6306-52-1Relevant academic research and scientific papers
Synthesis of two biofriendly anionic surfactants (N-n-decanoyl-L-valine and N-n-decanoyl-L-leucine) and their mixed micellization with nonionic surfactant Mega-10 in Tris-buffer medium at pH 9
Das, Sibani,Maiti, Susmita,Ghosh, Soumen
, p. 12275 - 12286 (2014)
Two biofriendly anionic amino acid surfactants (AAS), N-n-decanoyl-l-valine (C10-val) and N-n-decanoyl-l-leucine (C10-leu) were synthesized and mixed micellization of them with nonionic surfactant N-decanoyl-N-methyl-glucamine (Mega-10) was investigated by tensiometry and fluorimetry in 50 mM Tris-buffer (pH = 9) medium at 298 K. The critical micelle concentration (cmc), surface properties, e.g., Gibbs surface excess (Γmax), area of exclusion per surfactant monomer (A min) and surface pressure at cmc (Πcmc) were determined. Gibbs free energy of micellization (ΔG0m) and Gibbs free energy of adsorption (ΔG0ads) were also determined. Both the free energy values are negative indicating the spontaneity and stability of the mixed micelles. The size of the micelles was determined by dynamic light scattering (DLS) measurements. The deviation of mixed micelles from the ideal behavior was discussed on the basis of Clint, Motomura, Rubingh (regular solution theory), Rosen and Maeda's theory. Rubingh-Holland theory was applied on the ternary systems made by these three surfactants. The compositions of mixed micelle, the activity coefficients and the corresponding interaction parameters were evaluated from these theories. The interaction parameters (β) are negative, indicating attractive interaction between the ionic and nonionic surfactants. The micellar aggregation number (Nagg) and micropolarity were evaluated using steady state fluorescence measurements and the packing parameter (P) was determined on the basis of Israelachvili's theory. The standard free energy changes associated with the transfer of surfactant tail due to micellization of pure, binary and ternary combinations of surfactants were determined from Nagarajan's model. We report for the first time in detail the binary and ternary combinations using amino acid based surfactants.
GENERAL APPROACH TO THE QUANTITATION OF SYNTHETIC EFFICIENCY IN SOLID-PHASE PEPTIDE SYNTHESIS AS A FUNCTION OF CHAIN LENGTH.
Sarin,Kent,Mitchell,Merrifield
, p. 7845 - 7850 (1984)
A model peptide, Leu-Ala-Gly-Val, was synthesized by solid-phase methods at increasing distnces from a 1% cross-linked polystyrene resin support. The efficiency of the synthesis was evaluated by quantitatively measuring the amounts of the deletion peptides Leu-Ala-Val and Leu-Gly-Val that were produced during the synthesis of the tetrapeptide. By inserting an oxymethylphenylacetyl group between this test peptide and the peptide chains used to provide spacers from the support, it was possible to selectively evaluate the quality of the tetrapeptide without interference by the spacer. Low and constant levels of deletion peptides were found. No significant effect of distance from the support or of peptide loading on the synthetic efficiency could be detected up to a chain length of 60 residues and a peptide-to-resin weight ratio of 4:1.
C2 symmetric copper (II) complexes of L-valine and L-phenyl alanine based chiral diimines for catalytic asymmetric Henry reaction
Ananthi, Nallamuthu,Johnson, S. Jesu,Kumar, K. Vinoth,Nixon, Peter Daniel
supporting information, (2021/05/19)
New C2 symmetric chiral diimines were synthesized from the amino acids L-valine and L-phenyl alanine. In situ copper (II) complexes of the chiral diimine ligands were found to catalyze asymmetric Henry reaction. The chiral nitro aldols were formed in excellent yield (99%) and ee (99%). The synthetic utility of the chiral catalysts were screened with various substituted prochiral aromatic and heteroaromatic aldehydes. Possible catalytic cycle for the chiral diimine copper complex catalyzed asymmetric Henry reaction has been proposed. The stereoselectivity of the asymmetric Henry reaction was discussed based on the transition state in the catalytic cycle.
Microwave-Assisted Ruthenium- and Rhodium-Catalyzed Couplings of α-Amino Acid Ester-Derived Phosphinamides with Alkynes
Gong, Jun-Fang,Li, Xue-Hong,Song, Mao-Ping
supporting information, (2021/12/23)
Two different types of new phosphinamide α-amino ester derivatives have been prepared in moderate to high yields via ruthenium(II) and rhodium(III)-catalyzed ortho-C?H functionalization under microwave irradiation. Specifically, the ortho-alkenylated phosphinamides were produced through coupling of phosphinamides containing an α-substituted or α,α-disubstituted α-amino ester with internal alkynes under ruthenium catalysis. In contrast, Ru and the more effective Rh-catalyzed coupling of the α-unsubstituted glycine ester phosphinamide with alkynes resulted in formation of oxidative annulation products, phosphaisoquinolin-1-ones. The developed methods feature the use of easily accessible starting materials, short reaction time, exclusive E-stereoselectivity (for ortho-alkenylation) and good functional group tolerance. The alkenylation reaction was readily scaled up to gram scale. Furthermore, the obtained alkenylated phosphinamide could be transformed into P-containing dipeptides through hydrolysis of the ester group in the catalysis product and subsequent condensation with an α-amino ester.
Post-synthetic functionalization of tryptophan protected peptide sequences through indole (C-2) photocatalytic alkylation
Ackermann, Lutz,Berlinck, Roberto G. S.,Bernardi, Darlon I.,Delgado, José A. C.,Kaplaneris, Nikolaos,Lima, Rafaely N.,Paix?o, Márcio W.
supporting information, p. 5758 - 5761 (2021/06/16)
We report a selective, mild, and efficient C-H functionalization of tryptophan and tryptophan-containing peptides with activated α-bromo-carbonyl compounds under visible-light irradiation. The protocol efficiency is outlined by the wide substrate scope and excellent tolerance of sensitive functional groups present in the amino acid side chains. The method can be successfully extended to access pharmaco-peptide conjugate scaffolds.
Eco-friendly synthesis of peptides using fmoc-amino acid chlorides as coupling agent under biphasic condition
Kantharaju, Kamanna,Khatavi, Santosh Y.
, p. 699 - 707 (2021/08/23)
Background: Agro-waste derived solvent media act as a greener process for the peptide bond formation using Nα-Fmoc-amino acid chloride and amino acid ester salt with in situ neutralization and coupling under biphasic condition. The Fmoc-amino acid chlorides are prepared by the reported procedure of freshly distilled SOCl2 with dry CH2Cl2. The protocol found many added ad-vantages such as neutralization of amino acid ester salt and not required additional base for the neu-tralization, and directly coupling take place with Fmoc-amino acid chloride gave final product dipeptide ester in good to excellent yields. The protocol occurs with complete stereo chemical integrity of the configuration of substrates. Here, we revisited Schotten-Baumann condition, instead of using inorganic base. Objective: To develop green protocol for the synthesis of peptide bond using Fmoc-amino acid chloride with amino acid esters salt. Methods: The final product isolated is analyzed in several spectroscopic and analytical techniques such as FT-IR,1H-,13C-NMR, Mass spectrometry and RP-HPLC to check stereo integrity and puri-ty of the product. Conclusion: The present method developed greener using natural agro-waste (lemon fruit shell ash) derived solvent medium for the reaction and not required chemical entity.
Ribose conversion with amino acids into pyrraline platform chemicals-expeditious synthesis of diverse pyrrole-fused alkaloid compounds
Cho, Soohyeon,Gu, Lina,In, Ik Joon,Kim, Hakwon,Koo, Sangho,Lee, Taehoon,Wu, Bo
, p. 31511 - 31525 (2021/11/30)
One-pot conversion of sustainable d-ribose with l-amino acid, methyl esters produced pyrrole-2-carbaldehydes 5 in reasonable yields (32-63%) under pressurized conditions of 2.5 atm at 80 °C. The value-added pyrraline compounds 5 as platform chemicals were utilized for quick installation of poly-heterocyclic cores for the development of pyrrole-motif natural and artificial therapeutic agents. A pyrrole-fused piperazin-2-one scaffold 6 was prepared by reductive amination of pyrralines 5 with benzylamine. While further cyclization of pyrralines 5 with ethane-1,2-diamine produced pyrrolo-piperazin-2-ones 7 with an extra imidazolidine ring, the reaction with 2-amino alcohols derived from natural l-amino acids, alanine, valine, and phenylalanine, respectively provided pyrrolo-piperazin-2-ones 8, 9, and 10 with oxazolidine as the third structural core. Cell viability and an anti-inflammatory effect of the synthesized compounds were briefly tested by the MTT method and the Griess assay, among which 8h and 10g exhibited significant anti-inflammatory effects with negligible cell toxicity.
A Novel N-Substituted Valine Derivative with Unique Peroxisome Proliferator-Activated Receptor γbinding Properties and Biological Activities
Peiretti, Franck,Montanari, Roberta,Capelli, Davide,Bonardo, Bernadette,Colson, Cécilia,Amri, Ez-Zoubir,Grimaldi, Marina,Balaguer, Patrick,Ito, Keiichi,Roeder, Robert G.,Pochetti, Giorgio,Brunel, Jean Michel
, p. 13124 - 13139 (2020/12/02)
A proprietary library of novel N-Aryl-substituted amino acid derivatives bearing a hydroxamate head group allowed the identification of compound 3a that possesses weak proadipogenic and peroxisome proliferator-Activated receptor γ(PPARI) activating properties. The systematic optimization of 3a, in order to improve its PPARγagonist activity, led to the synthesis of compound 7j (N-Aryl-substituted valine derivative) that possesses dual PPARI/PPARα agonistic activity. Structural and kinetic analyses reveal that 7j occupies the typical ligand binding domain of the PPARγagonists with, however, a unique high-Affinity binding mode. Furthermore, 7j is highly effective in preventing cyclin-dependent kinase 5-mediated phosphorylation of PPARγserine 273. Although less proadipogenic than rosiglitazone, 7j significantly increases adipocyte insulin-stimulated glucose uptake and efficiently promotes white-To-brown adipocyte conversion. In addition, 7j prevents oleic acid-induced lipid accumulation in hepatoma cells. The unique biochemical properties and biological activities of compound 7j suggest that it would be a promising candidate for the development of compounds to reduce insulin resistance, obesity, and nonalcoholic fatty liver disease.
Amino acid conjugates of 2-mercaptobenzimidazole provide better anti-inflammatory pharmacology and improved toxicity profile
Khan, Muhammad T.,Nadeem, Humaira,Khan, Arif-ullah,Abbas, Muzaffar,Arif, Muazzam,Malik, Nadia Shamshad,Malik, Zulkifal,Javed, Ibrahim
, p. 1057 - 1072 (2020/08/13)
Benzimidazole is an important pharmacophore for clinically active drugs against inflammation and treatment of pain, however, it is associated with gastrointestinal side effects. Here we synthesized benzimidazole based agents with significant analgesic/anti-inflammatory potential but with less gastrointestinal adverse effects. In this study, we synthesized novel, orally bioavailable 2-mercaptobenzimidazole amino acid conjugates (4a–4o) and screened them for analgesic, anti-inflammatory and gastro-protective effects. The synthesized 2-mercaptbenzimidazole derivatives were characterized for their structure using FTIR, 1H NMR and 13C NMR spectroscopic techniques. The 2-mercaptobenzimidazole amino acid conjugates have found to possess potent analgesic, anti-inflammatory and gastroprotective activities, particularly with compound 4j and 4k. Most of the compounds exhibited remarkable anti-ulcer and antisecretory effects. Molecular docking studies were carried out to study the binding affinities and interactions of the synthesized compounds with target proteins COX-2 (PDB ID: 3LN1) and H+/K+-ATPase (PDB ID: 5Y0B). Our results support the clinical promise of these newly synthesized 2-mercaptobezimidazol conjugates as a component of therapeutic strategies for inflammation and analgesia, for which the gastric side effects are always a major limitation.
Synthesis and antimalarial activity of (S)-methyl-(7-chloroquinolin-4-ylthio)acetamidoalquilate derivatives
Colmenarez, Custodiana,Acosta, María,Rodríguez, Miguel,Charris, Jaime
, p. 161 - 166 (2020/01/09)
The synthesis of five new (S)-methyl-(7-chloroquinolin-4-ylthio)acetamidoalquilate derivatives is carried out under a modified version of the Steglich esterification reaction between different l-amino acid methyl esters and 2-(7-chloroquinolin-4-ylthio)acetic acid. Two of the compounds showed significant inhibition (>50%) of β-hematin formation. The two active structures were tested in vivo as potential antimalarials in mice infected with Plasmodium berghei ANKA, a chloroquine susceptible strain. Compounds 6b and 6e exhibited antimalarial activity comparable to that of chloroquine.
