Design of xanthone propionate photolabile protecting group releasing acyclovir for the treatment of ocular herpes simplex virusThis paper is part of a themed issue on photoremovable protecting groups: development and applications

We have attached the antiviral drug acyclovir (ACV) to a xanthone photolabile protecting group (or photocage) through the O6 position of acyclovir, a procedure designed for the treatment of ocular herpes simplex virus infections. Acyclovir is photoreleased from the photocage, under physiological conditions, with a quantum yield ( ACVrelease ) of 0.10.3 and an uncaging cross section ( ) of 4501350 M cm 1 . We demonstrate that this photorelease method outcompetes alternative reaction pathways, such as protonation. Furthermore, complete release of the drug is theoretically possible given a sufficient dose of light . Surprisingly the acyclovir photocage, also showed some antiviral activity towards HSV-1. The antiviral drug acyclovir has been attached to a xanthone photocage and releases the drug upon UVA excitation; it is designed for potential treatment of ocular herpes simplex virus infections.