To produce an aromatic polycarbonate excellent in physical properties and hue by a simplified step as compared with a conventional one. The present invention provides a glucokinase activator containing a compound represented by the formula :whereinR1 is a hydrogen atom or a halogen atom;R2 is a group represented bywherein each symbol is defined in the specification,or a salt thereof or a prodrug thereof. The rebates or rewards earned by a registered member can be applied to a variety of accounts, financial instruments or obligations. In another embodiment, fuel reactivity is adjusted by passing a portion of the fuel through a catalyst or a non-thermal plasma generator prior to injection into the engine.