Synthesis and human telomeric G-quadruplex DNA-binding activity of glucosaminosides of shikonin/alkannin.

The N-acetyl glucosaminosides of shikonin/alkannin were synthesized by chemical glycosylation, which provided an ideal approach to resolve the mixture of enantiomeric shikonin and alkannin co-existed in the Chinese herbs. The glycosylated shikonin and alkannin exhibited stronger binding activity to human telomeric G-quadruplex DNA than their parent structures. This research indicated that glycosylation of natural product with amino sugars is an effective strategy to improve their DNA-binding affinity.