THIOPHOSPHATE ANALOGS OF c-di-GMP: IMPACT ON POLYMORPHISM

Seven phosphorothioate analogs of c-di-GMP (all diastereomers of mono-, di-, and trithiophosphates) were prepared to assess the impact of the thioate substitutions on c-di-GMP polymorphism using 1D H-1 and P-31 NMR, along with 2D NOESY and DOSY, for both the Na+ and K+ salts. The K+ salts display more extensive higher order complex formation than the Na+ salts, resulting primarily in octamolecular complexes with K+, but tetramolecular complexes with Na+. Further, the presence of one or two [S-P] sulfurs specifically stabilizes anti complexes and/or destabilizes syn complexes, while the presence of two [S-P] sulfurs Promotes extensive aggregation.