0000000000711751
AUTHOR
Teppo O. Leino
Azulene as a biphenyl mimetic in orexin/hypocretin receptor agonists
Azulene is a rare ring structure in drugs, and we investigated whether it could be used as a biphenyl mimetic in known orexin receptor agonist Nag 26, which is binding to both orexin receptors OX1 and OX2 with preference towards OX2. The most potent azulene-based compound was identified as an OX1 orexin receptor agonist (pEC50 = 5.79 +/- 0.07, maximum response = 81 +/- 8% (s.e.m. of five independent experiments) of the maximum response to orexin-A in Ca2+ elevation assay). However, the azulene ring and the biphenyl scaffold are not identical in their spatial shape and electron distribution, and their derivatives may adopt different binding modes in the binding site. Peer reviewed
The azulene scaffold from a medicinal chemist's perspective: Physicochemical and in vitro parameters relevant for drug discovery.
Azulene is a bicyclic scaffold rarely applied in medicinal chemistry. Here we report physicochemical and in vitro parameters relevant for drug discovery for a series of diversely substituted azulenes. We synthesized and characterized several scaffold hopping series of analogously substituted azulenes, indoles and naphthalenes. This enabled a comparison of azulene with the more common scaffolds indole and naphthalene. Our data indicates that undesirably low photostability of azulenes is restricted to certain substitution patterns. Generally, we conclude that azulene is an underused lipophilic bicycle and should be considered as a valuable complement to the collection of medicinal chemistry s…