ABSTRACT
The short peptides, containing the amino acid sequence asparagine-glycine-arginine (NGR) and arginine-glycine-aspartic acid (RGD), possess the strong binding ability to N (APN/CD13) aminopeptidase receptor and integrin proteins involved in antitumor properties are overexpressed. A novel short N-terminal modified hexapeptides P1 and P2 was designed and synthesized using the Fmoc-chemistry solid phase peptide synthesis protocol. Notably, the cytotoxicity of the MTT assay demonstrated the viability of normal and cancer cells up to lower peptide concentrations. Interestingly, both peptides show good anticancer activities against the four cancer cells and normal cells namely, Hep-2, HepG2, MCF-7, A375, and Vero and compared with standard drugs, doxorubicin and paclitaxel. Additionally, in silico studies were applied to predict the binding sites and binding orientation of the peptides for potential anticancer targets. Steady-state fluorescence measurements showed that peptide P1 exhibits preferential interactions with POPC/POPG anionic bilayers rather than the zwitterionic POPC lipid bilayers and peptide P2, did not show any preferential interaction with lipids bilayers. But impressively, peptide P2 shows anticancer activity due to the NGR/RGD motif. Circular dichroism studies demonstrated that the peptide's secondary structure changes only minimally upon binding to the anionic lipid bilayers.
Subject(s)
Aminopeptidases , Lipid Bilayers , Lipid Bilayers/chemistry , Integrins , Peptides , Oligopeptides/pharmacology , Oligopeptides/chemistryABSTRACT
An efficient route to enantioenriched propargylamines via a three-component alkynylation reaction using cooperative catalysis with a CuI- iPrpyboxdiPh complex and N-Boc-(l)-proline has been accomplished. A variety of functionalized amines, aldehydes, and 2-ethynyl anilines were reacted smoothly at ambient temperature to furnish a wide range of propargylamines in high yields (up to 94%) and excellent enantioselectivities (up to 98% ee). Synthetic utility of the methodology has been demonstrated by transforming the products into various synthetically useful intermediates. Finally, propargylamines were transformed into biologically important (indol-2-yl)methanamines over two steps in good yields (up to 88%) with an excellent level of enantioselectivities (up to 95%).
ABSTRACT
A one-pot, three-component synthesis of widely substituted isoindolinones and isoquinolinones, featuring a Lewis acid-catalyzed efficient Strecker reaction and lactamization sequence, affording products in good to high yields is reported. The method has also been extended to the synthesis of tetrahydroisoquinolines (THIQs) in high yields.
ABSTRACT
A novel and efficient synthesis of a variety of isoindolinones and tetrahydroisoquinolines via a Lewis acid catalyzed domino Mukaiyama-Mannich lactamization/alkylation is achieved. This transformation comprises a sequential formation of three new bonds through a one-pot, three-component procedure to afford product in moderate to high yields. A concise synthesis of (±)-homolaudanosine (2b) has been achieved using this method.
Subject(s)
Indoles/chemical synthesis , Isoquinolines/chemical synthesis , Lewis Acids/chemistry , Alkylation , Catalysis , Indoles/chemistry , Isoquinolines/chemistry , Molecular StructureABSTRACT
An organocatalytic direct Mannich-lactamization sequence for the syntheses of pharmacologically important enantioenriched isoindolinones is reported. The method utilizes simple α-amino acids to deliver syn- and anti- selective isoindolinones with remarkably high enantioselectivity (up to >99% ee) in good to excellent yields and diastereomeric ratios. The overall sequence involves one C-C and two C-N bond forming events in one pot starting from inexpensive starting material.
Subject(s)
Amino Acids/chemistry , Isoindoles/chemical synthesis , Aldehydes/chemistry , Catalysis , Combinatorial Chemistry Techniques , Isoindoles/chemistry , Molecular Structure , StereoisomerismABSTRACT
An unprecedented highly efficient Lewis acid catalyzed one-pot cascade has been demonstrated as a general catalytic system for the synthesis of diversely substituted isoindolinones and tetrahydroisoquinolines. The cascade effects one C-C and two C-N bond-forming events in one pot. Several interesting transformations of the products into valuable synthetic intermediates are featured with the successful total synthesis of (±)-crispine A.
