Are Markush structures matters of chemistry and law or just figments of the imagination?

Very broad Markush claims were said to be “a problem for all” by the participants at a round table discussion held on 29 August 1990, during the National Meeting of the American Chemistry Society in Washington [G. W. A. Milne, Very broad Markush claims: a solution or a problem? J. Chem. Inf. Comput. Sci. 31, 9–30 (1991)]. Two main themes emerged from the discussion. The first was the problems that these broad Markush disclosures caused both database producers and users, and the second was the necessity for such claims expressed by the patent attorneys, especially in the pharmaceutical area. The authors of this paper looked at this problem paying particular attention to the requirements of patent law and to the needs of chemistry as a science. Account is taken of the views expressed in previous publications in the area. It is argued that the so-called “nasties” and “super-nasties” arise because the basic principles of science and of patent law are being ignored.