6955-17-5Relevant academic research and scientific papers
Synthesis, structure elucidation, in vitro biological activity, toxicity, and Caco-2 cell permeability of lipophilic analogues of α-conotoxin MII
Blanchfield, Joanne T.,Dutton, Julie L.,Hogg, Ronald C.,Gallagher, Oliver P.,Craik, David J.,Jones, Alun,Adams, David J.,Lewis, Richard J.,Alewood, Paul F.,Toth, Istvan
, p. 1266 - 1272 (2003)
The α-conotoxin MII is a two disulfide bridge containing, 16 amino acid long peptide toxin isolated from the marine snail Conus magus. This toxin has been found to be a highly selective and potent inhibitor of neuronal nicotinic acetylcholine receptors (nAChRs) of the subtype α3β2. To improve the bioavailability of this peptide, two lipidic analogues of MII have been synthesized, the first by coupling 2-amino-D,L-dodecanoic acid (Laa) to the N terminus (LaaMII) and the second by replacing Asn5 in the MII sequence with this lipoamino acid (5LaaMII). Both lipidic linear peptides were then oxidized under standard conditions. 1H NMR shift analysis of these peptides and comparison with the native MII peptide showed that the tertiary structure of the N-conjugated analogue, LaaMII, was consistent with that of the native conotoxin, whereas the 5LaaMII analogue formed the correct disulfide bridges but failed to adopt the native helical tertiary structure. The N terminus conjugate was also found to inhibit nAChRs of the subtype α3β2 with equal potency to the parent peptide, whereas the 5LaaMII analogue showed no inhibitory activity. The active LaaMII analogue was found to exhibit significantly improved permeability across Caco-2 cell monolayers compared to the native MII, and both peptides showed negligible toxicity.
Pro-apoptotic activity of lipidic α-amino acids isolated from Protopalythoa variabilis
Wilke, Diego Veras,Jimenez, Paula Christine,Araújo, Renata Mendona,Da Silva, Wildson Max Barbosa,Pessoa, Otília Deusdênia Loiola,Silveira, Edilberto Rocha,Pessoa, Claudia,De Moraes, Manoel Odorico,Skwarczynski, Mariusz,Simerska, Pavla,Toth, Istvan,Costa-Lotufo, Letícia Veras
scheme or table, p. 7997 - 8004 (2011/02/23)
Lipidic α-amino acids (LAAs) have been described as non-natural amino acids with long saturated or unsaturated aliphatic chains. In the continuing prospect to discover anticancer agents from marine sources, we have obtained a mixture of two cytotoxic LAAs (1a and 1b) from the zoanthid Protopalythoa variabilis. The anti-proliferative potential of 14 synthetic LAAs and 1a/1b were evaluated on four tumor cell lines (HCT-8, SF-295, MDA-MB-435, and HL-60). Five of the synthetic LAAs showed high percentage of tumor cell inhibition, while 1a/1b completely inhibited tumor cell growth. Additionally, apoptotic effects of 1a/1b were studied on HL-60 cell line. 1a/1b-treated cells showed apoptosis morphology, loss of mitochondrial potential, and DNA fragmentation.
2-Aminohydroxamic acid derivatives as inhibitors of Bacillus cereus phosphatidylcholine preferred phospholipase C PC-PLCBc
González-Bulnes, Patricia,González-Roura, Albert,Canals, Daniel,Delgado, Antonio,Casas, Josefina,Llebaria, Amadeu
supporting information; experimental part, p. 8549 - 8555 (2011/02/25)
Phosphatidylcholine preferring phospholipase C (PC-PLC) is an important enzyme that plays a key role in a variety of cellular events and lipid homoeostases. Bacillus cereus phospholipase C (PC-PLCBc) has antigenic similarity with the elusive mammalian PC-PLC, which has not thus far been isolated and purified. Therefore the discovery of inhibitors of PC-PLC Bc is of current interest. Here, we describe the synthesis and biological evaluation of a new type of compounds inhibiting PC-PLCBc. These compounds have been designed by evolution of previously described 2-aminohydroxamic acid PC-PLCBc inhibitors that block the enzyme by coordination of the zinc active site atoms present in PC-PLCBc [Gonzalez-Roura, A.; Navarro, I.; Delgado, A.; Llebaria, A.; Casas, J. Angew. Chem. Int. Ed. 2004, 43, 862]. The new compounds maintain the zinc coordinating groups and possess an extra trimethylammonium function, linked to the hydroxyamide nitrogen by an alkyl chain, which is expected to mimic the trimethylammonium group of the phosphatidylcholine PC-PLCBc substrates. Some of the compounds described inhibit the enzyme with IC 50's in the low micromolar range. Unexpectedly, the most potent inhibitors found are those that possess a trimethylammonium group but have chemically blocked the zinc coordinating functionalities. The results obtained suggest that PC-PLCBc inhibition is not due to the interaction of compounds with the phospholipase catalytic zinc atoms, but rather results from the inhibitor cationic group recognition by the PC-PLCBc amino acids involved in choline lipid binding.
Syntheses of polycationic dendrimers on lipophilic peptide core for complexation and transport of oligonucleotides
Wimmer, Norbert,Marano, Robert J.,Kearns, Philip S.,Rakoczy, Elizabeth P.,Toth, Istvan
, p. 2635 - 2637 (2007/10/03)
Synthesis of novel polycationic lipophilic peptide core(s) was accomplished and these agents successfully transfected human retinal pigment epithelium cells with ODN1 upon complexation with the oligonucleotide. The level of transfection was indirectly measured by the decreased production of the protein hVEGF (human vascular endothelial growth factor) in comparison to the transfection agent cytofectin GSV.
Potent immunosuppressants, 2-alkyl-2-aminopropane-1,3-diols
Fujita, Tetsuro,Hirose, Ryoji,Yoneta, Masahiko,Sasaki, Shigeo,Inoue, Kenichiro,Kiuchi, Masatoshi,Hirase, Susumu,Chiba, Kenji,Sakamoto, Hiroshi,Arita, Masafumi
, p. 4451 - 4459 (2007/10/03)
Several immunosuppressants, ISP-I [(2S,3R,4R)-(E)-2-amino-3,4-dihydroxy- 2-(hydroxymethyl)-14-oxoeicos-6-enoic acid, myriocin = thermozymocidin] and mycestericins A-G, were isolated from culture broths of Isaria sinclairii and Mycelia sterilia, respectively. In order to investigate structure-activity relationships, extensive modifications of ISP-I were conducted, and it was established that the fundamental structure possessing the immunosuppressive activity is a symmetrical 2-alkyl-2-aminopropane-1,3-diol. The tetradecyl, pentadecyl, and hexadecyl derivatives prolonged rat skin allograft survival in the combination of LEW donor and F344 recipient and were more effective than cyclosporin A. Among them, 2-amino-2-tetradecylpropane-1,3-diol hydrochloride, ISP-I-55, showed the lowest toxicity. ISP-I-55 is a promising lead compound for the development of effective immunosuppressants for organ transplantations and for the treatment of autoimmune diseases.
Lipidic Peptides, I Synthesis, Resolution and Structural Elucidation of Lipidic Amino Acids and Their Homo- and Hetero-Oligomers
Gibbons, William A.,Hughes, Richard A.,Charalambous, Mario,Christodoulou, Marika,Szeto, Alice,et al.
, p. 1175 - 1183 (2007/10/02)
The α-amino acids with long alkyl side chains, the so-called lipidic amino acids 1a-e, and their homo-oligomers, the lipidic peptides 1p-aj, represent a class of compounds which combine the structural properties of peptides and proteins with the characteristics of lipids and membranes.The amino acids were synthesised from the appropriate alkyl bromide and diethyl acetamidomalonate.Resolution was made chemically, by forming diastereomers of the amino acid esters with an optically pure α-pinene derivative.The protected homo-oligomers were synthesised in solution with the assistance of a water-soluble carbodiimide coupling agent.In order to modify the physical and chemical properties of the peptides, a series of protected hetero-oligomers were prepared, by similar methods, incorporating either other amino acids (3a-d, 7a-i) or side-chain-substituted lipidic amino acids (6a-d).
