caffeine vs theine

caffeine and theine both are nouns.

Word	Noun	Adjective	Verb	Adverb
caffeine	Yes	No	No	No
theine	Yes	No	No	No

As nouns, theine is a hyponym of caffeine; that is, theine is a word with a more specific, narrower meaning than caffeine:

caffeine: a bitter alkaloid found in coffee and tea that is responsible for their stimulating effects
theine: caffeine when present in tea.

Other hyponyms of caffeine include guaranine.

caffeine (noun)	theine (noun)
a bitter alkaloid found in coffee and tea that is responsible for their stimulating effects	caffeine when present in tea.