Introduction Organic derivatives of ammonia CH2CH3 Many are biologically active. CH2一CH一COOH OH HO CH2 H :NH2 HO CH-CH2-N CH2 CH3 HO HO dopamine epinephrine L-tryptophan a neurotransmitter an adrenal hormone an amino acid CH2OH CH2CH2NH2 HO CH2OH OH => piperazine nicotinic acid pyridoxine histamine kills intestinal worms niacin,a vitamin vitamin B6 dilates blood vesselsChapter 19 2 Introduction • Organic derivatives of ammonia • Many are biologically active. =>