Appeal No. 2001-2138
Application No. 08/403,276
invention was patentable because they discovered that the prior art product was a
racemate, i.e., comprised of optical isomers, that the isomers could be separated, and
that there were unexpected results. The court rejected the first two arguments, finding that,
in view of the textbook, one of ordinary skill in the art would have recognized the reference
product to be a racemate, and would also know how to separate the isomers. Id. at
954–55, 125 USPQ at 235. Finally, the court found the evidence of unexpected results
was not persuasive, and so affirmed the rejection. Because the court did not rely on the
general proposition that one optical isomer is prima facie obvious over its enantiomer,
Adamson does not stand for that proposition.
In Brenner v. Ladd, 247 F.Supp. 51, 147 USPQ 87 (D.D.C. 1965), the district court
agreed that, “in the absence of unexpected or unobvious beneficial properties, an optically
active isomer is unpatentable over either the isomer of opposite rotation or, as in this
case, the racemic compound itself.” Id. at 56, 147 USPQ at 91. The court’s decision,
however, appears to be based on its factual finding that the only disclosed utility for the
compounds L-acl or L-acl.HCL was their use as intermediates in the production of L-lysine.
Id. The court held, however, that this utility would have been obvious over a prior art
teaching that DL-acl (the racemate) could be hydrolyzed to DL-lysine through the
intermediate DL-acl.HCl. Id. In modern terminology, the court found that the only evidence
of record showed that L-acl had similar properties to the known DL-acl, and held that the
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