Trigonelline is an alkaloid with chemical formula C7H7NO2. It is a zwitterion formed by the methylation of the nitrogen atom of niacin (vitamin B3). Trigonelline is a product of niacin metabolism that is excreted in urine of mammals. Trigonelline occurs in many plants. It has been isolated from fenugreek seeds, garden peas, hemp seed, oats, potatoes, Stachys species, dahlia, Strophanthus species, and Dichapetalum cymosum. Trigonelline is also found in coffee. Higher levels of trigonelline is found in arabica coffee. Holtz, Kutscher, and Theilmann have recorded its presence in a number of animals. Trigonelline crystallizes as a monohydrate from alcohol in hygroscopic prisms. It is readily soluble in water or warm alcohol, less so in cold alcohol, and slightly so in chloroform or ether. The salts crystallize well, the monohydrochloride, in leaflets, sparingly soluble in dry alcohol.
-P995.gif)