Redoxon

[1][failed verification] Redoxon was first marketed to the general public by Roche in 1934, making it the first mass-manufactured synthetic vitamin in history.

[2][failed verification] The brand is now owned by German pharmaceutical company Bayer and is sold in many countries.

This used an intermediate step of creating sorbose using a bacterial fermentation method discovered by a French researcher, Gabriel Bertrand.

In this method, fruit flies were attracted to a mixture of wine, vinegar, yeast bouillon, and sorbitol, a substance easily chemically prepared from glucose.

[3] Despite concern about starting with a wild strain of bacteria for fermentation production of sorbose, the process was superior in cost and yield to a rival method by Albert Szent-Györgyi that isolated vitamin C from capsicum (peppers).