l-iilkyl-l-(Z-inercap Loethy1)guanidines aiicl lhe Corresyoiicliiig 'l'hiouveas, Disulfides, and ThiosulfaLes a b AnLibacterial AgenLs'
A iiew class of ailtibacterial ageill has beeii foruid, Iiiivii~gg ( ~ ( ~i t (t lu i i r o :tclivit>.:igaiii-t S'frep,(or.or.ccrsp ! p :~iidStuphylococcus uureus. Certain compounds possess iri vizw activity i The preparation arid antibacterial activity of tin iiit'errelated series coii 1hioiuea dihydrobromides (Y),I-alk~l-l-(~-merc:tptoet tiy1,iguaiiidine salt,.;( thiosulfates (IV) are reported.
Xlercaptoethyla~iiiiie has beeii v a r i o u d ~ +uhsti t u t cd hy ninny workers in attempts to develop :L useful antiradiation agent.2 In the present study 5onie ne11 dcrivativcs of mercapt oethylainiiic have uiicxpectcdly been found effective against the rnicroorgariisms S t i eptococcus pyogenes and Staphylocowus aweus. Structures which have stimulated much intei'est 212 :mt iradiation agents :ire S-'-(all;ylamino)et~i~ 1 thiobidfates (I)?and analogs of l-(~-niercaptoethyl)gu:liiidirie (I I ) . 4 T,ol~g-chain allq 1 derivative. of t > p e 111
xrr I' II,?;('NI€CIILC'If~SII. 11-1 I1
I im I CII,CI rzssoaFi I SI1
5-11
t'w 1)reparecl (C'hart I) eitlier b> i.earrairgc~riit,~il I is~~thiouro~iiurii halt< (Table 111) or by rcxtioti' of L'-nieth\ 1-2-thiourc:i 1~rn1isulf:it~ 11Ith iuitablr 2-alLj 1:rinirioet hniiethiolh. The p i c t iral sucreis of t h c method involving L'-nieth>1-2-thioure:t appeared t i ) clcpentl o n the drgrec of in5olu~~ilit\ of I11 in the rcwtioir mcdiuni. .I purc protlwt n a b readil). iwlatcd uheii :-I solid appenred inimediatel> oil mixing the t u o Ic1:ict:iint s i l l cth:iiiol solution. Wlmi a d i d did i i o t ininiediately appear, oily mixtures \-,ere obtained \z hich \\ rie clifirult to purify. Oxidation and substitution of tlic thiol are hide reactions \-,hich probably occurred. l'lic hubstitutctl niercapto~th> lguariidines 111 \\ crc' I)urti:illy oxidized by air t o the rorrespoIiding disulfides jcrucle) (('hart 11) and further oxidized by minioniuni iiilfitc iii thc ~ I C W I I W of air t o tliio\ulf:ite w t t m ITr. ( 1 1 i i ~M
of
(qH\tcl
I!
sI1
1Y
(Table I) have iiot been reported, dtliough conipcmid2 possessing R groups as large as isopropyl are known.5 In the case of IV (Table 11),only the unsubstituted, parent S-"( 1-guanidino)ethyl thiosulfate has been reported.6 l-Aill;yl derivatives I11 of 1-(2--mercaptoethyl)guaiiiC H 1111'
0
I11
--f
5-11
.1
l ~ *I' x ~ ~ C I I ~ c1 1 ~sl * s I l ' Ii 111
(1) This invrstigat,ion was bupported i n p a r t h y tlie U. 6 . l i r i i i y I I d i v a I Research and Development Command, Contract Xo. 1):\-4Y-l!J:i-~\IL)-2:i06. \Ye appreciat,e the interest and s u p p o r t of I h . D. 1'. Jacobus and T. R . Sweeney of \!'alter Reed Army Institute of Research. (2) F o r leading references see 1%'. 0. Foye in ".'innual Reports in N e & cinal Chemistry, 1965," C. K. Cain, Ed., Academic Press Inc.. Y e n Tork, N. Y . , 1966, Chapter 30. ( 3 ) 11. L. Klayman and IT. F. Gilmore. J . Med. Chem., 7, 823 (1964). (4) J. X. K h y m , D. G. Doherty, and R. Shapira, J . iim. Chem. Soc., 80, :3342 (1958). These agents generally are formulated as thiogseudoureas which readily rearrange under very slightly basic conditions t o giye mrrcaptoethylguanidines. ( 5 ) R. Shapira, D. G. Dohertp, and JV. T.Burnett, /i'urliatzo7~Hes.. 7 , 2 2 t
1STri).
~
~
~
~
~
~
~
~
~
l
,
~
l
I: Nll
1
+ II~NCSCII,.(~.;,~-I,SO,
I
11
1I
Sir
IC""~SII
11
I\
Biological Activity (Table IV) .*-E'er tlic 1-alkyl derivatives of l-(2-inercaptoetliyl)gua~iidirie(HI),higlt('st in vitro activity against S . pyogenes tii id A'. aureiib \vas found where the alkyl group was hexyl, heptyl, octyl, 2-ethylhexyl, and nonyl. The antibacterial activity was found t o diminish with either longer or shorter alkyl groups. The most active conipourid i i i the series n7as the 2-ethylhexjl derivative. For tlic S-2-( 1-alky1guanidino)ethyl thiosulfates (IT). opt iniuin tictivity 11 :L\ found with hepta 1, octyl, no11>,1,nnd c k c > I alkyl substituents. Pome of the compound. exhibited in u i t i o act i\ i t J against other bacterin. C'ompound 9 ( 2 - ~ t hlhex> \ 1 derivative of 111) had the broadest antibxtcrinl s p c ~ t ruin, giving complete inhibition of the growth oi S . C L U I - ~ U S. S , pyogenes, Salmonella typhitriun'uiii, K l d siella pneuitioniae, Escherichia coli, Dip1ococcu.c ptzcu(ti) .\. Kaluuzyner, Buli. I d b s t r . , 65, 3427 (1961). ( 7 ) Dr. T . R. S u e e n e r , v e r m i i a l ~.oiiiiiiuuioatitir1.1Uti.i. (8) k'or t h e general i n iwtro and i n v i u o test yrocwiurea scc 31. L\. 11. C. Manning, I.. A . Gagliardi, SI. R . Qaetz, and A . L. Erlauilson in biotics Annual l9*5!J-I980," .\nlii>iotica, Inc., N e w Y o r k , N. J.., 1!460, p i > 2YX303.
~
~
~
Sumun
DERIVATIVES AS , ~ T I B A C T E R I A LAGEXTS TABLEI
(111)
1-.kLKYb1-(2-MERC.4PTOETHYL)GUANIDINES
NH
I
R
--
Yield, No. 4 5 6 7 8 9 10 11 12
R
70
hIp, o c
CHs(CHd3 CHs(CH2)s CHa(CHz)6 CHa(CH47 CHa(CHd7 CH3(CHdaCH(C2Hs)CHz CHa(CHd8 CHa(CHds CHa(CHz)ii
43 45 92 56 77 31 23 60 64
213-215 208-210 204-207 195 102-104 106-109 198-201 202-204 119-123
C 37.46 42 99 45 08 47.11 42 30 42 30 48 93 60.61 48.89
+
d, %-
-Calc H
8 09 8.42 9 08 9 34 8 39 8 39 9 59 9 81 9.30
-Found, %-H N 7.76 18.90 8.69 16.51 9.01 15.71 9 . 2 1 14.99 8.18 13.41 8.26 13.40 9.60 14.15 9 . 7 6 13.43 9.03 11.35
7 7---
N
SH
C
18.74 16.72 15.77 14,98 13.46 13.46 14 27 13.61 11.41
14.75 13.16 12.41 11.81 10.60 10.60 11.23 10.73 8.iO
37.19 42.85 44.92 47.40 42.00 42,44 49.26 50.75 48.65
SHb
15.15 12.43 12.11 11.90 10.09 10.04 10.19 9.78 8.96
+
* Iodine titration; for a similar assay " A, RNHCH2CHXSH H2KkSCH,.0.5H,S04; B, R S H C H Z C H ~ S & N H ~ . ~ HNaOH. B~ see J. W. Kimball, R. L. Kramer, and E. E. Reid, J . Am. Chem. SOC.,43, 1199 (1921). It is apparent that the corresponding disulfide was present in some samples as a minor component'. Occasionally repeated recrystallization served only to increase the disulfide conFor the 2-(alkylamino)ethanet~hiol,see D. D. Reynolds, 1). L. Fields, and D. L. Johnson, J . Org. Chem., 26, 5125 (1961). d For tent. the 2-(alkylamino jethanethiol, see ref 13. TABLE I1 S-2-(1-AkLKYLGUANIDINO)ETHYLTHIOSULFATES (Iv)
NH
e
HZK NCHzCH2SS03H
I
R %
Mp, o c
C
H
N
S
C
-Found, H
70-
NO.
1 :3 14 15 16
20 53 20 69 72 75 69
197-200 202-205 175-173 128-130 149-152 1.52-154 123-126
32.92 38.13 40.38 42.41 44.31 45.99 49.01
6.71 7.47 7.i9 8.09 8.36 8.61 9.05
16.46 14.83 14.13 13.49 12.91 12.38 11.43
25.11 22.63 21.56 20.59 19.10 18.89 17.45
33.20 38.37 40.65 42.65 44.59 46.05 49.32
6.60 7.42 7.62 7.89 8.31 8.50 9.03
16.59 14.82 14.16 13.20 13.08 12.12 11.55
Calcd. 5%
Yield,
17 18 19
7
N
S
24.92 22.38 21.31 20.48 19.37 18.60 17.20
TABLE I11 ~-[~-(ALKYL.~~~Ih.O)ETHYL]-2-THIOUREA DIHYDROHROYIDES (y)
NH RNHCH,CH,S&NH,. 2HBra Yield,
No.
R
1 2
CHa(CH2h CH3(CH&yHCH2
70 80 81
XIp,
o c
Formula
-Calcd, C
%H
%--
N
S
-----Found, C
H
108-110 165-168
CllH2bN3S.2HBr 33.60 6.93 CllH25X3S.2HBr 33.60 6.93
10.69 10.69
8.16 8.16
33.63 33.89
6.64 6.87
250-252
C1~H33X3S.2HBr 40.00 7.83
9.33
7.12
40.00
7.40
N
S
10.68 8.18 10.56 8.33
I
C2Hs cH~(CH2)ii 3 RNHCHzCH2Br.HBr
r.
ia
+ H,NCSNH,.
moniae, and Shigella sonni and partial inhibition of Pseudonzonas aeruginosa and Mycobacterium tuberculosis. Compounds were tested against X. aureus in mice by oral and by subcutaneous administration. General in civo activity was demonstrated, but dose levels required were very close to toxic limits. A minimumprotective dose of 12.5 mg/lig given as a single subcutaneous injection was found for 1, 5, 6, 17, and 18. Similarly, the minimum protective dose was 10 mg/kg for 10 and 50 mg/kg for 15. Compound 7 was tested in mice (subcutaneous injection) ngnirist S . aureus. It exhibited a protective effect at 8.1 mg/kg.
Experimental Section9 2 4 0ctylamino)ethyl Bromide Hydrobromide.-To 900 g of 4870 HBr was added 232 g (1.34 moles) of 2-(octylamino)-
9.45
7.29
ethano1,lO and the resulting solution was heated under reflux for 2 hr. Approximately 250 ml of solvent was removed by distillation, and the remaining solution was again heated under reflux for 2 hr. The distillation of 250 ml of solvent and heating under reflux for 2 hr were repeated once more, and the solution was cooled and diluted with about 200 ml of EtPO. The solid 2(octy1amino)ethyl bromide hydrobromide was isolated and recrystallized from l\leOH-Et20 to give 180 g (42%) of product, mp 212-215'. Anal. Calcd for CloH22BrN.HBr: C, 37.88; H, 7.31; N, 4.42. Found: C, 37.83; H, 7.23; X, 4.5:. 2-(2-Ethylhexy1amino)ethyl Bromide Hydrobromide.-From 82 g (0.47 mole) of 2-(2-ethylhexylamino)ethano110 and 450 g of 4870 IIBr was obtained 12 g ( 8 % ) of pure product, mp 167168" (in addition l o crops of less pure material) in a manner identical with l.hat, used for "-(oct~l:triiiiio)ethq.lbromide hydrohromide wbove. (9) Melting points, determined using a Thomas-IIoorer melting point apparatus, are uncorrected. (10) J. R. Reasenberg and S. D. Goldberg, J. Am. Chem. Soc., 67, 933 (1945).
.lttd, Calcd for ClnlinnBrS.HBr:(7, ::;.8h: 11, 7.:31: S , 1.12. F o ~ u i d :C, 38.l'i; ET, 7.24; ?;, 4.41. 2 4 Dodecy1amino)ethyl bromide hydrobromide \vas pi,epared iii 27' ;. yield from ~-(dodecyl:imitio)eth:~iiol" i i i R maiiiier bromide hydroiclcilt i d nith that iihed for ~-(ociyl:iniiiici)etli~l
TZU^. C d d for C ~ ~ H ~ ~ B I . S . I c', I B I45.05; : [I, 3 . i 6 , Finuid: C, 43.3,j; H, 8.1:3:S , :3.%0.
s,
2-12-(Octylamino)ethyl]-2-thioureaDihydrobromidelY [ 1 ).-TI) 24 g (,O,:;lmole) of thiourea in 123 nil of i-PrOH heated t o .jOo w:i3 :idtieti 100 g (0,:3I inole) of 2-(oct!-laniiiio)eth!-l bromide liytli~i~~~riiniitle, u i t i the resultiiig riiisiui.e w:is heated uiidei.
