Functions as a non-oxidoreductive cyclase to promote the formation of cis-trans-nepetalactol. Cis-trans-nepetalactol is then oxidized by NEPS1 into cis-trans-nepetalactone, which belongs to a family of metabolites that are both insect-repellent and have euphoric effect in cats. Binds NAD(+) as classical short-chain dehydrogenase/reductase (SDR), but does not utilize it for its redox-neutral cyclase activity 