Tag: 200-300

In 2017,Tang, Mi; Sun, Rengwei; Li, Hao; Yu, Xinhong; Wang, Wei published 《An Unconventional Redox Cross Claisen Condensation-Aromatization of 4-Hydroxyprolines with Ketones》.Journal of Organic Chemistry published the findings.HPLC of Formula: 71432-55-8 The information in the text is summarized as follows:

Reaction of α-amino acids, particularly prolines and their derivatives with carbonyl compounds via decarboxylative redox process, is a viable strategy for synthesis of structurally diverse nitrogen centered heterocyclics. In these processes, the decarboxylation is the essential driving force for the processes. The realization of the redox process without decarboxylation may offer an opportunity to explore new reactions. Herein, we report the discovery of an unprecedented redox Claisen-type condensation aromatization cascade reaction of 4-substituted 4-hydroxyproline and its esters with unreactive ketones. We found that the use of propionic acid as a catalyst and a co-solvent can change the reaction course. The commonly observed redox decarboxylation and aldol condensation reactions are significantly minimized. Moreover, unreactive ketones can effectively participate in the Claisen condensation reaction. The new reactivity enables a redox cyclization via an unconventional Claisen-type condensation reaction of in situ formed enamine intermediates from ketone precursors with 4-substituted 4-hydroxyproline and its esters as electrophilic acylation partners. Under the reaction conditions, the cascade process proceeds highly regio- and stereoselectively to afford highly synthetically and biol. valued cis-2,3-dihydro-1H-pyrrolizin-1-ones with a broad substrate scope in efficient ‘one-pot’ operation, whereas such structures generally require multiple steps. The experimental part of the paper was very detailed, including the reaction process of tert-Butyl N,N’-diisopropylcarbamimidate(cas: 71432-55-8HPLC of Formula: 71432-55-8)

tert-Butyl N,N’-diisopropylcarbamimidate(cas: 71432-55-8) belongs to anime. The methylamines occur in small amounts in some plants. Many polyfunctional amines (i.e., those having other functional groups in the molecule) occur as alkaloids in plants—for example, mescaline, 2-(3,4,5-trimethoxyphenyl)ethylamine; the cyclic amines nicotine, atropine, morphine, and cocaine; and the quaternary salt choline, N-(2-hydroxyethyl)trimethylammonium chloride, which is present in nerve synapses and in plant and animal cells.HPLC of Formula: 71432-55-8

Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics

In 2012,Murakami, Yuko; Yanuma, Hiroto; Usuki, Toyonobu published 《Total synthesis of the elastin crosslinker (+)-desmopyridine》.Tetrahedron: Asymmetry published the findings.SDS of cas: 71432-55-8 The information in the text is summarized as follows:

Desmopyridine, isolated from the acid hydrolyzates of bovine ligamentum nuchae, is an elastin crosslinker and an amino acid that has a 3,4,5-trisubstituted pyridine skeleton. Herein we report the first total synthesis of (+)-desmopyridine in 10% yield over six steps starting from 4-aminopyridine via chemo- and regioselective palladium-catalyzed Sonogashira and Negishi cross-coupling reactions. The experimental part of the paper was very detailed, including the reaction process of tert-Butyl N,N’-diisopropylcarbamimidate(cas: 71432-55-8SDS of cas: 71432-55-8)

tert-Butyl N,N’-diisopropylcarbamimidate(cas: 71432-55-8) belongs to anime.Typically the presence of an amine functional group is deduced by a combination of techniques, including mass spectrometry as well as NMR and IR spectroscopies. 1H NMR signals for amines disappear upon treatment of the sample with D2O. In their infrared spectrum primary amines exhibit two N-H bands, whereas secondary amines exhibit only one.SDS of cas: 71432-55-8

Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics

Karatzas, Anastasis; Haataja, Johannes S.; Skoulas, Dimitrios; Bilalis, Panayiotis; Varlas, Spyridon; Apostolidi, Panagiota; Sofianopoulou, Sosanna; Stratikos, Efstratios; Houbenov, Nikolay; Ikkala, Olli; Iatrou, Hermis published their research in Biomacromolecules on December 9 ,2019. The article was titled 《Macromolecular Architecture and Encapsulation of the Anticancer Drug Everolimus Control the Self-Assembly of Amphiphilic Polypeptide-Containing Hybrids》.Category: amides-buliding-blocks The article contains the following contents:

Macromol. architecture plays an important role in the self-assembly process of block copolymer amphiphiles. Herein, two series of stimuli-responsive amphiphilic 3-miktoarm star hybrid terpolypeptides and their corresponding linear analogs were synthesized exhibiting the same overall composition and mol. weight but different macromol. architecture. The macromol. architecture was found to be a key parameter in defining the morphol. of the nanostructures formed in aqueous solutions as well as to alter the self-assembly behavior of the polymers independently of their composition In addition, it was found that the assemblies prepared from the star-shaped polymers showed superior tolerance against enzymic degradation due to the increased corona block d. on the outer surface of the nanoparticles. Encapsulation of the hydrophobic anticancer drug Everolimus resulted in the formation of intriguing non-spherical and non-sym. pH-responsive nanostructures, such as “”stomatocytes”” and “”multi-compartmentalized suprapolymersomes””, while the pH-triggered release of the drug was also investigated. Owing to the similarities of the developed “”stomatocytes”” with red blood cells, in combination with their pH-responsiveness and superior stability over enzymic degradation, they are expected to present advanced drug delivery properties and have the ability to bypass several extra- and intracellular barriers to reach and effectively treat cancer cells.H-Lys(Boc)-OH(cas: 2418-95-3Category: amides-buliding-blocks) was used in this study.

H-Lys(Boc)-OH(cas: 2418-95-3) belongs to amino acids. In addition to subunits of proteins, amino acids have many other functions as well, including osmoregulation (proline), neurotransmitters (gamma-aminobutyric acid), metabolic intermediates (ornithine and citrulline), and inhibitors (dehydroproline).Category: amides-buliding-blocks

Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics

Tyrrell, Elizabeth; Brawn, Peter; Carew, Mark; Greenwood, Iain published an article on January 19 ,2011. The article was titled 《An expedient conversion of α-amino acids into Weinreb amides using COMU as a coupling agent》, and you may find the article in Tetrahedron Letters.Electric Literature of C13H26N2O4 The information in the text is summarized as follows:

The use of COMU, as a non-hazardous partner, in the coupling of N-Boc α-amino acids with N-methoxy-N-methylamine to afford the corresponding Weinreb amides is discussed. From a practical point of view the reaction can be monitored visually by virtue of the color change associated with the conversion of substrates (yellow) into the products (orange). As the byproducts of the reaction are conveniently water-soluble, the products are isolated relatively pure and with minimal racemization. These factors coupled with the short reaction time make this a very useful procedure. In the experiment, the researchers used (S)-N-Methyl-N-methoxy-2-(tert-butoxycarbonylamino)-4-methylpentanamide(cas: 87694-50-6Electric Literature of C13H26N2O4)

(S)-N-Methyl-N-methoxy-2-(tert-butoxycarbonylamino)-4-methylpentanamide(cas: 87694-50-6) belongs to amides. Because of the greater electronegativity of oxygen, the carbonyl (C=O) is a stronger dipole than the N–C dipole. The presence of a C=O dipole and, to a lesser extent a N–C dipole, allows amides to act as H-bond acceptors.Electric Literature of C13H26N2O4 In primary and secondary amides, the presence of N–H dipoles allows amides to function as H-bond donors as well.

Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics

In 2020,Future Medicinal Chemistry included an article by Cao, Yucheng; Ni, Jingxuan; Ji, Wentao; Shang, Kangle; Liang, Kaicheng; Lu, Jing; Bi, Yi; Luo, Xiaomin. Recommanded Product: 2418-95-3. The article was titled 《Synthesis, antifungal activity and potential mechanism of fusidic acid derivatives possessing amino-terminal groups》. The information in the text is summarized as follows:

Aim: Fusidic acid (FA) is a narrow-spectrum bacteriostatic antibiotic. We inadvertently discovered that a FA derivative modified by an amino-terminal group at the 3-OH position, namely 2, inhibited the growth of Cryptococcus neoformans. Methods & results: Multiscale mol. modeling approaches were used to analyze the binding modes of 2 with eEF2. FA derivatives modified at the 3-OH position were designed based on in silico models; seven derivatives possessing different amino-terminal groups were synthesized and tested in vitro for antifungal activity against C. neoformans. Conclusion: Compound 7 had the strongest min. inhibitory concentration Two protonated nitrogen atoms of 7 interacted with a neg. electrostatic pocket of eEF2 likely explain the superiority of 7-2. In the part of experimental materials, we found many familiar compounds, such as H-Lys(Boc)-OH(cas: 2418-95-3Recommanded Product: 2418-95-3)

H-Lys(Boc)-OH(cas: 2418-95-3) belongs to amino acids. In addition to subunits of proteins, amino acids have many other functions as well, including osmoregulation (proline), neurotransmitters (gamma-aminobutyric acid), metabolic intermediates (ornithine and citrulline), and inhibitors (dehydroproline).Recommanded Product: 2418-95-3

Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics

Formula: C13H26N2O4On October 27, 1992 ,《Proteolysis of an active site peptide of lactate dehydrogenase by human immunodeficiency virus type 1 protease》 was published in Biochemistry. The article was written by Tomaszek, Thaddeus A. Jr.; Moore, Michael L.; Strickler, James E.; Sanchez, Robert L.; Dixon, J. Scott; Metcalf, Brian W.; Hassell, Anne; Dreyer, Geoffrey B.; Brooks, Isobel. The article contains the following contents:

Muscle and heart lactate dehydrogenases (LDHs) of rabbit and pig are specifically cleaved at a single position by HIV-1 protease, resulting in the conversion of 36-kDa subunits of the oligomeric enzymes into 21- and 15-kDa protein bands as analyzed by SDS-PAGE. While the proteolysis was observed at neutral pH, it became more pronounced at pH 6.0 and 5.0. The time courses of the cleavage of the 36-kDa subunits were commensurate with the time-dependent loss of both quaternary structure and enzymic activity. These results demonstrated that deoligomerization of rabbit muscle LDH at acidic pH rendered its subunits more susceptible to proteolysis, suggesting that a partially denatured form of the enzyme was the actual substrate. Proteolytic cleavage of the rabbit muscle enzyme occurred at a decapeptide sequence, His-Gly-Trp-Ile-Leu*Gly-Glu-His-Gly-Asp (scissile bond denoted throughout by an asterisk), which constitutes a strand-loop element in the muscle and heart LDH structures and contains the active site histidyl residue His-193. The kinetic parameters Km, Vmax/KmEt, and Vmax/Et for rabbit muscle LDH and the synthetic decapeptide Ac-His-Gly-Trp-Ile-Leu*Gly-Glu-His-Gly-Asp-NH2 were nearly identical, suggesting that the decapeptide within the protein substrate is conformationally mobile, as would be expected for the peptide substrate in solution Insertion of part of this decapeptide sequence into bacterial galactokinase likewise rendered this protein susceptible to proteolysis by HIV-1 protease, and site-directed mutagenesis of this peptide in galactokinase revealed that the Glu residue at the P2′ was important to binding to HIV-1 protease. Crystallog. anal. of HIV-1 protease complexed with a tight-binding peptide analog inhibitor derived from this decapeptide sequence revealed that the strand-loop structure of the protein substrate must adopt a β-sheet structure upon binding to the protease. The Glu residue in the P2′ position of the inhibitor likely forms hydrogen-bonding interactions with both the α-amide and γ-carboxylic groups of Asp-30 in the substrate-binding site. In the experiment, the researchers used (S)-N-Methyl-N-methoxy-2-(tert-butoxycarbonylamino)-4-methylpentanamide(cas: 87694-50-6Formula: C13H26N2O4)

(S)-N-Methyl-N-methoxy-2-(tert-butoxycarbonylamino)-4-methylpentanamide(cas: 87694-50-6) belongs to amides.Formula: C13H26N2O4 The solubilities of amides and esters are roughly comparable. Typically amides are less soluble than comparable amines and carboxylic acids since these compounds can both donate and accept hydrogen bonds.

Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics

HPLC of Formula: 106392-48-7On October 3, 1994 ,《Phosphorylation of JAK2 in thrombin-stimulated human platelets》 was published in FEBS Letters. The article was written by Rodriguez-Linares, Belen; Watson, Steve P.. The article contains the following contents:

We show the presence of the tyrosine kinase JAK2 in human platelets and demonstrate that it undergoes phosphorylation on tyrosine residues on challenge with the G protein receptor stimulus, thrombin, or the tyrosine phosphatase inhibitor, peroxovanadate. Thrombin-induced phosphorylation of JAK2 is inhibited by two structurally distinct inhibitors of tyrosine kinases, staurosporine and the tyrphostin ST271. The protein kinase C (PKC) inhibitor, Ro 31-8220, and intracellular Ca2+ chelator, BAPTA-AM, also inhibit thrombin-induced phosphorylation of JAK2, while the phorbol ester, phorbol dibutyrate (PDBu), and Ca2+ ionophore, A23187, induce tyrosine phosphorylation of JAK2. These results suggest that tyrosine phosphorylation of JAK2 stimulated by thrombin may be mediated downstream of phosphoinositide metabolism In the experiment, the researchers used many compounds, for example, 2-Cyano-3-(4-hydroxy-3,5-diisopropylphenyl)acrylamide(cas: 106392-48-7HPLC of Formula: 106392-48-7)

2-Cyano-3-(4-hydroxy-3,5-diisopropylphenyl)acrylamide(cas: 106392-48-7) belongs to amides.HPLC of Formula: 106392-48-7Amides are pervasive in nature and technology. Proteins and important plastics like Nylons, Aramid, Twaron, and Kevlar are polymers whose units are connected by amide groups (polyamides); these linkages are easily formed, confer structural rigidity, and resist hydrolysis.

Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics

Related Products of 71432-55-8In 2018 ,《Coordination-Mediated Synthesis of Purification-Free Bivalent 99mTc-Labeled Probes for in Vivo Imaging of Saturable System》 was published in Bioconjugate Chemistry. The article was written by Taira, Yuichiro; Uehara, Tomoya; Tsuchiya, Masao; Takemori, Hideaki; Mizuno, Yuki; Takahashi, Shiori; Suzuki, Hiroyuki; Hanaoka, Hirofumi; Akizawa, Hiromichi; Arano, Yasushi. The article contains the following contents:

In the synthesis of technetium-99m (99mTc) labeled target-specific ligands, the presence of a large excess of unlabeled ligands over 99mTc in the injectate hinders target accumulation of 99mTc-labeled ligands by competing for target mols. To circumvent the problem, we recently developed a concept of the metal coordination-mediated multivalency, and proved the concept with a 99mTc-labeled trivalent compound [99mTc(CO)3(CN-RGD)3]+. In this study, D-penicillamine (Pen) was selected as a chelating mol. and a cyclic RGDfK peptide was conjugated to Pen via a hexanoic linkage (Pen-Ahx-c(RGDfK)). 99mTc complexation reaction, and the stability, integrin αvβ3 binding affinity, and biodistribution of the 99mTc-labeled probe were investigated to evaluate the applicability of the concept to bivalent probes. 99mTc-[Pen-Ahx-c(RGDfK)]2 was obtained over 95% radiochem. yields under low Pen-Ahx-c(RGDfK) concentration (50 μM). 99mTc-[Pen-Ahx-c(RGDfK)]2 showed approx. 10-times higher integrin αvβ3 binding affinity than the monovalent compounds, Pen-Ahx-c(RGDfK) and c(RGDyV). In biodistribution studies, the tumor accumulation of 99mTc-[Pen-Ahx-c(RGDfK)]2 was decreased to 77% and 43% of HPLC-purified (Pen-Ahx-c(RGDfK)-free) 99mTc-[Pen-Ahx-c(RGDfK)]2 by the presence of 5 nmol of unlabeled Pen-Ahx-c(RGDfK) and Re-[Pen-Ahx-c(RGDfK)]2, resp. 99mTc-[Pen-Ahx-c(RGDfK)]2 provided tumor image without removing unlabeled ligand, while a 99mTc-labeled monovalent probe prepared from a monovalent ligand could not. These findings indicate the availability of the design concept to prepare 99mTc-labeled bivalent probes with a variety of 99mTc core and other metallic radionuclides of clin. relevance. In the experiment, the researchers used tert-Butyl N,N’-diisopropylcarbamimidate(cas: 71432-55-8Related Products of 71432-55-8)

tert-Butyl N,N’-diisopropylcarbamimidate(cas: 71432-55-8) belongs to anime. Nitrous acid converts secondary amines (aliphatic or aromatic) to N-nitroso compounds (nitrosamines): R2NH + HNO2 → R2N―NO. Some nitrosamines are potent cancer-inducing substances, and their possible formation is a serious consideration when nitrites, which are salts of nitrous acid, are present in foods or pharmaceutical preparations. Tertiary amines give rise to nitrosamines more slowly; an alkyl group is eliminated as an aldehyde or ketone, along with nitrous oxide, N2O.Related Products of 71432-55-8

Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics

In 2019,ChemistrySelect included an article by Porala, Subbanarasimhulu; Yerrabelly, Jayaprakash Rao; Kasireddy, Venkateshwar Reddy; Yerrabelly, Hemasri; Ghojala, Venkat Reddy; Rebelli, Pradeep. Synthetic Route of C9H19ClN2O2. The article was titled 《New and efficient synthesis of HCV NS3/4 A protease inhibitor Telaprevir》. The information in the text is summarized as follows:

An efficient and improved approach for the synthesis of HCV NS3/4 A (Hepatitis C virus Non-structural protein 3) protease inhibitor, Telaprevir has been developed, which involves the novel synthesis of key intermediates β-amino-α-hydroxy amide (I) and tripeptide acid (II). The synthesis of β-amino-α-hydroxy amide I was designed via the monochloro and dichloro intermediates using the crossed Claisen condensation followed by decarboxylation with good overall yield (29.62%). The tripeptide acid II was developed by the coupling of dipeptide acid with bicyclic nitrile followed by simple chem. conversions in less number of steps with good overall yield (61.2%). After reading the article, we found that the author used (3S)-3-Amino-N-cyclopropyl-2-hydroxyhexanamide hydrochloride(cas: 850252-34-5Synthetic Route of C9H19ClN2O2)

amides-buliding-blocks(cas:850252-34-5) is one of amino acids. Amino acids are organic compounds that contain both amino and carboxylic acid functional groups Although hundreds of amino acids exist in nature, by far the most prevalent are the alpha-amino acids, which comprise proteins.Synthetic Route of C9H19ClN2O2 Only 22 alpha amino acids appear in the genetic code.

Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics

Recommanded Product: 87694-50-6On May 6, 1998 ,《γ-Peptides forming more stable secondary structures than α-peptides. Synthesis and helical NMR-solution structure of the γ-hexapeptide analog of H-(Val-Ala-Leu)2-OH》 appeared in Helvetica Chimica Acta. The author of the article were Hintermann, Tobias; Gademann, Karl; Jaun, Bernhard; Seebach, Dieter. The article conveys some information:

For a comparison with the corresponding α- and β-hexapeptides H-(Val-Ala-Leu)2-OH (A) and H-(β-HVal-β-HAla-β-HLeu)2-OH (B), the corresponding γ-hexapeptide (I), built from the homochirally similar (S)-4-aminobutanoate, (R)-4-amino-5-methylhexanoate, and (R)-4-amino-6-methylheptanoate, was prepared The precursors were obtained either by double Arndt-Eistert homologation of protected Boc-Val-OH, Boc-Ala-OH, and Boc-Leu-OH, or by the superior route involving olefination/hydrogenation of the corresponding aldehydes, Boc-valinal, Boc-alaninal, and Boc-leucinal. Conventional peptide coupling (EDC/HOBt) furnished I through the intermediate γ-di- and γ-tripeptide. NMR measurements in (D5)pyridine and CD3OH solution (COSY, TOCSY, HSQC, HMBC, ROESY) reveal that I adopts a right-handed helical structure [(P)-2.61 helix of ∼5-Å pitch, containing 14-membered H-bonded rings] which is to be compared with the left-handed helix of β-peptide B [(M)-31 helix of 5-Å pitch, 14-membered H-bonded rings] and with the familiar right-handed, so-called α-helix of α-peptides [(P)-3.61 helix of 5.4-Å pitch, 13-membered rings]. Like the helix sense, the helix dipole reverses when going from α-(N→C) to β-(C→N) to γ-peptides (N→C). The surprising difference between the natural α-, and the analogous β- and γ-peptides is that the helix stability increases upon homologation of the residues. In the part of experimental materials, we found many familiar compounds, such as (S)-N-Methyl-N-methoxy-2-(tert-butoxycarbonylamino)-4-methylpentanamide(cas: 87694-50-6Recommanded Product: 87694-50-6)

(S)-N-Methyl-N-methoxy-2-(tert-butoxycarbonylamino)-4-methylpentanamide(cas: 87694-50-6) belongs to amides. Because of the greater electronegativity of oxygen, the carbonyl (C=O) is a stronger dipole than the N–C dipole. The presence of a C=O dipole and, to a lesser extent a N–C dipole, allows amides to act as H-bond acceptors.Recommanded Product: 87694-50-6 In primary and secondary amides, the presence of N–H dipoles allows amides to function as H-bond donors as well.

Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics