However, the results in Table 1 show that 4-hydroxytryptophan which so far has not been encountered in nature, in contrast to tryptophan does not function as a precursor of psilocybin. Tryptamine, which is readily formed from tryptophan by P. Cubensis, serves as a better precursor of psilocybin than tryptophan. If tryptamine is methylated to N-methyltryptamine, this is an even better progenitor of psilocybin with incorporations showing that more than half of the psilocybin was derived from the introduced labelled precursors (Expts. Nos. 38, 42). The corresponding dimethyl derivative N,N-dimethyltryptamine may, however, be considered as a poor precursor as judged from the incorporation percentages.
The culture conditions they used was a submerged culture, described in Acta Pharm. Suecica 3, 67 (1966). To find out why DMT was incorporated so poorly although it is a close relative to psilocin, they measured the amounts of uptake of precursors from medium by P. Cubensis. The uptakes are ordered as follows: psilocin (ca. 80%) > tryptamine (ca.65%) > 4-hydroxytryptamine (ca. 40%) > N-methyltryptamine (ca. 30%) > DL-4-hydroxytryptophan (ca. 25%) > DL-tryptophan (ca. 20%) > N,N-dimethyltryptamine (ca. 5%). The values are measurements after 26 hours, the time after which most of the uptake had already happened. If the DMT doesn't get absorbed, it is no wonder it's not incorporated into psiloc(yb)in. Scanning the whole article is also possible.
Therefore, it might be fruitful to find out plants that contain N-methyltryptamine or/and tryptamine. :)
Post 453575 (https://www.thevespiary.org/talk/index.php?topic=12923.msg45357500#msg45357500)
(Rhodium: "Ref 12: Biosynthesis of Psilocybin", Tryptamine Chemistry)