- α-Amino Diphenyl Phosphonates as Novel Inhibitors of Escherichia coli ClpP Protease
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Increased Gram-negative bacteria resistance to antibiotics is becoming a global problem, and new classes of antibiotics with novel mechanisms of action are required. The caseinolytic protease subunit P (ClpP) is a serine protease conserved among bacteria that is considered as an interesting drug target. ClpP function is involved in protein turnover and homeostasis, stress response, and virulence among other processes. The focus of this study was to identify new inhibitors of Escherichia coli ClpP and to understand their mode of action. A focused library of serine protease inhibitors based on diaryl phosphonate warheads was tested for ClpP inhibition, and a chemical exploration around the hit compounds was conducted. Altogether, 14 new potent inhibitors of E. coli ClpP were identified. Compounds 85 and 92 emerged as most interesting compounds from this study due to their potency and, respectively, to its moderate but consistent antibacterial properties as well as the favorable cytotoxicity profile.
- Moreno-Cinos, Carlos,Sassetti, Elisa,Salado, Irene G.,Witt, Gesa,Benramdane, Siham,Reinhardt, Laura,Cruz, Cristina D.,Joossens, Jurgen,Van Der Veken, Pieter,Br?tz-Oesterhelt, Heike,Tammela, P?ivi,Winterhalter, Mathias,Gribbon, Philip,Windshügel, Bj?rn,Augustyns, Koen
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p. 774 - 797
(2019/01/30)
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- Synthesis and Preclinical Evaluation of the First Carbon-11 Labeled PET Tracers Targeting Substance P1-7
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Two potent SP1-7 peptidomimetics have been successfully radiolabeled via [11C]CO2-fixation with excellent yields, purity, and molar activity. l-[11C]SP1-7-peptidomimetic exhibited promising ex vivo biodistribution profile. Metabolite analysis showed that l-[11C]SP1-7-peptidomimetic is stable in brain and spinal cord, whereas rapid metabolic degradation occurs in rat plasma. Metabolic stability can be significantly improved by substituting l-Phe for d-Phe, preserving 70% more of intact tracer and resulting in better brain and spinal cord tracer retention. Positron emission tomography (PET) scanning confirmed moderate brain (1.5 SUV; peak at 3 min) and spinal cord (1.0 SUV; peak at 10 min) uptake for l- and d-[11C]SP1-7-peptidomimetic. A slight decrease in SUV value was observed after pretreatment with natural peptide SP1-7 in spinal cord for l-[11C]SP1-7-peptidomimetic. On the contrary, blocking using cold analogues of l- and d-[11C]tracers did not reduce the tracers' brain and spinal cord exposure. In summary, PET scanning of l- and d-[11C]SP1-7-peptidomimetics confirms rapid blood-brain barrier and blood-spinal-cord barrier penetration. Therefore, further validation of these two tracers targeting SP1-7 is needed in order to define a new PET imaging target and select its most appropriate radiopharmaceutical.
- Peko?ak, Aleksandra,Bulc, Janez ?.,Korat, ?pela,Schuit, Robert C.,Kooijman, Esther,Vos, Ricardo,Rongen, Marissa,Verlaan, Mariska,Takkenkamp, Kevin,Beaino, Wissam,Poot, Alex J.,Windhorst, Albert D.
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p. 4872 - 4883
(2018/11/30)
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- Amidation of carboxylic acids via the mixed carbonic carboxylic anhydrides and its application to synthesis of antidepressant (1S,2R)-tranylcypromine
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Primary amidations of carboxylic acids 1 or 3 with NH4Cl in the presence of ClCO2Et and Et3N were developed to afford the corresponding primary amides in 22% to quantitative yields. Additionally, we have applied the amidation to the preparation of various amides containing hydroxamic acids and achieved the synthesis of (1S,2R)-tranylcypromine as an antidepressant medicine via Lossen rearrangement.
- Ezawa, Tetsuya,Kawashima, Yuya,Noguchi, Takuya,Jung, Seunghee,Imai, Nobuyuki
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p. 1690 - 1699
(2017/11/14)
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- Optimization and Structure-Activity Relationships of Phosphinic Pseudotripeptide Inhibitors of Aminopeptidases That Generate Antigenic Peptides
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The oxytocinase subfamily of M1 aminopeptidases, consisting of ER aminopeptidase 1 (ERAP1), ER aminopeptidase 2 (ERAP2), and insulin-regulated aminopeptidase (IRAP), plays critical roles in the generation of antigenic peptides and indirectly regulates human adaptive immune responses. We have previously demonstrated that phosphinic pseudotripeptides can constitute potent inhibitors of this group of enzymes. In this study, we used synthetic methodologies able to furnish a series of stereochemically defined phosphinic pseudotripeptides and demonstrate that side chains at P1′ and P2′ positions are critical determinants in driving potency and selectivity. We identified low nanomolar inhibitors of ERAP2 and IRAP that display selectivity of more than 2 and 3 orders of magnitude, respectively. Cellular analysis demonstrated that one of the compounds that is a selective IRAP inhibitor can reduce IRAP-dependent but not ERAP1-dependent cross-presentation by dendritic cells with nanomolar efficacy. Our results encourage further preclinical development of phosphinic pseudotripeptides as regulators of adaptive immune responses.
- Kokkala, Paraskevi,Mpakali, Anastasia,Mauvais, Francois-Xavier,Papakyriakou, Athanasios,Daskalaki, Ira,Petropoulou, Ioanna,Kavvalou, Sofia,Papathanasopoulou, Mirto,Agrotis, Stefanos,Fonsou, Theodora-Markisia,Van Endert, Peter,Stratikos, Efstratios,Georgiadis, Dimitris
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supporting information
p. 9107 - 9123
(2016/10/22)
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- Carbohydrates as efficient catalysts for the hydration of α-amino nitriles
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Directed hydration of α-amino nitriles was achieved under mild conditions using simple carbohydrates as catalysts exploiting temporary intramolecularity. A broadly applicable procedure using both formaldehyde and NaOH as catalysts efficiently hydrated a variety of primary and secondary susbtrates, and allowed the hydration of enantiopure substrates to proceed without racemization. This work also provides a rare comparison of the catalytic activity of carbohydrates, and shows that the simple aldehydes at the basis of chemical evolution are efficient organocatalysts mimicking the function of hydratase enzymes. Optimal catalytic efficiency was observed with destabilized aldehydes, and with difficult substrates only simple carbohydrates such as formaldehyde and glycolaldehyde proved reliable.
- Chitale, Sampada,Derasp, Joshua S.,Hussain, Bashir,Tanveer, Kashif,Beauchemin, André M.
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supporting information
p. 13147 - 13150
(2016/11/09)
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- LAT1 activity of carboxylic acid bioisosteres: Evaluation of hydroxamic acids as substrates
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Large neutral amino acid transporter 1 (LAT1) is a solute carrier protein located primarily in the blood–brain barrier (BBB) that offers the potential to deliver drugs to the brain. It is also up-regulated in cancer cells, as part of a tumor's increased metabolic demands. Previously, amino acid prodrugs have been shown to be transported by LAT1. Carboxylic acid bioisosteres may afford prodrugs with an altered physicochemical and pharmacokinetic profile than those derived from natural amino acids, allowing for higher brain or tumor levels of drug and/or lower toxicity. The effect of replacing phenylalanine's carboxylic acid with a tetrazole, acylsulfonamide and hydroxamic acid (HA) bioisostere was examined. Compounds were tested for their ability to be LAT1 substrates using both cis-inhibition and trans-stimulation cell assays. As HA-Phe demonstrated weak substrate activity, its structure–activity relationship (SAR) was further explored by synthesis and testing of HA derivatives of other LAT1 amino acid substrates (i.e., Tyr, Leu, Ile, and Met). The potential for a false positive in the trans-stimulation assay caused by parent amino acid was evaluated by conducting compound stability experiments for both HA-Leu and the corresponding methyl ester derivative. We concluded that HA's are transported by LAT1. In addition, our results lend support to a recent account that amino acid esters are LAT1 substrates, and that hydrogen bonding may be as important as charge for interaction with the transporter binding site.
- Zur, Arik A.,Chien, Huan-Chieh,Augustyn, Evan,Flint, Andrew,Heeren, Nathan,Finke, Karissa,Hernandez, Christopher,Hansen, Logan,Miller, Sydney,Lin, Lawrence,Giacomini, Kathleen M.,Colas, Claire,Schlessinger, Avner,Thomas, Allen A.
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p. 5000 - 5006
(2016/10/05)
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- Metastin derivatives and use thereof
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The invention provides stable metastin derivatives having excellent biological activities (a cancer metastasis suppressing activity, a cancer growth suppressing activity, etc.). By modifying the constituent amino acids of metastin with specific modifying groups, metastin derivatives having more improved blood stability, etc. than native metastin and showing excellent cancer metastasis suppressing activity or cancer growth suppressing activity have been found. Furthermore, it has been found that these metastin derivatives exhibit effects of suppressing gonadotropic hormone secretion, suppressing sex hormone secretion, etc., which are wholly different from the effects heretofore known.
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Paragraph 0250
(2016/08/23)
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- Synthesis of Nitriles from Aldoximes and Primary Amides Using XtalFluor-E
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The dehydration reaction of aldoximes and amides for the synthesis of nitriles using [Et2NSF2]BF4 (XtalFluor-E) is described. Overall, the reaction proceeds rapidly (normally 1 h) at room temperature in an environmentally benign solvent (EtOAc) with only a slight excess of the dehydrating agent (1.1 equiv). A broad scope of nitriles can be prepared, including chiral nonracemic ones. In addition, in a number of cases, further purification of the nitrile after the workup was not required.
- Keita, Massaba,Vandamme, Mathilde,Paquin, Jean-Fran?ois
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p. 3758 - 3766
(2015/11/28)
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- Exploration and pharmacokinetic profiling of phenylalanine based carbamates as novel substance P 1-7 analogues
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The bioactive metabolite of Substance P, the heptapeptide SP1-7 (H-Arg-Pro-Lys-Pro-Gln-Gln-Phe-OH), has been shown to attenuate signs of hyperalgesia in diabetic mice, which indicate a possible use of compounds targeting the SP1-7 bi
- Fransson, Rebecca,Nordvall, Gunnar,Bylund, Johan,Carlsson-Jonsson, Anna,Kratz, Jadel M.,Svensson, Richard,Artursson, Per,Hallberg, Mathias,Sandstr?m, Anja
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supporting information
p. 1272 - 1277
(2015/01/09)
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- Convenient preparation of primary amides via activation of carboxylic acids with ethyl chloroformate and triethylamine under mild conditions
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Primary amides were easily prepared in 22-99% yields from the corresponding carboxylic acids 1 or 5 with NH4Cl via activation with ClCO 2Et and Et3N. The enantiomers of the corresponding primary amides of Cbz-, Boc-, or Fmoc-α-amino acids can be separated by using a chiral column.
- Noguchi, Takuya,Sekine, Masahiro,Yokoo, Yuki,Jung, Seunghee,Imai, Nobuyuki
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p. 580 - 582
(2013/07/05)
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- Glycosylation mediated - BAIL in aqueous solution
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The use of Br?nsted acid ionic liquid (BAIL) as a catalyst for the activation of unreactive and unprotected glycosyl donors has been demonstrated for the first time in aqueous solution.
- Delacroix, Sébastien,Bonnet, Jean-Pierre,Courty, Matthieu,Postel, Denis,Van Nhien, Albert Nguyen
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- A convenient method for the one-step synthesis of phosphonic peptides
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A novel and efficient method for the synthesis of peptidyl derivatives of 1-aminoalkylphosphonate diaryl esters is presented. Phosphonic peptides were obtained in one step via an amidoalkylation reaction using amides of N-protected amino acids or peptides, triphenyl phosphite, and an appropriate aldehyde.
- Skoreński, Marcin,Oleksyszyn, Józef,Sieńczyk, Marcin
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supporting information
p. 4975 - 4977
(2013/09/02)
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- Predicting and improving the membrane permeability of peptidic small molecules
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We evaluate experimentally and computationally the membrane permeability of matched sets of peptidic small molecules bearing natural or bioisosteric unnatural amino acids. We find that the intentional introduction of hydrogen bond acceptor-donor pairs in
- Rafi, Salma B.,Hearn, Brian R.,Vedantham, Punitha,Jacobson, Matthew P.,Renslo, Adam R.
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experimental part
p. 3163 - 3169
(2012/06/18)
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- Direct synthesis of phosphinopeptides containing C-terminal α-aminoalkylphosphinic acids
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A series of phosphinopeptides containing C-terminal α- aminoalkylphosphinic acids were prepared in good yields directly in one-pot reactions of 2-(N-benzoxycarbonylamino)alkanamides/peptide amides, aldehydes, and aryldichlorophosphines, followed by hydrolysis. In the current method, the peptide bond was formed in a Mannichtype reaction. Springer-Verlag 2010.
- Meng, Fanhua,Xu, Jiaxi
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experimental part
p. 533 - 538
(2010/11/04)
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- AmIno Acid Homologation by the Blaise Reaction: A new entry into nitrogen heterocycles
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(Chemical Equation Presented) A general strategy for the amino acid homologation via Blaise reaction and subsequent reduction is presented. This strategy involves the preparation of protected α-amino nitriles from the corresponding amino acids, followed by the zinc-mediated condensation of tert-butyl bromoacetate, to give the imidazolidones after iminozincate cyclization. Reduction gave the saturated imidazolidinones with cis or trans stereochemistry, depending on the reduction conditions. This strategy was applied to nonfunctionalized amino acids and to functionalized amino acids such as serine and aspartic acid. Additionally, acidic hydrolysis of cis or trans imidazolidinones to the corresponding chiral 4-aminopyrrolidones is described.
- Cam, Thuy Hoang,Bouillere, Francelin,Johannesen, Sine,Zulauf, Anais,Panel, Cecilia,Pouilhes, Annie,Gori, Didier,Alezra, Valerie,Kouklovsky, Cyrille
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experimental part
p. 4177 - 4187
(2009/09/08)
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- N-urethane-protected amino alkyl isothiocyanates: Synthesis, isolation, characterization, and application to the synthesis of thioureidopeptides
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(Chemical Equation Presented) Synthetically useful N-Fmoc amino-alkyl isothiocyanates have been described, starting from protected amino acids. These compounds have been synthesized in excellent yields by thiocarbonylation of the monoprotected 1,2-diamines with CS2/TEA/p-TsCl, isolated as stable solids, and completely characterized. The procedure has been extended to the synthesis of amino alkyl isothiocyanates from Boc- and Z-protected amino acids as well. The utility of these isothiocyanates for peptidomimetics synthesis has been demonstrated by employing them in the preparation of a series of dithioureidopeptide esters. Boc-Gly-OH and Boc-Phe-OH derived isothiocyanates 9a and 9c have been obtained as single crystals and their structures solved through X-ray diffraction. They belong to the orthorhombic crystal system, and have a single molecule in the asymmetric unit (Z′ = 1). 9a crystallizes in the centrosymmetric space group Pbca, while 9c crystallizes in the noncentrosymmetric space group P212121.
- Sureshbabu, Vommina V.,Naik, Shankar A.,Hemantha,Narendra,Das, Ushati,Guru Row, Tayur N.
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supporting information; experimental part
p. 5260 - 5266
(2009/12/06)
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- A new chiral synthesis of a bicyclic enedione containing a seven-membered ring mediated by a combination of chiral amine and Bronsted acid
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Several chiral amines bearing a heterocyclic moiety such as pyrrolidine, piperazine or tetrazole were prepared from l-phenylalanine. The enantioselectivity of the intramolecular asymmetric aldol reaction mediated by a combination of the synthetic chiral a
- Nagamine, Takashi,Inomata, Kohei,Endo, Yasuyuki
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experimental part
p. 1191 - 1204
(2009/06/28)
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- A Stereoselective entry into functionalized 1,2-diamines by zinc-mediated homologation of α-aminoacids
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A general, stereoselective synthsis of 4,5-disubstituted imidazolidines-2-ones from α-aminoacids has been developed: the key steps are a Biaise reaction of bromoacetate on α-aminonitriles and further reduction. Although reduction with sodium cyanoborohydride afforded a mixture of cis and trans isomers 6a-e with moderate to good stereoselectivity, reduction with sodium in liquid ammonia gave the trans isomers 8a-e with complete stereoselectivity. Acidic hydrolysis of the urea gave 4-amino-pyrrolidinones, which can be precursors to β,γ-diaminoacids or 3-aminopyrrolidines.
- Hoang, Cam Thuy,Alezra, Valerie,Guillot, Regis,Kouklovsky, Cyrille
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p. 2521 - 2524
(2008/02/05)
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- Phenylalanyl-aminocyclophosphamides as model prodrugs for proteolytic activation: Synthesis, stability, and stereochemical requirements for enzymatic cleavage
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4-Aminocyclophosphamide (4-NH2-CPA, 7) was proposed as a prodrug moiety of phosphoramide mustard. Four diastereomers of phenylalanine-conjugates of 4-NH2-CPA were synthesized and their stereochemistry was assigned based on chromatogr
- Jiang, Yongying,Hu, Longqin
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p. 517 - 521
(2007/10/03)
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- Biological activity of cholecystokinin (30-33) tetrapeptide analogues
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Analogues of the endogenous peptide corresponding to the 30-33 sequence of cholecystokinin (Trp-Met-Asp-Phe-NH2) were synthesized, and their biological activity was studied. It was shown that, in rats, the N-succinylated Nle2 analogu
- Proskuryakova,Bespalova,Pal'keeva,Petrichenko,Pankratova,Shokhonova,Anokhina
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p. 119 - 127
(2007/10/03)
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- PHENYL OR HETEROARYL AMINO ALKANE DERIVATIVES AS IP RECEPTOR ANTAGONIST
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The present invention relates to a phenyl or heteroaryl amino alkane derivatives which are useful as an active ingredient of pharmaceutical preparations. The phenyl or heteroaryl amino alkanes of the present invention have IP receptor antagonistic activity, and can be used for the prophylaxis and treatment of diseases associated with IP receptor antagonistic activity. Such diseases include urological diseases or disorder as follows: bladder outlet obstruction, overactive bladder, urinary incontinence, detrusor hyper-reflexia, detrusor instability, reduced bladder capacity, frequency of micturition, urge incontinence, stress incontinence, bladder hyperreactivity, benighn prostatic hypertrophy (BPH), prostatitis, urinary frequency, nocturia, urinary urgency, pelvic hypersensitivity, urethritis, pelvic pain syndrome, prostatodynia, cystitis, or idiophatic bladder hypersensitivity. The compounds of the present invention are also useful for treatment of pain including, but not limited to inflammatory pain, neuropathic pain, acute pain, chronic pain, dental pain, premenstrual pain, visceral pain, headaches, and the like; hypotension; hemophilia and hemorrhage; and inflammation, since the diseases also is alleviated by treatment with an IP receptor antagonist.
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- Synthesis of new oxazole-containing peptidomimetics
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Enantiospecific syntheses of optically active amino acids containing an oxazole moiety are described. Two different strategies for their insertion in a peptidomimetic chain are also discussed. The procedures presented are based on materials readily available in multigram quantities.
- Falorni, Massimo,Dettori, Giovanna,Giacomelli, Giampaolo
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p. 1419 - 1426
(2007/10/03)
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- Chemistry of the mycalamides: Antiviral and antitumour compounds from a New Zealand marine sponge. Part 6. The synthesis and testing of analogues of the C(7)-C(10) fragment
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The key structural features associated with the potent cytotoxicity observed in the mycalamide, onnamide, pederin and theopederin series have been defined on the basis of structure-activity studies. A model pharmacophore structure has been proposed and selected examples, with modest bioactivity, synthesized.
- Abell, Andrew D.,Blunt, John W.,Foulds, Glenn J.,Munro, Murray H. G.
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p. 1647 - 1654
(2007/10/03)
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- A fast procedure for the preparation of amides/peptides from carboxylic acids and azides via two redox reactions: Application to the synthesis of methionine enkephalin
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A one-pot self regulated approach for the synthesis of amides/peptides based on two reduction-oxidation (redox) reactions has been described. The primary and secondary amides/peptides are made by using azidotrimethylsilane and alkyl azides/α-azido acid de
- Ghosh, Sunil K.,Verma, Rekha,Ghosh, Usha,Mamdapur, Vasant R.
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p. 1705 - 1711
(2007/10/03)
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- Phenylalanine-glycine compounds having anti-tumor activity, process for preparation thereof, and pharmaceutical composition containing said compounds
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A phenylalanine-glycine compound of formula (I): STR1 wherein R represents a residue of an antitumor substance, or a salt or ester thereof, a process for preparation thereof, and a pharmaceutical composition containing the same are described. The novel conjugate of the phenylalanine-glycine compound and the antitumor substance exhibits superior antitumor activity in comparison with the case wherein an antitumor substance is administered alone or as a mixture with phenylalanine.
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- Enzymatic ammoniolysis of amino acid derivatives
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The ammoniolysis of amino acid esters and their derivatives was performed with lipases and proteases yielding the corresponding amino acid amides with moderate to high enantioselectivity.Phenylglycine methyl ester racemized slowly under the reaction conditions.
- Zoete, M. C. de,Ouwehand, A. A.,Rantwijk, F. van,Sheldon, R. A.
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p. 171 - 174
(2007/10/02)
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- Activation of carboxylic acids by pyrocarbonates. Application of di-tert-butyl pyrocarbonate as condensing reagent in the synthesis of amides of protected amino acids and peptides
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Amides formation from protected amino acids and peptides was achieved in an easy and convenient one-pot procedure using di-tert-butyl pyrocarbonate as activating agent in the presence of pyridine and ammonium hydrogencarbonate. The method gave good yields and did not induce racemization during the amidation of urethane protected amino acids.
- Pozdnev, Vladimir F.
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p. 7115 - 7118
(2007/10/02)
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- Facile amide bond formation from esters of amino acids and peptides catalyzed by alkaline protease in anhydrous tert-butyl alcohol using ammonium chloride/triethylamine as a source of nucleophilic ammonia
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An industrial alkaline protease 'Alcalase', stable and active in tert-butyl alcohol, was used to catalyze the synthesis of N-protected amino acids or peptide amides in anhydrous tert-butyl alcohol using ammonium chloride/triethylamine as source of nucleophilic ammonia
- Chen,Jang,Wang
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p. 858 - 860
(2007/10/02)
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- 6-Nitro-1-β-Naphthalenesulfonyloxybenzotriazole : A Novel Coupling Reagent For Peptide Synthesis
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Synthesis of 6-nitro-1-β-naphthalenesulfonyloxybenzotriazole (N-NSBt) and its application as a peptide coupling ragent is being reported.It has been found to be suitable for rapid and quantitative synthesis of optically pure peptides in a stepwise manner.
- Devadas, Balekudru,Kundu, Bijoy,Srivastava, Alka,Mathur, Krishna B.
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p. 6455 - 6458
(2007/10/02)
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- RENIN INHIBITORS
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The invention is new renin inhibitor dipeptide and tripeptide derivatives of the formula: STR1
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- Novel peptidase inhibitors
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This invention relates to activated electrophilic ketone analogs of certain peptidase substrates which are useful in inhibiting serine-, carboxylic acid-and metallo-proteolytic enzymes, the inhibition of which will have useful physiological consequences i
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- Convenient Synthesis of N-Protected Amino Acid Amides
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Boc- or Z-amino acids were conveniently amidated at room temperature by a one-pot procedure employing ammonium hydrogencarbonate and N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline in yields of 81-96percent.The benzyl ester-type protector for the side chains of aspartic acid and glutamic acid was not affected by the procedure.
- Nozaki, Sukekatsu,Muramatsu, Ichiro
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p. 2647 - 2648
(2007/10/02)
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- Application of Diphenylphosphinic Carboxylic Mixed Anhydrides to Peptide Synthesis.
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Diphenylphosphinic carboxylic mixed anhydrides formed in situ from Nα-protected amino acids and diphenylphosphinic chloride have been critically evaluated in peptide synthesis.Wherever possible, 32.4 MHz 31P n.m.r. spectroscopy has been employed to follow the rates of both mixed anhydride formation and aminolysis.
- Ramage, Robert,Hopton, David,Parrott, Maxwell J.,Richardson, Reginald S.,Kenner, George W.,Moore, Geoffrey A.
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p. 461 - 470
(2007/10/02)
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- Aqueous Solutions Containing Amino Acids and Peptides. Part 17. --Pairwise Enthalpic Coefficients for the Interaction of N-Acetyl-L-Phenylalaninamide with some N-Acetylamino Acid Amines at 25 deg C
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Enthalpies of dilution of N-acetyl-L-phenylalaninamide and equimolal solutions of this with N-acetylglycinamide, N-acetyl-L-alaninamide, N-acetyl- L-valinamide and N-acetyl-L-leucinamide have been determined using microcalorimetry.The results obtained were used to calculate the pairwise enthalpic coefficients for both like-like (homotactic) and like-unlike (heterotactic) solute interactions.These were then used with a group-additivity approach, which works well for these systems, to obtain information on the interaction of defined groups with each other.
- Blackburn, G. Michael,Kent, Hilary E.,Lilley, Terence H.
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p. 2207 - 2214
(2007/10/02)
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- Dichlorotris(dimethylamino)phosphorane as a Dehydratisation Reagent for the Preparation of N-Protected Amino Acid Amides
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Besides for the synthesis of peptides and activated esters dichlorotris(dimethylamino)phosphorane (2) now proved to be an excellent reagent for the preparation of N-protected amino acid amides.
- Appel, Rolf,Hiester, Ernst
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p. 2037 - 2040
(2007/10/02)
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- Sulfonic acid esters
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A novel process for the amidation or esterification which comprises reacting a compound having a carboxy group with a compound having an amino or imino group which can be acylated or with a compound having a hydroxy group in the presence of a sulfonic acid ester of the formula: wherein R1 is an organic group and R2 O-- is a residue of a strongly acidic N-hydroxy compound as a condensation agent, and a novel sulfonic acid ester useful as such a condensation agent and a process for the preparation thereof.
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- α-AMINOACYL CONTAINING NEW PEPTIDES WITH GASTRIN EFFECTS AND A PROCESS FOR THE PREPARATION THEREOF
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Peptides of the formula: wherein A is tert.-butoxycarbonyl-aminooxy-acyl, benzyloxycarbonyl-aminooxy-acyl, (aminooxy)-acyl, or E-aminooxy-acyl, wherein E is benzoyl or straight-chain or branched C1-5 aliphatic acyl, B is methionyl, leucyl, norleucyl, norvalyl or 2-amino-decanoyl, and Y is hydrogen or carboxymethoxy, and pharmaceutically acceptable acid-addition salts or complexes thereof have gastric-acid secretion increasing effects.
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