茶素 is read as ちゃそ (chaso) and means theine.
ちゃそ
chaso
ちゃかっしょく
dark reddish-brown
ちゃづけ
chazuke
ちゃきぐみ
tea set
ちゃちゅうしゅつぶつ
tea extract
ちゃばんきょうげん
farce
ちゃつみうた
tea-picking song
ちゃうけ
cake or snack served with tea
ちゃつみ
tea harvesting (picking)
もと
cause
ようそ
element (e.g. in array)
すいそ
hydrogen (H)
さんそ
oxygen (O)