A method for at least one of increasing the synthesis of melatonin and promoting the secretion of melatonin is provided, wherein the method comprises administering to a subject in need an effective amount of a compound of formula (I): A method for at least one of treating diseases related to neurometabolic disorder, preventing diseases related to neurometabolic disorder, regulating appetite, regulating mood, regulating vasoconstriction, regulating hemostatic function and regulating immune response is also provided, wherein the method comprises administering to a subject in need an effective amount of a compound of formula (I) as described above.