Efficient Activation of 6‐Nitropiperonyloxymethylene (NPOM)‐Caged Nucleosides with Visible Light

Abstract

Caging groups are photoremovable protecting groups that render a molecule biologically inactive until light illumination, thereby allowing for temporal and spatial control of activity. While nitrobenzyl-based caging groups have advantageous synthetic and photochemical properties, red shifting of the absorption spectrum through chemical modification has led to reduced decaging efficiency. 6-Nitropiperonyloxymethylene (NPOM), a group with broad applicability in the caging of heterocyclic structures, in particular nucleic acids, traditionally requires ultraviolet (UV) irradiation for decaging. Herein, we investigated the decaging properties of NPOM under near visible light (400-450 nm) using N 3 -caged 5'-dimethoxytrityl (DMTr)-thymidine as a substrate. To our surprise, we discovered highly efficient decaging at wavelengths outside the UV range, in particular when compared to other nitrobenzyl chromophores. These results have implications in the selection of light sources for photoactivation and for sequential photolysis to achieve selective control of biological processes.

Direct Activation of Nucleobases with Small Molecules for the Conditional Control of Antisense Function

“…Thus, true orthogonality can be achieved through the combination of a small molecule activatable probe with a photocontrolled probe. We thus highlight the complementarity that our approach provides to the photocaging approach by targeting ntla and EGFP genes in an orthogonal manner through use of ntla ‐azMO and EGFP ‐NPOM MO, [6d] which can be readily activated by 405 nm light [43] . To demonstrate the orthogonality of our approach, zebrafish embryos were injected with EGFP mRNA and either the ntla ‐azMO or the EGFP ‐NPOM MO, and treated with 2DPBM for two 90 min treatments as performed previously, or irradiated with 405 nm light for 2 min.…”

Direct Activation of Nucleobases with Small Molecules for the Conditional Control of Antisense Function

“…We thus highlight the complementarity that our approach provides to the photocaging approach by targeting ntla and EGFP genes in an orthogonal manner through use of ntla-azMO and EGFP-NPOM MO, [6d] which can be readily activated by 405 nm light. [43] To demonstrate the orthogonality of our approach, zebrafish embryos were injected with EGFP mRNA and either the ntla-azMO or the EGFP-NPOM MO, and treated with 2DPBM for two 90 min treatments as performed previously, or irradiated with 405 nm light for 2 min. Phenotypic analysis for both MOs was performed at 24 hpf, at which time orthogonal activation was confirmed (Figure 6A-B, Supporting Figure 18).…”