Um 'acetate' don't just mean ester it also means ionically bonded acid ion, like maleate, sulphate, hydrochloride. However, I think that it might only be one acetic acid per tryptamine, because ammonia pulls off one hydrogen when it mixes with water, and amine freebases such as tryptamine (or any other amine freebase) don't do that real well either, that's why they don't mix with water. But they do form OH's in the water when the water is acidic (ie got H+ ions floating around), and many (and tryptamine is probably the same) make salts when the water's removed. Thus meme means does three acetic acid ions ionically bond to Tryptamine. Methinks no. But it probably does make one bond.
When you look at the molecular model that is done for tryptamine (get chime so you can look at the model linked from erowid's TiHKAL) they draw it so that the N is kinda exposed looking. Possibly the reason why DMT doesn't make many solid salts is that to bond ionically it pushes those methyls down, and they're repelled strongly by the hydrogens on the ethyl carbon chain between the amine and the indole, thus not many things can stick ionically. Fumarate and picrate do apparently. Picrate has an ionic oxygen on it which would probably help it bind. This may also be the reason why DMT isn't active by the nose, because it can't do ionic bonding very well.
Or maybe it's just the fact that the methyl brings a pair of three covalently bonded hydrogens really close, which makes bonding difficult without something defusing some of that excess sigma positive (like the oxygen on picrate)
Disclaimer: everything I said I pulled outta my arse
