Using sugar to convert methylene blue into leucomethylene blue

Methylene blue is well known compound which can converted into leucomethylene blue using reducing agent and hydrochloric acid. Scientists use vitamin C to convert methylene blue to leucomethylene blue; however, there are many reducing agent which can be also used for the conversion. Sugar which is one of well known reducing agent, can be used to convert methylene blue to leucomethylene blue as well. For this reason, we hypothesized that dextrose, glucose, fructose, d-ribose, and d-mannose can be used as reducing agents. After testing each sugar, dextrose took 30 sec, glucose 1 min, fructose 20 sec, d-ribose 1 min and 20 sec, and d-mannose 4 minutes for full conversion of methylene blue to leucomethylene blue. Since sugar is cheaper than vitamin c, sugar can be a good substitute for the conversion.