Although discovered in 1979, the micronutrient pyrroloquinoline quinone (PPQ) has only recently been identified as the first new vitamin isolated in 55 years. PPQ, which was originally viewed as a non-essential antioxidant, has been determined to belong to the B-complex family of vitamins and, in studies on laboratory mice, has an effect on skin health, reproduction, immunity, and amino acid breakdown, it was reported in the May 1, 2000 issue of Nature.

PPQ has been known as an antioxidant, but has not been recognized previously as a nutrient. Sources of PPQ include parsley, green peppers, kiwi and papaya, and green tea as well as natto, a Japanese dish made of fermented soybeans.