Synthesis and evaluation of light triggerable redox active species generators

Abstract

A majority of essential biomolecules or scaffolds are based upon carbon oxygen sulfur and nitrogen These molecules exist in a flux and are constantly broken down and resynthesized Some derivatives of O S and N form highly reactive species which can undergo redox processes in cells and are termed as redox active species Based on the reactive atom s these species are classified as reactive oxygen species ROS reactive sulfur species RSS and reactive nitrogen species RNS Amongst these ROS are oxygen derived species primarily generated by NAD P H oxidase and the leakage of electrons in electron transport chain ETC during oxidative phosphorylation in mitochondria When present in an optimum concentration ROS are known to regulate several essential signaling pathways However at elevated levels ROS damage essential biomolecules which in turn leads to cell death To counter ROS mediated damage cells have evolved antioxidant machinery which regulates ROS levels such as superoxide dismutase SOD catalases thiols etc Apart from ROS RSS such as glutathione GSH cysteine sulfur dioxide SO2 and hydrogen sulfide H2S are also important redox species in cellular metabolism For instance they play vital roles in signaling and antioxidant mechanisms In addition RNS 8211 nitric oxide based molecules 8211 are endogenously synthesized and perform important modulation for certain signaling mechanisms Therefore it becomes essential to have tools to probe into redox mediated cellular pathways In this attempt several molecules have been developed which are either triggered by one of several metabolic stimuli such as cellular thiols hydrogen peroxide and enzymes to generate the aforementioned reactive species or are spontaneous generators of the same Here the triggerable approach provides control over the release of these reactive species However due to the wide prevalence of the metabolic stimuli reactive species are produced in nearly all cells and achieving spatio temporal control over release becomes challenging Alternatively lig