Hyaluronic acid and yeast extract do not oxidize DOPA.

Hyaluronic acid and yeast extract, separately and in combination, were tested for their ability to oxidize dopa to pigment. Two types of hyaluronic acid and yeast extract were used. The activities were assayed both spectrophotometrically and by oxygen-uptake determinations. The results were uniformly negative. The biological role of hyaluronic acid is discussed. Use of pigment formation from phenolic compounds as an identification test of another organism is pointed out.