Amines, acetylation defined

Alkaloid Toxins. Only one alkaloid toxin has been chemically defined from the cyanobacteria. This is the secondary amine, 2-acetyl-9-azabicyclo (4-2-1) non-2-ene, called anatoxin-a. It is isolated from the filamentous strain Anabaena flos-aquae NRG-44-1 (18,19). 

Histamine is also excreted as a ring N-methyl derivative and as amino-N-acetylhistamine. The former product has not been obtained in a defined reaction the acetylation apparently is catalyzed by the enzyme that acetylates aromatic amines with acetyl CoA, or a very similar enzyme that is present in the same liver fractions. 

Diphenylpiperazine can be titrated in acetic anhydride with perchloric acid. The titration curve resulting from plotting millivolts vs. volume of titrant gives two equal and well-defined inflection points. Diphenylpiper-azine is a by-product in the synthesis of diphenylethylene-diamine and may be determined in the presence of the same by acetylation and titration in acetic acid with perchloric acid. It may be identified by separation and titration, obtaining the very characteristic curve in acetic anhydride. Interferences from other tertiary amines and aniline are dealt with in these determinations of diphenylpiperazine. 

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