The invention relates to compounds of general formula I wherein R is heteroaryl optionally substituted by R7； or R is heterocycloalkyl or heterocycloalkenyl, optionally substituted by R8； or R is X wherein X is &mdash；NR11R12； and pharmaceutically acceptable salts, hydrates, or solvates thereof, for use&mdash；alone or in combination with one or more other pharmaceutically active compounds&mdash；in therapy, for preventing, treating or ameliorating diseases or conditions responsive to stimulation of neutrophil oxidative burst, responsive to stimulation of keratinocyte IL-8 release or responsive to induction of necrosis.
