5‘-Tethered Stilbene Derivatives as Fidelity- and Affinity-Enhancing Modulators of DNA Duplex Stability

Abstract

A series of 5‘-linked stilbene-DNA conjugates with different substituents in the distal aromatic ring of the stilbene was prepared, and the effect of the modifications on duplex stability was determined via UV-melting curves. A trimethoxystilbene derivative as a 5‘-substituent increases duplex melting points by up to 12.2 °C per modification. With this alkoxystilbene substituent, terminal mismatches in DNA duplexes lower the melting point by up to 23.4 °C over the perfectly matched control, whereas terminal mismatches in unmodified DNA cause melting point depressions of no more than 6.1 °C. An aminomethylstilbene substituent linked to an oligopyrrolamide minor groove binder increases the melting point of an all-A/T decamer by up to 32.7 °C, thus shifting the melting point into a range typical for duplexes with statistical G/C-content. An affinity- and selectivity-enhancing effect was also observed when the trimethoxystilbene cap was employed on a small DNA microarray. The phosphoramidite of the trimethoxystilbene can be readily employed in automatic DNA synthesis, facilitating the generation of DNA chips with improved fidelity.