Complex sentence: Thus, chemically, rosmarinic acid is an ester of caffeic acid with 3,4-dihydroxyphenyl lactic acid, but biologically, it is formed from 4-coumaroyl-4'-hydroxyphenyllactate.
Split into simpler sentences: Thus, chemically, rosmarinic acid is an ester of caffeic acid with 3,4-dihydroxyphenyl lactic acid. It is formed from 4-coumaroyl-4'-hydroxyphenyllactate.