, respectively, and the analogous complexations by 66βCD2ur are characterized by K = 3.04 × 103, 3.42 × 104, and 2.42 × 105 dm3 mol-1 at pH 7.0 in aqueous 0.10 mol dm-3 NaCl at 298.2 K. Under the same conditions the dansyl substituent shows three fluorescence decay constants assigned to the aggregated (τ1 = 2.2, 2.5, and 3.2 ns), single (τ2 = 5.0, 5.3, and 9.5 ns), βCD (τ3 = 13.2, 11.7 ns, and undetected), and 66βCD2ur complexed dansyl substituent states (τ3 = 13.9, 20.8, and 19.3 ns) where the values in each data set correspond to PAADSen, PAADShn, and PAAddn solutions, respectively. 2D 1H NOESY NMR spectroscopy provides additional insight into dansyl substituent complexation by βCD and 66βCD2ur, as do rheological studies. These data are interpreted in terms of the factors affecting dansyl substituent fluorescence quenching and the impact of tether length on dansyl substituent aggregation, complexation, and network formation.

Photochromic spiropyrans modified with fluorophores were investigated as molecular platforms for the achievement of fluorescence switching through modulation of energy transfer. The dyads were designed in such a way that energy transfer is only observed for the open forms of the photochrome (merocyanine and protonated merocyanine), whereas the closed spiropyran is inactive as an energy acceptor. This was made possible through a deliberate choice of fluorophores (4-amino-1,8-naphthalimide, dansyl, and perylene) that produce zero spectral overlap with the spiro form and considerable overlap for the merocyanine forms. From the Foerster theory, energy transfer is predicted to be highly efficient and in some cases of 100 % efficiency. The combined switching by photonic (light of I>530 nm) and chemical (base) inputs enabled the creation of a sequential logic device, which is the basic element of a keypad lock. Furthermore, in combination with an anthracene-based acidochromic fluorescence switch, a reversible logic device was designed. This enables the unambiguous coding of different input combinations through multicolour fluorescence signalling. All devices can be conveniently reset to their initial states and repeatedly cycled. Copyright

Matrix metalloproteinases (MMPs) are overexpressed in various pathological conditions, including cancers. Although these isozymes have similar active sites, the patterns of exposed amino acids on their surfaces are different. Herein, we report the synthes

The design and synthesis of icosahedral polyhedral borane closomer motifs based upon carbonate and carbamate anchoring groups for biomedical applications are described. Dodecacarbamate closomers containing easily accessible groups of interest at their linker termini were synthesized via activation of the B-OH vertices as aryl carbonates and their subsequent reaction with primary amines. Novel dodecacarbonate closomers were successfully synthesized for the first time by reacting [closo-B12(OH)12]2- with an excess of respective aryl chloroformates, utilizing relatively short reaction times, mild conditions and simple purification strategies, all of which had previously presented difficulties in closomer chemistry. This methodology for the 12-fold degenerate synthesis of carbonate and carbamate closomers will greatly facilitate further exploration of closomers as monodisperse nanomolecular delivery platforms.

Here, we report on the first synthesis of fluorescent-labeled epidermal growth factor receptor-DNA targeting combi-molecules, and we studied the influence of P-glycoprotein status of human sarcoma MES-SA cells on their growth inhibitory effect and cellular uptake. The results showed that 6, bearing a longer spacer between the quinazoline ring and the dansyl group, was more stable and more cytotoxic than 4. In contrast to the latter, it induced significant levels of DNA damage in human tumor cells. Moreover, in contrast to doxorubicin, a drug known to be actively effluxed by P-gp, the more stable combi-molecule 6 induced almost identical levels of drug uptake and DNA damage in P-gp-proficient and -deficient cells. Likewise, in contrast to doxorubicin, 4 and 6 exerted equal levels of antiproliferative activity against the two cell types. The results in toto suggest that despite their size, the antiproliferative effects of 4 and 6 were independent of P-gp status of the cells.

The synthesis of a series of α-and β-configured sialosides using a Koenigs-Knorr methodology is described. The target compounds can serve as substrates for the investigation of biologically relevant sialate-O- acetyltransferase activity.

The synthesis of a set of new clickable fluorophores that virtually cover the whole visible spectrum reaching the near infra-red regime is presented herein. Besides dyes that are capable of participating in classical copper catalyzed 1,3-dipolar cycloaddition reactions with the counterparting function we have also prepared dyes containing a cyclooctyne moiety, an alkyne derivative that enables copper free clicking to azides. The suitability of these dyes for fluorescent labeling of biomolecules is presented by examples on model frameworks representing major biopolymer building blocks. The versatility of these dyes is presented in cell labeling experiments as well as by labeling the azide modified surface glycans of CHO-cells either by copper catalyzed or copper-free click reaction. These dyes are expected to have a large variety of applications in (bio)orthogonal labeling schemes both in vivo and in vitro.

The invention relates to the inhibition of DNA methyltransferase isoforms DNMT1 and DNMT3b2. The invention provides compounds and methods for inhibiting DNMT1 and DNMT3b2.

One of the major impediments to the implementation of displacement chromatography for the purification of biomolecules is the need to collect fractions from the column effluent for time-consuming offline analysis. The ability to employ direct online monit

Linear copolymers have been developed which carry binding sites tailored for sulfated sugars. All binding monomers are based on the methacrylamide skeleton and ensure statistical radical copolymerization. They are decorated with o-aminomethylphenylboronates for covalent ester formation and/ or alkylammonium ions for noncovalent Coulomb attraction. Alcohol sidechains maintain a high water solubility; a dansyl monomer was constructed as a fluorescence label. Statistical copoly merization of comonomer mixtures with optimized ratios was started by AIBN (AIBN = 2,2′-azoisobutyronitrile) and furnished water-soluble comonomers with an exceptionally high affinity for glucosaminoglucans. Heparin can be quantitatively detected with an unprecedented 30 nM sensitivity, and a neutral polymer without any ammonium cation is still able to bind the target with almost micromolar affinity. From this unexpected result, we propose a new binding scheme between the boronate and a sulfated ethylene glycol or aminoethanol unit. Although the mechanism of heparin binding involves covalent boronate ester formation, it can be completely reversed by protamine addition, similar to heparin's complex formation with antithrombin III.

Oleamide is an interesting compound, which shows various pharmacological activities including the inhibitory effect of gap junction formation. Recently, the studies of the gap junction have been some of the hot topics in biology and its inhibitors have become more useful tools [Cravatt, B. F.; Garcia, O. P.; Siuzdak, G.; Gilula, N. B.; Henriksen, S. J.; Boger, D. L.; Lerner, R. A. Science 1995, 268, 1506-1509; Cravatt, B. F.; Lerner, R. A.; Boger, D. L. J. Am. Chem. Soc. 1996, 118, 580-590; Guan, X; Cravatt, B. F.; Ehring, G. R.; Hall, J. E.; Boger, D. L.; Lerner, R. A.; Gilula, N. B. J. Cell Biol. 1997, 139, 1785-1792; Boger, D. L.; Patterson, J. E.; Guan, X.; Cravatt, B. F.; Lerner, R. A.; Gilula, N. B. Proc. Natl. Acad. Sci. U.S.A. 1998, 95, 4810-4815; Ito, A.; Morita, N.; Miura, D.; Koma, Y.; Kataoka, T. R.; Yamasaki, H.; Kitamura, Y.; Kita, Y.; Nojima, H. Carcinogenesis 2004, 25, 2015-2022]. However, many reports suggest that the functionalizations of oleamide to retain its biological activity were difficult [Boger, D. L.; Patterson, J. E.; Guan, X.; Cravatt, B. F.; Lerner, R. A.; Gilula, N. B. Proc. Natl. Acad. Sci. U.S.A. 1998, 95, 4810-4815; Ito, A.; Morita, N.; Miura, D.; Koma, Y.; Kataoka, T. R.; Yamasaki, H.; Kitamura, Y.; Kita, Y.; Nojima, H. Carcinogenesis 2004, 25, 2015-2022]. The synthesis of the functionalized oleamide derivatives, whose biological activity is not blocked, has become attractive in both the biological and chemical fields. Herein, by linking the fluorophore to the oleamide by alkyl chains, we synthesized the fluorescently tagged oleamide whose biological feature is similar to that of oleamide. Moreover, we also synthesized other bioactive derivatives tagged by other groups such as the sugars and biotin via alkyl chain linkers.

Assays of hydrolytic enzyme activity, such as of glycosidases and phosphatase, as well as several proteases, using a semi-wet supramolecular hydrogel array composed of a glycosylated amino acetate are described. It has been demonstrated that the microcavity formed by gel fibrils is suitable to immobilize native enzymes without denaturation under semi-wet conditions, and thus the nanofiber has been rationally used as a sensing domain to monitor enzymatic reactions. By using a fluorogenic substrate, reducing the size of the hydrogel can significantly improve the problem of suppressed diffusion within the gel matrix thus making the hydrogel a promising semi-wet matrix for evaluating enzyme activity. Confocal laser scanning microscopy observa lions have shown that an environmentally sensitive fluorescent probe accumulates in the hydrophobic domain of the gel fiber and emits fluorescence more strongly upon hydrolytic cleavage of the substrate peptides. Not only a simple environmentally sensitive probe but also a FRET (fluorescence resonance energy transfer)-type read-out mode can be devised to analyze the enzymatic hydrolysis-triggered redistribution of the probe between the nano-space and the nanofiber to accomplish a more clearly distinguished enzyme assay. Thus, it is clear that three distinct read-out modes, that is, 1) fluorogenic substrates, 2) substrates bearing an environmentally sensitive probe, or 3) a substrate exhibiting FRET, can operate under the semi-wet hydrogel conditions used in these investigations. In addition, owing to the unique properties of the present supramolecular hydrogel in semi-wet conditions, that is, its phase-segregation properties and dynamics, the supramolecular substrate/enzyme array has successfully been used for high-throughput screening of single and multiple enzymes based on their activity, lysate analysis, and quantitative evaluation of inhibitor potency and selectivity.

Fluorescent photoaffinity probe, which possesses a dansyl amide functional group on the maleic moiety of tautomycin, was prepared in order to detect the trace amount of labeled peptides. The parent compound dramatically showed fluorescence quenching befor

Using the steady-state and time-resolved fluorescence anisotropy, the mobility of 5-(dimethylamino)naphthalene-1-sulfonyl (dansyl) fluorophore in homologous 1-[2-acetamido-3-(1H-indol-3-yl)propanamido[-n-]5-(dimethylamino)naphthalene-1-s ulfonamido]alkanes 1 was studied in binary solvents glycerol-water. Steady-state fluorescence data were evaluated by the generalized Perrin equation and the micro-Brownian motion of dansyl fluorophore was described by means of average characteristics (rotational relaxation times) of the rotational relaxation spectrum. The rotational relaxation time of "fast" motions caused by torsional vibrations of single bonds within the rotational-isomeric states decreases with increasing number of methylene groups in homologous compounds. The rotational relaxation time of "slow" motions due to conformational changes of the chain between the tryptophane and dansyl fluorophore remains at first approximately constant with increasing number of methylene groups but increases considerably for long aliphatic chains. The observed decrease in the rate of conformational changes of a long aliphatic chain is probably due to intramolecular interaction of parts of the methylene chain in a medium with high water content. The values of activation enthalpy ΔH+ and activation entropy ΔS≠ calculated from experimental data corroborate such interpretation. Time-resolved anisotropy of dansyl fluorophore at a particular binary solvent composition confirmed the shape of rotational relaxation spectrum and the measured rotational correlation times have been discussed. The time-dependent decays of anisotropy supported our previous interpretation in terms of intramolecular association of the long aliphatic chain in polar medium.

Derivatives of fluorescein, 7-hydroxycoumarin, Sudan 1 and dansyl chloride with linker arms containing a conjugated terminal alkyne have been prepared. The Michael addition of the sulfanyl group of protected cysteine, the hydroxyl group of protected serine and the ε-amino group of protected lysine to the conjugated alkyne gave the expected heterosubstituted vinyl products.

A monofunctionalized β-cyclodextrin containing a dansyl moiety, 6-deoxy-6-N-(N'-(5-dimethylamino-1-naphthalenesulfonyl)diaminoethane)-β-cyclodextrin (CD-en-DNS, 2), was synthesized and its crystal structure determined.It was shown that the dansyl group is fully encapsulated within the cyclodextrin cavity, with the dimethylamino and sulfonyl groups emerging from opposite sides.The shape of the cavity is considerably flattened, since O(4)-O(4) distances parallel to the naphthalene ring were found to be longer than the others.The conformation of the diaminoethane linker was found to be determined by the inclusion of the dansyl group and by a hydrogen bond between the sulfonamide NH and one of the O(6)-H groups on the cyclodextrin rim.The self-inclusion features of the aromatic moiety were found to be consistent with the solution data: 1H NMR ROESY spectra suggested that the orientation of the dansyl moiety observed in the solid state was retained in aqueous solution; the circular dichroism spectrum was consistent with an axial complexation model.Fluorescence spectra showed that the inclusion of the dansyl group in the cyclodextrin cavity considerably increases the quantum yield; time-resolved fluorescence experiments showed the presence of a long-lifetime component (16.1 ns), which was attributed to the included fluorophore.The ability of 2 to act as a fluorescence sensor was evaluated by the addition of several guests of different shape; fluorescence intensity was lowered, especially upon addition of adamantane-carboxylic acid.All the data obtained were consistent with the model of the in-out movement of the dansyl group from the self-included conformation observed in the solid state to a position more exposed to the bulk solvent.Copper(II) was shown to enhance the difference in the fluorescence of 2 in the presence of guests by additional static quenching. - Keywords: crystal structure; cyclodextrins; dansyl derivatives; fluorescent sensors; self-inclusion

Cyclisation of N-alkylmaleic acids mediated by acetic anhydride in dimethylacetamide in the presence of traces of cobalt naphthenate has been used for efficient assembly of a range of fluorescent maleimide reagents.The fluorescence responses of these reagents to addition of thiol across the maleimide double bond, and to hydrolysis of the meleimide ring, are described.

A chelating compound of the formula: wherein R is an aromatic ring-containing organic group, A is a residue of an aminopolyacetic acid excluding acetic acid groups (--CH2 COOH) therefrom, m is an integer of at least two and n is an integer of 1 or 2, or its salt, which has a specificity to a hepatobiliary system so that a complex formed between said chelating compound and a metallic element through a coordinate bond is useful and a diagnostic or therapeutic agent for hepatobiliary organs and tissues.

The following two fluorescent peptides were prepared as substrates of the cyclicAMP-dependent protein kinase reaction: Leu-Arg-Arg-Ala-Ser-Leu-X; 1 (X = 2-(dansylamino)ethylamino or DAE) and 2 (X = 4-methyl-2-oxo-7-chromenylamino or MCA).Both peptides wer