The invention provides adenosine analog compounds that act at P2Y receptors, e.g., the P2Y2 receptor, including pharmaceutical compositions； and uses thereof to treat or prevent diseases associated with that receptor, e.g., disorders relating to mucus secretion, such as cystic fibrosis, chronic obstructive pulmonary disorder (COPD), asthma, constipation, chronic idiopathic constipation, dry mouth (xerostomia), gum disease, and gastrointestinal problems caused by radiation and chemotherapy for cancer.
