115424-05-0Relevant articles and documents
Synthesis of Water-Soluble Chiral DOTA Lanthanide Complexes with Predominantly Twisted Square Antiprism Isomers and Circularly Polarized Luminescence
Dai, Lixiong,Zhang, Junhui,Chen, Yuqing,Mackenzie, Lewis E.,Pal, Robert,Law, Ga-Lai
, p. 12506 - 12510 (2019)
One-step cyclization of a tetraazamacrocycle 5 with 70% yield in a 25-g scale was performed. Its chiral DOTA derivatives, L4, has ?93% of TSAP coordination isomer in its Eu(III) and Yb(III) complexes in aqueous solution. [GdL4]5- exhibits a high relaxivity, making it a promising and efficient MRI contrast agent. High luminescence dissymmetry factor (glum) values of 0.285 (ΔJ = 1) for [TbL3]- and 0.241 (ΔJ = 1) for [TbL4]5- in buffer solutions were recorded.
Asymmetric synthesis of unnatural amino acids and tamsulosin chiral intermediate
Arava, Veera Reddy,Amasa, Srinivasulu Reddy,Goud Bhatthula, Bharat Kumar,Kompella, Laxmi Srinivas,Matta, Venkata Prasad,Subha
, p. 2892 - 2897 (2013/09/02)
An efficient and enantioselective hydrogenation of N-acetylamino phenyl acrylic acids was successfully developed by using ruthenium catalyst. This methodology is important in the field of pharmaceuticals and provides a new process for the preparation of unnatural amino acids and tamsulosin chiral intermediate.
Synthesis and biological activity of new potential agonists for the human adenosine A2A receptor
Bosch, M. Pilar,Campos, Francisco,Niubó, Itziar,Rosell, Gloria,Díaz, J. Luis,Brea,Loza, M. Isabel,Guerrero, Angel
, p. 4041 - 4053 (2007/10/03)
New adenosine derivatives have been synthesized and tested as putative agonists of adenosine receptors. Compounds 2-6 derive from the introduction of several types of substituents (electron donating, electron withdrawing, and halogens) in the para-position of the phenyl ring of the parent compound 1, and compound 7 lacks the hydroxyl group of amino alcohol 1. In radioligand binding assays using recombinant human A1, A2A, A2B, and A3 receptors, all compounds showed very low or negligible affinity for A1 and A2B receptors but compounds 3, 5, and 7 displayed a remarkably potent affinity for the A2A receptor with Ki values of 1-5 nM. Bromo derivative 3 displayed a selectivity A1/A2A = 62 and A3/A2A = 16 whereas the presence of a hydroxyl group (compound 5) improved the selectivity of A 1/A2A and A3/A2A to 120- and 28-fold, respectively. When the methoxy derivative 4 lacks the hydroxyl group on the side chain (compound 7), the binding affinity for A2A is increased to 1 nM, improving selectivity ratios to 356- and 100-fold against A1 and A3, respectively. In Chinese hamster ovary cells transfected with human A2A and A2B receptors, most compounds showed a remarkable activity for the A2A receptor, except chloro derivative 2, with EC50 values ranging from 1.4 to 8.8 nM. The compounds behaved as good A2A agonists, and all were more selective than 5′-(N-ethylcarboxamino)adenosine (NECA), with A2B/A 2A ratios of cAMP accumulation ranging from 48 for compound 2 to 666 for compound 7 while the corresponding A2B/A2A ratio for NECA was only 9. Compounds 1, 3, 5, and 7 also displayed higher selectivities than NECA up to 100-fold in isolated aortas of rat and guinea pig. In guinea pig tracheal rings precontracted by carbachol, compounds 2 and 4 were more potent than adenosine (100-fold) and NECA (10-fold), whereas compounds I and 7 displayed similar effects to NECA. Pretreatment of the tracheal rings with A2, A2A, and A2B receptor antagonists 3,7-dimethyl-L-propargylxanthine, 8-(3-chlorostyryl)caffeine, and alloxazine produced a marked inhibition of the tracheal relaxations induced by compounds 1, 2, and 4, but none of the compounds showed selectivity toward any of the adenosine receptors.
