乙酰胆碱

yǐ xiān dǎn jiǎn

acetylcholine ACh (amine related to vitamin B complex)

second of the ten Heavenly Stems 十天干[shi2 tian1 gan1]

xiān

acid radical

dǎn

gall bladder

jiǎn

variant of 鹼|碱[jian3]