Follow my logic.
Homovanillic acid (HVA) a common metabolite of dopamine and oter
The vanilloid receptor 1 (VR1) or capcaicin receptor, it mediates
apoptosis in some cases.
Esters of homovanillic acid can be potent VR1 receptor agonists
3-Acyloxy-2-phenalkylpropyl amides and esters of homovanillic acid as
novel vanilloid receptor agonists.
Bioorg Med Chem Lett. 1999 Oct 18;9(20):2909-14.
Could it not be possible that HVA has agonistic properties on the VR1
receptor? I mean, look at the two molecules, apart from the hyrdophic
chain, HVA and capcaicin look very similar in regards to charge
distribution. Might explain why dopaminergic neurons are always so damn
I don't know, just the musing of an undergraduate.