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Ionic liquids using amino acid ester as cations is a new generation of green ionic liquids. It is found for the first time that they can be used as co-initiators to initiate radical photopolymerization in the presence of commercial type II sensitizer, camphorquinone (CQ) under mild irradiation conditions. To intensively investigate this new function, we synthesized a series of glycine ester ionic liquids by a very simple method, and then evaluated their performance as co-initiators in radical photopolymerization. The polymerization studies show that their coinitiation abilities depend strongly on the structures of N-terminal substituents and ester groups, as well as the type of anion moiety. And the pH values of the formula also have a heavy influence on their performances. More interestingly, when a small amount of hydroxyethyl acrylate (HEA) was added, under irradiation this multicomponent system composed of CQ, ionic liquids when anion moiety is P[F.sub.6.sup.-1], B[F.sub.4.sup.-1] or Sb[F.sub.6.sup.-1], and HEA, can release [H.sup.+] to initiate cationic polymerization. These facts demonstrated that the investigated glycine ester ionic liquids can be considered as valid, environmentally friendly alternatives to toxic aromatic amines co-initiators. Besides, the corresponding photoinitiation mechanism is suggested. KEYWORDS cationic photopolymerization, glycine ester ionic liquid, initiation system, photoinitiation efficiency, radical photopolymerization, 1 | INTRODUCTION The photopolymerization technique has been widely used in in coating, ink, adhesives, 3D printing materials, optics, medicine, microelectronics, nanotechnology, and so on f11. Radical and cationic photopolymerization [...]

Acyclovir and valacyclovir are oxidized on a glassy carbon electrode (GCE) with immobilized reduced graphene oxide coated with a polyglycine film. We selected the conditions for forming a polymer film, reducing graphene oxide on the GCE, and recording the maximum catalytic current on the composite surface. A procedure was developed for the selective voltammetric determination of acyclovir and valacyclovir on an electrode with a reduced graphene oxide-polyglycine film composite. A method is proposed for the amperometric detection of guanine-based antiviral drugs with this modified electrode under the conditions of flow-injection analysis. The dependence of the analytical signal on the concentration of acyclovir and valacyclovir is linear up to 5 x 10.sup.-6 M in the static mode and up to 1 x 10.sup.-7 M in the flow-injection system. The developed voltammetric method for determining acyclovir and valacyclovir was tested in the analysis of pharmaceutical preparations., Author(s): L. G. Shaidarova [sup.1] , A. V. Gedmina [sup.1] , A. A. Poadnyak [sup.1] , I. A. Chelnokova [sup.1] , H. C. Budnikov [sup.1] Author Affiliations: (1) grid.77268.3c, 0000 [...]

The chains and segments of unordered cationic polypeptides are complex and may produce unexpected biological activities. Herein, the Ugi's 4CC reaction is adopted to synthesize a cationic alternating copolymer comprising ornithine and glycine (poly(Orn-alter-Gly)) with an ordered sequence for enhanced bacterial resistance. In this technique, potassium isocyanate, 4-(N-carbobenzyloxyamino)-1-butyraldehyde and l-(4-Methoxyphenyl)ethylamine react to produce MPE-substituted poly(Orn-alter-Gly) in one step without using a catalyst and then poly(Orn-alter-Gly) is obtained by removing the N-(l-p-methoxyphenethyl) (MPE) group. [sup.1]H NMR, Fourier transform infrared spectroscopy, and automatic amino acid analysis confirm that ornithine and glycine are linked alternately in the poly(Orn-alter-Gly) chains. Both MPE-substituted poly(Orn-alter-Gly) and poly(Orn-alter-Gly) have excellent antibacterial activity against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa as well as excellent biocompatibility. The synthesis strategy and materials provide new information on how to obtain ordered sequence cationic polypeptides. KEYWORDS alternating copolymer, antibacterial activity, biocompatibility, cationic polypeptide, Ugi's 4CC reaction, 1 | INTRODUCTION Cationic polypeptides prepared by chemical synthesis are important biomaterials for their antibacterial properties and biocompatibility. [1-6] They are generally composed of cationic amino acids (ornithine, lysine, arginine, [...]

The pivotal role played by a single glycine hinge residue in the structure of BBAT1, a (beta)(beta)(alpha) peptide that forms a discrete homotrimeric structure in solution, is evaluated with 11 new peptide sequences which differently in their identity of the residue at the hinge position. The difference between the thermodynamic stabilities and oligomeric states of these peptides illustrates the pivotal role of the hinge residue in the oligomerization of the (beta)(beta)(alpha) peptides.

The retrosynthetic route for preparing 1,2-unsubstituted pyrazino[2,1-b]quinazoline-3,6-diones starts with the unprotected glycine derivatives and double cyclization of open-chain 'tripeptides', in which the N-terminal residue is the anthranilic acid unit bearing an azido group with an amino function.

We have devised and evaluated a stable-isotopic method for measuring DNA synthesis rates. The probe is [1-13C]glycine that is incorporated into purines via de novo biosynthesis. The human hepatoma cell line HEP G2 was grown in medium containing [1-13C]glycine, the cells were harvested at various times, and the DNA was extracted. Following hydrolysis to the nucleosides, a reversed-phase HPLC separation was used to provide separate peaks for deoxythymidine (dT), deoxyadenosine (dA), and deoxyguanosine (dG). The HPLC effluent was continuously fed into a chemical reaction interface and an isotope ratio mass spectrometer (HPLC/CRI/IRMS). The isotope ratio of the C[O.sub.2] produced in the CRI was used to monitor for enrichment. The cells were grown continuously for 5 days in labeled medium and also in a 1-day pulse labeling experiment where the washout of label was observed for the subsequent 9 days. As predicted from the role of glycine in de novo purine biosynthesis, the isotope ratio of the pyrimidine dT did not change. However, for the two purines, dA and dG, the characteristic log growth behavior of the cells was observed in their 13C/12C ratios and good agreement in the doubling time was obtained for each type of experiment. Parallel experiments that measured the HEP G2 doubling time in culture using tritiated thymidine incorporation and direct cell counts were carried out compare to our new method with established ones. We believe that the use of [1-13C]glycine and the HPLC/CRI/IRMS is a highly sensitive and selective approach that forms the basis of a method that can measure DNA synthesis rates using a nonradioactive, nontoxic tracer.

Multinuclear solid state nuclear magnetic resonance is used to examine the effect of the antiviral, antifusion peptide ZfFG on phosphatidylcholine conformation in membranes. Many conformations in the lipid bilayer are reached by phosphatidylcholine, and ZfFG in the membrane surface causes on alteration in the average conformation of the phospholipid.

Crystallographic, spectroscopic and potentiometric techniques are used in an analysis of structures and stabilities of metal(II) complexes of tyrosine- (tyr-) containing dipeptide (L), L-tyr.X (X = glycine (gly), L-/D-alanine, -tyr, -tryptophan and -phenylalanine) and diamines (DA = ethylenediamine (en), 2,2'-bipyridine (bpy) and 1,10-phenanthroline (phen)). Stabilization of Cu(DA)(L) is validated. Intramolecular stacking can control the conformation of side chain aromatic rings and coordination structures.

Cadmium-amino acid compounds reveal a cadmium surrounding, which is studied by solid-state 113 Cd NMR spectroscopy. The anisotropy and isotropy of the chemical shift are determined by this process. The cadmium surrounding is further qualified by the coupling to 14N. A powder sample of bis (L-alaninato) cadmium (II) trihydrate is assumed to possess two diastereoisomers because of the 113 Cd NMR process, which also facilitates the prediction of the hitherto unknown geometry of cadmium cysteinate.

Guanosine 5'-(beta, gamma-imido) triphosphate (GppNHp) is used to study the three-dimensional structures and biochemical properties of two mutants of the G-domain of p21H-ras, p21(G12D) and p21(G12P) with residues 1-166 in its triphosphate-bound structure. The oncogenic and nononcogenic mutations of Gly-12 are related to the structures and properties of the mutants respectively. The weak affinity of GAP (GTPase-activating protein) toward Pro-12 is the result of the outward pyrrolidine ring of pro-12. This also prevents GAP from inducing GTP hydrolysis.

This paper describes an extensive kinetic study of the reactions involved in the determination of acetoacetate in body fluids. It is concluded that acetoacetate reacts with glycine to produce an imine intermediate that tautomerizes to an enamine. It is also concluded that nitroprusside reacts with the imine intermediate to produce an unstable product with an absorption maximum near 540 nm. This product decays slowly to produce a stable product with an absorption maximum near 393 nm. A proposed reaction pathway is used to develop kinetic equations, rate constants, equilibrium constants, and molar absorptivity of the unstable product that permit quantitative prediction of the kinetic behavior for a wide range of reactant concentrations.

A beta-hydroxy-alpha-amino acid serves as a key intermediate in the short, flexible and diastereoselctive synthesis of the carbacephem skeleton. The process involves the aldol condensation of an oxazolidinone-protected glycine with succinic semialdehyde methyl ester. This step not only forms virtually all the needed carbon atoms. It also installs the two stereocenters and opens the way to functional manipulation. Varying the aldehyde likewise allows flexibility in elaboration of the basic framework.

(N-acetylglycyl)oligopeptide-linked anthraquinone (AQ) undergoes photocyclization to give ring-closure products in 23-58% yields. The peptide chains are bonded through their C-terminal amino acid to the ester group of AQ. The yield depends on the spacer length between glycine and AQ, with too short or too long spacers inhibiting the ring closure. The photoreaction involves intramolecular proton abstraction from the glycine methylene by AQ, followed by a site-selective formation of a C-O bond. The spacer length and sequence also control the site selectivity.

The enantioselective synthesis of (2R,3S)- and (2R,3R)-phenylcysteines involves the stereoselective aldol condensation of N-(X-acetyl)oxazolidinone with benzaldehyde and SN2 displacement of the mesylate with a sulfur nucleophile. For the syn reaction, the DBU salt of thiolacetic acid is used to minimize the elimination product. Deacetylation, thiol protection and hydrolysis are accomplished with NaOH in the presence of p-methylbenzyl thioether. Deblocking of the methyl ester is carried out with LiCl in dimethylformamide to avoid elimination. The synthesized 3-phenylcysteines find use in peptide-receptor interaction studies.

Co-Ce-O films were synthesized by a newly developed electrochemical method called the 'metal-oxide co-electrodeposition method,' i.e., the simultaneous deposition of Co and Ce[O.sub.2] from a reaction solution containing COS[O.sub.4], Ce[Cl.sub.3], and glycine. Giycine acts as the complexing agent for [Co.sup.2+] and was effective in avoiding the precipitation of Co[(OH).sub.2]. The Co-Ce-O films prepared had a smooth surface. The Co content in the deposited films was subject to change from 0 to 100 vol.%, depending on the concentration of the COS[O.sub.4] in the reaction solution. Coercivity and sheet resistivity decrease suddenly at 22 vol.% Co. Therefore, the nano-size structure of the films may be changed at this concentration. Index Terms--Co-Ce-O, glycine, metal-oxide co-electrodeposition, metal-oxide granular film.

The use of urea as a quantitative probe of coupled folding and other large-scale coupled conformational changes in protein-DNA interactions and other protein associations is discussed. Urea is successful for the sensitive probe of alpha-helix formation and other local folding or unfolding processes and also helps in selective detection of changes in exposure of polar amide surface.