- Synthesis of new, pyrene-containing, metal-chelating lipids and sensing of cupric ions
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(Matrix presented) The syntheses of several saturated, pyrene-containing, metal-chelating lipids are described. These lipids are capable of strongly binding to transition metal ions employing the metal-chelating headgroup. The excimer-to-monomer ratio of
- Roy, Bidhan C.,Chandra, Binita,Hromas, Daniel,Mallik, Sanku
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Read Online
- LIPID PRODRUGS OF NEUROSTEROIDS
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The present invention provides lymphatic system-directing lipid prodrugs, pharmaceutical compositions thereof, methods of producing such prodrugs and compositions, as well as methods of improving the bioavailability or other properties of a therapeutic agent that comprises part of the lipid prodrug. The present invention also provides methods of treating a disease, disorder, or condition such as those disclosed herein, comprising administering to a patient in need thereof a disclosed lipid prodrug or a pharmaceutical composition thereof.
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Paragraph 00381-00382
(2021/08/13)
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- Synthesis of α,ω-Diketodiesters from Betulin
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A new synthesis of 3-oxo-28-hydroxylup-20(29)-ene from the available natural triterpenoid betulin was developed. α,ω-Diketodiesters were prepared for the first time by different methods from 3-oxo-28-hydroxylup-20(29)-ene and a series of natural dicarboxylic acids. Steglich reaction conditions gave the highest yields. One of the synthesized α,ω-diketodiesters was moderately active in vitro against A-549 lung carcinoma.
- Ishmuratov, G. Yu.,Sayakhov, R. R.,Talipov, R. F.,Vydrina, V. A.,Yakovleva, M. P.,Zileeva, Z. R.
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p. 706 - 711
(2021/07/31)
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- LIPID PRODRUGS OF JAK INHIBITORS AND USES THEREOF
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The present invention provides lymphatic system-directing lipid prodrugs, pharmaceutical compositions thereof, methods of producing such prodrugs and compositions, and methods of improving the bioavailability or other properties of a therapeutic agent that comprises part of the lipid prodrug. The present invention also provides methods of treating a disease, disorder, or condition such as those disclosed herein, comprising administering to a patient in need thereof a disclosed lipid prodrug or a pharmaceutical composition thereof.
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Paragraph 00450-00451
(2020/09/12)
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- LIPID PRODRUGS OF PREGNANE NEUROSTEROIDS AND USES THEREOF
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The present invention provides lymphatic system-directing lipid prodrugs, pharmaceutical compositions thereof, methods of producing such prodrugs and compositions, as well as methods of improving the bioavailability or other properties of a therapeutic agent that comprises part of the lipid prodrug. The present invention also provides methods of treating a disease, disorder, or condition such as those disclosed herein, comprising administering to a patient in need thereof a disclosed lipid prodrug or a pharmaceutical composition thereof.
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Paragraph 00331; 00332
(2020/02/23)
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- LIPID PRODRUGS OF BTK INHIBITORS AND USES THEREOF
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The present invention provides lymphatic system-directing lipid prodrugs, pharmaceutical compositions thereof, methods of producing such prodrugs and compositions, and methods of improving the bioavailability or other properties of a therapeutic agent that comprises part of the lipid prodrug. The present invention also provides methods of treating a disease, disorder, or condition such as those disclosed herein, comprising administering to a patient in need thereof a disclosed lipid prodrug or a pharmaceutical composition thereof.
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Paragraph 00405; 00459; 00460
(2020/09/12)
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- LIPID PRODRUGS OF GLUCOCORTICOIDS AND USES THEREOF
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The present invention provides lymphatic system-directing lipid prodrugs, pharmaceutical compositions thereof, methods of producing such prodrugs and compositions, and methods of improving the bioavailability or other properties of a therapeutic agent that comprises part of the lipid prodrug. The present invention also provides methods of treating a disease, disorder, or condition such as those disclosed herein, comprising administering to a patient in need thereof a disclosed lipid prodrug or a pharmaceutical composition thereof.
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Paragraph 00444
(2020/09/12)
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- LYMPHATIC SYSTEM-DIRECTING LIPID PRODRUGS
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The present invention provides lymphatic system-directing lipid prodrugs, pharmaceutical compositions thereof, methods of producing such prodrugs and compositions, as well as methods of improving the bioavailability or other properties of a therapeutic agent that comprises part of the lipid prodrug. The present invention also provides methods of treating a disease, disorder, or condition such as those disclosed herein, comprising administering to a patient in need thereof a provided lipid prodrug or a pharmaceutical composition thereof.
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Paragraph 00460; 00461
(2019/03/17)
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- Symmetric dimeric adamantanes for exploring the structure of two viroporins: Influenza virus M2 and hepatitis C virus p7
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Background: Adamantane-based compounds have been identified to interfere with the ion-channel activity of viroporins and thereby inhibit viral infection. To better understand the difference in the inhibition mechanism of viroporins, we synthesized symmetric dimeric adamantane analogs of various alkyl-spacer lengths. Methods: Symmetric dimeric adamantane derivatives were synthesized where two amantadine or rimantadine molecules were linked by various alkyl-spacers. The inhibitory activity of the compounds was studied on two viroporins: the influenza virus M2 protein, expressed in Xenopus oocytes, using the two-electrode voltage-clamp technique, and the hepatitis C virus (HCV) p7 channels for five different genotypes (1a, 1b, 2a, 3a, and 4a) expressed in HEK293 cells using whole-cell patch-clamp recording techniques. Results: Upon testing on M2 protein, dimeric compounds showed significantly lower inhibitory activity relative to the monomeric amantadine. The lack of channel blockage of the dimeric amantadine and rimantadine analogs against M2 wild type and M2-S31N mutant was consistent with previously proposed drug-binding mechanisms and further confirmed that the pore-binding model is the pharmacologically relevant drug-binding model. On the other hand, these dimers showed similar potency to their respective monomeric analogs when tested on p7 protein in HCV genotypes 1a, 1b, and 4a while being 700-fold and 150-fold more potent than amantadine in genotypes 2a and 3a, respectively. An amino group appears to be important for inhibiting the ion-channel activity of p7 protein in genotype 2a, while its importance was minimal in all other genotypes. Conclusion: Symmetric dimeric adamantanes can be considered a prospective class of p7 inhibitors that are able to address the differences in adamantane sensitivity among the various genotypes of HCV.
- Mandour, Yasmine M.,Breitinger, Ulrike,Ma, Chunlong,Wang, Jun,Boeckler, Frank M.,Breitinger, Hans-Georg,Zlotos, Darius P.
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p. 1019 - 1031
(2018/05/22)
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- Synthesis of bis-4H-furo[3,4-b]indoles
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We describe the synthesis of two novel bis-4H-furo[3,4-b]indoles from indole. Several alternative pathways to these potential DNA bis-intercalator precursors are discussed, and the synthesis of a novel semi-rigid tether is reported.
- McGowan, Meredeth A.,Perreault, Denise M.,Thornton, Nancy B.,Garaas, Sarah D.,Gribble, Gordon W.
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p. 334 - 347
(2018/09/10)
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- RUBBER COMPOSITION AND VULCANIZATION AID
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A rubber composition comprising a compound having one or more groups represented by formula (X) and a rubber component is provided. wherein ring W1 represents a cyclic group having at least one selected from the group consisting of —C(═O)— and
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Paragraph 0133
(2017/08/01)
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- Thermotropic liquid crystalline polyesters derived from 2-chloro hydroquinone
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Abstract: Synthesis of thermotropic liquid crystalline polyesters derived from bis[4-hydroxy benzoyloxy]-2-chloro-1,4-benzene (BHBOCB) and aliphatic dicarboxylic acid chlorides by interfacial polycondensation methodology is presented. Synthesised polyesters consist of bis[4-hydroxy benzoyloxy]-2-chloro-1,4-benzene as a mesogen and aliphatic diacid chloride as flexible spacer. The length of oligomethylene units in the polymer was varied from the trimethylene to the dodecamethylene groups. Synthesized polyesters were characterized by differential scanning calorimetry and optical microscopy. The transition temperatures and thermodynamic properties were studied for all these polymers. These polyesters exhibited thermotropic liquid crystalline behavior and showed nematic texture except decamethylene spacer. Decamethylene spacer based polyester showed marble texture of smectic C. Mesophase stability of these polyesters was higher than 123 °C (except first heating cycle of PE-1). Graphical Abstract:: SYNOPSIS The present study deals with the synthesis of thermotropic liquid crystalline polyesters derived from bis[4-hydroxy benzoyloxy]-2-chloro-1,4-benzene (BHBOCB) and aliphatic dicarboxylic acid chlorides by interfacial polycondensation methodology. [Figure not available: see fulltext.].
- Manurkar, Nagesh,More, Sayaji,Mulani, Khudbudin,Ganjave, Nitin,Chavan, Nayaku
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p. 1461 - 1468
(2017/09/27)
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- A new route to α,ω-diamines from hydrogenation of dicarboxylic acids and their derivatives in the presence of amines
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A new and selective route for the synthesis of polymer precursors, primary diamines or N-substituted diamines, from dicarboxylic acids, diesters, diamides and diols using a Ru/triphos catalyst is reported. Excellent conversions and yields are obtained under optimised reaction conditions. The reactions worked very well using 1,4-dioxane as solvent, but the greener solvent, 2-methyl tetrahydrofuran, also gave very similar results. This method provides a potential route to converting waste biomass to value added materials. The reaction is proposed to go through both amide and aldehyde pathways.
- Shi, Yiping,Kamer, Paul C. J.,Cole-Hamilton, David J.
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supporting information
p. 5460 - 5466
(2017/11/22)
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- A twelve-carbon acyl-synthesis method of aspartic acid ammonium salt
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The invention discloses a synthetic method of n-dodecanoyl di(ammonium aspartate), which is characterized in that cyclohexane is taken as a solvent, caprolactam is taken as a catalyst, dodecanedioic acid and thionyl chloride are subjected to a backflow reaction to generate dodecanedioic dichloride; a mixture of dodecanedioic acid and dodecanedioic dichloride is reacted in a tetrahydrofuran solvent of sodium aspartate, charging is carried out, pH is adjusted to 9-10 by an acid binding agent during a reaction process to generate the n-dodecanoyl di(sodium aspartate), the reaction material is diluted by water, and is slowly added with an acid solution, pH is adjusted to about 1.0, a solid product is precipitated, products are repeatedly washed by water to obtain the n-dodecanoyl di(aspartic acid); the n-dodecanoyl di(aspartic acid) is added in concentrated ammonia liquor, and is subjected to the processes of stirring, dissolving, heating, cooling, crystallization and drying to obtain the n-dodecanoyl di(ammonium aspartate), the compound has strong antirust effect, has the effects of calcium and magnesium ion complexation, and has antiwear/antifriction effect.
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Paragraph 0023-0031
(2017/09/02)
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- Synthesis and bio-evaluation of Tc-99 m-labeled fatty acid derivatives for myocardial metabolism imaging
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11C, 18F and 123I fatty acids are used for myocardial imaging, and 99mTc-labeled fatty acids are more desirable substitutes than other radiolabeled fatty acids. In the work reported, [99mTc]-CpTT-10-oxo-FPA (1c), [99mTc]-CpTT-12-oxo-FPA (2c), [99mTc]-CpTT-14-oxo-FPA (3c) and [99mTc]-CpTT-16-oxo-FPA (4c) were prepared with 60.76–70.92% of radiochemical yield and purity of more than 95%. These radiotracers (1c, 2c, 3c, 4c) were chemically stable when incubated in Sprague Dawley rat serum for 3 h at 37 °C. Tissue distribution studies in female mice indicated that 2c had high initial heart uptake (8.84%ID g?1 at 1 min post-injection) and 4c had long retention in the heart (1.45%ID g?1 at 30 min post-injection). Metabolite analysis showed 4c could be metabolized to 5c via β-oxidation with loss of two ?CH2? in the myocardium, the radiometabolite being excreted via urine. However, low heart uptake suggested that 4c cannot be used as a diagnostic imaging agent. Copyright
- Liu, Jianping,Xue, Qianqian,Wang, Huan,Wang, Hang,Wang, Dawei,Fang, Yu,Zhang, Huabei
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p. 596 - 604
(2016/07/16)
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- Investigation of novel ropinirole analogues: Synthesis, pharmacological evaluation and computational analysis of dopamine D2 receptor functionalized congeners and homobivalent ligands
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Herein, we report the development of novel functionalized congeners of ropinirole toward the design of pharmacological tools to probe structural requirements at the dopamine D2 receptor. Subsequently, we have used the functionalized amine congener 11 and synthesized and pharmacologically evaluated a series of homobivalent ligands of ropinirole with designated spacer lengths ranging from 14 to 30 atoms. The most potent homobivalent ligands (22-, 26- and 30-atom spacers) showed approximately 20- to 80-fold greater potency (EC50 = 3.9, 6.2 and 14 nM, respectively) than ropinirole (304 nM) in a [35S]GTPγS functional assay. Molecular modeling studies suggest that the observed increase in potency of the homobivalent ligands is possibly due to a bitopic binding mode involving the orthosteric site and an allosteric interaction at the dopamine D2 receptor protomer rather than bridging interactions at two orthosteric sites across a dopamine D 2 receptor dimer. This research has the potential to advance the development of structurally related bitopic ligands, biomarkers such as radioligands and fluorescently labeled probes, and furnish new homo- and heterobivalent ligands towards a better understanding of the dopamine D 2 receptor and potential novel treatment for Parkinson's disease.
- J?rg, Manuela,Kaczor, Agnieszka A.,Mak, Frankie S.,Lee, Kiew Ching K.,Poso, Antti,Miller, Neil D.,Scammells, Peter J.,Capuano, Ben
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supporting information
p. 891 - 898
(2014/07/08)
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- Synthesis and binding profile of haloperidol-based bivalent ligands targeting dopamine D2-like receptors
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Homodimers of dopamine D2-like receptors are suggested to be of particular importance in the pathophysiology of schizophrenia and, thus, serve as promising targets for the discovery of atypical antipsychotics. This study describes the development of a series of novel bivalent molecules with a pharmacophore derived from the dopamine receptor antagonist haloperidol. These dimers were investigated in comparison to their monomeric analogues for their D2long, D2short, D3, and D4 receptor binding and the ability to bridge two neighboring receptor protomers. Radioligand binding studies provided diagnostic insights when Hill slopes close to two for the bivalent ligand 13 incorporating 22 spacer atoms and a comparative analysis with monovalent control ligands indicated a bivalent binding mode with a simultaneous occupancy of two neighboring binding sites.
- Salama, Ismail,L?ber, Stefan,Hübner, Harald,Gmeiner, Peter
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supporting information
p. 3753 - 3756
(2014/09/16)
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- Prodrugs of N-dicarboximide derivatives of the rat selective toxicant norbormide
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Norbormide [5-(α-hydroxy-α-2-pyridylbenzyl)-7-(α-2- pyridylbenzylidene)-5-norbornene-2,3-dicarboximide] (NRB), an existing but infrequently used rodenticide, is known to be uniquely toxic to rats but relatively harmless to other rodents and mammals. However, one major drawback of NRB as a viable rodenticide relates to an evolutionary aversion developed by the rat leading to sub-lethal dosing due to either its unpleasant 'taste' or rapid onset of effects. A series of NRB-derived prodrugs were prepared in an effort to 'mask' this acute response. Their synthesis and biological evaluation (in vitro vasoconstrictory activity, in vitro hydrolytic and enzymatic stability and lethality/palatability in vivo) is described. Prodrug 2 displayed the most promising profile with respect to a delay in the onset of symptoms and was subsequently demonstrated to be significantly more palatable to rats. Moreover, prodrug 25 was found to be largely accepted by rats in a choice trial, resulting in high mortality.
- Rennison, David,Laita, Olivia,Conole, Daniel,Jay-Smith, Morgan,Knauf, Jan,Bova, Sergio,Cavalli, Maurizio,Hopkins, Brian,Linthicum, Darwin S.,Brimble, Margaret A.
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supporting information
p. 5886 - 5899
(2013/09/12)
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- Titanium(IV) enolates of 2-nitrocarboxylic esters and their oxidative chlorinationa convenient route to α-chloro-α-nitrocarboxylates
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A new method for the synthesis of 2-chloro-2-nitrocarboxylic esters from 2-nitrocarboxylates is described. The procedure consists of the oxidative chlorination of titanium(IV) enolates of 2-nitro esters in the presence of ammonium nitrate. Esters of 2-chloro-2-nitrocarboxylic acids are formed in very good to quantitative yields. Application of this method for the chlorination of α,α′-dinitrodicarboxylates leads to α,α′- dichloro-α,α′-dinitrocarboxylic esters with high meso-diastereoselectivity. The absence of ammonium nitrate from the reaction mixture affects the reduction of nitro groups and leads to partial transformation of 2-nitrocarboxylic esters into 2-(hydroxyimino)carboxylates. Georg Thieme Verlag Stuttgart - New York.
- Ciez, Dariusz,Kalinowska-T?us?cik, Justyna
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supporting information; experimental part
p. 267 - 271
(2012/03/11)
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- Homobivalent ligands of the atypical antipsychotic clozapine: Design, synthesis, and pharmacological evaluation
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To date all typical and atypical antipsychotics target the dopamine D 2 receptor. Clozapine represents the best-characterized atypical antipsychotic, although it displays only moderate (submicromolar) affinity for the dopamine D2 receptor. Herein, we present the design, synthesis, and pharmacological evaluation of three series of homobivalent ligands of clozapine, differing in the length and nature of the spacer and the point of attachment to the pharmacophore. Attachment of the spacer at the N4′ position of clozapine yielded a series of homobivalent ligands that displayed spacer-length-dependent gains in affinity and activity for the dopamine D 2 receptor. The 16 and 18 atom spacer bivalent ligands were the highlight compounds, displaying marked low nanomolar receptor binding affinity (1.41 and 1.35 nM, respectively) and functional activity (23 and 44 nM), which correspond to significant gains in affinity (75- and 79-fold) and activity (9- and 5-fold) relative to the original pharmacophore, clozapine. As such these ligands represent useful tools with which to investigate dopamine receptor dimerization and the atypical nature of clozapine.
- McRobb, Fiona M.,Crosby, Ian T.,Yuriev, Elizabeth,Lane, J. Robert,Capuano, Ben
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supporting information; experimental part
p. 1622 - 1634
(2012/04/17)
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- Synthesis and characterization of cyclic alkyl tetraynes
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Cyclic (4a-e) and linear (10) tetraynes have been studied. Macrocycles 4a-e are unstable to isolation as neat compounds, but 4b-e have been characterized in solution. 13C NMR spectroscopy shows a consistent downfield shift of the acetylenic resonances of 4c-e as ring strain increases. UV-vis spectroscopy demonstrates that ring strain has little effect on the HOMO-LUMO gap. X-ray crystallography of tetrabromoolefin 6b confirms the monomeric constitution of the precursors.
- Spantulescu, Andreea,Luu, Thanh,Yuming, Zhao,McDonald, Robert,Tykwinski, Rik R.
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p. 609 - 612
(2008/04/05)
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- Hydrogelation agents
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A gelatinizer is provided having a component which promises to have biological compatibility, which can easily be mass-produced by a simple method, and which can solidify a large amount of water or aqueous solution when only a very small weight of it is used. This invention is a hydrogelatinizer represented by the general formula: R-An where A, which may be identical or different, are respectively nucleotides, n is 2 or 3, and R is a hydrocarbon chain (when n is 2, R is bivalent, and when n is 3, R is trivalent), said hydrocarbon being bonded to a phosphoric acid part of said nucleotides.
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Page/Page column 3
(2008/06/13)
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- Syntheses of Phospholipids Containing 2-Nitrobenzyl Ester Moieties at the Terminals of Alkyl Chains and Properties of Photodegradable Liposomes from the Lipids
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Phospholipid 1a bearing 2-nitrobenzyl ester moieties as a photocleavable group at the terminal of alkyl chains was synthesized from the corresponding terminal carboxy-bearing phospholipid 2 by the reaction with 2-nitrophenyl-substituted diazomethane. Phospholipid, 1b bearing α-methyl-2-nitrobenzyl group, 1c bearing 4,5-dimethoxy-2-nitrobenzyl group, and 1d bearing α-methyl-4,5-dimethoxy-2-nitrobenzyl group were similarly synthesized by the use of the respective diazo compounds. The order of photolysis rates of 2-nitrobenzyl ester linkage of phospholipids by ultrahigh-pressure mercury lamp is 1b≥1d > 1a > 1c. Liposomes of 1a-1d containing calcein in the inner aqueous layer were prepared by vortexing, sonication, and gel-filtration. UV irradiation resulted in fast release of the entrapped fluorescence dye. The order of release rates : 1b≥1d > 1c> 1a is consistent with that of photolysis rates except for 1c, which has poor retention of the dye.
- Yamaguchi, Kazuo,Tsuda, Yoshihiro,Shimakage, Taka-Aki,Kusumi, Akihiro
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p. 1923 - 1929
(2007/10/03)
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- Synthesis of novel α,ω-type 1-glucosamide and 1-galactosamide bolaamphiphiles
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A new family of bolaamphiphiles in which two glucosylamine or galactosylamine moieties are linked via a β-N-glycosdic bond to an α,ω-dicarboxylic acid has been described. The 1-D-glucosamide and 1-D-galactosamide bolaamphiphiles were obtained in good yield by the condensation of the dicarboxylic acid dichloride with the corresponding 1-aldopyranosylamine.
- Masuda, Mitsutoshi,Shimizu, Toshimi
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p. 405 - 416
(2007/10/03)
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- Behavior of Ruthenium Trisbipyridine-Anthraquinone Conjugates Connected with Alkyl Spacers in Homogeneous and Microheterogeneous Media
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A series of mononuclear Ru trisbypiridine complexes connected to an anthraquinone unit by a flexible alkyl chain of varying lengths and a bolaamphiphilic dinuclear ruthenium complex bearing an anthraquinone unit in the middle of alkyl chain spacers were synthesized. Their conformational preference in CH3CN and in dihexadecyl phosphate vesicles was probed by utilizing the intramolecular electron-transfer quenching of the metal-to-ligand charge-transfer excited state of the Ru center by the appended quinone moiety. The length of the alkyl chain spacer had little effect on the quenching efficiency in either medium. A marked difference in the quenching behavior was observed only in the case of the dinuclear Ru complex in vesicles. These results indicate that the bolaamphiphilic structure is necessary and effective for the set of immobilized molecules to take a stretched conformation spanning a bilayer membrane.
- Otsuki, Joe,Ogawa, Hiroyuki,Okuda, Naotoshi,Araki, Koji,Seno, Manabu
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p. 2077 - 2084
(2007/10/03)
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- Bimane cyclic esters, possible stereologues of trypanothione as antitrypanosomal agents. Bimanes 29
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Tricyclic esters derived from bimanes have been synthesized with ring sizes near or equal to that of trypanothione disulfide (T(S)2), a bis-glutathionylspermidine that is involved in regulating the thiol status of Leishmania and other trypanosomatids. Modest activity for many of the compounds against Leishmania donovani with a maximum at the T(S)2 ring size suggests that the esters act as T(S)2 surrogates. However, no inhibition of T(S)2-reductase is observed for a number of the compounds. A series of tricyclic bimane amides with structures more closely analogous to T(S)2 are inactive in biological tests. New approaches were developed for the synthesis of the amides. The surprising effectiveness of the cyclic ester synthesis is explained. Acid chloride formation catalyzed by sulfides is briefly described.
- Kosower,Radkowsky,Fairlamb,Croft,Neal
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p. 659 - 671
(2007/10/02)
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- Synthesis of Cross-Linked Polyamines
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Several synthetic approaches are explored for the preparation of polyamines which are cross-linked at the central, secondary nitrogen moiety.Diethylenetriamine, norspermidine and spermidine were used as examples. - Keywords: Cross-Linked Polyamines, Dieth
- Sosnovsky, George,Lukszo, Jan
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p. 1580 - 1585
(2007/10/02)
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- Ultrathin Monolayer Lipid Membranes from a New Family of Crown Ether-Based Bola-Amphiphiles
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Twelve novel α,Ω-bis(N-azacrown ether) compounds have been prepared, characterized, and converted into a previously unknown type of niosome.Four are bis(15-crown-5) derivatives having the following spacer chains: (CH2)12 (1), (CH2)16 (2), CO(CH2)20CO (3), and (CH2)22 (4).The eight bis(aza-18-crown-6) derivatives have the following spacers: (CH2)10 (5), CO(CH2)10CO (6), (CH2)12 (7), CO(CH2)14CO (8), (CH2)16 (9), (CH2)22 (10), (CH2)12O(CH2)12 (11), and CO(CH2)11S(CH2)12S(CH2)11CO (12).Aggregation studies of 1 and 7, employing transmission electron microscopy as well as dynamic and static light scattering, demonstrate that these compounds form a novel class of spherical monolayer lipid membrane vesicles when dispersed in water.Debye light-scattering profiles obtained from a suspension of large (ca. 200 nm diameter) vesicles indicate a relative refractive index near 1.Dynamic turbidimetry in acidic media on a suspension of bola-amphisomes formed from 1, suggested that the contribution of micelle-vesicle equilibria to the bolyte aggregation state is negligible.In neutral or slightly alkaline pH at 35 deg C, the vesicles grew irreversibly to yield large, probably multilamellar, aggregates.In acidic media at pH 2, the bola-amphisomes do not coalesce, even at 65 deg C.On the basis of the observations presented here, bola-amphiphiles having a hydrocarbon span of 10-12 carbon atoms aggregate in aqueous media into vesicles.When the aliphatic backbone incorporates 16 or more carbon atoms, micelles are formed.
- Munoz, Servando,Mallen, Jesus,Nakano, Akio,Chen, Zhihong,Gay, Isabelle,et al.
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p. 1705 - 1711
(2007/10/02)
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- Lariat Ether Bola-amphiphiles: Formation of Crown Ether Based Bola-amphiphisomes
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The first crown ether-based bola-amphiphiles are prepared and are shown to aggregate into a previously unknown type of niosome.
- Munoz, Servando,Mallen, Jesus V.,Nakano, Akio,Chen, Zhihong,Gay, Isabelle,et al.
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p. 520 - 522
(2007/10/02)
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- Design, synthesis, and activity of membrane-disrupting bolaphiles
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Four new classes of bolaphiles ("double-headed" single-chain surfactants) have been prepared, via condensation of an homologous series of linear saturated, olefinic, and acetylenic α,ω-dicarboxylic acids with hexaethylene glycol, and evaluated for their ability to induce the release of 5(6)-carboxyfluorescein (CF) entrapped within large unilamellar vesicles derived from 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). Operationally, the membrane-disrupting activity of the bolaphiles has been found to vary by a factor of ca. 100, when the total number of carbon atoms which separate the carboxylate moieties range from 12 to 24; the most active bolaphile is approximately three times more active than Triton X-100. When the affinity of the bolaphiles toward POPC membranes is considered, the intrinsic membrane-disrupting activity varies by a factor of ca. 230. A "loop" model is proposed to account for the general trends in bolaphile activity that are observed, where the depth of loop penetration and loop width are presumed to be the key factors involved in determining membrane-disrupting activity. The potential utility of these surfactants as antimicrobial agents, and as anti-HIV agents in particular, is briefly discussed.
- Jayasuriya, Nimal,Bosak, Stanislav,Regen, Steven L.
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p. 5844 - 5850
(2007/10/02)
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- INTRAMOLECULAR END-TO-END REACTIONS OF PHOTOACTIVE TERMINAL GROUPS LINKED BY POLYMETHYLENE CHAINS.
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Intramolecular end-to-end reactions of a pair of photoactive terminal groups, dibenz left bracket b,f right bracket azepine (DBA) chromophores, linked by a series of polymethylene chains (DBA-CO(CH//2)//nCO-DBA, n equals 2-30) were studied by two different approaches. One approach is to measure the intramolecular deactivation rate constants of the excited triplet state of terminal DBA groups by the nanosecond laser photolysis and the other is to measure the intramolecular photocyclization rates of these bichromophoric compounds by the quantitative product analysis with GPC. The excited triplet state of the DBA group is the intermediate of the reaction.
- Ashikaga,Ito,Yamamoto,Nishijima
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p. 198 - 204
(2007/10/02)
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- Micelle-Mimetic Ionene Polyelectrolytes
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The properties of a series of linear cationic polyelectrolytes of the -ionene type (dimethylammonium charge centers interconnected by alternating chain segments containing n and m CH2 groups, respectively) have been investigated in aqueous solution.Ionenes with short segments, i.e., the -ionene and the -ionenes with m -ionenes with m > 14 are quite distinct.Thus, increasing m beyond 14 results in a progressive increase in the net degree of bromide counterion association to the ionene (conductivity data), enhanced solubilization of hydrophobic substrates (pyrene) in a progressively less aqueous environment, a gradual increase in the fluorescence anisotropy of an ionene-adsorbed anionic fluorescein derivative, and an increase in the selctivity of chloride/bromide counterion exchange at the ionene surface.These m-dependent changes in solution properties, which correlate nicely with the m-dependent onset and rise of catalytic activity (acceleration of the rate of alkaline hydrolysis of p-nitrophenyl octanoate), are consistent with a change in ionene conformation, going from extended to progressively more compact (globular or micellelike) as the segment length m is increased beyond 14.Indeed, the observed effects of the -, -, and -ionenes on reaction rate can be quantitatively reproduced by using the pseudophase ion-exchange formalism originally developed for micellar systems.The marked similarity between the -ionene and the CTAB micelle with respect to counterion binding, counterion-exchange selectivity, substrate solubilization, and catalytic rate enhancement suggests that amphiphilic ionenes of this type should be excellent prototypes for the rational design of micelle-mimetic polyelectrolytes.
- Soldi, Valdir,Erismann, Norma de Magalhaes,Quina, Frank H.
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p. 5137 - 5143
(2007/10/02)
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- Both-faces Hindered Porphyrins. Part 3. Synthesis and Characterization of Internally Five-co-ordinated Iron(II) Basket Handle Porphyrins derived from 5,10,15,20-Tetrakis(o-aminophenyl)porphyrin
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The synthesis of a series of so-called amide 'hanging base' porphyrins (10), (14) and (18), derived from 5,10,15,20-tetrakis(o-aminophenyl)porphyrin (αβαβ-atropisomer) (3), in which one of the faces is hindered by an alkylene or an arylene-p-bisalkylene bridge and the other face is bridged by a pyridine-3,5-diyl-bisalkylene or an imidazolyl-alkylene chain, is described.The structural assignment of the various compounds is based on the 1H n.m.r. spectra of the free bases, and of their zinc(II) and iron(II) complexes.Unlike the ether 'hanging base' metalloporphyrins, the metallic ion of amide 'hanging base' porphyrins is actually five-co-ordinated by the proximal base.Furthermore, not only is the equilibrium pyridine plane orientation dependent on the length of its linking chain, but the bridging forces the amide protons to point toward the centre of the macrocycle core.These structural properties are potential factors which may affect the binding of dioxygen.The synthesis of a bis-pyridine 'basket handle' porphyrin is also reported.
- Momenteau, Michel,Mispelter, Joel,Loock, Bernard,Lhoste, Jean-Marc
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p. 221 - 232
(2007/10/02)
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- BILAYER COATED CAPSULE MEMBRANES. PART 2. PHOTORESPONSIVE PERMEABILITY CONTROL OF SODIUM CHLORIDE ACROSS A CAPSULE MEMBRANE
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Two types of photoresponsive nylon capsules coated with synthetic bilayer membranes were prepared.In one system, the azobenzene chromophore is incorporated in the bilayer component (System I); the other system contains the azobenzene moiety as part of the polyamide chain (System II).Release of NaCl from nylon capsules coated with photoresponsive bilayer membranes (System I) was reversibly regulated by alternate irradiation with u.v. or visible light.Thus, permeation of NaCl was enhanced due to the distored cis-configuration ot the azobenzene unit in bilayers, and reverted to the original rate by recovery of the trans-configuration.NaCl release was also affected by the phase transition of the coating bilayer membrane.The permeation mechanism is discussed from the activation energy data.Permeation of the System II capsule, in which the azobenzene unit is linked covalently, was not changed by photoirradiation.
- Okahata, Yoshio,Lim, Han-jin,Hachiya, Satoshi
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p. 989 - 994
(2007/10/02)
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- Design of Inhibitors from the Three-Dimensional Structure of Alcohol Dehydrogenase. Chemical Synthesis and Enzymatic Properties
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Inhibitors of liver alcohol dehydrogenase were designed from the three-dimensional structure of the enzyme.The ligand to the catalytic zinc ion is an amide group or, better, a formamide group.With the latter function, a hydrogen bond between the NH group and the hydroxyl group of Ser-48 may be formed.The hydrophobic substrate binding site brings structural restraints. α-ω bifunctional molecules show good inhibitory properties possibly due to the interactions with polar residues at the entrance of the substrate binding site.
- Freudenreich, Charles,Samama, Jean-Pierre,Biellmann, Jean-Francois
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p. 3344 - 3353
(2007/10/02)
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