Alkane chain-extended pterin through a pendent carboxylic acid acts as triple functioning fluorophore, 1O2 sensitizer, and membrane binder

NILUKSHA WALALAWELA; MARIA NOEL URRUTIA; SARAH J. BELH; ANDRÉS H. THOMAS; ALEXANDER GREER; MARIANA VIGNONI

Baltimore, Maryland, Estados Unidos.

Congreso; 47th Middle Atlantic Regional Meeting (MARM), American Chemical Society (ACS).; 2019

American Chemical Society (ACS)

In order to develop a new long alkane chain pterin with an unperturbed pterin core, we synthesized decyl pterin-6-carboxyl ester (CapC) which preserves the pterin amide group. CapC has a decyl chain at the carboxylic acid position and DMF condensed at the N2 position. Positioning the alkane chain on the pendent carboxylic acid group retains the acid-base equilibrium of the pterin headgroup. This new CapC compound has relatively high fluorescence emission and singlet oxygen quantum yields, which can be attributed to the lack of through-bond interaction between the long alkane chain and the pterin headgroup. The calculated lipophilicity for CapC is higher than that of the parent pterin and pterin-6-carboxylic acid (Cap), and comparable to previously reported O- and N-decyl pterin derivatives. The binding constant Kb (8000 M-1) and ΦF:Φ∆ ratio (0.26:0.40) reveal CapC to be a good triple functioning compound, although the hydrolytic stability of CapC is modest due to its ester conjugation. CapC can function not only as a membrane intercalator, but also fluorophore and 1O2 sensitizer, leading to a ?self-monitoring? membrane fluorescent probe and a membrane photodamaging agent.