???COOH, ???SO3H, ???OSO3H, ???OPO3H2 or by a radical ???NH???C(O)???O-G??? wherein G??? is the radical of an anionic carbohydrate; a radical ???CONY5Y6 wherein Y5 is C1-C24-alkyl which is substituted by ???COOH, ???SO3H, ???OSO3H, or ???OPO3H2 and Y6 independently has the meaning of Y5 or is hydrogen or C1-C12-alkyl; or ???SO3H; or a salt thereof, for example a sodium, potassium, ammonium or the