[gpcr1949]

Of course, it's somewhat disappointing that any molecule you look at will result in isomerization of cis-retinal to trans-retinal - including a picture of the consumed cis-retinal.

Another interesting example where molecules will produce themselves is chiral amplification with autocatalysis. This article is fairly technical, but a nice example of a reaction product being a catalyst for its own (chiral!) formation: https://sci-hub.se/10.1021/ar9900820