The base pairs and hydrogen-bond network of the 5-Amino-8-(β-L-furanosyl)pyrimido[4,5-d]pyrimidine-2,4(3H,8H)-dione

Abstract

Supramolecular morphogenesis is a fundamentally important process in fields ranging from structural biology to materials chemistry. Our previous works demonstrated that the sugar structural parameters can decree the supramolecular morphogenesis of Janus-type nucleosides. However, the chiral effect in this regards has not yet been tackled. Here, the self-associated superstructures of J-AT l-ribonucleoside (J-AT-L, 1) was investigated in both solid state and solution by single-crystal X-ray analysis and scanning electron microscope (SEM). The results indicate a high mirror symmetry in both monomeric level and hydrogen bond patterns in solid state between compound 1 and its enantiomeric counterpart J-AT d-ribonucleoside (J-AT-D, 2), except the distinct interactions between A–B and B–B conformers. The SEM experiments display that J-AT-L forms a porous microsphere-flower-like superstructure, instead of a radial-petal-flower-like superstructure of the d-enantiomer (2), which could be attributed to the different interactions of A–B and B–B conformers among these two series. This study provides for the first time the evidences of how the chiral information of the monomeric J-AT nucleosides is translated into the diverse supramolecular morphologies.