Chemical Information Sources/SIRCh/Chemical Patent Searches/Markush Structure

Example of a Markush Chemical Patent Claim


Newsgroups: misc.int-property,sci.chem From: srctran@world.std.com (Gregory Aharonian) Subject: PATNEWS: A humongous, hierarchical, chemical Markush group Date: Thu, 2 Mar 1995 06:45:27 GMT


   The following patent recently caught my eye for a variety of reasons

(check out its sprawling multi-page OG entry).

   First it is one of those rare, verrrrrry lengthy first independent claim

patents. Second, this lengthy first claim being a Markush group, results in zillions (2.94777 zillion to be exact) of combinations, for which I assume the examiner and applicant did quantum chemical GAUSSIAN evaulations for each one :-)

   But most interestingly, this is one of the few clean hierarchical Markush

groups I have ever seen. Usually the chemical Markush groups state something like "this is made of A B and C, where A is any benzene derivative...", a two level hierarchy. This patent, however, is a three and four level hierarchy "this is made of A B C, where A is R1, and R1 is benzene or R121". It has a reductionist elegance in its hierarchical style.

   This style can be used quite effectively to create havoc in the software

patent arena, if you use a similar hierarchy to claim some object schema and all applications that are derivable from the claimed object class structure (which I still claim at least one company is trying to do :-)

   Anyways, add it to your patent claim style list.

Greg Aharonian Internet Patent News Service (for subscription info, send 'help' to patents@world.std.com ) (for prior art search services info, send 'prior' to patents@world.std.com ) (for WWW patent searching, try http://sunsite.unc.edu/patents/intropat.html )


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5387671 Hexa- and heptapeptide anaphylatoxin-receptor ligands Abbott Laboratories

    1. An anaphylotoxin activity modulating compound of the formula:

                              A-B-D-E-G-J-L-M-Q

or a pharmaceutically acceptable salt thereof wherein the groups A through Q have the values:

A   is R.sub.1 -R.sub.2 -R.sub.3 ;

B   is selected from the group consisting of R.sub.4 -R.sub.5 -R.sub.6,
 R.sub.31, R.sub.32, R.sub.35 and R.sub.37 ;

D   is selected from the group consisting of R.sub.7 -R.sub.8 -R.sub.9,
 R.sub.31, R.sub.32, R.sub.35 and R.sub.37 ;

E   is selected from the group consisting of R.sub.10 -R.sub.11 -R.sub.12,
 R.sub.31, R.sub.32, R.sub.35 and R.sub.37 ;

G   is selected from the group consisting of R.sub.13 -R.sub.14 -R.sub.15,
 R.sub.31, R.sub.32, R.sub.35 and R.sub.37 ;

J   is selected from the group consisting of R.sub.16 -R.sub.17 -R.sub.18,
 R.sub.31, R.sub.32, R.sub.35 and R.sub.37 ;

L   is selected from the group consisting of R.sub.19 -R.sub.20 -R.sub.21,
 R.sub.31, R.sub.32, R.sub.35 and R.sub.37 ;

M   is a valence bond, or is selected from the group consisting of R.sub.22
 -R.sub.23 -R.sub.24, R.sub.31, R.sub.32, R.sub.35, and R.sub.37 ;

Q   is R.sub.25 -R.sub.26 -R.sub.27 ; or

B and D, taken together, optionally represent a group selected from the
 group consisting of R.sub.33, R.sub.34, R.sub.38, R.sub.39, R.sub.40,
 R.sub.41, R.sub.42, R.sub.43, and R.sub.44 ;

D and E, taken together, optionally represent a group selected from the
 group consisting of R.sub.33, R.sub.34, R.sub.38, R.sub.39, R.sub.40,
 R.sub.41, R.sub.42, R.sub.43, and R.sub.44 ;

E and G, taken together, optionally represent a group selected from the
 group consisting of R.sub.33, R.sub.34, R.sub.38, R.sub.39, R.sub.40,
 R.sub.41, R.sub.42, R.sub.43, and R.sub.44 ;

G and J, taken together, optionally represent a group selected from the
 group consisting of R.sub.33, R.sub.34, R.sub.38, R.sub.39, R.sub.40,
 R.sub.41, R.sub.42, R.sub.43, and R.sub.44 ;

J and L, taken together, optionally represent a group selected from the
 group consisting of R.sub.33, R.sub.34, R.sub.38, R.sub.39, R.sub.40,
 R.sub.41, R.sub.42, R.sub.43, and R.sub.44 ;

L and M, taken together, optionally represent a group selected from the
 group consisting of R.sub.33, R.sub.34, R.sub.38, R.sub.39, R.sub.40,
 R.sub.41, R.sub.42, R.sub.43, and R.sub.44 ; and one or more of the groups
 R.sub.5 -R.sub.6 -R.sub.7, R.sub.8 -R.sub.9 -R.sub.10, R.sub.11 -R.sub.12
 -R.sub.13, R.sub.14 -R.sub.15 -R.sub.16, R.sub.17 -R.sub.18 -R.sub.19,
 R.sub.20 -R.sub.21 -R.sub.22, and R.sub.23 -R.sub.24 -R.sub.25,
 independently may optionally represent R.sub.36 ;

wherein

(a) R.sub.1 is selected from the group consisting of lower alkyl, aryl,
 arylalkyl, and hydrogen;

(b) R.sub.2 is selected from the group consisting of >CR.sub.99 R.sub.100
 and oxygen, with the proviso that when R.sub.2 is oxygen, R.sub.1 is aryl,
 lower alkyl, or arylalkyl;

(c) R.sub.3 is selected from the group consisting of >C.dbd.O and
 >CH.sub.2, with the proviso that when R.sub.3 is >CH.sub.2 then R.sub.2
 cannot be oxygen;

(d) R.sub.4 is >NR.sub.101 where R.sub.101 is selected from the group
 consisting of hydrogen, lower alkyl, arylalkyl, and alkenyl;

(e) R.sub.5 is selected from the group consisting of >CR.sub.201 R.sub.202,
 >NR.sub.203 >C.dbd.CR.sub.205 R.sub.206, existing in either the Z- or
 E-configuration, and substituted cyclopropyl of the formula
 ##STR28##
 (f) R.sub.6, R.sub.9, R.sub.12, R.sub.15, and R.sub.18 are independently
 selected from the group consisting of >C.dbd.O, >CH.sub.2, --CH.sub.2
 C(O)--, --NHC(O)--, >C.dbd.S, >SO.sub.2, and >P(O)X where X is selected
 from hydroxy, alkoxy, amino, alkylamino and dialkylamino;

(g) R.sub.7, R.sub.10, R.sub.13, R.sub.16, R.sub.19, and R.sub.22, are
 independently selected from the group consisting of >CH.sub.2 and
 >NR.sub.50 where R.sub.50 is selected from the group consisting of
 hydrogen, lower alkyl, arylalkyl, aryl, hydroxy and alkoxy;

(h) R.sub.21, and R.sub.24 are independently selected from the group
 consisting of >C.dbd.O, --CH.sub.2 C(O)--,--NHC(O)--, >C.dbd.S, >SO.sub.2,
 and >P(O)X where X is selected from the group consisting of hydroxy,
 alkoxy, amino, alkylamino and dialkylamino, with the proviso that when
 R.sub.22 -R.sub.23 -R.sub.24 is present, R.sub.21 is >CH.sub.2

(i) R.sub.8 is selected from the group consisting of >CR.sub.210 R.sub.211,
 >NR.sub.213, >C.dbd.CR.sub.215 R.sub.216, existing in either the Z- or
 E-configuration, and substituted cyclopropyl of the formula
 ##STR29##
 (j) R.sub.11 is selected from the group consisting of >CR.sub.220
 R.sub.221, >NR.sub.223, >C.dbd.CR.sub.225 R.sub.226, existing in either
 the Z- or E-configuration, and substituted cyclopropyl of the formula
 ##STR30##
 (k) R.sub.14 is selected from the group consisting of >CR.sub.230
 R.sub.231, >NR.sub.233, >C.dbd.CR.sub.235 R.sub.236, existing in either
 the Z- or E-configuration, and substituted cyclopropyl of the formula
 ##STR31##
 (l) R.sub.17 is selected from the group consisting of >CR.sub.301
 R.sub.302, >NR.sub.303, >C.dbd.CR.sub.305 R.sub.306, existing in either
 the Z- or E-configuration, and substituted cyclopropyl of the formula
 ##STR32##
 (m) R.sub.20 is selected from the group consisting of >CR.sub.310
 R.sub.311, >C.dbd.CR.sub.315 R.sub.316, existing in either the Z- or
 E-configuration, and substituted cyclopropyl of the formula
 ##STR33##
 (n) R.sub.23 is selected from the group consisting of >CR.sub.320
 R.sub.321, >C.dbd.CR.sub.325 R.sub.326, existing in either the Z- or
 E-configuration, and substituted cyclopropyl of the formula
 ##STR34##
 (o) R.sub.25 is selected from the group consisting of >O, and >NR.sub.109
 where R.sub.109 is selected from the group consisting of hydrogen, lower
 alkyl, and arylalkyl;

(p) R.sub.26 is selected from the group consisting of hydrogen, lower
 alkyl, arylalkyl and >NR.sub.110 where R.sub.110 is selected from the
 group consisting of hydrogen, lower alkyl, or arylalkyl with the provisos
 that

 (i) when R.sub.25 is >O then R.sub.26 is lower alkyl, and

 (ii) when R.sub.26 is hydrogen, lower alkyl, or arylalkyl, then R.sub.27 is
  absent;

(q) R.sub.27 is selected from the group consisting of hydrogen, and aryl;

(r) R.sub.31 is
 ##STR35##
 where m and n are integers independently selected from 0, 1 and 2; (s)
 R.sub.32 is
 ##STR36##
 where p and q are integers independently selected from 0, 1 and 2; (t)
 R.sub.33 is
 ##STR37##
 where t and v are integers independently selected from 0, 1, 2 and 3; (u)
 R.sub.34 is
 ##STR38##
 where r and s are integers independently selected from 0, 1, 2 and 3; (v)
 R.sub.35 is
 ##STR39##
 where f is an integer of 0 to 2, X is selected from the group consisting
 of >C.dbd.O and --CH.sub.2 -- and R is selected from the group consisting
 of hydrogen and lower alkyl, with the provisos that

 (i) when f is 0, X is at C-2 and R is at C-3 or C-4;

 (ii) when f is 1, X is at C-2 and R is at C-3, C-4 or C-5 and C-3,4 are
  saturated or unsaturated;

 (iii) when f is 2, X is at C-2, C-3 or C-4 and R is at C-2, C-3, C-4, C-5
  or C-6 when the position is unoccupied by X and C-3,4 or C-4,5 are
  saturated or unsaturated; and

(w) R.sub.36 is
 ##STR40##
 where g is an integer of from 0 to 3; (x) R.sub.37 is
 ##STR41##
 wherein h is 1 and j is 0 or 1; (y) R.sub.38 is
 ##STR42##
 where k is an integer of from zero to two; (ae) R.sub.44 is
 ##STR43##
 (af) R.sub.1 and R.sub.2, taken together, optionally represent a group
 selected from the group consisting of aryl, and hydrogen;

(ag) R.sub.1, R.sub.2 and R.sub.3, taken together, optionally represent a
 group selected from the group consisting of lower alkyl, arylalkyl,
 alkenyl, hydrogen, and an N-terminal protecting group;

(ah) R.sub.6 and R.sub.7 ; R.sub.9 and R.sub.10 ; R.sub.12 and R.sub.13 ;
 R.sub.15 and R.sub.16 ; R.sub.18 and R.sub.19 ; R.sub.21 and R.sub.22 ;
 each pair taken together, optionally and independently represent a group
 selected from the group consisting of --C(O)NH--, >CH.sub.2,
 --(CH.sub.2).sub.3 --, --CH.dbd.CH--, --CH(OH)--,
 --C.tbd.C--,--C(.dbd.CH.sub.2)CH.sub.2 --, --CH(OH)CH.sub.2 --, --C(O)O--,
 --C(O)S--, --CH.sub.2 C(O)O--, --CH.sub.2 C(O)S--, --CH.sub.2 O--,
 --CH.sub.2 S--, and --NHC(O)--, with the provisos that

 (i) at least one of said pair, taken together, must be other than
  --C(O)NH--; and

 (ii) when R.sub.5 is >NR.sub.203 or >C.dbd.CR.sub.205 R.sub.206, R.sub.6
  and R.sub.7, taken together, represent --C(O)NH-- or --C(O)NCH.sub.3 ;

 (iii) when R.sub.8 is >NR.sub.213 or >C.dbd.CR.sub.215 R.sub.216, R.sub.9
  and R.sub.10, taken together, represent --C(O)NH-- or --C(O)NCH.sub.3 --;

 (iv) when R.sub.11 is >NR.sub.223 or >C.dbd.CR.sub.225 R.sub.226, R.sub.12
  and R.sub.13, taken together represent --C(O)NH-- or --C(O)NCH.sub.3 --;

 (v) when R.sub.14 is >NR.sub.233 or >C.dbd.CR.sub.235 R.sub.236, R.sub.15
  and R.sub.16, taken together, represent --C(O)NH-- or --C(O)NCH.sub.3 --;

 (vi) when R.sub.17 is >NR.sub.303 or >C.dbd.CR.sub.305 R.sub.306, R.sub.18
  and R.sub.19, taken together, represent --C(O)NH-- or --C(O)NCH.sub.3 --;

 (vii) when R.sub.20 is >C.dbd.CR.sub.315 R.sub.316, R.sub.21 and R.sub.22,
  taken together, represent --C(O)NH-- or --C(O)NCH.sub.3 --;

(ai) R.sub.26 and R.sub.27, taken together, optionally represent hydrogen,
 with the proviso that when R.sub.25 is >O then R.sub.26 and R.sub.27,
 taken together, represent hydrogen, lower alkyl, or arylalkyl;

(aj) R.sub.99, R.sub.202, R.sub.211, R.sub.221, R.sub.231, R.sub.302,
 R.sub.311, and R.sub.321 are independently selected from the group
 consisting of hydrogen, arylalkyl with the proviso that for R.sub.302 and
 R.sub.311, arylalkyl is limited to benzyl when R.sub.19 -R.sub.20
 -R.sub.21 or R.sub.22 -R.sub.23 -R.sub.24 respectively represent an
 L-arginyl residue, and lower alkyl;

(ak) R.sub.100 is selected from the group consisting of hydrogen, and lower
 alkyl;

(al) R.sub.201 is selected from the group consisting of hydrogen, lower
 alkyl, alkenyl, aryl, arylalkyl, (cycloalkyl)alkyl, aminoalkyl,
 amidoalkyl, hydroxyalkyl, guanidinoalkyl, carboxyalkyl,
 (carboxyamido)alkyl, (carboxyhydrazino)alkyl, ureidoalkyl,
 (heterocyclic)alkyl, (thioalkoxy)alkyl, and sulfhydrylalkyl;

(am) R.sub.201 and R.sub.202, R.sub.210 and R.sub.211, R.sub.220 and
 R.sub.221, R.sub.230 and R.sub.231, R.sub.301 and R.sub.302, R.sub.310 and
 R.sub.311, R.sub.320 and R.sub.321, each pair taken together,
 independently may optionally represent --(CH.sub.2).sub.z -- where z is an
 integer of from 2 to 6;

(an) R.sub.203 is selected from the group consisting of hydrogen, lower
 alkyl, alkenyl, arylalkyl, (cycloalkyl)alkyl, aminoalkyl, amidoalkyl,
 hydroxyalkyl, guanidinoalkyl, carboxyalkyl, (carboxyamido)alkyl,
 (carboxyhydrazino)alkyl, ureidoalkyl, (heterocyclic)alkyl,
 (thioalkoxy)alkyl, and sulfhydrylalkyl with the proviso that R.sub.203 may
 not be a vinyl group nor have a heteroatom directly attached to the
 nitrogen or separated from it by one methylene unit;

(ao) R.sub.205, R.sub.206, R.sub.215, R.sub.216, R.sub.225, R.sub.226,
 R.sub.235, R.sub.236, R.sub.305, and R.sub.306 are independently selected
 from the group consisting of hydrogen, lower alkyl, aryl, arylalkyl,
 wherein arylalkyl is excluded from R.sub.305 and R.sub.306 when R.sub.19
 -R.sub.20 -R.sub.21 represents an L-arginyl residue, (cycloalkyl)alkyl,
 amidoalkyl, wherein benzoyl amides and their heterocyclic variants are
 excluded from R.sub.305 and R.sub.306 when R.sub.19 -R.sub.20 -R.sub.21
 represents an L-arginyl residue (carboxyamido)alkyl, wherein aniline
 amides and their heterocyclic variants are excluded from R.sub.305 and
 R.sub.306 when R.sub.19 -R.sub.20 -R.sub.21 represents an L-arginyl
 residue; ureidoalkyl, and (heterocyclic)alkyl, wherein when R.sub.19
 -R.sub.20 -R.sub.21 represents an L-arginyl residue, then the heterocycle
 at from R.sub.305 and R.sub.306 can only be separated by one methylene
 unit from the alpha-carbon;

(ap) R.sub.210 selected from the group consisting of lower alkyl,
 arylalkyl, aminoalkyl,and guanidinoalkyl;

(aq) R.sub.213 is selected from the group consisting of lower alkyl,
 arylalkyl, aminoalkyl, and guanidinoalkyl with the proviso that R.sub.213
 may not be a vinyl group nor have a heteroatom directly attached to the
 nitrogen or separated from it by one methylene unit;

(ar) R.sub.220 is selected from the group consisting of hydrogen, lower
 alkyl, arylalkyl, (cycloalkyl)alkyl, and guanidinoalkyl;

(as) R.sub.223 is selected from the group consisting of hydrogen, lower
 alkyl, arylalkyl, (cycloalkyl)alkyl,and guanidinoalkyl, with the proviso
 that R.sub.223 may not be a vinyl group nor have a heteroatom directly
 attached to the nitrogen or separated from it by one methylene unit;

(at) R.sub.230 is selected from the group consisting of hydrogen, lower
 alkyl, arylalkyl, and (cycloalkyl)alkyl;

(au) R.sub.233 is selected from the group consisting of hydrogen, lower
 alkyl, arylalkyl, and (cycloalkyl)alkyl with the proviso that R.sub.233
 may not be a vinyl group nor have a heteroatom directly attached to the
 nitrogen or separated from it by one methylene unit;

(av) R.sub.301 is independently selected from the group consisting of
 hydrogen; lower alkyl; alkenyl; aryl; arylalkyl, wherein arylalkyl is
 limited to benzyl, when R.sub.19 -R.sub.20 -R.sub.21 represents an
 L-arginyl residue; (cycloalkyl)alkyl; aminoalkyl, wherein aryl and
 arylalkyl amines are excluded when R.sub.19 -R.sub.20 -R.sub.21 represents
 an L-arginyl residue; amidoalkyl, wherein benzoyl amides and their
 heterocyclic variants are excluded when R.sub.19 -R.sub.20 -R.sub.21
 represents an L-arginyl residue; hydroxyalkyl; guanidinoalkyl;
 carboxyalkyl; (carboxyamido)alkyl, wherein aniline amides of aspartyl
 residues and heterocyclic variants are excluded when R.sub.19 -R.sub.20
 -R.sub.21 represents an L-arginyl residue; carboxyhydrazino)alkyl;
 ureidoalkyl; (heterocyclic)alkyl, wherein when R.sub.19 -R.sub.20
 -R.sub.21 represents an L-arginyl residue, then the heterocycle can only
 be separated by one methylene unit from the alpha-carbon;
 (thioalkoxy)alkyl, and sulfhydrylalkyl;

(aw) R.sub.303 is independently selected from the group consisting of lower
 alkyl, arylalkyl, wherein arylalkyl is limited to benzyl when R.sub.19
 -R.sub.20 -R.sub.21 represents an L-arginyl residue, and
 (cycloalkyl)alkyl, with the proviso that R.sub.303 may not be a vinyl
 group or have a heteroatom directly attached to the nitrogen or separated
 from it by one methylene unit;

(ax) R.sub.304 is independently selected from the group consisting of
 hydrogen; lower alkyl; alkenyl; aryl, arylalkyl, wherein arylalkyl is
 excluded when R.sub.19 -R.sub.20 -R.sub.21 represents an L-arginyl
 residue; (cycloalkyl)alkyl; aminoalkyl, wherein aryl and arylalkyl amines
 are excluded when R.sub.19 -R.sub.20 -R.sub.21 represents an L-arginyl
 residue; amidoalkyl, wherein benzoyl amides and their heterocyclic
 variants are excluded when R.sub.19 -R.sub.20 -R.sub.21 represents an
 L-arginyl residue; hydroxyalkyl; guanidinoalkyl; carboxyalkyl;
 (carboxyamido)alkyl, wherein aniline amides and heterocyclic variants are
 excluded when R.sub.19 -R.sub.20 -R.sub.21 represents an L-arginyl
 residue; (carboxyhydrazino)alkyl; ureidoalkyl; (heterocyclic)alkyl,
 wherein (heterocyclic)alkyl is excluded when R 19-R.sub.20 -R.sub.21
 represents an L-arginyl residue; (thioalkoxy)alkyl; and sulfhydrylalkyl;

(ay) R.sub.307 and R.sub.317 are independently selected from hydrogen;
 lower alkyl; aryl and arylalkyl, wherein arylalkyl is excluded for
 R.sub.307 and R.sub.317 when R.sub.19 -R.sub.20 -R.sub.21 and R.sub.22
 -R.sub.23 -R.sub.24 respectively represent an L-arginyl residue;

(az) R.sub.310 is independently selected from the group consisting of
 hydrogen; lower alkyl; alkenyl; aryl; arylalkyl, wherein arylalkyl is
 limited to benzyl when R.sub.22 -R.sub.23 -R.sub.24 represents an
 L-arginyl residue; (cycloalkyl)alkyl; aminoalkyl, aryl and arylalkyl
 amines are excluded when R.sub.22 -R.sub.23 -R.sub.24 represents an
 L-arginyl residue; amidoalkyl, wherein benzoyl amides and their
 heterocyclic variants are excluded, when R.sub.22 -R.sub.23 -R.sub.24
 represents an L-arginyl residue; hydroxyalkyl; guanidinoalkyl;
 (carboxyamido)alkyl, wherein aniline amides of aspartyl residues and
 heterocyclic variants are excluded when R.sub.22 -R.sub.23 -R.sub.24
 represents an L-arginyl residue; (carboxyhydrazino)alkyl; ureidoalkyl;
 (heterocyclic)alkyl, wherein when R.sub.22 -R.sub.23 -R.sub.24 represents
 an L-arginyl residue, then the heterocycle can only be separated by one
 methylene unit from the alpha-carbon; and sulfhydrylalkyl;

(ba) R.sub.312 is independently selected from the group consisting of
 hydrogen; lower alkyl; alkenyl; aryl; arylalkyl, wherein arylalkyl is
 excluded when R.sub.22 -R.sub.23 -R.sub.24 represents an L-arginyl
 residue; (cycloalkyl)alkyl; aminoalkyl, wherein aryl and arylalkyl amines
 are excluded when R.sub.22 -R.sub.23 -R.sub.24 represents an L-arginyl
 residue; amidoalkyl, wherein benzoyl amides and their heterocyclic
 variants are excluded when R.sub.22 -R.sub.23 -R.sub.24 represents an
 L-arginyl residue; hydroxyalkyl; guanidinoalkyl; carboxyalkyl;
 (carboxyamido)alkyl, wherein aniline amides and heterocyclic variants are
 excluded when R.sub.22 -R.sub.23 -R.sub.24 represents an L-arginyl
 residue; (carboxyhydrazino)alkyl; ureidoalkyl; (heterocyclic)alkyl,
 wherein (heterocyclic)alkyl is excluded when R.sub.22 -R.sub.23 -R.sub.24
 represents an L-arginyl residue; (thioalkoxy)alkyl; and sulfhydrylalkyl;

(bb) R.sub.315 and R.sub.316 are independently selected from the group
 consisting of hydrogen, lower alkyl, arylalkyl, wherein arylalkyl is
 excluded when R.sub.22 -R.sub.23 -R.sub.24 represents an L-arginyl
 residue, and (cycloalkyl)alkyl;

(bc) R.sub.310 it is selected from the group consisting of hydrogen, lower
 alkyl, arylalkyl, alkenyl, (cycloalkyl)alkyl, aminoalkyl, and
 guanidinoalkyl;

(bd) R.sub.325 and R.sub.326 are independently selected from the group
 consisting of hydrogen, lower alkyl, aryl, arylalkyl, and
 (cycloalkyl)alkyl;

all of the foregoing with the provisos that

(i) when more than one sulfhydrylalkyl is present in the compound, the
 compound exists in the oxidized disulfide form producing a cyclic
 molecule, or the two sulfhydryl moieties are connected by a C.sub.2 to
 C.sub.8 alkylene chain and

(ii) when the compound contains a free amino group and carboxyl group, they
 can be cyclized to give the corresponding lactam.
Last modified on 4 March 2011, at 18:24