Determination of the alkylation position of dT* by NMR

The alkylated thymidine dT* obtained by enzymatic hydrolysis of the alkylated ODN5 and ODN6 was dissolved in DMSO-d6 containing 10 μM 4,4-dimethyl-4-silapentane-1-sulfonic acid (DSS), the final concentration being 400 μM. DSS was used as an internal chemical shift reference. The COSY, edited-HSQC and HMBC spectra were recorded at 37°C using Bruker BioSpin DRX 600 and AVANCE III HD 600 spectrometers equipped with a cryogenic probe and a Z-gradient.