Ex Parte LI et al

Board of Patent Appeals and Interferences

Sep 29, 2004

09318186 (B.P.A.I. Sep. 29, 2004)

1 Appellants waived their request for oral hearing, therefore we consider this
appeal on Brief.
2 The examiner’s Answer refers to a claims 72, 73, 78 and 79 in error, as these
claims were cancelled in Paper No. 31. The above stated claims are the only
claims at issue in this appeal.
1
The opinion in support of the decision being entered today was not written
for publication and is not binding precedent of the Board.
Paper No. 37
UNITED STATES PATENT AND TRADEMARK OFFICE
__________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________
Ex parte TINYU LI and YAN WANG
__________
Appeal No. 2004-0275
Application No. 09/318,186
__________
ON BRIEF1
__________
Before WINTERS, WILLIAM F. SMITH, and MILLS, Administrative Patent
Judges.
MILLS, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on the appeal under 35 U.S.C. § 134 from the
examiner’s final rejection of claims 60-65, 67-69, 71, 74, 77, and 802, which are
all the pending claims in the application.
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Application No. 09/09/318,186
2
Claim 60 is illustrative of the claims on appeal and reads as follows:
60. A method for screening chiral selectors from a parallel library
comprising:
(a) forming a parallel library by individually synthesizing chiral selectors
onto a polymeric synthesis resin;
(b) incubating each individual chiral selector, attached on the polymeric
resin, with an analyte having a mixture of a R-enantiomer and a S-enantiomer:
(c) analyzing the resultant of step (b) to identify which chiral selector
selectively adsorbed one of the R-enantiomer and the S-enantiomer;
(d) attaching the identified chiral selector onto a support; and
(e) resolving the analyte of step (b) into the R-enantiomer and the S-
enantiomer with the attached chiral selector on the support.
The references relied upon by the examiner are:
Lam et al. (Lam) 5,858,670 Jan. 12, 1999
Welch, et al. (Welch), “Microscale Synthesis and Screening of Chiral Stationary
Phases,” Enantiomer, Vol. 3, pp. 471-476 (1998).
Liu, et al. (Liu), “Polymer- versus Silica-Based Separation Media: Elimination of
Nonspecific Interactions in the Chiral Recognition Process through Functional
Polymer Design,” Anal. Chem., Vol. 69, pp. 61-65 (1997).
Weingarten, et al. (Weingarten), “Enantioselective Resolving Resins from a
Combinatorial Library. Kinetic Resolution of Cyclic Amino Acid Derivatives,” J.
Am. Chem. Soc., Vol. 120, pp. 9112-9113 (1988).
Pirkle, et al. (Pirkle), “A Chiral Stationary Phase Which Affords Unusually High
Levels of Enantioselectivity,” Chirality, Vol. 3, pp. 183-187 (1991).
Grounds of Rejection
Claims 60-65, 67, 69, 71, 74 and 80 stand rejected under 35 U.S.C. §
103(a) for obviousness over Welch in view of Liu and further in view of
Weingarten.
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Claims 60 and 77 stand rejected under 35 U.S.C. § 103(a) as being
unpatentable over Welch, Liu, and Weingarten, in view of Lam.
Claims 60-65, 67-69, 71 and 74 are rejected under 35 U.S.C. § 103(a) as
being unpatentable over Welch, Liu, and Weingarten in view of Pirkle.
We affirm these rejections.
Claim Grouping
According to appellants, the claims stand or fall together. Appeal Brief,
page 5. Since the individual claims are not argued, we decide this appeal with
respect to the prior art rejection on the basis of claim 60. 37 CRF § 1.192(c)(7)
(1998). In re McDaniel, 293 F.3d 1379, 63 USPQ2d 1462, 1466 (Fed. Cir.
2002).
DISCUSSION
In reaching our decision in this appeal, we have given consideration to
appellants’ specification and claims, to the applied references, and to the
respective positions articulated by appellants and the examiner. As a
consequence of our review, we make the determinations that follow.
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Application No. 09/09/318,186
3 As noted in the Answer, page 2, claim 80, added in an amendment after final
rejection is rejected on the same basis as claim 60.
4
35 U.S.C. § 103(a)
Claims 60-65, 67, 69, 71, 74 and 803 stand rejected under 35 U.S.C.
§103(a) for obviousness over Welch in view of Liu and further in view of
Weingarten. In addition, claims 60 and 77 stand rejected under 35 U.S.C.
§103(a) as being unpatentable over Welch, Liu, and Weingarten, in view of Lam.
Furthermore, claims 60-65, 67-69, 71 and 74 are rejected under 35 U.S.C. §
103(a) as being unpatentable over Welch, Liu, and Weingarten in view of Pirkle.
Claim 60 is selected as the representative claim for each rejection.
In rejecting claims under 35 U.S.C. § 103(a), the examiner bears the initial
burden of presenting a prima facie case of obviousness. See In re Rijckaert, 9
F.3d 1531, 1532, 28 USPQ2d 1955, 1956 (Fed. Cir. 1993). A prima facie case of
obviousness is established when the teachings from the prior art itself would
appear to have suggested the claimed subject matter to a person of ordinary skill
in the art. In re Bell, 991 F.2d 781, 783, 26 USPQ2d 1529, 1531 (Fed. Cir.
1993).
Claim 60 is directed to a “method for screening chiral selectors” and
includes steps of synthesizing chiral selectors onto a polymer resin, incubating
the chiral selector with an analyte, analyzing the selectors to identify which ones
selectively adsorbed which enantiomers, attaching the identified selectors onto a
support, and resolving the analyte mixture with the attached chiral selector. It is
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the examiner’s position that the instant claims are obvious in light of Welch, in
view of Liu, and further in view of Weingarten.
Welch teaches a method for rapid screening of libraries of candidate chiral
selectors using a parallel library. Answer, page 8. Microscale synthesis and
screening is performed by Welch to evaluate the enantioselectivity of the
candidate chiral stationary phases. Id. Welch uses libraries synthesized on
silica; therefore the reference lacks the teaching of using the polymeric synthesis
resins set forth in the instant claim. Id. Liu teaches that silica has
disadvantages such as nonspecific interactions and polymer beads have
desirable characteristics. Answer, page 10.
According to the examiner (Answer, pages 6-7):
[I]t would have been prima facie obvious to one of ordinary skill in the art
at the time the invention was made to make the library of chiral selectors
taught by Welch et al on amino functionalized polystyrene as taught by
Weingarten et al. A person of ordinary skill in the art would have been
motivated to do so based on the teachings of Liu et al that using a polymer
support avoids the disadvantages of silica and allows for a potential
enhancement of enantioselectivity. Weingarten et al also teach that such
polymer supported materials can be easily synthesized and screened.
Moreover, it would have been prima facie obvious to one of ordinary skill
in the art at the time the invention was made to further use the identified
selectors in additional separations, as taught by Welsh [sic] et al.
We agree that the examiner has presented sufficient evidence to support
a prima facie case of obviousness. In particular, Welch describes a parallel
library system for use in the microscale synthesis and screening of chiral
molecule stationary phases which is very similar to the claimed invention.
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However, Welch synthesizes its chiral stationary phase on silica, as opposed to a
polymeric resin, as claimed. Liu recites the advantages of using a polymeric
stationary phase in place of a silica phase in chiral molecule resolution. Although
Liu uses the polymer stationary phase at a later step in a chiral separation
process than in claim 60 steps (a)-(c), the disadvantages of silica, namely
nonspecific interactions caused by the presence of residual silanol groups, and
advantages associated with the use of a polymeric resin, would have been
recognized by one of ordinary skill in the art as also applicable to a step of
screening for chiral selectors as well as a step of using the selectors to separate
a mixture.
Steps (d) and (e) of claim 60 are directed toward using the library of chiral
selectors synthesized in steps (a)-(c) to separate a mixture of enantiomers. This
use, although not specifically described in Welch, is suggested at page 471,
column one, which states that the selective stationary phases are useful for large
scale preparative enantioseparation. Weingarten specifically uses a selective
library to resolve a solution, separating a racemic mixture. Thus, in our view,
Weingarten in combination with Welch and Liu, would have reasonably
suggested the claimed chiral separation method to one of ordinary skill in the art.
Where the prior art, as here, gives reason or motivation to make the
claimed invention, the burden then falls on appellants to rebut that prima facie
case. Such rebuttal or argument can consist of any other argument or
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presentation of evidence that is pertinent. In re Dillon, 919 F.2d 688, 692-93, 16
USPQ2d 1897, 1901 (Fed. Cir. 1990) (en banc), cert. denied, 500 U.S. 904
(1991).
Appellants argue that the instant claims are not obvious under 35 U.S.C.
§103 in view of the cited references. Brief, page 12. Appellants argue that, “one
of ordinary skill in the art would not look to bits and pieces of the secondary
references in that manner suggested if the references are considered as a
whole.” Brief, page 6. Appellants point out that Welch does not describe
synthesizing chiral selectors on a polymeric synthesis resin, Liu does not
describe synthesizing chiral selectors on a resin, and Weingarten fails to disclose
forming a parallel library. Brief, pages 5-9.
These attempts to rebut the examiner's prima facie case of obviousness
are unpersuasive. Obviousness can be established by combining or modifying
the teachings of the prior art to produce the claimed invention where there is
some teaching, suggestion, or motivation to do so found either in the references
themselves or in the knowledge generally available to one of ordinary skill in the
art. In re Fine, 837 F.2d 1071, 1074, 5 USPQ2d 1596, 1598 (Fed. Cir. 1988), In
re Jones, 958 F.2d 347, 350, 21 USPQ2d 1941, 1943 (Fed. Cir. 1992).
We agree with the examiner that the prior art references provide the
necessary reason, suggestion or motivation to make the claimed invention and
we are not persuaded by appellants’ arguments to the contrary. Appellants
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cannot show nonobviousness by attacking references individually where the
rejections are based on combinations of references. In re Keller, 642 F.2d 413,
425, 208 USPQ 871, 881 (CCPA 1981); In re Merck & Co., Inc., 800 F.2d 1091,
1097, 231 USPQ 375, 380 (Fed. Cir. 1986).
More particularly, appellants argue that Welch does not describe
“synthesizing chiral selectors onto a polymeric synthesis resin. However, the
examiner explains that Liu provides the motivation to combine the polymer base
with Welch and Weingarten by describing the advantages of the use of a
polymer resin over the silica base in preparing chiral molecule selectors.
Answer, pages 6-7.
Additionally, appellants argue that Welch does not describe using the
polymeric resins set forth in claim 60, (i.e., does not describe steps (d) and (e)),
namely the use of a screening library for the resolution of a racemic mixture. The
examiner acknowledges Welch lacks the specific teaching of steps (d) and (e),
but notes that Welch states in both the introduction and conclusion that the
purpose of screening the chiral stationary phases (CSPs) is to identify CSPs
useful for large scale preparative enantioseparation. Answer, page 5. In
addition, Liu recites steps for synthesizing the selector on a base, and
Weingarten uses a selector library to resolve a mixture. Thus, appellants'
arguments are unpersuasive when viewed in light of the combination of
references.
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According to appellants, although Liu states that silica has disadvantages,
and describes the use of a polymer base, Liu does not offer strong motivation to
combine the references because Liu does not prepare chiral selectors onto
polymeric synthesis resin for subsequent use in a step that would correspond to
the synthesis step of the present invention. Brief, page 7. In addition, appellants
argue that Liu describes chiral separation according to step (d), a downstream
step of the claimed process, and it is inappropriate to use Liu as a teaching of
claim 60, synthesis step (a), as Liu fails to disclose or suggest a process of
individually synthesizing a chiral selector onto a polymeric synthesis resin. Id.,
pages 7-8. Thus, according to appellants, one would not be motivated to
combine the references.
However, Liu is used by the examiner as evidence to suggest that a
polymer base has advantages over a silica base in chiral compound selection.
Answer, page 6. In our view, Liu provides a strong motivation to combine with
Welch and Weingarten to establish obviousness because it emphasizes
advantages of a polymer base over a silica base in chiral molecule selection. The
strongest rationale for combining references is a recognition, expressly or
impliedly in the prior art or drawn from a convincing line of reasoning based on
established scientific principles or legal precedent, that some advantage or
expected beneficial result would have been produced by their combination In re
Sernaker, 702 F.2d 989, 994-995, 217 USPQ 1, 5-6 (Fed. Cir. 1983). Liu
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teaches that silica has disadvantages, such as allowing for nonspecific
interactions between polar silanol groups and analyte enantiomers. Liu then
goes on to state that polymer bases overcome the disadvantages of a silica
base, thereby increasing the yield of a resolution. Since Liu discusses the
advantages of using a polymer base over a silica base for chiral molecule
selection, it provides a strong reason, suggestion or motivation to substitute a
polymer base for a silica base in chiral molecule resolution and selection.
Furthermore, appellants argue that Weingarten discloses a method of
preparing chiral resolution resins using a different procedure than the procedure
claimed in the invention. Brief, page 9.
Appellants argue that Weingarten is directed to a different type of
procedure altogether, and that one of ordinary skill in the art would not associate
it with Liu or Welch. Id. Appellants argue that the method of Weingarten is a
pool/split procedure, where polymer beads are pooled and re-divided during
synthesis. Id. Appellants state that the claims in the present invention are
directed to a parallel library, and thus argue that the Weingarten reference has
no connection to the present invention. Brief, pages 9-12.
However, Weingarten is not cited by the examiner for the method used to
prepare the library. Weingarten is cited for its teaching of a library of chiral
selectors immobilized on polymer beads. Answer, page 6. It is of no
consequence that the procedure used in Weingarten is a split/pool procedure
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and not a parallel library, as Welch discloses and is relied on for its use of a
parallel library.
In view of above, the rejections of claims 60-65, 67, 69, 71, 74 and 80
over Welch, Liu and Weingarten are affirmed. The rejections of claims 60 and 77
under 35 U.S.C. § 103(a) as being unpatentable over Welch, Liu, and
Weingarten, in view of Lam, and claims 60-65, 67-69, 71 and 74 under 35 U.S.C.
§ 103(a) as being unpatentable over Welch, Liu, and Weingarten in view of
Pirkle, also fall with claim 60 based upon the primary combination of references.
CONCLUSION
The rejection of claims 60-65, 67, 69, 71, 74 and 80 under 35 U.S.C. §
103(a) for obviousness over Welch in view of Liu and further in view of
Weingarten is affirmed.
The rejections of claims 60 and 77 under 35 U.S.C. § 103(a) as being
unpatentable over Welch, Liu, and Weingarten, in view of Lam, and claims 60-65,
67-69, 71 and 74 under 35 U.S.C. § 103(a) as being unpatentable over Welch,
Liu, and Weingarten in view of Pirkle, also fall with claim 60 based upon the
primary combination of references and are affirmed.
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No time period for taking any subsequent action in connection with this
appeal may be extended under 37 CFR § 1.136(a).
AFFIRMED
SHERMAN D. WINTERS )
Administrative Patent Judge )
)
)
) BOARD OF PATENT
WILLIAM F. SMITH )
Administrative Patent Judge ) APPEALS AND
)
)
) INTERFERENCES
DEMETRA J. MILLS )
Administrative Patent Judge )
Appeal No. 2004-0275
Application No. 09/09/318,186
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