52641-32-4Relevant academic research and scientific papers
Hybrids of arenobufagin and benzoisoselenazol reducing the cardiotoxicity of arenobufagin
Hou, Wen,Huang, Zhi-Xing,Xu, Hong-Gui,Lin, Jing,Zhang, Dong-Mei,Peng, Qun-Long,Lin, Hui,Chang, Yi-Qun,Wang, Long-Hai,Yao, Zhe,Sun, Ping-Hua,Chen, Wei-Min
, p. 3391 - 3394 (2018/09/11)
Arenobufagin is a naturally occurring bufadienolide showing promising antitumor activity accompanied however with apparent cardiac toxicity. Following the recent discovery that oxidative damage possibly be an important cause of the cardiac toxicity of cardenolides, a strategy fusing the antitumor agent arenobufagin with a benzoisoselenazol fragment, a reactive oxygen species (ROS) scavenger, has been developed. Six novel hybrids were synthesized and their ROS scavenging activities as well as their in vitro cytotoxicity against the human hepatocellular carcinoma cell line HepG2, an adriamycin-resistant subline HepG2/ADM, and the human myocardial cell line AC16 were evaluated. The results indicate that the hybrids exhibit various degrees of in vitro ROS scavenging activities, and weaker cytotoxicity than that of arenobufagin against the myocardial cell line AC16. These findings suggest the feasibility of a strategy in which the cardiotoxicity of the potential antitumor agent arenobufagin is reduced.
Structural optimization of azadipeptide nitriles strongly increases association rates and allows the development of selective cathepsin inhibitors
Frizler, Maxim,Lohr, Friederike,Furtmann, Norbert,Kl?s, Julia,Gütschow, Michael
supporting information; scheme or table, p. 396 - 400 (2011/03/18)
Using the example of cathepsin K, we demonstrate the design of highly potent and selective azadipeptide nitrile inhibitors. A systematic scan with respect to P2 and P3 substituents was carried out. Structural modifications strongly affected the enzyme-inh
Polypeptide dendrimers: Self-assembly and drug delivery
Xu, Xianghui,Li, Caixia,Li, Haiping,Liu, Rong,Jiang, Chao,Wu, Yao,He, Bin,Gu, Zhongwei
experimental part, p. 326 - 333 (2012/01/15)
Amphiphilic dendritic poly(glutamic acid)-b-polyphenylalanine copolymers were synthesized using generation 3 dendritic poly(glutamic acid) as the macroinitiator in the ring-opening polymerization of NCA-Phe. The block copolymers self-assembled micelles with polyphenylalanine segments as core and dendritic poly(glutamic acid) segments as shell. The biocompatibility of the micelles was studied. The release of the anticancer drug doxorubicin from the micelles was investigated in vitro. The results showed that the sustaining release of the drug could last for 60 h. The micellar drug release system was efficient in inhibiting the proliferation of HepG2 liver cancer cells, 75% cancer cells were killed under appropriate in vitro incubation.
A convenient, one-pot procedure for the preparation of acyl and sulfonyl fluorides using Cl3CCN, Ph3P, and TBAF(t -BuOH) 4
Kim, Joong-Gon,Jang, Doo Ok
experimental part, p. 3049 - 3052 (2011/02/25)
Various carboxylic acids were converted into acyl fluorides in excellent yields by treatment with trichloroacetonitrile, triphenylphosphine, and TBAF(t-BuOH)4 at room temperature. The reaction was applicable to the preparation of acid-sensitive amino acid fluorides without deprotection or rearrangement
Synthesis of N-urethane protected β-amino alcohols employing N-(protected-α-aminoacyl)benzotriazoles
Sureshbabu, Vommina V.,Sudarshan,Muralidhar,Narendra
, p. 683 - 685 (2008/09/20)
A simple and racemisation-free synthesis of N-urethane protected α-amino/peptidyl alcohols by the reduction of the corresponding easily accessible N-acylbenzotriazoles is described. The method is practical, straightforward, fast and efficient for the synt
Parallel synthesis of a library of benzoxazoles and benzothiazoles using ligand-accelerated copper-catalyzed cyclizations of ortho-halobenzanilides
Evindar, Ghotas,Batey, Robert A.
, p. 1802 - 1808 (2007/10/03)
A general method for the formation of benzoxazoles via a copper-catalyzed cyclization of ortho-haloanilides is reported. This approach complements the more commonly used strategies for benzoxazole formation which require 2-aminophenols as substrates. The reaction involves an intramolecular C-O cross-coupling of the ortho-haloanilides and is believed to proceed via an oxidative insertion/reductive elimination pathway through a Cu(I)/Cu(III) manifold. The reaction is also applicable to the formation of benzothiazoles. A variety of ligands including 1,10-phenanthroline and N,N′- dimethylethylenediamine were shown to provide ligand acceleration/stabilization in the reaction. Optimal conditions for cyclization used a catalyst combination of CuI and 1,10-phenanthroline (10 mol %). The method was amenable to a parallel-synthesis approach, as demonstrated by the synthesis of a library of benzoxazoles and benzothiazoles substituted at various positions in the ring. Most examples utilized the cyclization of ortho-bromoanilides, but orthoiodoanilides and ortho-chloroanilides also undergo a reaction under these conditions. The rate of reaction of the ortho-haloanilides follows the order I > Br > Cl, consistent with oxidative addition being the rate-determining step.
Amino acid amides of 2-benzimidazole as acid-stable prodrugs of potential inhibitors of H+/K+ ATPase
Hirai, K,Koike, H,Ishiba, T,Ueda, S,Makino, I,et al.
, p. 143 - 158 (2007/10/02)
A series of amino acid amides of 2-benzimidazole were prepared and found to possess gastric antisecretory activity on oral administration. (Glycylaminobenzyl)sulfinyl compound 23a, stable in artificial gastric juice (pH 1.2), was given orally to dogs.It was absorbed efficiently and converted into aniline derivative 7a which showed a very high plasma concentration.Compound 23a was hydrolyzed by the action of aminopeptidase present in plasma or the brush border fraction of the small intestine to release the terminal glycine. o-Aniline derivatives showed good activity in in vitro H+/K+-ATPase inhibition as well as in the inhibition of histamine stimulated acid secretion in isolated bullfrog gastric mucosa.Although these o-aniline derivatives showed no or weak gastric antisecretory activity in rat by id administration, they were active when administered ip.Therefore, these amino acid amides were considered to be acid stable prodrugs of proton pump inhibiting o-aniline derivatives.The mechanism of H+/K+-ATPase inhibition of 7a was also examined.
Amino Acids and Peptides; 67. Easy Preparation and Use of Benzyloxycarbonyl Derivatives of Amino Acid Chlorides and α-Hydroxycarboxylic Acid Chlorides
Schmidt, Ulrich,Kroner, Matthias,Beutler, Ulrich
, p. 475 - 477 (2007/10/02)
N-Benzyloxycarbonyl amino acid chlorides and α-benzyloxycarbonyloxy carboxylic acid chlorides are readily available by treating the corresponding carboxylic acids with 1-chloro-N,N,2-trimethyl-1-propen-1-amine.They can be immediately reacted with O-, N- and C-nucleophiles to afford peptides, ketones and esters.
Selective Cleavage of the Allyl and Allyloxycarbonyl Groups through Palladium-Catalyzed Hydrostannolysis with Tributyltin Hydride. Application to the Selective Protection-Deprotection of Amino Acid Derivatives and in Peptide Synthesis
Dangles, O.,Guibe, F.,Balavoine, G.,Lavielle, S.,Marquet, A.
, p. 4984 - 4993 (2007/10/02)
N-Allyloxycarbonyl (Alloc) derivatives of amines and amino acids are quantitatively and very rapidly converted to free amino compounds by palladium-catalyzed hydrostannolytic cleavage with tributyltin hydride in the presence of a proton donor (acetic acid, p-nitrophenol, pyridinium acetate, water).A similar procedure can be used for the deprotection of allyl (All) carboxylates and allyl aryl ethers.Deprotection experiments were performed on various mixed N-Alloc and O-Bzl, N-Z and O-All, N-Alloc and O-t-Bu, and N-alloc- and N-Boc-protected amino acid derivatives.The palladium-catalyzed hydrostannolytic cleavage is fully compatible with the Bzl and Z protecting groups; furthermore the BOC and t-Bu groups and the Alloc and All groups appear to be ortogonal.The reliability of the Alloc methodology for temporary protection of the α-amino functions is ilustrated by the solid-phase synthesis of the biologically active undecapeptide substance P.
