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The continuously growing interest in the understanding of peptide folding led to the conformational investigation of methylamides of N-acetyl-amino acids as diamide models. Here we report the results of detailed conformational analysis on Ac-Pro-NHMe and Ac-β-HPro-NHMe diamides. These compounds were
When L-proline or O-benzyl-trans-4-hydroxy-L-proline phenacyl ester was coupled with Boc-amino acids in dimethylformamide using water-soluble carbodiimide (WSCI) in the presence of anhydrous 1-hydroxybenzotriazole (HOBt) as coupling reagents, extensive racemization was observed at the C alpha of the
Two spiro[indoline-3,3'-pyrrolizine] derivatives have been synthesized in good yield with high regio- and stereospecificity using one-pot reactions between readily available starting materials, namely L-proline, substituted 1H-indole-2,3-diones and electron-deficient alkenes. The products have been
Stereoselective total synthesis of (-)-(2S, 4R)-3`-methoxy citreochlorol, and (-)-(2S, 4S)-3`-methoxy citreochlorol is demonstrated. A proline based imidazolidinone was synthesized and used as chiral auxiliary for asymmetric acetate aldol reaction to generate initial chirality. Geminal
N-Benzoxycarbonylglycyl-L-proline (L-ZGP) has been introduced as a chiral selector for enantioseparation of amines in non-aqueous capillary electrophoresis. Methanol mixed with different proportions of dichloromethane, 1,2-dichloroethane or 2-propanol containing L-ZGP and ammonium acetate was used
A normal-phase chromatographic method for the determination of (R)- and (S)-propranolol in plasma is described. The chiral separation is performed by adding an optically active complexing agent, N-benzoxycarbonylglycyl-L-proline, to the mobile phase (dichloromethane). The solid phase is LiChrosorb
Propylene carbonate is shown to be an environmentally friendly and sustainable replacement for dichloromethane and acetonitrile in proline-catalysed a-hydrazinations of aldehydes and ketones. Enantioselectivities comparable to those obtained in conventional solvents or ionic liquids can be obtained,
This report describes general methods for the synthesis of biodegradable poly(amide anhydrides) and poly(amide esters) based on naturally occurring amino acids. The polymers were synthesized from dicarboxylic acids prepared by amidation of the amino group of an amino acid with a cyclic anhydride, or
Four trityl-type (i.e. non-substituted trityl-, o-Cl-trityl-, o-F-trityl- and p-CN-trityl-) amidomethyl polystyrene resins were evaluated comparatively, in terms of the stability of the trityl-ester bond in slightly acidic dichloromethane solutions, and the p-CN-trityl-amidomethyl polystyrene resin
The effects in vivo of dichloromethanediphosphonate and 1-hydroxyethane 1,1-diphosphonate on collagen solubility, hydroxylation of lysine and proline and on the formation of collagen intermolecular cross-links were studied by using rat bone, cartilage and skin tissues. Dichloromethanediphosphonate
Direct coupling of enolizable aldehydes with C-alkynyl imines is realized affording the corresponding propargylic Mannich adducts of syn configuration, thus complementing previous methods that gave access to the anti-isomers. The combination of proline and a urea Brønsted base cocatalyst is key for
The aim of this study was to investigate the effects of various stabilizers on the encapsulation efficiency and release of exenatide-loaded PLGA (poly(lactic-co-glycolic acid)) microspheres prepared by the water-in-oil-in-water (W/O/W) solvent evaporation (SE) method. It was shown that the
The increasing importance of hydrogenase enzymes in the new energy research field has led us to examine the structure and dynamics of potential hydrogenase mimics, based on a ferrocene-peptide scaffold, using molecular dynamics (MD) simulations. To enable this MD study, a molecular mechanics force
The isolation of the membrane-modifying polypeptide antibiotics from the mycelium of Trichoderma viride 5242 was optimized via extraction with dichloromethane and chromatography on Sephadex LH-20. The components trichotoxin A40 and A50 were separated from each other and purified by multiplicative
More than 10 kinds of heterocyclic amines (HCAs), showing mutagenic and carcinogenic potency, have been isolated from cooked fish and meat. But many researchers say that the contribution ratio of HCAs to human cancer is very low. Our purpose in this experiment was to investigate the possibility of