- 9-(2-Aryloxyethyl) derivatives of adenine - A new class of non-nucleosidic antiviral agents
-
New 9-(aryloxyalkyl) derivatives of adenine have been prepared by alkylation of adenine with tosylates, bromides, and α-chloro ethers containing terminal aromatic fragments in anhydrous DMF in the presence of potassium carbonate. The compounds of the 9-(2-phenoxyethyl)adenine series appear to be highly reactive against cytomegaloviruses of mankind in vitro, while derivatives of 9-(2-benzyloxyethyl)adenine demonstrate anti-HIV-1 activity. Compounds with shorter or longer chains, and also compounds which do not have aromatic fragments at the ends of the chains, do not possess antiviral activity.
- Petrov,Ozerov,Novikov,Pannecouque,Balzarini,De Clercq
-
-
Read Online
- Salt- and pH-Triggered Helix-Coil Transition of Ionic Polypeptides under Physiology Conditions
-
Controlling the helix-coil transition of polypeptides under physiological conditions is an attractive way toward smart functional materials. Here, we report the synthesis of a series of tertiary amine-functionalized ethylene glycol (EGx)-linked polypeptide electrolytes with their secondary structures tunable under physiological conditions. The resultant polymers, denoted as P(EGxDMA-Glu) (x = 1, 2, and 3), show excellent aqueous solubility (>20 mg/mL) regardless of their charge states. Unlike poly-l-lysine that can form a helix only at pH above 10, P(EGxDMA-Glu) undergo a pH-dependent helix-coil switch with their transition points within the physiological range (pH ~5.3-6.5). Meanwhile, P(EGxDMA-Glu) exhibit an unusual salt-induced helical conformation presumably owing to the unique properties of EGx linkers. Together, the current work highlights the importance of fine-tuning the linker chemistry in achieving conformation-switchable polypeptides and represents a facile approach toward stimuli-responsive biopolymers for advanced biological applications.
- Yuan, Jingsong,Zhang, Yi,Sun, Yue,Cai, Zhicheng,Yang, Lijiang,Lu, Hua
-
-
Read Online
- Examples of amphitropic polymers: Monolayer film, Langmuir-Blodgett film and liquid-crystalline properties of some polymeric amphiphiles containing cholestanol moieties and those of some closely related non-polymeric amphiphiles
-
A range of alternating copolymers were prepared by free-radical-initiated copolymerizations of maleic anhydride with a series of α-alkenes containing cholestanyl moieties. Derivatives of these copolymers were prepared by reacting the anhydride residues with methanol, water, dimethylamine and/or morpholine. A related series of non-polymeric amphiphiles containing steroid moieties was also prepared. Isotherms were measured for monolayers of the various polymers and the various non-polymeric amphiphiles on water and, where possible, Langmuir-Blodgett (LB) multilayers were prepared. The majority of the materials gave good isotherms (relatively steep with collapse pressures >40 mN m-1) indicating that the monolayers were ordered and, as determined by the detection of Bragg peaks by X-ray diffraction, Y-type LB films with regular layer structures. Appropriate materials were also examined, by optical microscopy and differential scanning calorimetry (DSC), for possible liquid-crystalline properties. Four polymers and one non-polymeric amphiphile exhibited smectic A mesophases. Another non-polymeric amphiphile exhibited a cholesteric mesophase. Thus, examples were found of amphitropic polymers and non-polymeric amphiphiles which can form organised molecular arrangements both because they are amphiphilic and because they contain mesogens.
- Ali-Adib, Ziad,Bomben, Andrea,Davis, Frank,Hodge, Philip,Tundo, Pietro,Valli, Ludovico
-
-
Read Online
- Chain extender as well as preparation method and application thereof
-
The invention relates to a chain extender. The chain extender is 3-(2-(2, 3-dihydroxy propyl) sulfo) ethyoxyl) propyl 3-(3-(tert-butyl)-4-hydroxy-5-methyl phenyl) propionate (GL), and the structural formula of the chain extender is shown in the specification. The prepared chain extender GL has an excellent toughening effect; the elongation at break of a polyurethane elastomer prepared from the GL reaches 1531.1594%, the toughness reaches 12.315% MJ/m , the repairing efficiency reaches 103.62% after the polyurethane elastomer is repaired for 6 h at the normal temperature, and the repairing efficiency reaches 125.53% after the polyurethane elastomer is repaired for 2 h at the temperature of 80 DEG C. The prepared chain extender GL can be compounded with other reinforced chain extenders so as to be used, and the tensile strength and toughness of the polyurethane elastomer are further improved synergistically.
- -
-
Paragraph 0038; 0041; 0043; 0046; 0048; 0051
(2022/01/20)
-
- Non-natural amino acid and application thereof Recombinant protein and recombinant protein conjugate comprising same
-
The invention provides a non-natural amino acid. A compound represented by formula (I) or an enantiomer thereof. The invention also provides application of the non-natural amino acid. Further, the present invention also provides a protein conjugate comprising the recombinant protein and of the non-natural amino acid prepared from the recombinant protein. The non-natural amino acid provided by the invention is simple and convenient to prepare, good in safety, not prone to inactivation when inserted into a protein, high in coupling ratio with a coupling part, good in stability of the obtained conjugate, and capable of being applied to various fields, especially in preparation of recombinant protein or recombinant protein conjugate.
- -
-
Paragraph 0094; 0098; 0099-0100
(2021/10/27)
-
- Discovery of a series of efficient, centrally efficacious bace1 inhibitors through structure-based drug design
-
The identification of centrally efficacious β-secretase (BACE1) inhibitors for the treatment of Alzheimers disease (AD) has historically been thwarted by an inability to maintain alignment of potency, brain availability, and desired absorption, distribution, metabolism, and excretion (ADME) properties. In this paper, we describe a series of truncated, fused thioamidines that are efficiently selective in garnering BACE1 activity without simultaneously inhibiting the closely related cathepsin D or negatively impacting brain penetration and ADME alignment, as exemplified by 36. Upon oral administration, these inhibitors exhibit robust brain availability and are efficacious in lowering central Amyloid β (Aβ) levels in mouse and dog. In addition, chronic treatment in aged PS1/APP mice effects a decrease in the number and size of Aβ-derived plaques. Most importantly, evaluation of 36 in a 2-week exploratory toxicology study revealed no accumulation of autofluorescent material in retinal pigment epithelium or histology findings in the eye, issues observed with earlier BACE1 inhibitors.
- Butler, Christopher R.,Brodney, Michael A.,Beck, Elizabeth M.,Barreiro, Gabriela,Nolan, Charles E.,Pan, Feng,Vajdos, Felix,Parris, Kevin,Varghese, Alison H.,Helal, Christopher J.,Lira, Ricardo,Doran, Shawn D.,Riddell, David R.,Buzon, Leanne M.,Dutra, Jason K.,Martinez-Alsina, Luis A.,Ogilvie, Kevin,Murray, John C.,Young, Joseph M.,Atchison, Kevin,Robshaw, Ashley,Gonzales, Cathleen,Wang, Jinlong,Zhang, Yong,Oneill, Brian T.
-
p. 2678 - 2702
(2015/04/14)
-
- Structurally Simple Benzyl-Type Photolabile Protecting Groups for Direct Release of Alcohols and Carboxylic Acids
-
Structurally simple benzyl-type photolabile protecting groups (PPGs) have been developed to release alcohols and carboxylic acids. Release of two substrates from one PPG chromophore has also been accomplished. (Chemical Equation Presented).
- Wang, Pengfei,Lu, Wenya,Devalankar, Dattatray A.,Ding, Zhenying
-
supporting information
p. 2114 - 2117
(2015/05/13)
-
- Pd-catalyzed reaction of allyl carbonate with polyols: The role of CO 2 in transesterification versus etherification of glycerol
-
An intermolecular Pd/PPh3-catalyzed transesterification of diallyl carbonate with glycerol to generate glycerol carbonate has been developed. Analysis of the reaction kinetics in THF indicates a first-order dependence on Pd and diallyl carbonate, that the Pd bears two phosphines during the turnover limiting event, and that increasing the glycerol concentration inhibits reaction, possibly via change in the polarity of the medium. 13C isotopic labeling studies demonstrate that the Pd-catalyzed transesterification requires at least one allyl carbonate moiety and that there is rapid equilibrium of the allyl carbonate with CO2 in solution, even when present only at low concentrations. A mechanism that is consistent with these results involves oxidative addition of the allyl carbonate to Pd followed by reversible decarboxylation, with the intermediate I·1- and I·3-allyl Pd alkoxides mediating direct and indirect transesterification reactions with the glycerol. Using this model, successful simulations of the kinetics of reactions conducted under atmospheres of N2 or CO2 could be achieved, including switching in selectivity between etherification and transesterification in the early stages of reaction. Reactions with the higher polyols threitol and erythritol are also efficient, generating the terminal (1,2) monocarbonates with high selectivity. It's a gas: A Pd-catalyzed transesterification of diallyl carbonate with polyols has been developed. The CO2 concentration is shown to control the relative rates of etherification and transesterification. Kinetic and isotopic labeling studies suggest that intermediate I·1-allyl Pd alkoxides mediate indirect intermolecular transesterification. The higher polyols erythritol and threitol selectively generate monocarbonates. Copyright
- Gordillo, Alvaro,Lloyd-Jones, Guy C.
-
supporting information; experimental part
p. 2660 - 2665
(2012/04/11)
-
- Diphilic carbosilane dendrimers with different densities of the hydrophilic layer
-
A universal method for the synthesis of hydrophilic dendrimers was considered. The method is based on a combination of carbosilane dendrimers with different molecular organizations and hydrophilizing agents, viz., substituted hydride silanes containing one and three protected hydroxyl groups. The combination of a limited set of the mentioned reagents makes it possible to control the ratio of hydrophilic and hydrophobic moieties of the molecular structure in wide limits. A simple and convenient method for the removal of trimethylsilyl protection of hydroxyl groups in the surface layer of dendrimers was developed.
- Getmanova,Tereshchenko,Ignat'eva,Tatarinova,Myakushev,Muzafarov
-
p. 137 - 143
(2007/10/03)
-
- An expedient synthesis of monodispersed oligo(ethylene glycols)
-
A convenient approach to the synthesis of oligo(ethylene glycols) under phase transfer conditions is described. Oligo(ethylene glycols) (x = 7-12) are obtained in excellent yields and high purity via modular, bi-directional elongation of readily available ethylene glycol bis-tosylates.
- Burkett, Brendan A.,Chan, Tak Hang
-
p. 1007 - 1010
(2007/10/03)
-
- FUMARATE DERIVATIVE, METHOD FOR PRODUCING THE SAME
-
This invention is to provide a polymerizable composition having excellent curability and surface hardness, and a cured product thereof. A novel fumarate derivative having two or more fumarate groups within one molecule and ensuring high copolymerizability with the terminal alkenyloxy group, a method for producing the derivative, a polymerizable composition containing the derivative, and a cured product thereof are provided.
- -
-
-
- Synthesis of Ether Betaine Lipids: O4-(2,3-Dipropionyloxypropyl)-N,N,N-trimethylhomoserine
-
Novel synthesis of O4-(2,3-Dipropionyloxypropyl)-N,N,N-trimethylhomoserine
- Choudhury, Manash Kumar
-
p. 1022 - 1037
(2007/10/03)
-
- Reductive Cyclization of Ketones Tethered to Activated Olefins Mediated by Magnesium in Methanol
-
The reductive cyclization of various ketones tethered to activated olefins such as α,β-unsaturated esters, nitriles, sulfoxides, and sulfides mediated by magnesium in dry methanol in the presence of mercuric chloride.When traeted with magnesium in dry methanol at -23 deg C all of the ketones except nitrile 9 (42percent) and 5-oxa-8-keto-2-enoate 5 (13percent) gave excellent yields (79-98percent) of mono- and bicyclic alcohol products resulting from carbon-carbon bond formation between the β-carbon of the activated olefin and the carbonyl carbon.The reaction was accelerated by the catalytic amount of mercuric chloride, although the stereoselectivity was not affected by the catalyst.For all the substrates except 8-keto-2-enoate 3 and 5-aza-8-keto-2-enoate 6, the configuration of the major product was trans between the hydroxy and (methoxycarbonyl)methyl groups.The product isomer ratios were independent of the substrate geometry (E or Z).In contrast to the ketones, aldehydes tethered to α,β-unsaturated esters gave products of simple reduction of the double bond and/or saturated alcohols instead of the cyclized products.When the reaction temperature was lowered, the yields of cyclized product were significantly affected by the production of appreciable amounts of saturated product, but the stereoselectivity was not improved.Under the same reaction conditions α,β-unsaturated sulfoxide 16 gave deoxygenated sulfide 18 (85percent) as the major product along with a small amount (9percent) of cyclized product 19t.In contrast, sulfone 17 underwent desulfonylation instead of cyclization to give olefin 20 (54percent).With excess magnesium (15 equiv), however, α,β-unsaturated sulfoxide 16 gave cyclized sulfide 19t (95percent) via deoxygenated sulfide 18.Both 16Z and 16E afforded product 19t as a single isomer.It is suggested that the reductive cyclization of the α,β-unsaturated esters and nitriles proceed by means of nucleophilic attack of a β-carbon radical anion, formed by initial electron transfer from magnesium metal to the activated olefin, on the carbonyl group.The cyclization of the α,β-unsaturated sulfide proceeds by nucleophilic attack of the ketyl on the olefinic double bond.
- Lee, Ge Hyeong,Choi, Eun Bok,Lee, Eun,Pak, Chwang Siek
-
p. 1428 - 1443
(2007/10/02)
-
- Approaches to new water soluble phosphines
-
Approaches to water-soluble phosphines are described which involve conversion of ethylene glycol derivatives and sugar diacetonides into monoallyl ethers, and hydrophosphorylation of the latter.In the case of the sugars, water-solubility is conferred by a subsequent hydrolysis.
- Mitchell, Terence N.,Heesche-Wagner, Kerstin
-
-