Opioid peptides

Opioid peptides including those of the formula ##STR1## in which A.sub.1 is the identifying group of an amino acid selected from 3,4-dihydroxyphenylalanine, 3,4-dimethoxyphenylalanine, azatyrosine, and 2,6-dimethyltyrosine; A.sub.2 is the identifying group of an amino acid selected from D-Ala and D-Arg; A.sub.3 is H, or the identifying group of an amino acid selected from of 3,4-dihydroxyphenylalanine and 3,4-dimethoxyphenylalanine, A.sub.4 is H, cyclohexylmethyl, the identifying group of an amino acid selected from 3,4-dihydroxyphenylalanine, 3,4-dimethoxyphenylalanine, Phe, and substituted Phe with its benzene ring substituted by halogen, NO.sub.2, OH, or CH.sub.3 ; A.sub.5 is the identifying group of a D- or L-amino acid selected from Leu, Nle, Lys, Met and Met(O), or is deleted together with R.sub.4 --CH attached thereto; each R.sub.1 and R.sub.2 is --H, --C(NH.sub.2).dbd.NH, or C.sub.1-12 alkyl; R.sub.3 is ##STR2## R.sub.4 is ##STR3## and R.sub.5 is --(CH.sub.2).sub.n+1 OH, ##STR4## wherein m is 0-6, n is 0-6, and X is H, C.sub.1-12 alkyl, C.sub.6-12 aryl, C.sub.7-18 aralkyl, C.sub.7-18 alkaryl, C.sub.7-18 alkayl, C.sub.6-17 pyridylalkyl, or C.sub.6-17 alkylpyridyl; provided that when one of R.sub.1 and R.sub.2 is --C(NH.sub.2).dbd.NH, the other must be H; or a pharmaceutically acceptable salt thereof.

FIELD OF THE INVENTION 
The present invention relates to short peptides. More particularly, it 
relates to short peptides capable of selectively binding to receptors on 
cells. 
BACKGROUND OF THE INVENTION 
Since the discovery of endogenous opioid peptides in the 1970's, extensive 
research in opioid chemistry and biology have suggested the existence of 
multiple opioid receptors: .mu. (mu), .delta. (delta) and .kappa. (kappa). 
The identification of multiple receptors is particularly interesting in 
that many opioids exert a variety of effects including analgesia, 
addiction, respiratory depression, inhibition of gut transit, and 
cardiotoxicity. See e.g., The Pharmacological Basis of Therapeutics, 
McMillan, pp. 496-536, New York (1980); Hruby et al., Med. Res. Rev. 9:343 
(1989); and Zimmermann, et al., J. Med. Chem. 33:895 (1990). 
Recent work has suggested that opioid peptides may also be involved in 
pathological states, including cancer. As shown in Table 1, multiple 
opioid receptors are present on numerous tumor cell lines. 
While the exact role played by opioid peptides in oncogenic events remains 
unknown, opioids have been found to alter cell function and growth 
[Slotkin et al. Life Sci. 26:861 (1980); and Wilson et al. J. Pharmacol. 
Exp. Ther. 199:368 (1976)], to inhibit the growth of cultured 
neuroblastoma cells [Zagon et al. Brain Res. Bull. 7:25 (1981)], and to 
inhibit neuroblastoma tumor growth and 
TABLE 1 
______________________________________ 
Opiate Receptor Binding-Tumors or Tumor Cell Lines* 
Opiate Receptor Conc. 
Tumor Receptor Subtype 
(fmol/mg protein) 
______________________________________ 
Inventors' Data 
SCLC NCI-H69 mu 0 
SCLC NCl-H69 delta 23 
SCLC NCI-H69 kappa 0 
A549 NSCLC mu 0 
A549 NSCLC delta 0 
A549 NSCLC kappa 0 
MCF-7 mu 0 
MCF-7 delta 23 
MCF-7 kappa 0 
M 5123 Hepatoma mu 0 
B16 Melanoma mu 0 
B16 Melanoma kappa 129 
R3327 Prostate mu 0 
Data from Maneckjee et al. Proc. Natl. Acad. Sci. USA 87:3294 (1990) 
SCLC NCI-H187 nonselective 
450 
SCLC NCl-H69 nonselective 
202 
SCLC NCI-H146 nonselective 
172 
SCLC NCI-N417 nonselective 
39 
SCLC NCI-H345 nonselective 
18 
NSCLC NCl-H322 nonselective 
293 
NSCLC NCI-H460 nonselective 
194 
NSCLC NCI-H157 nonselective 
157 
NSCLC NCl-H23 nonselective 
119 
NSCLC NCI-H290 nonselective 
78 
Data from Zagon et al. J. Natl. Cancer Inst. 79:1059 (1987) 
Breast Adenocarcinoma 
delta 8.3 
Brent Adenocarcinoma 
mu 14.2 
Breast Adenocarcinoma 
kappa 10.0 
Overian Fibroma delta 225.0 
Overian Fibroma kappa 15.5 
Endometrial Adenocarcinoma 
delta 1.03 
Endometrial Adenocarcinoma 
kappa 30.2 
Rectal Adenocarcinoma 
delta 41.0 
Rectal Adenocarcinoma 
kappa 54.0 
______________________________________ 
*does not exclude tumors expressing yet uncharacterized opiate receptor 
isotypes. 
prolong survival times, in an opioid antagonist sensitive manner, in mice 
with transplanted neuroblastomas, B-16 melanoma, MCF-7 breast cancer, 
human lung cancer cells and others [Zagon et al. Life Sci. 28:1095 (1981); 
Zagon et al. Science 221:671 (1983); and Von Hoff et al. Proc., Am. Assoc. 
Cancer Res., Abstract 932, p. 236 (1982); Srisuchark et al. Int. J. 
Immunopharm. 11(5):487 (1989); Minna et al. Proc. Natl. Acad. Sci., 
87:3294 (1990); ibid. 89:1169 (1992)]. 
SUMMARY OF THE INVENTION 
Structures and Abbreviations 
AHPPA=(3S, 4S) -4-amino-3-hydroxy-5-phenyl-pentanoic acid 
##STR5## 
ACHPA=(3S, 4S)-4-amino-5-cyclohexyl-3-hydroxy-pentamoic acid 
##STR6## 
APP=(4R)-4-amino-5-phenylpentanoic acid 
##STR7## 
PEG=N-phenylethylglycine 
##STR8## 
azatyrosine=L-3-(5-hydroxy-2-pyridyl)alanine 
##STR9## 
DOPA=3,4-dihydroxyphenylalanine 
##STR10## 
homophenylalanine 
##STR11## 
Nle=Norleucine Met(O)=methionine sulfoxide 
The present invention disclose a class of novel opioid peptides. 
More specifically, one aspect of the invention relates to peptides of the 
formula: 
##STR12## 
In which 
A.sub.1 is the identifying group of an amino acid selected from 
3,4-dihydroxyphenylalanine, 3,4-dimethoxyphenylalanine, azatyrosine, and 
2,6-dimethyltyrosine; 
A.sub.2 is the identifying group of an amino acid selected from D-Ala and 
D-Arg; 
A.sub.3 is H, or the identifying group of an amino acid selected from of 
3,4-dihydroxyphenylalanine and 3,4-dimethoxyphenylalanine, 
A.sub.4 is H, cyclohexylmethyl, the identifying group of an amino acid 
selected from 3,4-dihydroxyphenylalanine, 3,4-dimethoxyphenylalanine, Phe, 
and substituted Phe with its benzene ring substituted by halogen, 
NO.sub.2, OH, or CH.sub.3 ; 
A.sub.5 is the identifying group of a D- or L-amino acid selected from Leu, 
Nle, Lys, Met and Met(O), or is deleted together with R.sub.4 --CH 
attached thereto; 
each R.sub.1 and R.sub.2 is --H, --C(NH.sub.2).dbd.NH, or C.sub.1-12 alkyl; 
R.sub.3 is 
##STR13## 
R.sub.4 is 
##STR14## 
and 
R.sub.5 is --(CH.sub.2).sub.n+1 OH, 
##STR15## 
(m is 0-6, n is 0-6, and X is H, C.sub.1-12 alkyl, C.sub.6-12 aryl, 
C.sub.7-18 aralkyl, C.sub.7-18 alkaryl, C.sub.7-18 alkaryl, C.sub.6-17 
pyridylalkyl, or C.sub.6-17 alkylpyridyl); provided that when one of 
R.sub.1 and R.sub.2 is --C(NH.sub.2).dbd.NH, the other must be H. 
Preferably, A.sub.1 is the identifying group of an amino acid selected from 
3,4-dihydroxyphenylalanine and 3,4-dimethoxyphenylalanine; A.sub.5 is the 
identifying group of a D- or L-amino acid selected from Leu, Met and 
Met(O), or is deleted together with R.sub.4 --CH attached thereto; each 
R.sub.1 and R.sub.2 is --H or --C(NH.sub.2).dbd.NH; R.sub.3 is 
##STR16## 
R.sub.4 is 
##STR17## 
R.sub.5 is --(CH.sub.2).sub.n+1 OH or 
##STR18## 
m is 0-2; n is 0-2; and X is H, C.sub.1-12 alkyl, or C.sub.7-18 aralkyl. 
Another aspect of the invention relates to peptides of formula (I), in 
which 
A.sub.1 is the identifying group of an amino acid selected from 
3,4-dihydroxyphenylalanine, 3,4-dimethoxyphenylalanine, azatyrosine, Tyr, 
and 2,6-dimethyltyrosine; 
A.sub.2 is the identifying group of an amino acid selected from D-Ala and 
D-Arg; 
A.sub.3 is H or the identifying group of an amino acid selected from 
3,4-dihydroxyphenylalanine and 3,4-dimethoxyphenylalanine; 
A.sub.4 is H, cyclohexylmethyl, or the identifying group of an amino acid 
selected from 3,4-dihydroxyphenylalanine and 3,4-dimethoxyphenylalanine; 
A.sub.5 is the identifying group of a D- or L-amino acid selected from Leu, 
Nle, Lys, Met and Met(O), or is deleted together with R.sub.4 --CH 
attached thereto; 
each R.sub.1 and R.sub.2 is --H, --C(NH.sub.2).dbd.NH, or C.sub.1-12 alkyl; 
R.sub.3 is 
##STR19## 
R.sub.4 is 
##STR20## 
and 
R.sub.5 is --(CH.sub.2).sub.n+1 OH, 
##STR21## 
(m is 0-6, n is 0-6, and X is H, C.sub.1-12 alkyl, C.sub.6-12 aryl, 
C.sub.7-18 aralkyl, C.sub.7-18 alkaryl, C.sub.6-17 pyridylalkyl, or 
C.sub.6-17 alkylpyridyl); provided that when one of R.sub.1 and R.sub.2 is 
--C(NH.sub.2).dbd.NH, the other must be H. 
Preferably, A.sub.1 is the identifying group of an amino acid selected from 
3,4-dihydroxyphenylalanine, 3,4-dimethoxyphenylalanine, and Tyr; A.sub.5 
is the identifying group of a D- or L-amino acid selected from Leu, Met 
and Met(O), or is deleted together with R.sub.4 --CH attached thereto; 
each R.sub.1 and R.sub.2 is --H or --C(NH.sub.2).dbd.NH; R.sub.3 is 
##STR22## 
R.sub.4 is 
##STR23## 
R.sub.5 is --(CH.sub.2).sub.n+1 OH or 
##STR24## 
m is 0-2; n is 0-2; and X is H, C.sub.1-12 alkyl, or C.sub.7-18 aralkyl. 
A further aspect of the invention relates to peptides of formula (I), in 
which 
A.sub.1 is the identifying group of an amino acid selected from 
3,4-dihydroxyphenylalanine, 3,4-dimethoxyphenylalanine, azatyrosine, Tyr, 
and 2,6-dimethyltyrosine; 
A.sub.2 is the identifying group of an amino acid selected from D-Ala and 
D-Arg; 
A.sub.3 is H or the identifying group of an amino acid selected from 
3,4-dihydroxyphenylalanine and 3,4-dimethoxyphenylalanine; 
A.sub.4 is the identifying group of an amino acid selected from Phe, and 
substituted Phe with its benzene ring substituted by halogen, NO.sub.2, 
OH, or CH.sub.3 ; 
A.sub.5 is the identifying group of a D- or L-amino acid selected from Leu, 
Nle, Lys, Met and Met(O), or is deleted together with R.sub.4 --CH 
attached thereto; 
each R.sub.1 and R.sub.2 is --H, --C(NH.sub.2).dbd.NH, or C.sub.1-12 alkyl; 
R.sub.3 is 
##STR25## 
R.sub.4 is 
##STR26## 
and 
R.sub.5 is --(CH.sub.2).sub.n+1 OH, 
##STR27## 
(m is 1-6, n is 0-6, and X is H, C.sub.1-12 alkyl, C.sub.6-12 aryl, 
C.sub.7-18 aralkyl, C.sub.7-18 alkaryl, C.sub.7-18 alkaryl, C.sub.6-17 
pyridylalkyl, or C.sub.6-17 alkylpyridyl); provided that when one of 
R.sub.1 and R.sub.2 is --C(NH.sub.2).dbd.NH, the other must be H. 
Preferably, A.sub.1 is the identifying group of an amino acid selected from 
3,4-dihydroxyphenylalanine, 3,4-dimethoxyphenylalanine, and Tyr; A.sub.5 
is the identifying group of a D- or L-amino acid selected from Leu, Met 
and Met(O), 
or is deleted together with R.sub.4 --CH attached thereto; each R.sub.1 and 
R.sub.2 is --H or --C(NH.sub.2).dbd.NH; R.sub.3 is 
##STR28## 
R.sub.4 is 
##STR29## 
R.sub.5 is --(CH.sub.2).sub.n+1 OH or 
##STR30## 
m is 1-2; n is 0-2; and X is H, C.sub.1-12 alkyl, or C.sub.7-18 aralkyl. 
The present invention also covers peptides of formula (I), in which 
A.sub.1 is the identifying group of an amino acid selected from 
3,4-dihydroxyphenylalanine, 3,4-dimethoxyphenylalanine, azatyrosine, Tyr, 
and 2,6-dimethyltyrosine; 
A.sub.2 is the identifying group of an amino acid selected from D-Ala and 
D-Arg; 
A.sub.3 is H or the identifying group of an amino acid selected from 
3,4-dihydroxyphenylalanine and 3,4-dimethoxyphenylalanine; 
A.sub.4 is H, cyclohexylmethyl, the identifying group of an amino acid 
selected from 3,4-dihydroxyphenylalanine, 3,4-dimethoxyphenylalanine, Phe, 
and substituted Phe with its benzene ring substituted by halogen, 
NO.sub.2, OH, or CH.sub.3 ; 
A.sub.5 is the identifying group of a D- or L-amino acid selected from Leu, 
Nle, Lys, Met and Met(O), or is deleted together with R.sub.4 --CH 
attached thereto; 
each R.sub.1 and R.sub.2 is --H, --C(NH.sub.2).dbd.NH, or C.sub.1-12 alkyl; 
R.sub.3 is --CH.sub.2 NH-- or --CO.cndot.NH--; 
R.sub.4 is --CH.sub.2 NH-- or --CO.cndot.NH--; and 
R.sub.5 is --(CH.sub.2).sub.n+1 OH, 
##STR31## 
(n is 0-6, and X is H, C.sub.1-12 alkyl, C.sub.6-12 aryl, C.sub.7-18 
aralkyl, C.sub.7-18 alkaryl, C.sub.7-18 alkaryl, C.sub.6-17 pyridylalkyl, 
or C.sub.6-17 alkylpyridyl); provided that: when one of R.sub.1 and 
R.sub.2 is --C(NH.sub.2).dbd.NH, the other must be H; and one and only one 
of R.sub.3 and R.sub.4 is --CH.sub.2 NH--. 
Preferably, A.sub.1 is the identifying group of an amino acid selected from 
3,4-dihydroxyphenylalanine, 3,4-dimethoxyphenylalanine, and Tyr; A.sub.5 
is the identifying group of a D- or L-amino acid selected from Leu, Met 
and Met(O), or is deleted together with R.sub.4 --CH attached thereto; 
each R.sub.1 and R.sub.2 is --H or --C(NH.sub.2).dbd.NH; R.sub.5 is 
--(CH.sub.2).sub.n+1 OH or 
##STR32## 
n is 0-2; and X is H, C.sub.1-12 alkyl, or C.sub.7-18 aralkyl. It is 
particularly preferred that A.sub.4 be the identifying group of an amino 
acid selected from 3,4-dihydroxyphenylalanine and 
3,4-dimethoxyphenylalanine. 
Also within the invention are peptides of the formula: 
##STR33## 
in which 
A.sub.1 is the identifying group of an amino acid selected from 
3,4-dihydroxyphenylalanine, 3,4-dimethoxyphenylalanine, azatyrosine, Tyr, 
and 2,6-dimethyltyrosine; 
A.sub.2 is the identifying group of an amino acid selected from D-Ala and 
D-Arg; 
A.sub.3 is the identifying group of an amino acid selected from 
3,4-dihydroxyphenylalanine and 3,4-dimethoxyphenylalanine, or is deleted 
together with CO--NH--CH attached thereto; 
each R.sub.1 and R.sub.2 is --H, --C(NH.sub.2).dbd.NH, or C.sub.1-12 alkyl; 
R.sub.3 is --(CH.sub.2).sub.n+1 OH, 
##STR34## 
(n is 0-6; and X is H, C.sub.1-12 alkyl, C.sub.6-12 aryl, C.sub.7-18 
aralkyl, C.sub.7-18 alkaryl, C.sub.7-18 3,4-dihydroxyphenylalkyl, 
C.sub.7-18 3,4-dimethoxyphenylalkyl, C.sub.6-17 pyridylalkyl, or 
C.sub.6-17 alkylpyridyl). 
Preferably, A.sub.1 is the identifying group of an amino acid selected from 
3,4-dihydroxyphenylalanine, 3,4-dimethoxyphenylalanine, and Tyr; each 
R.sub.1 and R.sub.2 is --H or --C(NH.sub.2).dbd.NH; R.sub.3 is 
##STR35## 
(X is H, C.sub.1-12 alkyl, or C.sub.7-18 aralkyl). It is particularly 
preferred that A.sub.3 be deleted together with CO--NH--CH attached 
thereto. 
Illustrative and non-limiting examples of peptides of the present invention 
are provided below: 
DOPA-D-alanyl-glycyl-phenylalanyl-methionine amide, 
DOPA-D-alanyl-glycyl-phenylalanyl methioninol, 
DOPA-D-arginyl-glycyl-phenylalanyl-methionine amide, 
DOPA-D-arginyl-glycyl-phenylalanyl methioninol, 
3,4-dimethoxyphenylalanyl-D-alanyl-glycyl-phenylalanylmethionine amide, 
3,4-dimethoxyphenylalanyl-D-alanyl-glycyl-phenylalanyl methioninol, 
3,4-dimethoxyphenylalanyl-D-arginyl-glycyl-phenylalanylmethionine amide, 
3,4-dimethoxyphenylalanyl-D-arginyl-glycyl-phenylalanylmethionine, 
DOPA-D-alanyl-DOPA-.beta.-alanine amide, 
DOPA-D-arginyl-DOPA-.beta.-alanine amide, 
DOPA-D-alanyl-DOPA-.beta.-alaninol, 
DOPA-D-arginyl-DOPA-.beta.-alaninol, 
3,4-dimethoxyphenylalanyl-D-alanyl-DOPA-.beta.-alanine amide, 
3,4-dimethoxyphenylalanyl-D-arginyl-DOPA-.beta.-alanine amide, 
3,4-dimethoxyphenylalanyl-D-alanyl-DOPA-.beta.-alaninol, 
3,4-dimethoxyphenylalanyl-D-arginyl-DOPA-.beta.-alaninol, 
DOPA-D-alanyl-glycyl-PEG amide, 
DOPA-D-arginyl-glycyl-PEG amide, 
DOPA-D-alanyl-glycyl-APP amide, 
DOPA-D-arginyl-glycyl-APP amide, 
tyrosyl-D-alanyl-glycyl-PEG-methionine amide, 
tyrosyl-D-arginal-glycyl-PEG-methionine amide, 
tyrosyl-D-alanyl-glycyl-PEG methioninol, 
tyrosyl-D-arginyl-glycyl-PEG methioninol, 
tyrosyl-D-alanyl-glycyl-ACHPA amide, 
tyrosyl-D-arginyl-glycyl-ACHPA amide, 
tyrosyl-D-alanyl-glycyl-PEG amide, 
tyrosyl-D-arginyl-glycyl-PEG amide, 
tyrosyl-D-alanyl-DOPA-ACHPA amide, 
tyrosyl-D-arginyl-DOPA-ACHPA amide, 
tyrosyl-D-alanyl-DOPA-PEG amide, 
tyrosyl-D-arginyl-DOPA-PEG amide, 
tyrosyl-D-alanyl-3,4-dimethoxyphenylalanyl-ACHPA amide, 
tyrosyl-D-arginyl-3,4-dimethoxyphenylalanyl-ACHPA amide, 
tyrosyl-D-alanyl-3,4-dimethoxyphenylalanyl-PEG amide, 
tyrosyl-D-arginyl-3,4-dimethoxyphenylalanyl-PEG amide, 
amidinotyrosyl-D-alanyl-glycyl-PEG amide, 
amidinotyrosyl-D-arginyl-glycyl-PEG amide, 
tyrosyl-D-alanyl-DOPA-.beta.-alanine amide, 
tyrosyl-D-arginyl-DOPA-.beta.-alanine amide, 
tyrosyl-D-alanyl-DOPA-.beta.-alaninol, 
tyrosyl-D-arginyl-DOPA-.beta.-alaninol, 
tyrosyl-D-alanyl-DOPA-glycinol, 
tyrosyl-D-arginyl-DOPA-glycinol, 
tyrosyl-D-alanyl-glycyl-DOPA amide, 
tyrosyl-D-arginyl-glycyl-DOPA amide, 
tyrosyl-D-alanyl-3,4-dimethoxyphenylalanyl-.beta.-alanine amide, 
tyrosyl-D-arginyl-3,4-dimethoxyphenylalanyl-.beta.-alanine amide, 
tyrosyl-D-alanyl-3,4-dimethoxyphenylalanyl-.beta.-alaninol, 
tyrosyl-D-arginyl-3,4-dimethoxyphenylalanyl-.beta.-alaninol, 
tyrosyl-D-alanyl-glycyl-3,4-dimethoxyphenylalanyl amide, 
tyrosyl-D-arginyl-glycyl-3,4-dimethoxyphenylalanyl amide, 
tyrosyl-D-alanyl-glycyl-APP-methionine amide, 
tyrosyl-D-alanyl-glycyl-APP methioninol, 
tyrosyl-D-arginyl-glycyl-APP-methionine amide, 
tyrosyl-D-arginyl-glycyl-APP methioninol, 
tyrosyl-D-alanyl-glycyl-homophenylalanyl-methionine amide, 
tyrosyl-D-alanyl-glycyl-homophenylalanyl methioninol, 
tyrosyl-D-arginyl-glycyl-homophenylalanyl-methionine amide, 
tyrosyl-D-arginyl-glycyl-homophenylalanyl methioninol, 
tyrosyl-D-alanyl-glycyl-AHPPA amide, 
tyrosyl-D-arginyl-glycyl-AHPPA amide, 
tyrosyl-D-alanyl-glycyl-APP amide, 
tyrosyl-D-arginyl-glycyl-APP amide, 
tyrosyl-D-alanyl-glycyl-homophenylalanine amide, 
tyrosyl-D-arginyl-glycyl-homophenylalanine amide, 
tyrosyl-D-alanyl-DOPA-AHPPA amide 
tyrosyl-D-arginyl-DOPA-AHPPA amide 
tyrosyl-D-alanyl-DOPA-APP amide 
tyrosyl-D-arginyl-DOPA-APP amide 
tyrosyl-D-alanyl-DOPA-homophenylalanine amide, 
tyrosyl-D-arginyl-DOPA-homophenylalanine amide, 
tyrosyl-D-alanyl-3,4-dimethoxyphenylalanyl-AHPPA amide, 
tyrosyl-D-arginyl-3,4-dimethoxyphenylalanyl-AHPPA amide, 
tyrosyl-D-alanyl-3,4-dimethoxyphenylalanyl-APP amide, 
tyrosyl-D-arginyl-3,4-dimethoxyphenylalanyl-APP amide, 
tyrosyl-D-alanyl-3,4-dimethoxyphenylalanyl-homophenylalanine amide, 
tyrosyl-D-arginyl-3,4-dimethoxyphenylalanyl-homophenylalanine amide, 
tyrosyl-D-alanyl-glycyl-.psi.(CH.sub.2 NH)-phenylalanine ethylamide, 
tyrosyl-D-alanyl-glycyl-.psi.(CH.sub.2 NH)-phenylalanine propylamide, 
tyrosyl-D-arginyl-glycyl-.psi.(CH.sub.2 NH)-phenylalanine ethylamide, 
tyrosyl-D-arginyl-glycyl-.psi.(CH.sub.2 NH)-phenylalanine propylamide, 
amidinotyrosyl-D-alanyl-glycyl-.psi.(CH.sub.2 NH)-phenylalanine ethylamide, 
amidinotyrosyl-D-alanyl-glycyl-.psi.(CH.sub.2 NH)-phenylalanine 
propylamide, 
amidinotyrosyl-D-arginyl-glycyl-.psi.(CH.sub.2 NH)-phenylalanine 
ethylamide, 
amidinotyrosyl-D-arginyl-glycyl-.psi.(CH.sub.2 NH)-phenylalanine 
propylamide, 
tyrosyl-D-arginal-glycyl-phenylalanyl-.psi.(CH.sub.2 NH)-leucine amide, 
tyrosyl-D-alanyl-DOPA-.psi.(CH.sub.2 NH)-phenylalanine ethylamide, 
tyrosyl-D-alanyl-DOPA-.psi.(CH.sub.2 NH)-phenylalanine propylamide, 
tyrosyl-D-arginyl-DOPA-.psi.(CH.sub.2 NH)-phenylalanine ethylamide, 
tyrosyl-D-arginyl-DOPA-.psi.(CH.sub.2 NH)-phenylalanine propylamide, 
amidinotyrosyl-D-alanyl-DOPA-.psi.(CH.sub.2 NH)-phenylalanine ethylamide, 
amidinotyrosyl-D-alanyl-DOPA-.psi.(CH.sub.2 NH)-phenylalanine propylamide, 
amidinotyrosyl-D-arginyl-DOPA-.psi.(CH.sub.2 NH)-phenylalanine ethylamide, 
amidinotyrosyl-D-arginyl-DOPA-.psi.(CH.sub.2 NH)-phenylalanine propylamide, 
tyrosyl-D-arginal-DOPA-Phenylalanyl-.psi.(CH.sub.2 NH)-leucine amide, 
tyrosyl-D-alanyl-3,4-dimethoxyphenylalanyl-.psi.(CH.sub.2 NH)-phenylalanine 
ethylamide, 
tyrosyl-D-alanyl-3,4-dimethoxyphenylalanyl-.psi.(CH.sub.2 NH)-phenylalanine 
propylamide, 
tyrosyl-D-arginyl-3,4-dimethoxyphenylalanyl-.psi.(CH.sub.2 
NH)-phenylalanine ethylamide, 
tyrosyl-D-arginyl-3,4-dimethoxyphenylalanyl-.psi.(CH.sub.2 
NH)-phenylalanine propylamide, 
amidinotyrosyl-D-alanyl-3,4-dimethoxyphenylalanyl-.psi.(CH.sub.2 
NH)-phenylalanine ethylamide, 
amidinotyrosyl-D-alanyl-3,4-dimethoxyphenylalanyl-.psi.(CH.sub.2 
NH)-phenylalanine propylamide, 
amidinotyrosyl-D-arginyl-3,4-dimethoxyphenylalanyl-.psi.(CH.sub.2 
NH)-phenylalanine ethylamide, 
amidinotyrosyl-D-arginyl-3,4-dimethoxyphenylalanyl-.psi.(CH.sub.2 
NH)-phenylalanine propylamide, 
tyrosyl-D-arginal-3,4-dimethoxyphenylalanyl-phenylalanyl-.psi.(CH.sub.2 
NH)-leucine amide, 
tyrosyl-D-alanyl-DOPA amide, 
tyrosyl-D-arginyl-DOPA amide, 
tyrosyl-D-alanyl-3,4-dimethoxyphenylalanine amide, 
tyrosyl-D-arginyl-3,4-dimethoxyphenylalanine amide, 
tyrosyl-D-alanine 3-(3',4'-dihydroxyphenylpropyl)amide, 
tyrosyl-D-arginine 3-(3',4'-dihydroxyphenylpropyl)amide, 
tyrosyl-D-alanine 3-(3',4'-dimethoxyphenylpropyl)amide, 
tyrosyl-D-arginine 3-(3',4'-dimethoxyphenylpropyl)amide, 
DOPA-D-alanine 3-phenylpropylamide, 
DOPA-D-alanine 2-(2-aminoethylpyridyl)amide, and 
DOPA-D-arginine 2-(2-aminoethylpyridyl)amide. 
In this disclosure, the identifying group of an .alpha.-amino acid is the 
atom or group of atoms bound to the asymmetric .alpha.-carbon atom, other 
than the carbonyl carbon atom, the amino nitrogen atom and the H atom. To 
illustrate by examples, the identifying group of alanine is --CH.sub.3 and 
the identifying group of phenylalanine is (C.sub.6 H.sub.5)CH.sub.2 --. 
Also, unless specified as an L- or D-isomer, an amino acid is intended to 
be an L amino acid. 
Further, a short line between two amino acid residues (e.g., DOPA-D-alanine 
3-phenylpropylamide) represents a peptide bond; that is, a covalent bond 
between C of a carbonyl group and N of an amino group. The symbol .psi. 
indicates the presence of a non-peptide bond and the nature of the 
non-peptide bond is described in the parentheses following .psi. (e.g., 
tyrosyl-D-alanyl-glycyl-.psi.(CH.sub.2 NH)-phenylalanine ethylamide). 
Thus, --.psi.(CH.sub.2 NH)-- represents the presence of a bond between two 
amino acid residues in which the carbon atom participating in the bond is 
reduced from a carbonyl carbon to a methylene carbon. 
A detailed discussion of the chemistry of non-peptide bonds is given in Coy 
et al. Tetrahedron 44:835 (1988); Tourwe Janssen Chim. Acta 3:3-15, 17-18 
(1985); and Spatola in Chemistry and Biochemistry of Amino Acids, Peptides 
and Proteins (B. Weinstein, ed.), M. Dekker, New York and Basal, pp. 
267-357 (1983). All of them are hereby incorporated by reference. 
Pharmaceutically acceptable salts of the above-described peptides are also 
within the present invention. Examples of preferred salts include those 
formed with therapeutically acceptable acids, e.g., hydrochloric, 
hydrobromic, sulfuric, nitric, phosphoric, citric, acetic, maleic, lactic, 
malic, ascorbic succinic, benzoic, fumaric, salcyclic, methanesulfonic, 
trifluoroacetic, toluenesulfonic, or pamoic acid, as well as polymeric 
acids such as tannic acid or carboxymethyl cellulose, lactate/glycolate. 
Opioid peptides are known to possess analgesic, antitussive, and 
antidiarrheal activity and thus may be used in human or veterinary 
medicine for the relief or prevention of pain, for the treatment of 
diarrhea or dysentery, for the suppression of cough and for hypertension. 
Further, the opioid peptides of the invention are effective in treating 
various cancers (e.g., lung, breast, melanoma, or neuroblastoma). 
A therapeutically effective amount of a peptide of the invention and a 
pharmaceutically acceptable carrier substance (e.g., magnesium carbonate 
or lactose) can be formulated to form a therapeutic composition, such as 
(i) a pill, tablet, capsule, or liquid for oral administration to a 
patient; (ii) a liquid or an ointment capable of being administered by 
inhalation, transdermally, nasally, rectally or sublingually; (iii) a 
liquid capable of being administered intravenously, parenterally, 
subcutaneously or intraperitoneally; or (iv) an oral or a parenteral 
sustained release formulation. Thus, the opioid peptide of the invention 
may be administered to a mammal, particularly a human, in one of the 
traditional modes (e.g., orally, parenterally, transdermally, or 
transmucosally), in a sustained release formulation using a biodegradable 
biocompatible polymer, or by on-site delivery using micelles, gels and 
liposomes. The peptides can be administered to a human patient in a dosage 
of 1000 .mu.g/kg/day to 50 mg/kg/day. 
The peptides of the present invention can also be used as tools for 
detecting specific opioid receptors in cells of certain tissues or organs. 
Other features and advantages of the invention will be apparent from the 
following description of the preferred embodiments thereof, and from the 
claims.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Synthesis 
The peptides of this invention can be readily prepared by standard solution 
or solid phase peptide synthesis. Thus, procedures analogous to those 
disclosed in Solid Phase Peptide Synthesis by Stewart and Young, Pierce 
Co., Illinois, 1984 or Principles of Peptide Synthesis by Springer-Verlag, 
Berlin, 1984 may be followed. Both of them are hereby incorporated by 
reference. 
Peptides of the invention that contain a CH.sub.2 NH non-peptide bond can 
be prepared by reacting on N-protected amino acid aldehyde with the free 
amino group of another C-protected amino acid using NaCNBH.sub.3, as 
described in Martinez et al. J. Med. Chem. 28:1874 (1985) and Coy et al. 
Tetrahedron 44:835 (1988), both of which are hereby incorporated by 
reference. 
AHPPA and ACHPA can be synthesized according to the method of Hui et al. J. 
Med. Chem. 30:1281 (1987); Schuda et al., 1987, J. Org. Chem. 53:873; and 
Rich et al., 1988, J. Org. Chem. 53:869. All three of them are hereby 
incorporated by reference. 
To obtain N-terminal amidinotyrosyl peptides, the peptide salt (e.g., an 
acetates or trifluoroacetate salt) was reacted with 
3,5-dimethylpyrazolo-1-carboxamidine nitrate in the presence of base, e.g. 
triethylamine, diisopropylamine, or aqueous NaOH (pH 9.3-9.5), in inert 
solvents, e.g. alcohol, water, tetrahydrohuran or its mixture, at 
0.degree.-80.degree. C., 2 hours to several days. The intermediates and 
final products were isolated and purified by standard methods, e.g., by 
column chromatography, crystallization on high performance liquid 
chromatography ("HPLC"). Purity was determined using chromatographic, 
spectroscopic and chemical analysis. 
Benzyloxycarbonyl ("CBZ")-tyrosyl-D-alanyl-glycyl-PEG glycine amide was 
synthesized as follows. 2.3 ml diisopropylamine was added to a mixture of 
CBZ-tyrosyl-D-alanine (1.65 g), glycyl-PEG amide trifluoroacetic acid salt 
(1.5 g) and BOP reagent (i.e., benzotriazol-1-yloxytris 
(dimethylamine)phosphonium hexafluorophosphate) (2.1 g) in 20 ml 
dimethylformamide ("DMF") and the mixture was stirred at room temperature 
overnight. Solvent was removed in vacuo to a dryness and the residue 
partitioned between ethylacetate and water. The organic layer and any 
partially insoluble solids were combined, the solvent evaporated, and the 
residue recrystallized from ethylacetate. Yield: 0.65 g; Thin layer 
chromatography ("TLC") (Silica gel: CHCl.sub.3 /MeOH 9:1, Rf 0.37). 
CBZ-tyrosyl-D-alanyl-glycyl-PEG amide (0.6 g) in 20 ml methanol was 
hydrogenated under 32 psi using 100 mg 10% Pd-C for 4 hours. The mixture 
was then filtered through celite pad, washed with alcohol. Thereafter, the 
filtrate was concentrated in vacuo to dryness. Yield: 0.49 g colorless 
solid; TLC (silica gel; CHCl.sub.3 /MeOH=4:1, Rf 0.1). Synthetic amino 
acids are commercially available. 
(4R)-Boc-amino-5-phenyl-pentanoic acid was synthesized as follows. To a 
partial solution of Boc-phenylalanine aldehyde (2.3 g) in 30 ml 
dichloromethane cooled to 0.degree.-5.degree. C., was added 
carbethoxymethylene triphenylphosphorane (10 g). The mixture was stirred 
at 0.degree.-5.degree. C. for 3 hours then room temperature overnight. 
Solvent was evaporated in vacuo to a dryness and the residue was 
triturated with boiling ether (.about.200 ml). Ether extract was 
concentrated in vacuo and the residue was chromatographed on silica gel 
(50 g) using hexane/ethylacetate (5:1) as eluants. Appropriate fractions 
were pooled and solvents removed in vacuo to a dryness. Yield: 2.1 g; TLC 
(Silica gel: hexane/ethylacetate=2:1, Rf 0.57). The product was then 
dissolved in 20 .mu.l EtOH to which 150 mg of 10% Pd-C was added. 
Hydrogenation was carried out under 30 psi for 51/2 hours. The mixture was 
filtered through celite pad, washed with alcohol and the filtrate was 
concentrated in vacuo to a dryness. Yield: 2.1 g colorless solid. 1.4 g of 
the colorless solid was suspended in 20 ml methanol and, upon addition of 
6 ml 2N-NaOH, stirred at room temperature for 1 hour. After evaporation of 
solvent, aqueous layer was acidified to pH 2-3, extracted with 
ethylacetate, and dried (MgSO.sub.4). Solvent was evaporated in vacuo to a 
dryness. Yield: 1.23 g colorless solid; TLC (Silica gel: CHCl.sub.3 
/MeOH/HoAC 9:1:0.1, Rf 0.62). 
Tyrosyl-D-alanyl-glycyl-AHPPA amide was synthesized as follows. Boc-AHPPA 
was first incorporated on 4-methylbenzhydrylamine resin. 1.0 g (0.64 
mmole) 4-methylbenzhydrylamine-polystyrene resin (Bachem, Inc.) in the 
chloride ion form was placed in the reaction vessel of an Advanced 
ChemTech 200 peptide synthesizer programmed to perform the following 
reaction cycle: (a) methylene chloride; (b) 10% triethylamine in 
chloroform; (c) methylene chloride; and (d) dimethylformamide. The 
neutralized resin was mixed for 18 hours with the preformed active ester 
made from Boc AHPPA (1.92 mmole), diisopropyl carbodiimide (1.92 mmole), 
and hydroxybenzotriazole hydrate (1.92 mmole) in dimethylformamide in an 
ice bath for 1 hour. The resulting amino acid resin was washed on the 
synthesizer with dimethylformamide followed by methylene chloride. 
Acetylation of any free amino group of the resin was performed by mixing 
the amino acid resin for 15 minutes with N-acetyl imidazole (5 mmole) in 
methylene chloride. 
The remaining amino acids were coupled as follows. The peptide synthesizer 
was programmed to perform the following reaction cycle: (a) methylene 
chloride; (b) 33% trifluoroacetic acid ("TFA") in methylene chloride 2 
times (5 min. and 25 min. each); (c) methylene chloride; (d) isopropyl 
alcohol; (e) 10% triethylamine in chloroform; and (f) methylene chloride. 
The following amino acid (e.g. Boc-glycine) and diisopropyl carbodiimide 
(3 eq. each) in methylene chloride were mixed for 2 hours and the 
resulting amino acid resin was then cycled through steps (a) to (f) in the 
above procedure. The next following Boc-amino acids (Boc-D-alanine, 
Boc-tyrosine) (3 eq. each) were coupled successively following the same 
procedure. After drying, the resin (1.3 g) was mixed with anisole (5 ml), 
dithiothreitol (200 mg) and anhydrous hydrogen fluoride (35 ml) at 
0.degree. C. for 45 minutes. Excess hydrogen fluoride was evaporated 
rapidly under a stream of dry nitrogen and the free peptide was 
precipitated and washed with ether. The crude peptide was then dissolved 
in a minimum volume of 1M acetic acid and applied to Vydac C18 column 
(2.54 cm I.D..times.35 cm). The peptide was eluted with a gradient 
(20%-80%) of 50/50 0.1% trifluoroacetic acid/acetonitrile in 0.1% 
trifluoroacetic acid in water. Fractions were examined by analytical HPLC. 
Most of the solvent was removed in vacuo to yield a small volume, and 
thereafter the product lyophilized. Yield: 24 mg colorless solid. 
Tyrosyl-D-arginyl-glycyl-phenylalanyl-.psi.(CH.sub.2 NH)-leucine amide was 
synthesized as follows. The procedure is essentially as described above 
except for the following reductive alkylation step. Boc-phenylalanine 
aldehyde (2.5 eq), prepared by the method of Pehrentz and Castro, 
Synthesis, p. 676 (1983), hereby incorporated by reference, was first 
dissolved in 5 ml of dry DMF and then added to the suspension of TFA salt 
of leucine resin in DMF containing 1% acetic acid, followed by the 
portion-wise addition of sodium cyanoborohydride (4 eq) over 40 minutes. 
After stirring for 1 hour, the resin mixture was found to be negative to 
ninhydrin reaction. 
Other compounds can be prepared in one or more of the manners described 
above and screened for effectiveness following procedures set forth below. 
Both the synthetic and screening methods are well known to a person of 
ordinary skill in the art. 
Activity 
(1) In vitro inhibition of radioligand to opioid receptors 
The ability of various opioid peptides of the present invention to 
selectively inhibit binding of .mu. receptor ligand to .mu. receptor is 
shown in Table 2. 
TABLE 2 
______________________________________ 
IN VITRO RECEPTOR BINDING-Ki (nM) 
.mu. 
RECEPTOR .delta. RECEPTOR 
.kappa. RECEPTOR 
CODE DAGO DPPE U69,593 
______________________________________ 
BIM-38052 
0.19 .+-. 0.03 
27.17 .+-. 
3.23 241.67 .+-. 
10.93 
BIM-38031 
0.65 .+-. 0.05 
12.60 .+-. 
2.52 205.00 
BIM-38020 
1.18 .+-. 0.09 
1014.00 .+-. 
420.00 
319.75 .+-. 
9.92 
BIM-38007 
1.36 .+-. 0.28 
129.67 .+-. 
108.72 
524.67 .+-. 
23.25 
BIM-38039 
1.48 .+-. 0.24 
297.00 .+-. 
52.60 3763.33 .+-. 
728.28 
BIM-38012 
2.57 .+-. 0.30 
540.00 .+-. 
432.24 
369.00 .+-. 
42.75 
BIM-38009 
2.92 .+-. 0.69 
14482.00 3258.33 .+-. 
165.30 
BIM-38046 
2.92 .+-. 1.12 
72.65 .+-. 
2.59 849.00 
BIM-38040 
3.97 .+-. 0.67 
1440.33 .+-. 
368.08 
1413.61 .+-. 
201.26 
BIM-38013 
4.01 .+-. 0.48 
161.50 .+-. 
450 192.00 .+-. 
27.71 
BIM-38026 
4.27 .+-. 0.46 
225.00 .+-. 
72.00 2755.00 .+-. 
2246.00 
BIM-38023 
4.73 .+-. 1.55 
413.50 .+-. 
215.50 
5201.33 .+-. 
2241.98 
______________________________________ 
The following procedure was used to determine the ability of various opioid 
peptides to inhibit binding at opioid receptors. Crude membranes were 
prepared by homogenization of guinea-pig or rat forebrain samples in 20 ml 
of ice-cold 50 mM Tris-HCl with a Brinkman Polytron (setting 6, 15 sec.). 
Buffer was added to obtain a final volume of 40 ml, and the homogenate 
centrifuged in a Sorval SS-34 rotor at 39,000 g for 10 min. at 
0.degree.-4.degree. C. The resulting supernatant was decanted and 
discarded. The pellet was rehomogenized in ice-cold buffer, pre-incubated 
at 37.degree. C. for 45 min., diluted, and centrifuged as before. The 
final pellet was resuspended in 50 mM Tris HCl and held on ice for the 
receptor binding assay. 
Aliquots of the washed membrane preparation (described above) were 
incubated in 50 mM Tris HCl at a total volume of 2.0 ml at 25.degree. C. 
with an opioid receptor ligand (see below) and various concentrations of 
the unlabeled test compounds. Mu and kappa receptor assays were incubated 
for 60 minutes. Delta receptor assays were incubated for 40 minutes. At 
the end of the incubation periods, the assays were terminated by rapid 
filtration though Whatman GF/B glass fiber filters, and the bound 
radioactivity trapped on the filters counted by liquid scintillation 
spectrometry. For each of the three receptor subtypes, specific binding 
was calculated as the total radioligand bound minus that bound in the 
presence of 1000 nM levallorphan. 
Three radiolabeled opioid receptor ligands, DAGO, DPPE, and U69,593, were 
used in .mu. receptor, 6 receptor and .kappa. receptor assays, 
respectively. The structures of the ligands are as follows. 
DAGO: Tyr-D-Met-Gly-Me-Phe-NH-CH.sub.2 -CH.sub.2 -OH; 
DPPE: Tyr-D-Peniciliamine-Gly-Phe-D-Peniciliamine (cyclized); and 
U69,953: 
(5,7,8)-(-)-N-methyl-N-(7-(1-pyrrolidinyl)-1-oxaspiro-(4,5)dec-8-yl)-benze 
neacetamide. 
Inhibition constants ("Ki") were calculated from the equation Ki-IC.sub.50 
/(1+L/Kd), where L is the radioligand concentration and Kd is the 
equilibrium dissociation constant for the radioligand. The IC.sub.50 was 
derived from the inhibition data by linear least squares regression of log 
(B/Bt-B) versus log I, where I is the test compound concentration, Bt is 
the total amount of radioligand specifically bound, and B is the amount of 
specific binding in the presence of a given concentration of the unlabeled 
peptide. The IC.sub.50 is the antilog of log I, when the expression, log 
(B/Bt-B) equals zero. 
The structures of the test compounds are as follows. 
BIM-38052: tyrosyl-D-arginyl-glycyl-APP amide 
BIM-38031: tyrosyl-D-alanyl-glycyl-App amide 
BIM-38020: tyrosyl-D-arginyl-glycyl-PEG amide 
BIM-38007: tyrosyl-D-alanyl-glycyl-AHPPA amide 
BIM-38039: tyrosyl-D-alanyl-glycyl-PEG-methionine amide 
BIM-38012: tyrosyl-D-alanyl-glycyl-ACHPA amide 
BIM-38009: tyrosyl-D-alanyl-glycyl-PEG amide 
BIM-38046: tyrosyl-D-alanyl-glycyl-homophenylalanine amide 
BIM-38040: tyrosyl-D-alanyl-glycyl-PEG methioninol 
BIM-38013: tyrosyl-D-arginyl-glycyl-phenylalanyl-.psi.-(CH.sub.2 
NH)-leucine amide 
BIM-38026: tyrosyl-D-alanyl-glycyl-.psi.(CH.sub.2 NH)-phenylalanine 
propylamide 
BIM-38023: tyrosyl-D-alanyl-glycyl-.psi.(CH.sub.2 NH)-phenylalanine 
ethylamide 
(2) Sodium ions discriminate opioid agonist/antagonist properties 
NaCl decreases the potency of opioid agonists (i.e., morphine) and has no 
effect on the potency of oipoid antagonists (i.e., naloxone). Several 
tested opioid peptides of the invention all showed some degree of agonist 
property, as evidenced by a decreased potency in the presence of NaCl. See 
Table 3 below. 
TABLE 3 
______________________________________ 
The Effect of Sodium Ion on the Binding to 
Mu Opiate Receptors In Vitro 
Ki (nM) 
-NaCl +NaCl* -NaCl/+NaCl 
______________________________________ 
BIM-38007 4.0 .+-. 0.6(3) 
13 .+-. 4.0(2) 
3.3 
BIM-38009 6.9 .+-. 3.6(3) 
68 .+-. 8.5(2) 
9.9 
BIM-38005 19 .+-. 3.6(5) 
145 .+-. 14(3) 
7.6 
Morphine 3.6 140 39 
[D-Ala.sup.2, D-Leu.sup.3 ] 
15 560 37 
enkephalin 
naloxone 0.9 0.7 0.8 
______________________________________ 
*100 mM 
The binding experiments described in Table 3 were performed as described 
above, except for the presence of 100 mMNaCl. 
(3) In Vivo Growth Inhibition of Melanomas by Opioid Peptide 
As shown in Table 4, administration of two opioid peptides (BIM-38007 and 
BIM-38009, see above for structures) inhibited the growth of B16-F10 
melanomas in in vivo animal experiments. In these experiments, tumors were 
induced in BALB/c athymic nude mice. 50 .mu.g of peptide in 0.2 ml of 
saline was injected subcutaneously twice a day on days 1-5, 6-days 
Subrenal Capsule Assay ("SRCA"). 
Control animals received 0.2 ml of saline subcutaneously twice daily on 
days 1-5. Mice were sacrificed on day 6 and tumor size determined by a 
microscope. The results are reported as the change in tumor size from day 
0 (time of tumor implantation) to day 6 (time of assay termination). 
TABLE 4 
______________________________________ 
Effect of Opioid Peptides on Tumor Size 
B-16 Melanoma 
Change In % 
Group No. 
Treatment Tumor Sixe (omu) 
T/C 
______________________________________ 
1 Vehicle Treated Control 
21.3 .+-. 3.3 
-- 
2 BIM-38007 18.1 .+-. 2.0 
85 
3 BIM-38009 14.7 .+-. 3.1 
69 
______________________________________ 
omu = ocular micrometer unit, 1.0 mm = 10 omu; 
% T/C = omu experimental/omu control 
Table 5 compares the antitumor activity of an opioid BIM-38009 versus 
methadone. A subcutaneous tumor assay was used in which xenografts of the 
human non-small cell lung cancer were implanted s.c. in athymic nude mice. 
Test compounds were administered s.c. or i.p., twice daily, from day 4 
post tumor implantation to day 35. The results are reported as 
means.+-.s.e.m. on 8 animals per group. For structure of BIM-38009, see 
above. 
TABLE 5 
______________________________________ 
Antitumor Activity of BIM-38009: Human NSLC A549 
Tumor Weight (mg) 
& 
Group No. 
Treatment (Day 34) T/C 
______________________________________ 
1 Saline Vehicle Treated 
305 .+-. 60 -- 
control, 0.2 ml/inj., 
s.c., b.i.d, q.d. 4-35 
2* BIM-38009, 500 .mu.g/inj., 
134 .+-. 36 44 
s.c., b.i.d., q.d., 
4-35 
3 Methadone, 10 mg/kg/inj., 
337 .+-. 57 110 
i.p., q.d. 4-35 
______________________________________ 
*Significance of difference from control: p &lt; 0.01 
OTHER EMBODIMENTS 
The foregoing description has been limited to specific embodiments of this 
invention. It will be apparent, however, that variations and modifications 
may be made to the invention, with the attainment of some or all of the 
advantages of the invention. Such embodiments are also within the scope of 
the following claims.