Loveall said:If a bio-transformation did happen, what could it give? Melatonin is interesting because the nitrogen that attaches to the acetyl group seems prime for methylation, similar to how tryptamine gets its second methylation when transforming to psilocin. One bio transformation possibility is shown below consisting of two simple steps (see first image where melatonin is in the first row, and the ~equivalent psilocin steps are in the second row).
Mass-spec would show a peak in the 262-264 range (see second image). It could be named 4-OH-5-MEO-MACT (where MACT = MethylACetylTryptamine). A close relative to it could be 4-HO-5-MeO-DMT.
To be clear, this is not a claim of a result, only discussing one of the possibilities there could be.
I doubt you will be seeing any N methylation on melatonin
NHAc is an amide and NH2 or NHMe are amines.
The enzymes for N-methylation are only for amines. Amides are a very different functional group, they are non basic (pka ~17) and very stable functional groups that are not easily cleaved. The properties of the amine are also vital for receptor binding in the brain, so that N-acetylated tryptamines or phenethylamines are not active psychedelics (unless first deacetylated invivo, maybe a pathway for melatonin).
Though as we have discussed in length, the other transformations are very possible.