Our group has long been interested in the photochemical delivery of small molecule bioregulators like nitric oxide (NO) and carbon monoxide (CO).  Ancillary evidence in the literature indicates possible therapeutic roles for another interesting small molecule, carbon disulfide (CS2).  For instance, CS2 is known to react with amines to form dithiocarbamates, recognized inhibitors of NF-?B, a crucial mediator in inflammation induced tumor growth.  In a recent communication,1 we described a photochemical pathway for CS2 delivery using 1,1-dithiooxalate (DTO) conjugated to the surface of cadmium selenide quantum dots (CdSe QDs).  DTO is readily oxidized (0.6 V vs Ag/AgCl) to produce CS2 and innocuous CO2, a process also stimulated by visible light using QDs as catalysts in the presence of an oxidant, here molecular oxygen.  Semiconducting QDs exhibit size and composition dependent optical properties and customizable solubility, making them ideal for probing this charge transfer stimulated release of CS2.  We have further characterized the mechanism of this reaction, as well as the photochemical behavior of the ligand DTO alone and expanded this work to DTO-based esters with the basic formula CS2COOR- (where R is t-butyl, benzyl, a sugar, etc).  Modification of the R-group on the ester will allow for tuning of the photochemical properties, including the quantum yield of CS2 production, as well as tuning a complex for biological selectivity and uptake.  Finally, understanding the biological role of CS2 is crucial, and reactions under biologically relevant conditions with various amino acids are under study. 1Bernt, et al.  J. Am. Chem. Soc. 2014 , 136(6), 2192-2195.

Mechanistic insights and new systems based on 1,1-dithiooxalate, a photochemical precursor to carbon disulfide, a small molecule with biological potential

248th National Meeting (2014)

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