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Pseudomonas aeruginosa ( P. aeruginosa ), a Gram-negative opportunistic pathogen, produces virulent factors and forms biofilms through a quorum sensing (QS) mechanism. Modulating QS networks is considered an effective strategy for treating P. aeruginosa infections. Particularly, the rhl system, one of the QS networks, can be a potential target in treating patients with chronic infections. We previously discovered that gingerol acts as a RhlR antagonist of P. aeruginosa . Based on the chemical structure of gingerol, we have designed and synthesized gingerol derivatives by introducing various functional groups in the middle and tail regions. A comprehensive structure-activity relationship study showed that compound 5a substituted with phenyl group in the tail region was the most potent in various biological assessments, such as RhlR binding affinity, rhl gene expression, and virulence factor production of P. aeruginosa . Furthermore, compound 5a decreased the biofilm formation and pathogenicity of P. aeruginosa . Interestingly, compound 5a also influenced las system in addition to the rhl system. Taken together, compound 5a can be utilized as a potent compound for controlling P. aeruginosa infection., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Polyunsaturated fatty acids and their metabolites have been reported in which their pathway has potential for the modulation of cancer cell growth. 13-( S )-HODE and 15-( S )-HETE, both of which are main metabolites of 15-LOXs, play an important role as endogenous ligands in biological systems. However, the modification of 13-( S )-HODE and 15-( S )-HETE in pharmaceutical applications has not been explored widely. Herein, we report the stereoselective syntheses of 13-( S )-HODE, 15-( S )-HETE, and its derivatives to enable the synthesis of bioactive fatty acid analogues.

The straightforward and rapid incorporation of a thiazolidinedione scaffold into prefunctionalized (hetero)aromatic compounds is in demand for the development of antidiabetic glitazones and other pharmaceuticals. Herein, we report the unprecedented N- and O-directed C-H alkylation of various (hetero)arenes with methylene thiazolidinediones under rhodium(III) catalysis. The applicability of the developed protocol in challenging contexts is exhibited by the late-stage installation of a methylene thiazolidinedione moiety on the C-H bond of commercially available drug molecules. Combined mechanistic investigations aided the elucidation of a plausible reaction mechanism.

The direct functionalization of N -heterocycles is a vital transformation for the development of pharmaceuticals, functional materials, and other chemical entities. Herein, the transition-metal-free alkylation and acylation of C(sp 2 )-H bonds in biologically relevant 2-benzoxazinones with 1,4-dihydropyridines as readily accessible radical surrogates is described. Excellent functional group compatibility and a broad substrate scope were attained. Gram-scale reaction and transformations of the synthesized adducts via Suzuki coupling with heteroaryl boronic acids demonstrated the synthetic potential of the developed protocol.

The site-selective modification of quinolines and their analogs has emerged as a pivotal topic in medicinal chemistry and drug discovery. Herein, we describe the rhodium(III)-catalyzed C8-alkylation of quinoline N -oxides with maleimides as alkylating agents, resulting in the formation of bioactive succinimide-containing quinoline derivatives. The reaction proceeds under mild conditions with complete functional group tolerance.

Pseudomonas aeruginosa ( P. aeruginosa ) is an opportunistic human pathogen that forms biofilms and produces virulence factors via quorum sensing (QS). Blocking the QS system in P. aeruginosa is an excellent strategy to reduce biofilm formation and the production of virulence factors. RhlR plays an essential role in the QS system of P. aeruginosa . We synthesized 55 analogues based on the chemical structure of 4-gingerol and evaluated their RhlR inhibitory activities using the cell-based reporter strain assay. Comprehensive structure-activity relationship studies identified the alkynyl ketone 30 as the most potent RhlR antagonist. This compound displayed selective RhlR antagonism over LasR and PqsR, strong inhibition of biofilm formation, and reduced production of virulence factors in P. aeruginosa . Furthermore, the survival rate of Tenebrio molitor larvae treated with 30 in vivo greatly improved. Therefore, compound 30 , a pure RhlR antagonist, can be utilized for developing QS-modulating molecules in the control of P. aeruginosa infections.

In an effort to seek novel agents targeting prostate-specific membrane antigen (PSMA), 16 ligands ( L1 - L16 ) with structural modifications in S1' binding pocket were synthesized and evaluated for PSMA inhibition. ( S )-3-(Carboxyformamido)-2-(3-(carboxymethyl)ureido)propanoic acids proved to be potent PSMA ligands with K i values ranging from 0.08 nM to 8.98 nM, which are in the range of or are higher in potency compared to previously published urea-based ligands. Computational docking was performed to study the binding mode of the two most potent ligands discovered. FITC-conjugated L14 could selectively stain PSMA + LNCaP cells over PSMA - PC3 cells. IRDye800CW conjugated L16 can effectively image tumors in a murine xenograft model of prostate cancer.

Prostate-specific membrane antigen (PSMA) is an excellent biomarker for the early diagnosis of prostate cancer progression and metastasis. The most promising PSMA-targeted agents in the clinical phase are based on the Lys-urea-Glu motif, in which Lys and Glu are α-(l)-amino acids. In this study, we aimed to determine the effect of β- and γ-amino acids in the S1 pocket on the binding affinity for PSMA. We synthesized and evaluated the β- and γ-amino acid analogues with ( S )- or ( R )-configuration with keeping α-(l)-Glu as the S1'-binding pharmacophore. The structure-activity relationship studies identified that compound 13c , a β-amino acid analogue with ( R )-configuration, exhibited the most potent PSMA inhibitory activity with an IC 50 value of 3.97 nM. The X-ray crystal structure of PSMA in complex with 13c provided a mechanistic basis for the stereochemical preference of PSMA, which can guide the development of future PSMA inhibitors.

Stereo- and regioselective formation of glycosidic linkages is a challenging topic in oligosaccharide syntheses. The stereoselective construction of 1,2- trans -glycosides generally involves neighboring group participation, which is less successful when synthesizing β-1,3-linked oligosaccharides. The combined steric effect of a 2- O -substituent and an aglycon moiety in acceptors increases the efficiency of glycosylation via neighboring group participation. This steric effect was reduced by using vicinal polyol acceptors and was demonstrated in the synthesis of 1,3-linked branched oligosaccharides.

There are few hybrid positron emission tomography (PET)/fluorescence imaging agents available for brain imaging. For this purpose, BODIPY dye is very attractive because one of its fluorine atoms can be readily exchanged with 18 F, and it can be modified to produce red-shifted fluorescence. In this study, therefore, we synthesized and investigated a 18 F-labeled red-shifted BODIPY dye as a prosthetic group for brain hybrid PET/optical imaging agents and determined the optimal dose of this radioligand for hybrid imaging. The red-shifted BODIPY dye (1) was synthesized, and one of its fluorine atoms was exchanged with 18 F using SnCl 4 in high yield. Partition coefficients of 18 F-labeled BODIPY dye ([ 18 F]1) and 1 were measured using its radioactivity and fluorescence, respectively, which were shown to be suitable for brain penetration. Optimal dose for hybrid imaging was determined by analysis of PET/CT and optical images of Balb/C nude mice injected with [ 18 F]1 and 1, respectively. Hybrid PET/optical images of mice injected with optimal dose of [ 18 F]1 showed strong radioactivity and fluorescence signal in the brain at 2 min after injection, with rapid clearance by 30 min. Tissue distribution data confirmed the in vivo and ex vivo PET/optical imaging data, indicating desirable brain pharmacokinetics of the radioligand. Taken together, the results of this study suggest that [ 18 F]1 can be widely used as a prosthetic group for brain hybrid PET/optical imaging agents.

Tumor-derived exosomes are bound and internalized to organ-specific cells, affecting metastasis. Heparan sulfate proteoglycans mediate the interaction between cells and exosomes. Exosome transfer to the recipient cell can be competitively blocked by heparinoids, because heparin is structurally similar to heparan sulfate. It is hypothesized that there may be structural requirements of heparinoids to attenuate the cellular uptake and metastatic activity of tumor-derived exosomes. Here, we compared the properties of unfractionated heparin (UFH), glycol-split UFH, low-molecular-weight heparin (LMWH), glycol-split LMWH, and ultra-LMWH premixed with A549-derived exosomes. Uptake of A549-derived exosomes (0.1 mg/mL) into BEAS-2B cells was significantly blocked by 0.4 mg/mL of heparinoids. Heparinoids attenuated migration of BEAS-2B cells stimulated by A549-derived exosomes. Glycol-split LMWH with no antifactor Xa activity exhibited the strongest antimigratory effects than other heparinoids. Thus, heparinoids with proper molecular weight and structure can inhibit tumor-derived exosomes, not proportionally to the anticoagulant activity.

The microenvironment of pancreatic islets gets disrupted during enzyme digestion and causes islets to remain in a vulnerable state, leading to poor outcome in the initial days of transplantation. To avoid immune invasion while allowing the reconstruction of the microenvironment of the transplanted site, we propose immunoisolation polymers, which can nanoencapsulate islets quickly without cytotoxicity. Here, nonhuman primate (NHP) islets were nanoencapsulated with hyperbranched polyethylene glycol (hb-PEG) and heparin by layer-by-layer technology and transplanted into the kidney subcapsular space of diabetic C57BL/6 mice. An immunosuppressive drug protocol was applied to increase the survival time until the animals were sacrificed. The recipients of NHP islets exhibited high nonfasting blood glucose level (BGL) for 2-3 weeks, which was normalized afterward. Immunohistochemical (IHC) analysis revealed an immature vascular basement membrane and cell surface integrins directly associated with poor initial insulin production. The transplanted grafts regained their own microenvironment within a month without any outside stimuli. No lymphocyte infiltration was observed in the grafts at any time. Humoral and cell-mediated immune responses were prominently diminished by the hb-PEG/Heparin nanoencapsulated islets. Immunoisolation accompanied by an immunosuppressive drug protocol protects islets by helping them avoid immunogenesis while at the same time allowing them to reconstruct their microenvironment.

Gas adsorption over zeolites is at the basis of important applications of this class of microporous crystalline solids, notably as separation media and catalysts, but it may also be complex and not straightforward to understand. Here we report that for temperature below 323 K propane adsorption on the small-pore pure-silica zeolite ITW exhibits a clear step (pseudosaturation). This is absent in the case of propene and the other small linear alkanes. An intermediate plateau, clearly observed in the 293 K isotherm, always occurs when one molecule of propane is loaded in every other cage, i.e., at half-saturation. The simulation results show a swelling of the ITW structure upon propane adsorption. The strong dependence of available pore volume on the adsorbate loading level implies that adsorption cannot occur on the void structure while saturation can only be reached on highly loaded structures. To account for this unprecedented adsorption phenomenon, we propose the term "guest-modulated effect".

Pseudomonas aeruginosa is a causative agent of chronic infections in immunocompromised patients. Disruption of quorum sensing circuits is an attractive strategy for treating diseases associated with P. aeruginosa infection. In this study, we designed and synthesized a series of gingerol analogs targeting LasR, a master regulator of quorum sensing networks in P. aeruginosa. Structure-activity relationship studies showed that a hydrogen-bonding interaction in the head section, stereochemistry and rotational rigidity in the middle section, and optimal alkyl chain length in the tail section are important factors for the enhancement of LasR-binding affinity and for the inhibition of biofilm formation. The most potent compound 41, an analog of (R)-8-gingerol with restricted rotation, showed stronger LasR-binding affinity and inhibition of biofilm formation than the known LasR antagonist (S)-6-gingerol. This new LasR antagonist can be used as an early lead compound for the development of anti-biofilm agents to treat P. aeruginosa infections.

Heparin and low molecular weight heparins (LMWHs) have been the drug of choice for the treatment or the prevention of thromboembolic disease. Different methods are employed to prepare the LMWHs that are clinically approved for the market currently. In particular, enoxaparin, which has a reducing sugar moiety at the end-site of polysaccharide, is prepared by alkaline depolymerization. Focusing on this end-site-specific activity of LMWHs, we conjugated the tetraoligomer of deoxycholic acid (TetraDOCA; TD) at the end-site of enoxaparin via nonenzymatic glycosylation reaction. The end-site-specific conjugation is important for polysaccharide drug development because of the heterogeneity of polysaccharides. This study also showed that orally active enoxaparin and tetraDOCA conjugate (EnoxaTD) had therapeutic effect on deep vein thrombosis (DVT) without bleeding in animal models. Considering the importance of end-specific conjugation, these results suggest that EnoxaTD could be a drug candidate for oral heparin development.

Low molecular weight heparin (LMWH) and its derivatives have been reported to possess antiangiogenic effect via electrostatic interaction with various angiogenic growth factors such as VEGF165. However, clinical applications of LMWH for anticancer therapy have been restricted due to its anticoagulant effect and insufficient therapeutic efficacy. To overcome these limitations and enhance the antiangiogenic efficacy, LMWH was conjugated with suramin fragments that have a binding affinity to the heparin-binding domain (HBD) of proteins. The conjugation of suramin fragments to LMWH enhanced the antiangiogenic effect of LMWH by increasing the binding affinity to VEGF165, while decreasing its anticoagulant activity. The chemical conjugate of LMWH and suramin fragments (LHsura) showed a substantial inhibitory effect on VEGF165-mediated cell proliferation, migration, and tube formation of HUVECs without significant cytotoxicity in vitro. Finally, we confirmed the anticancer effect of LHsura (61.4% vs control) in a SCC7-bearing mouse model.

The current study demonstrates the process of selecting an optimal structure for a caspase-3-cleavable doxorubicin prodrug that could be synthesized by simple chemistry in high yields. The prodrug was intended to activate in the presence of caspase-3, whose expression can be exogenously regulated by inducing apoptosis with radiation therapy at a specific site of interest. For this purpose, doxorubicin was conjugated with a DEVD peptide via a heterobifunctional linker. Since the active form of the prodrug comprises the linker besides doxorubicin, we tested several different linkers and selected EMCS based on the examination of its in vitro biological activities. Consequently, DEVD-cysteamide-EMCS-doxorubicin was synthesized as the final compound. According to the various in vitro and in vivo studies, the synthesized prodrug was highly selective for tumors when coupled with radiation therapy, with the added benefit of ease of production.

Regulation of cholesterol and bile acid homeostasis has been attracting attention as a pharmaceutical target for the treatment of diseases, such as hypercholesterolaemia and type 2 diabetes. In recent years, small bile acid analogues have been developed for the purpose of apical sodium-dependent bile acid transporter (ASBT) inhibition. Here, we designed a novel hydrophilic ASBT inhibitor using oligomeric bile acid with a high affinity with ASBT. Polyacrylic acid-tetraDOCA conjugates (PATD) have the ability to bind to ASBT in order to induce hypocholesterolemic effects. Both the viability and the functionality of PATD were evaluated in vitro, showing that PATDs were effective in inhibiting the increases of cholesterol in the blood and oil in the liver induced by high fat diet (HFD). The results indicated that the newly developed biomaterials with oligomeric bile acids and a hydrophilic polymer are potent therapeutic agents for hyperlipidemia.

Currently, oral administration of insulin still remains the best option to avoid the burden of repeated subcutaneous injections and to improve its pharmacokinetics. The objective of the present investigation was to demonstrate the absorption mechanism of insulin in the physical complexation of deoxycholyl-l-lysyl-methylester (DCK) for oral delivery. The oral insulin/DCK complex was prepared by making a physical complex of insulin aspart with DCK through ion-pair interaction in water. For the cellular uptake study, fluorescein-labeled insulin or DCK were prepared according to a standard protocol and applied to Caco-2 or MDCK cell lines. For the PK/PD studies, we performed intrajejunal administration of different formulation of insulin/DCK complex to diabetic rats. The resulting insulin and DCK complex demonstrated greatly enhanced lipophilicity as well as increased permeation across Caco-2 monolayers. The immunofluorescence study revealed the distribution of the complex in the cytoplasm of Caco-2 cells. Moreover, in the apical sodium bile acid transporter (ASBT) transfected MDCK, the insulin/DCK complex showed interaction with ASBT, and also demonstrated absorption through passive diffusion. We could not find that any evidence of endocytosis in relation to the uptake of insulin complex in vitro. In the rat intestine model, the highest absorption of insulin complex was observed in the jejunum at 1 h and then in the ileum at 2-4 h. In PK/PD study, the complex showed a similar PK profile to that of SC insulin. Overall, the study showed that the effect of DCK on enhancing the absorption of insulin resulted from transcellular processes as well as bile acid transporter activity.

Heparin is a highly sulfated, long, and linear polysaccharide, which can inhibit tumor growth by interacting with growth factors such as bFGF and VEGF. Several researchers have shown the anti-angiogenic effect of heparin and its conjugates in relation to growth factor inhibition. For drug development and inhibition of growth factors using heparin conjugates, the molecular size of heparin may be crucial considering the size of the heparin binding site of growth factors. In this study, we synthesized heparin fragments and deoxycholic acid conjugated heparin fragments (HFD) to search for the optimal size-controlled conjugate that will inhibit the angiogenic effect of VEGF165. We have also shown that the HFDs could have an enhanced therapeutic effect in vitro and in vivo consequent to the molecular size control. HFDs have significant anti-angiogenic effects by blocking the angiogenic activity of VEGF165 depending on its molecular size. Among them, HFD2 was a promising candidate for oral angiogenesis inhibitor. These results suggest that size-controlled synthesis is necessary for heparin-based drug development.

Technetium-99m, the most commonly used radionuclide in nuclear medicine, can be attached to biologically important molecules through a variety of chelating agents, the choice of which depends upon the imaging application. The prostate-specific membrane antigen (PSMA) is increasingly recognized as an important target for imaging and therapy of prostate cancer (PCa). Three different (99m)Tc-labeling methods were employed to investigate the effect of the chelator on the biodistribution and PCa tumor uptake profiles of 12 new urea-based PSMA-targeted radiotracers. This series includes hydrophilic ligands for radiolabeling with the [(99m)Tc(CO)3](+) core (L8-L10), traditional NxSy-based chelating agents with varying charge and polarity for the (99m)Tc-oxo core (L11-L18), and a (99m)Tc-organohydrazine-labeled radioligand (L19). (99m)Tc(I)-Tricarbonyl-labeled [(99m)Tc]L8 produced the highest PSMA+ PC3 PIP to PSMA- PC3 flu tumor ratios and demonstrated the lowest retention in normal tissues including kidney after 2 h. These results suggest that choice of chelator is an important pharmacokinetic consideration in the development of (99m)Tc-labeled radiopharmaceuticals targeting PSMA.

Targeted near-infrared (NIR) optical imaging can be used in vivo to detect specific tissues, including malignant cells. A series of NIR fluorescent ligands targeting the prostate-specific membrane antigen (PSMA) was synthesized and each compound was tested for its ability to image PSMA+ tissues in experimental models of prostate cancer. The agents were prepared by conjugating commercially available active esters of NIR dyes, including IRDye800CW, IRDye800RS, Cy5.5, Cy7, or a derivative of indocyanine green (ICG) to the terminal amine group of (S)-2-(3-((S)-5-amino-1-carboxypentyl)ureido)pentanedioic acid 1, (14S,18S)-1-amino-8,16-dioxo-3,6-dioxa-9,15,17-triazaicosane-14,18,20-tricarboxylic acid 2 and (3S,7S)-26-amino-5,13,20-trioxo-4,6,12,21-tetraazahexacosane-1,3,7,22-tetracarboxylic acid 3. The K(i) values for the dye-inhibitor conjugates ranged from 1 to 700 pM. All compounds proved capable of imaging PSMA+ tumors selectively to varying degrees depending on the choice of fluorophore and linker. The highest tumor uptake was observed with IRDye800CW employing a poly(ethylene glycol) or lysine-suberate linker, as in 800CW-2 and 800CW-3, while the highest tumor to nontarget tissue ratios were obtained for Cy7 with these same linkers, as in Cy7-2 and Cy7-3. Compounds 2 and 3 provide useful scaffolds for targeting of PSMA+ tissues in vivo and should be useful for preparing NIR dye conjugates designed specifically for clinical intraoperative optical imaging devices.

The purpose of this study was to optimize an Exendin-4 (Ex4-Cys) site-specific PEGylation method with a high-molecular-weight trimeric PEG. Here, we describe the preparation of C-terminal specific PEGylated Ex4-Cys (C40-tPEG-Ex4-Cys), which was performed using cysteine and amine residue specific coupling reactions between Ex4-Cys and activated trimeric PEG. The C40-PEG-Ex4-Cys was obtained at high yields (~83%) and characterized by MALDI-TOF mass spectrometry. The receptor binding affinity of C40-PEG(5K)-Ex4-Cys was 3.5-fold higher than that of N-terminal PEGylated Ex4-Cys (N(ter)-PEG(5K)-Ex4-Cys), and receptor binding by the trimeric PEG (tPEG; 23, 50 kDa) adduct was much higher than that of branched PEG (20 kDa). Furthermore, C40-tPEG(50K)-Ex4-Cys was found to have greater blood circulating t(1/2) and AUC(inf) values than native Ex4-Cys by 7.53- and 45.61-fold, respectively. Accordingly, its hypoglycemic duration was much greater at 59.2 h than that of native Ex4-Cys at 7.3 h, with a dose of 25 nM/kg. The results of this study show that C-terminal specific PEGylation using trimeric PEG is effective when applied to Ex4-Cys and suggest that C40-tPEG(50K)-Ex4-Cys has considerable potential as a type 2 antidiabetic agent.

The synthesis and initial biological evaluation of 3-carboranylthymidine analogues (3CTAs) that are (radio)halogenated at the closo-carborane cluster are described. Radiohalogenated 3CTAs have the potential to be used in the radiotherapy and imaging of cancer because they may be selectively entrapped in tumor cells through monophosphorylation by human thymidine kinase 1 (hTK1). Two strategies for the synthesis of a (127)I-labeled form of a specific 3CTA, previously designated as N5, are described: (1) direct iodination of N5 with iodine monochloride and aluminum chloride to obtain N5-(127)I and (2) initial monoiodination of o-carborane to 9-iodo-o-carborane followed by its functionalization to N5-(127)I. The former strategy produced N5-(127)I in low yields along with di-, tri-, and tetraiodinated N5 as well as decomposition products, whereas the latter method produced only N5-(127)I in high yields. N5-(127)I was subjected to nucleophilic halogen- and isotope-exchange reactions using Na(79/81)Br and Na(125)I, respectively, in the presence of Herrmann's catalyst to obtain N5-(79/81)Br and N5-(125)I, respectively. Two intermediate products formed using the second strategy, 1-(tert-butyldimethylsilyl)-9-iodo-o-carborane and 1-(tert-butyldimethylsilyl)-12-iodo-o-carborane, were subjected to X-ray diffraction studies to confirm that substitution at a single carbon atom of 9-iodo-o-carborane resulted in the formation of two structural isomers. To the best of our knowledge, this is the first report of halogen- and isotope-exchange reactions of B-halocarboranes that have been conjugated to a complex biomolecule. Human TK1 phosphorylation rates of N5, N5-(127)I, and N5-(79/81)Br ranged from 38.0% to 29.6% relative to that of thymidine, the endogenous hTK1 substrate. The in vitro uptake of N5, N5-(127)I, and N5-(79/81)Br in L929 TK1(+) cells was 2.0, 1.8, and 1.4 times greater than that in L929 TK1(-) cells.

Virtually all low molecular weight inhibitors of human glutamate carboxypeptidase II (GCPII) are highly polar compounds that have limited use in settings where more lipophilic molecules are desired. Here we report the identification and characterization of GCPII inhibitors with enhanced liphophilicity that are derived from a series of newly identified dipeptidic GCPII substrates featuring nonpolar aliphatic side chains at the C-terminus. To analyze the interactions governing the substrate recognition by GCPII, we determined crystal structures of the inactive GCPII(E424A) mutant in complex with selected dipeptides and complemented the structural data with quantum mechanics/molecular mechanics calculations. Results reveal the importance of nonpolar interactions governing GCPII affinity toward novel substrates as well as formerly unnoticed plasticity of the S1' specificity pocket. On the basis of those data, we designed, synthesized, and evaluated a series of novel GCPII inhibitors with enhanced lipophilicity, with the best candidates having low nanomolar inhibition constants and clogD > -0.3. Our findings offer new insights into the design of more lipophilic inhibitors targeting GCPII.

Heparin, as therapeutic medications, cannot be administered orally because of its hydrophilic and high molecular weight. Here, we present a new technology to enhance the absorption of heparin in the intestine through its chemical conjugation with deoxycholic acid (DOCA) that can interact with bile acid transporter in the intestine. For the ampiphilic property and complete dissolution, the modified heparin was physically complexed with dimethylsulfoxide (DMSO). The DOCA-conjugated heparin could form nanoparticles in aqueous solution, whereas it was completely dissolved when treated with above 10% DMSO solution. Molecular dynamics computation study and two-dimensional homonulcear (1)H nuclear overhauser effect spectroscopy (NOESY) NMR spectra demonstrated that one heparin molecule was chemically conjugated with two DOCA molecules that were physically interacted with six DMSO molecules within 4 Å via hydrophobic interactions and partly via hydrogen bonding. Its therapeutic efficacy was also pharmaceutically analyzed. When the DMSO-bound DOCA-conjugated heparin was orally administered into mice, its therapeutic efficacy was enhanced according to the amount of bound DMSO. Also, after oral administration of fluorescence-labeled DMSO-bound DOCA-conjugated heparin, it was circulated in the whole body for above 2 h. However, the DOCA-conjugated heparin without DMSO binding was fast eliminated after oral absorption. This study demonstrates that the interaction of structural constraints, DOCA and DMSO, with heparin can serve as a platform technology for potential macromolecule oral delivery.

Heparin immobilization on surfaces has drawn a great deal of attention because of its potential application in enhancing blood compatibility of various biomedical devices such as catheters, grafts, and stents. Existing methods for the heparin immobilization are based on covalent linkage formation and electrostatic interaction between substrates and heparin molecules. However, complicated multistep procedures and uncontrolled desorption of heparin are limitations of these methods. In this work, we report a new heparin derivative that exhibits robust adhesion on surfaces. The derivative, called hepamine, was prepared via conjugation of dopamine, a mussel-inspired adhesive moiety, onto a heparin backbone. Immersion of poly(urethane) substrates into an aqueous solution of hepamine resulted in robust heparin coating of the poly(urethane), the most widely used polymeric material for blood-contacting medical devices. The hepamine-coated poly(urethane) substrate showed significant inhibition of blood coagulation and platelet adhesion. The use of hepamine for surface modification is advantageous for several reasons: for example, no chemical pretreatment of the substrates is necessary, and surface functionalization is a simple, one-step procedure. Thus, the heparin immobilization method described herein is an excellent alternative approach for the introduction of heparin molecules onto surfaces.

Dimerization is viewed as the most effective means of increasing receptor binding affinity, and both dimerization and PEGylation effectively prolong the life spans of short-lived peptides and proteins in vivo by delaying excretion via the renal route. Here, we describe the high binding affinities of two long-acting exendin-4 (Ex4) conjugates, dimerized Ex4 (Di-Ex4) and PEGylated Di-Ex-4 (PEG-Di-Ex4). Di-Ex4 and PEG-Di-Ex4 were prepared using cysteine and amine residue specific coupling reactions using Ex4-Cys, bisMal-NH(2), and activated PEG. The Ex4 conjugates produced were of high purity (>98.5%), as determined by size-exclusion chromatography and MALDI-TOF mass spectrometry. The receptor binding affinity of Di-Ex4 on RIN-m5F cells was 3.5-fold higher than that of Ex4, and the in vivo antihyperglycemic efficacy of Di-Ex4 was also greater than that of native Ex4 in type 2 diabetic db/db mice. Furthermore, Di-Ex4 and PEG-Di-Ex4 were found to have greater blood circulating t(1/2) and AUC(inf) values than native Ex4 by 2.7- and 13.7-fold, and by 4.0- and 17.3-fold, respectively. Accordingly, hypoglycemic durations were greatly increased to 15.0 and 40.1 h, respectively, at a dose of 25 nmol/kg (native Ex4 7.3 h). The results of this study show that combined dimerization and PEGylation are effective when applied to Ex4, and suggest that PEG-Di-Ex4 has considerable potential as a type 2 anti-diabetic agent.

A nanoencapsulation technique was applied to an oxygen-scavenging system, and thermal processing was investigated as an activator to trigger the oxygen-scavenging reaction. α-Tocopherol-loaded polycaprolactone (PCL) nanoparticles (NPs) were prepared using an oil-in-water emulsion solvent evaporation method. The influences of iron(II) chloride, water, and thermal processing on the oxygen-scavenging capability were investigated. NPs without iron(II) chloride, moisture, and thermal processing had no oxygen-scavenging effect. However, the oxygen content (%) in the cup headspace of 20.9% decreased to 20.4% when the oxygen-scavenging system contained NPs, water, and iron(II) chloride. The oxygen content (%) decreased further to 19.5% when water was eliminated from the mixture. In this research, NPs and iron(II) chloride with thermal processing had an oxygen-scavenging capacity of 6.44 cm3 of O2/g and an oxygen-scavenging rate of 0.21 cm3 of O2 g(-1) day(-1). Results indicated that NPs and iron(II) chloride in an oxygen-scavenging system can be used as a heat-activated oxygen scavenger.

Thermal plasma treatment has been regarded as a viable alternative for the treatment of highly toxic wastes, such as incinerator residues, radioactive wastes, and medical wastes. Therefore, a gasification/vitrification unit for the direct treatment of municipal solid waste (MSW), with a capacity of 10 tons/day, was developed using an integrated furnace equipped with two nontransferred thermal plasma torches. The overall process, as well as the analysis of byproducts and energy balance, has been presented in this paper to assess the performance of this technology. It was successfully demonstrated that the thermal plasma process converted MSW into innocuous slag, with much lower levels of environmental air pollutant emissions and the syngas having a utility value as energy sources (287 Nm3/MSW-ton for H2 and 395 Nm3/MSW-ton for CO), using 1.14 MWh/MSW-ton of electricity (thermal plasma torch (0.817 MWh/MSW-ton)+utilities (0.322 MWh/MSW-ton)) and 7.37 Nm3/MSW-ton of liquefied petroleum gas.

Gallium-68 is a generator-produced radionuclide for positron emission tomography (PET) that is being increasingly used for radiolabeling of tumor-targeting peptides. Compounds [(68)Ga]3 and [(68)Ga]6 are high-affinity urea-based inhibitors of the prostate-specific membrane antigen (PSMA) that were synthesized in decay-uncorrected yields ranging from 60% to 70% and radiochemical purities of more than 99%. Compound [(68)Ga]3 demonstrated 3.78 +/- 0.90% injected dose per gram of tissue (%ID/g) within PSMA+ PIP tumor at 30 min postinjection, while [(68)Ga]6 showed a 2 h PSMA+ PIP tumor uptake value of 3.29 +/- 0.77 %ID/g. Target (PSMA+ PIP) to nontarget (PSMA- flu) ratios were 4.6 and 18.3, respectively, at those time points. Both compounds delineated tumor clearly by small animal PET. The urea series of imaging agents for PSMA can be radiolabeled with (68)Ga, a cyclotron-free isotope useful for clinical PET studies, with maintenance of target specificity.

Oral insulin therapy has great potential benefits over conventional therapy for diabetic patients as well as mimicking the physiological fate of insulin. Here we evaluated the characteristics of insulin and deoxycholate-based synthetic N(alpha)-deoxycholyl-L-lysyl-methylester (DCK) complex, and diabetes correction in pancreatectomized canines after oral administration. After the insulin/DCK complexation was made, the insulin's folding structure, stability against digestive enzymes, lipophilicity and permeability to Caco-2 monolayer were evaluated in vitro. Diabetic canines were kept under fasting conditions, and Eudragit-coated gelatin capsules containing insulin or insulin/DCK powder were singly or triply administered. Evaluation of glucodynamics, pharmacokinetics, oral glucose tolerance test (OGTT) and reproducibility were carried out. After complexation with DCK, the folding structure of insulin did not become denatured and the resistance against digestive enzymes was powerfully improved. The lipophilicity and permeability of insulin/DCK (coupling ratio up to 1:10) were also highly increased. The insulin/DCK complex, administered orally into diabetic canines at the doses of 21, 42, and 81 IU/kg, reduced the plasma glucose levels by about 28%, 44% and 67%, respectively, while the plasma insulin concentrations increased. During OGTT, insulin/DCK nearly maintained the normoglycemic state in the diabetic canines, whereas the hyperglycemic state of placebo-treated controls was not corrected. During oral administration of insulin/DCK, it repetitively showed similar therapeutic efficacy in diabetic canines for 3 days. The therapeutic efficacy of insulin/DCK was exhibited in its digestive enzyme resistance, deoxycholate-based lipophilicity for enhancing permeability and intact insulin delivery without chemical modification, providing potential oral therapeutic remedy as an alternative to injectable insulin medication.

The need for an efficacious and safe oral anticoagulant that does not require monitoring has been largely unmet. Many efforts have centered on preparing orally available heparin to improve patient compliance. In this study, novel orally active heparin derivatives (LHD), i.e. low molecular weight heparin (LMWH) conjugated with deoxycholic acid (DOCA), were evaluated in vitro and in vivo for their enhancement effect of oral heparin absorption. After oral administration of 10 mg/kg of water-soluble LHD, Ws-LHD1.5 showed optimum oral efficacy and its bioavailability was about 24% in rats. The oral absorption of LHD1.5 was also enhanced by several solubilizers, among which Poloxamer 407 provided the best results. When 5 mg/kg of LHD1.5 with Poloxamer 407 was orally administered to monkeys, the maximum anti-FXa activity in plasma was 0.26 +/- 0.04 IU/mL and its bioavailability was 17.4%. In a rat thrombosis model, 5 mg/kg of orally administered LHD1.5 formulated with Poloxamer reduced thrombus formation by 63.9 +/- 16.6%, which was higher than the efficacy of clinically used enoxaparin (49.4 +/- 17.8% at 100 IU/kg, sc). Considering the oral absorption efficacy and therapeutic effect, the conjugation ratio was optimized as about 1.5 molecules of DOCA per mole of heparin. Therefore, LHD1.5 with Poloxamer 407 can be further formulated as a solid oral anticoagulant drug.

This work investigated the oxidation chemistry of elemental mercury (Hg(0)) by chlorine-containing species produced indirectly through the gas-to-solid phase reaction between NO(x) gases and NaClO(2) powder (NaClO(2)(s)), where both experiment and simulation results were compared to clarify which species are responsible for the oxidation of Hg(0). At first, we introduced 30 ppm of NO(2) into the pack-bed reactor containing NaClO(2)(s) to produce OClO species and then injected NO and Hg(0) (260 microg/Nm(3)) to Mixer, where the concentration of NO was varied up to 180 ppm and the reaction temperature was set to 130 degrees C. We observed for the first time that the degree of Hg(0) oxidation is completely controlled by the introduced concentration of NO: for example, the oxidation efficiency of Hg(0) is drastically increased to become 100% at near 7 ppm NO, but further increasing NO concentration results in the oxidation efficiency of Hg(0) being gradually decreased. The simulation results indicated that such a propensity of Hg(0) oxidation efficiency to NO concentration can be attributed to the NO concentration-dependent Cl, ClO, and Cl(2) formation which plays a critical role in the oxidation of Hg(0).

NO oxidation is an important prerequisite step to assist selective catalytic reduction at low temperatures (< 250 degrees C). If sodium chlorite powder (NaClO2(s)) can oxidize NO to NO2, the injection of NaClO2(s) can be simply adapted to NO oxidation. Therefore, we explored the reaction pathways of NO oxidation by NaClO2(s). Known concentrations of NO and NO2 in N2 balance were injected into packed-bed reactor containing NaClO2(s) at 130 degreesC. NaClO2(s) oxidized NO to NO2 which reacts again with NaClO2(s) to produce OClO. Comparison of experimental data with simulation results demonstrates that each NO2 molecule removed by the reaction with NaClO2(s) generated one OClO molecule, which also oxidized NO to NO2 with the production of ClNO and ClNO2. Using these results, we conclude that the oxidation of NO by NaClO2(s) occurred by two pathways. One is through the direct reaction of NO with NaClO(s). The other is through both the reaction of NO with OlCO produced by the reaction of NO2 with NaClO2(s) and the reaction of NO with ClO produced by the reaction of NO with OClO.

To extend our development of new imaging agents targeting the prostate-specific membrane antigen (PSMA), we have used the versatile intermediate 2-[3-(5-amino-1-carboxy-pentyl)-ureido]-pentanedioic acid (Lys-C(O)-Glu), which allows ready incorporation of radiohalogens for single photon emission computed tomography (SPECT) and positron emission tomography (PET). We prepared 2-[3-[1-carboxy-5-(4-[(125)I]iodo-benzoylamino)-pentyl]-ureido]-pentanedioic acid ([(125)I]3), 2-[3-[1-carboxy-5-(4-[(18)F]fluoro-benzoylamino)-pentyl]-ureido]-pentanedioic acid ([(18)F]6), and 2-(3-[1-carboxy-5-[(5-[(125)I]iodo-pyridine-3-carbonyl)-amino]-pentyl]-ureido)-pentanedioic acid ([(125)I]8) in 65-80% (nondecay-corrected), 30-35% (decay corrected), and 59-75% (nondecay-corrected) radiochemical yields. Compound [(125)I]3 demonstrated 8.8 +/- 4.7% injected dose per gram (%ID/g) within PSMA(+) PC-3 PIP tumor at 30 min postinjection, which persisted, with clear delineation of the tumor by SPECT. Similar tumor uptake values at early time points were demonstrated for [(18)F]6 (using PET) and [(125)I]8. Because of the many radiohalogenated moieties that can be attached via the epsilon amino group, the intermediate Lys-C(O)-Glu is an attractive template upon which to develop new imaging agents for prostate cancer.

Urea-based, low molecular weight ligands of glutamate carboxypeptidase II (GCPII) have demonstrated efficacy in various models of neurological disorders and can serve as imaging agents for prostate cancer. To enhance further development of such compounds, we determined X-ray structures of four complexes between human GCPII and urea-based inhibitors at high resolution. All ligands demonstrate an invariant glutarate moiety within the S1' pocket of the enzyme. The ureido linkage between P1 and P1' inhibitor sites interacts with the active-site Zn(1)(2+) ion and the side chains of Tyr552 and His553. Interactions within the S1 pocket are defined primarily by a network of hydrogen bonds between the P1 carboxylate group of the inhibitors and the side chains of Arg534, Arg536, and Asn519. Importantly, we have identified a hydrophobic pocket accessory to the S1 site that can be exploited for structure-based design of novel GCPII inhibitors with increased lipophilicity.

The prostate-specific membrane antigen (PSMA) is increasingly recognized as a viable target for imaging and therapy of cancer. We prepared seven (99m)Tc/Re-labeled compounds by attaching known Tc/Re chelating agents to an amino-functionalized PSMA inhibitor (lys-NHCONH-glu) with or without a variable length linker moiety. K i values ranged from 0.17 to 199 nM. Ex vivo biodistribution and in vivo imaging demonstrated the degree of specific binding to engineered PSMA+ PC3 PIP tumors. PC3-PIP cells are derived from PC3 that have been transduced with the gene for PSMA. Despite demonstrating nearly the lowest PSMA inhibitory potency of this series, [(99m)Tc(CO)3( L1)] (+) ( L1 = (2-pyridylmethyl)2N(CH2) 4CH(CO2H)NHCO-(CH2) 6CO-NH-lys-NHCONH-glu) showed the highest, most selective PIP tumor uptake, at 7.9 +/- 4.0% injected dose per gram of tissue at 30 min postinjection. Radioactivity cleared from nontarget tissues to produce a PIP to flu (PSMA-PC3) ratio of 44:1 at 120 min postinjection. PSMA can accommodate the steric requirements of (99m)Tc/Re complexes within PSMA inhibitors, the best results achieved with a linker moiety between the epsilon amine of the urea lysine and the chelator.

We describe new DOC (sodium deoxycholate)-heparin nanoparticles for in vivo tumor targeting and inhibition of angiogenesis based on chemical conjugation and the enhanced permeability and retention (EPR) effect. Heparin has been used as a potent anticoagulant agent for 70 years, and has recently been found to inhibit the activity of growth factors which stimulate the smooth muscle cells around tumor. From the results, DOC and heparin were conjugated by bonding carboxyl groups of heparin with amine groups of aminated sodium deoxycholate. Larger antitumor effects of the DOC-heparin VI (8.5 mol of DOC coupled with 1.0 mol heparin) were achieved in animal studies, compared to heparin alone. We confirmed that the conjugated heparin retained its ability to inhibit binding with angiogenic factor, showing a significant decrease in endothelial tubular formation. These results provide new insights into the nontoxic anticancer drug carrier as well as the design of multifunctional bioconjugates for targeted drug delivery.

3-[5-{2-(2,3-Dihydroxyprop-1-yl)-o-carboran-1-yl}pentan-1-yl]thymidine (compound 1, N5-2OH) belongs to a novel class of boron delivery agents for neutron capture therapy, which was designated 3-carboranylthymidine analogue (3CTAs). Two shorter and more convenient synthetic routes were developed for the synthesis of 1 in the 10B-enriched form, which is necessary for its preclinical and clinical evaluation in neutron irradiation studies. For more insight on structure-activity relationships, various stereochemical and geometrical isomers of 1 were synthesized and their specificities as substrate for human thymidine kinase 1 (hTK1) were evaluated. A computational model for the binding of various isomers of 1 to the active site of hTK1 was developed. Preliminary studies carried out in F98 glioma bearing rats that had received a 10B-enriched form of 1 followed by neutron irradiation demonstrated a significant prolongation in survival times compared to control animals, suggesting that further studies are warranted to evaluate the therapeutic potential of 1.

The syntheses of the bright deep blue emitting mixed ligand Ir(III) complexes comprising two cyclometalating, one phosphine and one cyano, ligands are reported. In this study, a firm connection between the nature of the excited states and the physicochemical behavior of the complexes with different ligand systems is elucidated by correlating the observed crystal structures, spectroscopic properties, and electrochemical properties with the theoretical results obtained by the density functional theory (DFT) methods. The cyclometalating ligands used here are the anions of 2-(4',6'-difluorophenyl)-pyridine (F2ppy), 2-(4',6'-difluorophenyl)-4-methyl pyridine (F2ppyM), and 4-amino-2-(4',6'-difluorophenyl)-pyridine (DMAF2ppy). The phosphine ligands are PhP(O-(CH2CH2O)3-CH3)2 and Ph2P(O-(CH2CH2O)n-CH3), where Ph = phenyl and n = 1 (P1), 3 (P3), or 8 (P350). The thermal stabilities of the complexes were enhanced upon increasing the "n" value. The crystal structures of the complexes, [(DMAF2ppy)2Ir(P1)CN], (P1)DMA, and [(F2ppyM)2Ir(P3)CN], (P3)F2M, show the cyano and phosphine groups being in a cis configuration to each other and in a trans configuration to the coordinating Cring atoms. The long Ir-Cring bond lengths are ascribed to the trans effect of the strong phosphine and cyano ligands. DFT calculations indicate that the highest occupied molecular orbital (HOMO) is mainly contributed from the d-orbitals of the iridium atom and the pi-orbitals of cyclometalating and cyano ligands, whereas the lowest unoccupied molecular orbital (LUMO) spreads over only one of the cyclometalating ligands, with no contribution from phosphine ligands to both frontier orbitals. Dimethylamino substitution increases the energy of the emitting state that has more metal-to-ligand-charge-transfer (MLCT) character evidenced by the smaller vibronic progressions, smaller difference in the 1MLCT and 3MLCT absorption wavelengths, and higher extinction coefficients (epsilon) than the F2ppy and F2ppyM complexes. However, the increase in the basicity of the dimethylamino group in the DMAF2ppy complexes in the excited states leads to distortions and consequent nonradiative depopulation of the excited states, decreasing their lower photoluminescence (PL) efficiency. The effect of the substituents in the phosphine ligand is more pronounced in the electroluminescence (EL) than in the PL properties. Multilayer organic light emitting devices (OLEDs) are fabricated by doping the Ir(III) complexes in a blend of mCP (m-bis(N-carbazolyl benzene)) and polystyrene, and their device characteristics are studied. The (P3)F2M complex shows a maximum external quantum efficiency (etaex) of 2%, a maximum luminance efficiency (etaL) of 4.13 cd/A at 0.04 mA/cm2, and a maximum brightness of 7200 cd/m2 with a shift of the Commission Internationale de L'Eclairage (CIE) coordinates from (0.14, 0.15) in film PL to (0.19, 0.34) in EL.

Bile acids have been considered very useful in the preparation of new pharmaceuticals, and more recently in the preparation of peptide and protein drugs because of their natural chemical and biological properties. In this study, we modified recombinant human insulin by covalently attaching deoxycholic acid (DOCA) derivatives in order to synthesize orally active insulin analogues. DOCA derivatives, namely succinimido deoxycholate and succinimido bisdeoxycholyl-L-lysine were prepared and site specifically conjugated at Lys(B29) of insulin. The resultant insulin conjugates, [N(B29)-deoxycholyl] insulin (Ins-DOCA) and [N(B29)-bisdeoxycholyl-L-lysil] insulin (Ins-bisDOCA), were studied for their chemical, structural, and biological properties. Their chemical properties were determined by HPLC, MALDI-TOF mass spectroscopy, and dynamic light scattering. Lipophilicity and self-aggregation behavior of insulin conjugates were enhanced with increasing number of labeled bile acid. The far-ultraviolet region of circular dichroism spectra showed no significant change of the tertiary structure of insulin in aqueous solution due to conjugation. Competitive insulin binding assay with HepG2 cells revealed that monosubstituted insulin conjugates still retained high binding affinity to the insulin receptor. When the insulin conjugates were intravenously administered (0.33 IU/kg) to streptozotocin (STZ)-induced diabetic rats, the conjugates showed sustained biological activity for a longer period with the similar lowest blood glucose level (glucose nadir), compared to native insulin. In further studies, the resulting new insulin conjugates will be investigated for their oral efficiency as a long-acting insulin formulation for the treatment of diabetic patients.

Glucagon-like peptide-1-(7-36) (GLP-1) is a hormone derived from the proglucagon molecule, which is considered a highly desirable antidiabetic agent mainly due to its unique glucose-dependent stimulation of insulin secretion profiles. However, the development of a GLP-1-based pharmaceutical agent has a severe limitation due to its very short half-life in plasma, being primarily degraded by dipeptidyl peptidase IV (DPP-IV) enzyme. To overcome this limitation, in this article we propose a novel and potent DPP-IV-resistant form of a poly(ethylene glycol)-conjugated GLP-1 preparation and its pharmacokinetic evaluation in rats. Two series of mono-PEGylated GLP-1, (i) N-terminally modified PEG(2k)-N(ter)-GLP-1 and (ii) isomers of Lys(26), Lys(34) modified PEG(2k)-Lys-GLP-1, were prepared by using mPEG-aldehyde and mPEG-succinimidyl propionate, respectively. To determine the optimized condition for PEGylation, the reactions were monitored at different pH buffer and time intervals by RP-HPLC and MALDI-TOF-MS. The in vitro insulinotropic effect of PEG(2k)-Lys-GLP-1 showed comparable biological activity with native GLP-1 (P = 0.11) in stimulating insulin secretion in isolated rat pancreatic islet and was significantly more potent than the PEG(2k)-N(ter)-GLP-1 (P < 0.05) that showed a marked reduced potency. Furthermore, PEG(2k)-Lys-GLP-1 was clearly resistant to purified DPP-IV in buffer with 50-fold increased half-life compared to unmodified GLP-1. When PEG(2k)-Lys-GLP-1 was administered intravenously and subcutaneously into rats, PEGylation improved the half-life, which resulted in substantial improvement of the mean plasma residence time as a 16-fold increase for iv and a 3.2-fold increase for sc. These preliminary results suggest a site specifically mono-PEGylated GLP-1 greatly improved the pharmacological profiles; thus, we anticipated that it could serve as potential candidate as an antidiabetic agent for the treatment of non-insulin-dependent diabetes patients.

Novel 3-carboranyl thymidine analogues (3CTAs) were synthesized as potential boron delivery agents for boron neutron capture therapy (BNCT). This library includes six zwitterionic NH(3)(+)-nido-m-carborane-substituted thymidine analogues (Thds) and the corresponding neutral NH(2)-closo-m-carborane-substituted counterparts. All compounds of this library were good substrates for recombinant human thymidine kinase 1 (TK1) with phosphorylation rates up to 89% relative to that of Thd. One compound out of this library, 3-[3-(7-NH(3)(+)-nido-m-carboran-1-yl)propan-1-yl]thymidine (19b), showed selective retention in TK1-expressing murine L929 wild-type tumors versus L929 TK1 (-) tumors in biodistribution studies. The biological evaluation of the zwitterionic NH(3)(+)-nido-m-carborane-substituted Thds indicated improved aqueous solubility and similar or even superior potential as BNCT agents compared with different classes of 3CTAs (Cancer Res. 2004, 64, 6280-6286 and 6287-6295). To complete previous structure-activity relationship (SAR) studies, 3-[(closo-o-carboranyl)methyl]thymidine (4) was also synthesized and evaluated.

Various deoxycholic acid (DOCA) bearing heparin (HD) amphiphilic conjugates with different degrees of substitution (DS) with DOCA were synthesized using heparin as a hydrophilic segment and DOCA as a hydrophobic segment. Structural characteristics of these HD conjugates were investigated using 1H NMR, dynamic light scattering, zeta potential, transmission electron microscopy (TEM), and fluorescence spectroscopy. HD conjugates provided monodispersed self-aggregates in water, with mean diameters decreasing with increasing DOCA DS in the range of 120-200 nm. HD aggregates were covered with negatively charged heparin shells, exhibiting xi potentials near -56 mV. The critical aggregation concentration (cac) of the HD (0.02-0.003 mg/mL) depended upon DOCA DS. TEM images demonstrated that the shape of the self-aggregates was spherical. Partition equilibrium constants, Kv, for pyrene in the self-aggregates in water indicated that increasing DS enhanced the hydrophobicity of the self-aggregate inner core. The mean aggregation number of DOCA per hydrophobic microdomain, estimated by the fluorescence quenching methods using cetylpyridinium chloride, indicated that five to nine of HD chains comprised a hydrophobic domain in the conjugates.

We have prepared a chemically anchored monolayer of PEG (poly(ethylene glycol)) and phospholipid mixture (PEG/phospholipid) on a methacryloyl-terminated substrate by in situ photopolymerization. Both monoacryloyl phospholipid (acryloyl-PC, 1-palmitoyl-2-[12-(acryloyloxy)dodecanoyl]-sn-glycero-3-phosphocholine) and monoacryloyl PEG (acryloyl-PEG, 12-(acryloyloxy)dodecanoyl-PEG) were synthesized by modifyingphospholipid and PEGwith 12-(acryloyloxy)-1-dodecanoic acid and 12-(acryloyloxy)-1-dodecanol, respectively. The surface pressure-area (pi-A) isotherm showed that acryloyl-PEG molecules were stable in the phospholipid monolayer and that they could be evenly inserted into a phospholipid monolayer at the air/water interface. By adding 10 mol % acryloyl-PEG into phosholipid vesicles, we could produce a PEG/phosholipid monolayer on methacryloyl-terminated substrates using vesicle fusion for 3 h. Then, this polymerizable PEG/phospholipid monolayer was in situ photopolymerized onto a methacryloyl-terminated substrate with eosin Y/triethanolamine as co-initiators. Optimal vesicle fusion and irradiation condition were determined with respect to the vesicle fusion time and duration of irradiation. As confirmed by atomic force microscopy and X-ray reflectivity studies, the polymerized PEG/phosholipid surface formed a PEG-covered phospholipid monolayer with thicknesses of 3 and 6 nm for the base phospholipid monolayer and the covering PEG layer, respectively. The chemical anchoring efficiency ofpolymerized PEG and phospholipid molecules, which was calculated by the relative carbon ratio of each surface before and after methanol washing using X-ray photoelectron spectroscopy, was 98%. This polymerized PEG/phosholipid monolayer showed good stability in organic solution due to firm chemical anchoring to a solid surface.

5-Aryl-2,2-dialkyl-4-phenyl-3(2H)furanone derivatives were studied as a novel class of selective cyclooxygenase-2 inhibitors with regard to synthesis, in vitro SAR, antiinflammatory activities, pharmacokinetic considerations, and gastric safety. 1f, a representative compound for methyl sulfone derivatives, showed a COX-2 IC(50) comparable to that of rofecoxib. In case of 20b, a representative compound for sulfonamide derivatives, a potent antiinflammatory ED(50) of 0.1 mg kg(-1) day(-1) was observed against adjuvant-induced arthritis by a preventive model, positioning 20b as one of the most potent COX-2 inhibitors ever reported. Furthermore, 20b showed strong analgesic activity as indicated by its ED(50) of 0.25 mg/kg against carrageenan-induced thermal hyperalgesia in the Sprague-Dawley rat. 3(2H)Furanone derivatives showed due gastric safety profiles as selective COX-2 inhibitors upon 7-day repeat dosing. A highly potent COX-2 inhibitor of the 3(2H)furanone scaffold could be considered suitable for a future generation COX-2 selective arthritis medication with improved safety profiles.

Synthesis, structures, and unusual solution dynamic processes of d(10) metal complexes of hexakis(3,5-dimethylpyrazolyl)cyclotriphosphazene (L) are reported. Reaction systems with three MX(n):L mole ratios (MX(n) = d(10) metal halide) in CH(2)Cl(2) have resulted in the formation of [ICu(&mgr;,eta(3),eta(3)-L)CuI] (1), [Cl(2)Zn(&mgr;,eta(2),eta(3)-L)ZnCl(2)] (2), [Cl(2)Cd(&mgr;,eta(3),eta(3)-L)CdCl(2)] (3), and [(eta(3)-L)HgCl(2)] (4). These compounds were characterized by single crystal X-ray diffraction studies, and crystallographic data are given in the order of compound: crystal system; space group; unit cell parameters; Z; unique data (I > 2sigma(I)); R(1). 1.0.5CH(2)Cl(2): monoclinic; P2(1)/c; a = 8.268(4) Å; b = 22.365(5) Å; c = 23.325(8) Å, beta = 93.06(1) degrees; 4; 5736; 4.82. 2.CH(3)CN: monoclinic; P2(1)/c; a = 17.021(3) Å; b = 12.161(2) Å; c = 23.608(5) Å; beta = 107.72(1) degrees; 4; 5469; 3.16. 3.CH(2)Cl(2): monoclinic; P2(1)/n; a = 18.585(5) Å; b = 17.585(4) Å; c = 14.404(3) Å; beta = 102.71(2) degrees; 4; 3814; 3.65. The structure of 4 was attempted but resulted in data of low precision. Reaction of L with CuI and ZnCl(2) in an equimolar ratio afforded [ICu(&mgr;,eta(3),eta(3)-L)ZnCl(2)] (5) which crystallizes in monoclinic space group P2(1)/n with a = 22.876(5) Å, b = 21.594(4) Å, c = 9.177(2) Å, beta = 93.54(2) degrees, Z = 4, and R(1) = 7.00 for 3806 (I > 2sigma(I)) data. In all cases, metal halide centers except the Td zinc site in 2 are coordinated by L via a kappa(3)N binding core consisting of two nongeminal pyrazolyl nitrogen atoms and one phosphazene ring nitrogen atom. The eta(2)-N(2) coordination in 2 involves two geminal pyrazolyl nitrogen atoms. Factors which govern the nuclearity of the complex were partially demonstrated. The intermetallic distances in dinuclear metallophosphazenes range from 6.790 to 7.195 Å. The solution behavior of five compounds was studied by variable temperature (31)P{(1)H}, (1)H, and (113)Cd FT NMR spectroscopy. Compounds 1 and 4 are associated with fluxional motions involving A(2)B low-temperature limit spectrum while compounds 2 and 5 show solvent-dependent dynamic processes with ABX and A(2)B low-temperature limit spectral patterns. Compounds 3 constitutes a fluxional system involving three A(2)B species. Accounts of solution NMR spectra were attempted by using PANIC, by assuming the formation of new solution metallophosphazene species and by considering several types of dynamic processes such as a ring-around type hopping motion for the kappa(3)N metal site, a Td conformational change for the geminal pyrazolyl kappa(2)N metal site, and a wigwag motion for the nongeminal pyrazolyl kappa(2)N metal unit.