TY  - JOUR
A1  - Tan, Aaron
A1  - Babak, Maria V.
A1  - Venkatesan, Gopalakrishnan
A1  - Lim, Clarissa
A1  - Klotz, Karl-Norbert
A1  - Herr, Deron Raymond
A1  - Cheong, Siew Lee
A1  - Federico, Stephanie
A1  - Spalluto, Giampiero
A1  - Ong, Wei-Yi
A1  - Chen, Yu Zong
A1  - Loo, Jason Siau Ee
A1  - Pastorin, Giorgia
T1  - Design, Synthesis and Evaluation of New Indolylpyrimidylpiperazines for Gastrointestinal Cancer Therapy
JF  - Molecules
N2  - Human A3 adenosine receptor hA3AR has been implicated in gastrointestinal cancer, where its cellular expression has been found increased, thus suggesting its potential as a molecular target for novel anticancer compounds. Observation made in our previous work indicated the importance of the carbonyl group of amide in the indolylpyrimidylpiperazine (IPP) for its human A2A adenosine receptor (hA2AAR) subtype binding selectivity over the other AR subtypes. Taking this observation into account, we structurally modified an indolylpyrimidylpiperazine (IPP) scaffold, 1 (a non-selective adenosine receptors’ ligand) into a modified IPP (mIPP) scaffold by switching the position of the carbonyl group, resulting in the formation of both ketone and tertiary amine groups in the new scaffold. Results showed that such modification diminished the A2A activity and instead conferred hA3AR agonistic activity. Among the new mIPP derivatives (3–6), compound 4 showed potential as a hA3AR partial agonist, with an Emax of 30% and EC50 of 2.89 ± 0.55 μM. In the cytotoxicity assays, compound 4 also exhibited higher cytotoxicity against both colorectal and liver cancer cells as compared to normal cells. Overall, this new series of compounds provide a promising starting point for further development of potent and selective hA3AR partial agonists for the treatment of gastrointestinal cancers.
KW  - gastrointestinal cancer
KW  - hA<sub>3</sub>AR
KW  - partial agonists
KW  - indolylpyrimidylpiperazines
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-193271
SN  - 1420-3049
VL  - 24
IS  - 20
ER  - 
TY  - JOUR
A1  - Federico, Stephanie
A1  - Redenti, Sara
A1  - Sturlese, Mattia
A1  - Ciancetta, Antonella
A1  - Kachler, Sonja
A1  - Klotz, Karl-Norbert
A1  - Cacciari, Barbara
A1  - Moro, Stefano
A1  - Spalluto, Giampiero
T1  - The Influence of the 1-(3-Trifluoromethyl-Benzyl)-1H-Pyrazole-4-yl Moiety on the Adenosine Receptors Affinity Profile of Pyrazolo[4,3-e][1,2,4]Triazolo[1,5-c]Pyrimidine Derivatives
JF  - PLoS One
N2  - A new series of pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidine (PTP) derivatives has been developed in order to explore their affinity and selectivity profile at the four adenosine receptor subtypes. In particular, the PTP scaffold was conjugated at the C2 position with the 1-(3-trifluoromethyl-benzyl)-1H-pyrazole, a group believed to confer potency and selectivity toward the human (h) A\(_{2B}\) adenosine receptor (AR) to the xanthine ligand 8-(1-(3-(trifluoromethyl) benzyl)-1H-pyrazol-4-yl)-1,3-dimethyl-1H-purine-2,6(3H, 7H)-dione (CVT 6975). Interestingly, the synthesized compounds turned out to be inactive at the hA\(_{2B}\) AR but they displayed affinity at the hA\(_3\) AR in the nanomolar range. The best compound of the series (6) shows both high affinity (hA\(_3\) AR K\(_i\) = 11 nM) and selectivity (A\(_1\)/A\(_3\) and A\(_{2A}\)/A\(_3\) > 9090; A\(_{2B}\)/A\(_3\) > 909) at the hA\(_3\) AR. To better rationalize these results, a molecular docking study on the four AR subtypes was performed for all the synthesized compounds. In addition, CTV 6975 and two close analogues have been subjected to the same molecular docking protocol to investigate the role of the 1-(3-trifluoromethyl-benzyl)-1H-pyrazole on the binding at the four ARs.
KW  - drug
KW  - human A(3)
KW  - protein-coupled receptors
KW  - classification
KW  - subtypes
KW  - potent
KW  - antagonists
KW  - mast cells
KW  - targets
KW  - A(2B) receptors
KW  - international union
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-137133
VL  - 10
IS  - 12
ER  -