Intramolecular crankshaft-type rearrangement in a photoisomerised glycoconjugate
†.
RSC Adv 2023;
13:9413-9417. [PMID:
36968057 PMCID:
PMC10034262 DOI:
10.1039/d3ra01678a]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 03/16/2023] [Indexed: 03/24/2023] Open
Abstract
High-resolution NMR spectroscopy revealed that a novel glycoconjugate, consisting of two β-glucopyranoses attached to a quinazolinone-like structure, exhibited photoisomerization around the –N–N
<svg xmlns="http://www.w3.org/2000/svg" version="1.0" width="13.200000pt" height="16.000000pt" viewBox="0 0 13.200000 16.000000" preserveAspectRatio="xMidYMid meet"><metadata>
Created by potrace 1.16, written by Peter Selinger 2001-2019
</metadata><g transform="translate(1.000000,15.000000) scale(0.017500,-0.017500)" fill="currentColor" stroke="none"><path d="M0 440 l0 -40 320 0 320 0 0 40 0 40 -320 0 -320 0 0 -40z M0 280 l0 -40 320 0 320 0 0 40 0 40 -320 0 -320 0 0 -40z"/></g></svg>
and CH–C– bonds of the –N–NCH–C– linkage in the same timeframe (the so-called “crankshaft rotation”) upon exposure to UV light. Experimental NMR data combined with DFT calculations discovered that the attachment of carbohydrate residues to photoactive compounds significantly changed the isomerization process and intramolecular rearrangement compared to the unglycosylated system, while the overall molecular structure remained virtually unchanged.
A reversible photoinduced intramolecular crankshaft-type rearrangement in a glycoconjugate proceeds simultaneously at both the –N–N and CH–C– bonds.![]()
Collapse