Water-soluble, UV-absorbing and/or fluorescing compound having an isoelectric point greater than 10, can be obtained using molecules chosen from the group of molecules consisting of those containing at least one secondary alcohol OH group with a PK.sub.a value greater than 10 and at least one amino group with a pK.sub.b value smaller than 5, those containing at least one primary alcohol OH group and at least one secondary alcohol OH group with respective PK.sub.a values greater than 10 and at least one amino group with a pK.sub.b value smaller than 5 or a quaternary ammonium group, and those containing at least two secondary alcohol OH groups with respective pK.sub.a values greater than 10 and at least one amno group with a pK.sub.b value smaller than 5 or a quaternary ammonium group; and having at least one UV absorbing group or at least one fluorescing group or a combination thereof. The invention includes methods for producing such compounds.