Appeal No. 1997-2795
Application No. 08/438,933
reduction, (d) fractionation and (e) collection of derivatives having a molecular weight not less than that
of the starting heparin material. Claim 14 further requires an initial step of “subjecting porcine heparin
to a mild chemical sulfation” prior to the periodate oxidation step.
Fransson (M) and Casu both describe preparing periodate-oxidized derivatives of heparin of
porcine or bovine origin (in Fransson (M), see abstract and page 133, Materials; in Casu, see abstract
and page 639, § 2.1). According to the examiner, “the sulfation of FRANSSON is considered to be
‘mild’” (answer, page 15). However, the examiner has not pointed out, and we do not find, where
either Fransson (M) or Casu disclose or suggest “subjecting porcine heparin to a mild chemical
sulfation” prior to periodate oxidation as required by claims 14 and 16. Accordingly, we conclude that
the examiner has not established a prima facie case of obviousness as to claims 14 and 16.
As to the remaining claims and method steps, Fransson (M) discloses periodate oxidation at
either pH 3.0 and 4EC or pH 7.0 and 37EC, either sodium borohydride reduction or alkali
elimination, and fractionation of the degradation products of heparin by gel chromatography (page 134,
para. 2). According to Fransson (M), periodate oxidation at pH 3.0 and 4EC destroyed uronic acid
residues, while periodate oxidation at pH 7.0 and 37EC produced significant cleavage of the C-2—C-
3 bond in 2-amino-2-deoxy-"-D-glucose residues (page 136, first full para.). Casu discloses
periodate oxidation of heparin at pH 5.3 at 4EC in the dark, followed by sodium borohydride reduction
and recovery of degradation products by dialysis (page 639, § 2.1).
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