any of a class of organic heterocyclic compounds containing nitrogen in a six-membered ring, including [[吡啶|吡啶|bi3 ding4]], [[哒嗪|噠嗪|da1 qin2]], and [[嘧啶|嘧啶|mi4 ding4]]

(loanword) pyrazine; a specific type of organic chemical compound containing a nitrogen-rich ring structure

(loanword) phenazine

piperazine; an organic compound used in medicine to treat parasitic worm infections, such as roundworms and pinworms

(organic compound) pyridazine; pyrazine; an organic chemical with the formula C4H4N2

thiazine; a group of heterocyclic compounds containing sulfur and nitrogen; loanword

isoalloxazine; a tricyclic organic compound that forms the core structure of riboflavin

(loanword) cetirizine; an antihistamine medication used to treat allergies