吩

头孢噻吩

tóu bāo sāi fēn

(pharm.) cefalotin (aka cephalothin)

卟吩

bǔ fēn

porphin C20H14N4 (loanword)

吩咐

fēn fu

to tell; to instruct; to command

吩嗪

fēn qín

phenazine (loanword)

吩坦尼

fēn tǎn ní

fentanyl (loanword) (Tw)

噻吩

sāi fēn

thiophene (chemistry) (loanword)

苯并噻吩

běn bìng sāi fēn

benzothiophene C8H9, a heterocyclic compound (with one benzene ring and one cyclopentene ring)