Micro-flowers changing to nano-bundle aggregates by translocation of the sugar moiety in Janus TA nucleosides

Abstract

We designed and synthesized the Janus-type TA nucleosides (1-3) by using a transglycosylation protocol. Surprisingly, the subtle translocation of the ribose from N8 to N1 by about 230 pm in space leads to the formation of entirely different shaped superstructures, micro-flowers for J-AT and nano-bundles for J-TA.

The effect of the glycosylation position on the base pairing and supramolecular structure of the 5′-deoxyribosyl Janus-type AT nucleosides

“…Finally, we followed an unusual transglycosylation following our previous synthesis of N1-glycosylated ribosyl AT nucleoside to obtain the N1-isomer successfully [22]. Comparing these three isomers, compound 1 and 2 have the similar, and compound 3 has a distinct electronic configuration on the fused ring system: the former two have a similar structure like alloxazine form, and the latter one has the isoalloxazinic form of pteridine derivatives.…”

“…Theoretically, then the AT pyrimido [4,5-d]pyrimidine nucleoside system can also form either one of this base air motif. Interestingly, our previous researches showed that for the AT pyrimido [4,5-d]pyrimidine system, the reverse Watson-Crick seemed to be the more preferred base pair motif, and its existence was firmly confirmed by several N8 glycosylated Janus-type AT nucleosides single crystals X-ray analysis [22,23]. However, according to our previous studies the glycosylation position and the configuration of sugar residue have profound effects on the base pair patterns for AT pyrimido [4,5-d] pyrimidine system.…”

“…Especially, the N1-and N8-connected AT ribonucleosides display entirely distinct morphological supramolecular structure in solution state, nanobundles for the N1 isomer and microflowers for the N8-isomer [22]. This raised our interest to investigate the specific effect of sugar positions on the base pairing property and supramolecular structure of this Janus-type AT nucleosides.…”

Theoretical and experimental evidence of conformational transformation in stereoisomers of nucleoside analogues

“…NAs are capable of self‐assembling in both solution and the dry state. In solution, NAs and their derivatives can self‐assemble into helices, vesicles, hydrogels, ribbons, nanotubes, and flowers . In dry environments, and in particular on an Au (111) substrate, racemic DHPA, self‐assemble into long and well‐organized noncovalent supramolecular polymers .…”

Isomeric effects on the self-assembly of a plausible prebiotic nucleoside analogue: A theoretical study

“…They are also becoming increasingly important in nanotechnology due to their ability to self‐assemble in both aqueous and dry environments. In aqueous environments, NAs and derivatives have been found to self‐assemble into helices, vesicles, hydrogels, ribbons, nanotubes, and flowers . In dry environments, and in particular on a Au(111) substrate, the molecule N(9)‐(2,3‐dihydroxypropyl Adenine) (DHPA, Figure a,b), which is a NA of adenosine, was found to self‐assemble into a 100 nm long and well‐organized supramolecular polymer .…”