synthesize
verb [ T ] chemistry specialized (UK usually synthesise) uk/ˈsɪn.θə.saɪz/ us/ˈsɪn.θə.saɪz/
合成
to produce a substance by a chemical reaction in plants or animals
There are many vitamins that the body cannot synthesize itself. 有很多维生素是人体自身无法合成的。