The Cucurbit[7]Uril‐Based Supramolecular Chemistry for Reversible B/Z‐DNA Transition

Abstract

As a left‐handed helical structure, Z‐DNA is biologically active and it may be correlated with transcription and genome stability. Until recently, it remained a significant challenge to control the B/Z‐DNA transition under physiological conditions. The current study represents the first to reversibly control B/Z‐DNA transition using cucurbit[7]uril‐based supramolecular approach. It is demonstrated that cucurbit[7]uril can encapsulate the central butanediamine moiety [HN(CH2)4NH] and reverses Z‐DNA caused by spermine back to B‐DNA. The subsequent treatment with 1‐adamantanamine disassembles the cucurbit[7]uril/spermine complex and readily induces reconversion of B‐ into Z‐DNA. The DNA conformational change is unequivocally demonstrated using different independent methods. Direct evidence for supramolecular interactions involved in DNA conformational changes is further provided. These findings can therefore open a new route to control DNA helical structure in a reversible way.

Synthesis and Optical Properties of Alkaloid Quindoline, Its Structural Analogues and Substituted δ‐Carbolines

“…At the same time, the substituents in the benzene ring have practically no effect on the position of absorption and emission maxima in the spectra of quindoline derivatives 8 a–e , just like the quantum luminescence yield, ranging from 0.29 to 0.34. When passing from less polar solvents (cyclohexane, THF, toluene) to more polar ethanol, bathochromic shift of the emission band was observed in the spectra of the solutions of compounds 2 a , 7 a and 8 a , which indicates that the excited state of the molecule has a larger dipole moment than in the main (Table S1 in the SI) ,…”

“…δ‐Carboline derivatives are phosphors that allow the use of fluorescent methods for studying the mechanisms of their biological action . They are used as materials for highly efficient organic light emitting diodes (OLEDs) of thermally activated delayed fluorescence (TADF) ,. Absorption spectra and photophysical properties of unsubstituted δ‐carboline, quindoline and cryptolepine have been studied in detail,, but there are scarce data on the effect of their structure on optical properties.…”

Cucurbituril‐Based Biomacromolecular Assemblies

“…[35] Consequently,t hree types of 5formylcytosine-involved biochemical reactions,i ncluding DNApolymerase elongation, restriction endonuclease digestion, and polymerase chain reaction, were terminated by the host-guest interaction of the bulky CB [7] with the exposed adamantyl site and then restored by competitive complexation with adamantylamine.S ubsequently,t he spermine-CB [7] binding pair was employed to reversibly control the DNAc hiral transition by the same team (Figure 4c). [36] The spermine-induced switchable transition between the rightand left-handed DNAh elices could be efficiently controlled by the alternating addition of CB [7] and adamantylamine. These studies demonstrate that both the structures and bioactivities of DNAc an be adjusted by strong and dynamic CB-guest interactions,which is beneficial for the construction -based DNA aptamer.…”

“…[35] c) DNA chiral transition by the competitive binding with CB [7] and spermine. [36] Angewandte Chemie Kurzaufsätze of advanced genetic materials with biorecognition and environmentally responsive capabilities.…”

“…b) Modulationo f5formylcytosine-targeted biochemical reactions by CB[7]-adamantane complexation [35]. c) DNA chiral transition by the competitive binding with CB[7] and spermine [36].…”