1528534-36-2Relevant academic research and scientific papers
Rigidity versus Flexibility: Is This an Issue in σ1 Receptor Ligand Affinity and Activity?
Weber, Frauke,Brune, Stefanie,B?rgel, Frederik,Lange, Carsten,Korpis, Katharina,Bednarski, Patrick J.,Laurini, Erik,Fermeglia, Maurizio,Pricl, Sabrina,Schepmann, Dirk,Wünsch, Bernhard
, p. 5505 - 5519 (2016/07/06)
Stereoisomeric 2,5-diazabicyclo[2.2.2]octanes 14 and 15 were prepared in a chiral-pool synthesis starting from (S)- or (R)-aspartate. The key step in the synthesis was a Dieckmann-analogous cyclization of (dioxopiperazinyl)acetates 8, which involved trapping of the intermediate hemiketal anion with Me3SiCl. The σ1 affinity was tested using membrane preparations from animal (Guinea pig) and human origin. The binding of bicyclic compounds was analyzed by molecular dynamics simulations based on a 3D homology model of the σ1 receptor. The good correlation between Ki values observed in the σ1 assays and calculated free binding energy, coupled with the identification of four crucial ligand/receptor interactions, allowed the formulation of structure-affinity relationships. In an in vitro antitumor assay with seven human tumor cell lines, the bicyclic compounds inhibited selectively the growth of the cell line A427, which is due to induction of apoptosis. In this assay, the compounds behave like the known σ1 receptor antagonist haloperidol.
Involvement of apoptosis and autophagy in the death of RPMI 8226 multiple myeloma cells by two enantiomeric sigma receptor ligands
Korpis, Katharina,Weber, Frauke,Brune, Stefanie,Wünsch, Bernhard,Bednarski, Patrick J.
, p. 221 - 233 (2014/12/12)
Over-expression of σ receptors by many tumor cell lines makes ligands for these receptors attractive as potential chemotherapeutic drugs. Enantiomeric piperazines (S)-4 and (R)-4 were prepared as potential σ-receptor ligands in a chiral pool synthesis starting from (S)- and (R)-aspartate. Both compounds showed high affinities for the σ1 and σ2 receptors. In the human multiple myeloma cell line RPMI 8226, a line expressing high levels of σ receptors, both compounds inhibited cell proliferation with IC50 values in the low μM range. No chiral differentiation between either the σ receptor binding affinity or the cytotoxicity of the two enantiomers was observed. Both compounds induced apoptosis, which was evidenced by nuclear condensation, binding of annexin-V to phosphatidylserine in the outer leaf of the cell membrane, cleavage products of poly(ADP-ribose) polymerase-1 (PARP-1) and caspase-8 as well as the expression of bcl2 family members bax, bad and bid. However, apoptosis appeared to be caspase independent. Increased levels of the phosphorylated form of the microtubule associated protein light chain 3-II (LC3-II), an autophagosome marker, gave evidence that both compounds induced autophagy. However, further data (e.g., treatment with wortmannin) indicate that autophagy is incomplete and not cytoprotective. Lipid peroxidation (LPO) was observed in RPMI 8226 cells treated with the two compounds, and the lipid antioxidant α-tocopherol attenuated LPO. Interestingly, α-tocopherol reduced significantly both apoptosis and autophagy induced by the compounds. These results provide evidence that, by initiating LPO and changes in mitochondrial membrane potential, both compounds induce apoptosis and autophagy in RPMI 8226 cells.
Synthesis, pharmacological evaluation, and σ1 receptor interaction analysis of hydroxyethyl substituted piperazines
Weber, Frauke,Brune, Stefanie,Korpis, Katharina,Bednarski, Patrick J.,Laurini, Erik,Dal Col, Valentina,Pricl, Sabrina,Schepmann, Dirk,Wünsch, Bernhard
, p. 2884 - 2894 (2014/05/06)
Starting from (S)- or (R)-aspartate, three synthetic strategies were explored to prepare hydroxyethyl substituted piperazines with different substituents at the N-atoms. σ receptor affinity was recorded using receptor material from both animal and human o
