... fermented by a kind of microorganism.,called Kojic acid. 2). Kojic acid is white or cream colored acicular crytal, ... , acetone, slightly dissolving ether second ester of second acid, chloroform and pyridine, non-dissolving benzene;molecular formula C6H6O4 ... brightening cosmetic, bath cream midtoothpaste. The products containing kojic acid can treat freckle, acne, pigmentation and macula effectively ...