TY - JOUR AU - Paragi, Gábor AU - Kovács, Lajos AU - Kupihár, Zoltán AU - Szolomájer, János AU - Penke, Botond AU - C, Fonseca Guerra AU - F M, Bickelhaupt TI - Neutral and positively charged new purine tetramer structures: a computational study of xanthine and uric acid derivatives JF - NEW JOURNAL OF CHEMISTRY J2 - NEW J CHEM VL - 35 PY - 2011 IS - 1 SP - 119 EP - 126 PG - 8 SN - 1144-0546 DO - 10.1039/c0nj00613k UR - https://m2.mtmt.hu/api/publication/1451072 ID - 1451072 N1 - Megjegyzés-21243297 M1: Copyright (C) 2011 American Chemical Society (ACS). All Rights Reserved. CAPLUS AN 2010:1592847(Journal) AB - New tetramer structures, based on 9-methylxanthine (Xa), 9-methylxanthine protonated at N7 (XaH+) and 9-methyluric acid (Ua), were investigated by high-level density functional calculations. We have found that homo- and heterotetrads (XaH+)4, (XaH+–Xa)2, (XaH+–Ua)2 carrying positive charges can be formed by low barrier hydrogen bonds. Systems with zero charge [(Xa)4, (Xa–Ua)2, (Ua)4] were also constructed, investigated and compared to the guanine tetrad [(G)4]. It was shown that the new tetramers can bind cations and anions without the necessity of stacking interactions. Application of the calculated systems in higher-ordered structures (e.g. quadruplexes) is promising with or without intercalating ions. LA - English DB - MTMT ER -