Photocalibrated NO Release from N-Nitrosated Napthalimides upon One-Photon or Two-Photon Irradiation

Abstract

NO donors are routinely used as the exogenous source in in vitro studies. However, the kinetics or the dose of NO release from the existing donors is not readily monitored. This complicates the elucidation of the involvement of NO in a biological response. We report herein a series of NO donors (NOD545a-g), whose NO release is triggered by UV light at 365 nm or a two-photon laser at 740 nm, and importantly, their NO release is accompanied by a drastic fluorescence turn-on, which has been harnessed to follow the kinetics and dose of NO release in a real-time fashion with spectroscopic methods or microscopic methods in in vitro studies. These merits have rendered NOD545a-g useful molecular tools in NO biology.

Visible light-triggered NO generation from Naphthalimide-based probe for photoreceptor-mediated plant root growth regulation

“…27 However, the recently reported light-induced NO-donors suffer from ultraviolet and two-photon excitation. 28 29-31 Therefore, there is an urgent need of a visible-light triggered efficient NO-donor with considerable water-solubility.…”

“…Further, to testify the photo-triggered generation of NO, an EPR experiment was also performed using 2-phenyl-4, 4, 5, 5,-tetramethylimidazoline-1-oxyl-3-oxide (PTIO) as a spin trap for NO. 29,35 After the photo-irradiation of a mixture of PTIO and Ni-NO 2 for 30 min the EPR spectrum was recorded.…”

A Fluorescent Naphthalenediimide-Alkoxyfuroxan Photoinduced Nitric Oxide Donor

“…We have attempted to directly confirm the photoinduced generation of NO radical from compound 6 using a spin-trapping method with 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3oxide (PTIO) as a radical-trapping reagent, 36 but failed to detect the EPR signal of the corresponding imino nitroxide product. Therefore, it is of note that at present we have not confirmed that the NO species detected by the Griess test are only in the NO redox form, it may be possible that NO2or NOare also released.…”

“…Despite recent progress, there is little variety in PINODs and their release mechanisms, especially those utilizing irradiation wavelengths in the visible or near-IR region. [11][12][13][14][15][16][17][18][19][20] Therefore, the development of new PINODs with novel release mechanisms are required in pursuit of controllable discharge of NO under biologically inert conditions.…”

A Photo-triggered and photo-calibrated nitric oxide donor: Rational design, spectral characterizations, and biological applications

“…PPIX/AFX/Fluor-RSE [36][37][38] , FlEt [39] , BODIPY labled NONOates [33] , o-trifluoromethyl nitrobenzene [40,41] and NOBL-1 [42] (Figute 1).We recently proposed to develop NO donors with both a robust photo-trigger to render a spatiotemporal control of NO release, and a built-in calibration mechanism in form of a concomitant fluorescence turn-on to allow convenient monitoring of NO release. The first embodiment of such photo-triggered and photo-calibrated NO donors is Nnitrosated naphthalimides (NOD545) [43] , whose scope of applications is however limited by the fact that a UV light at 365 nm was in need to trigger NO release. Ideally, a photo-triggered and photo-calibrated NO donor should exhibit high chemostability to avoid unintended NO release, easy photo-activation by visible light to avoid cytotoxicity, a large fluorescence turn-on ratio to facilitate monitoring of NO release, clean photo-decomposition pathway, high cell permeability, and low cytotoxicity.…”