Ethoxyquinolin and Chitenin 403 



A few loopfuls of pneumococcus suspension were added to the 

 solution of the substance in 0.9 per cent. NaCl, and after the de- 

 sired interval transpired to rabbit blood agar plates and incu- 

 bated 24 hours. We find that, like the aromatic compounds, 

 there is practically no difference in the action of the two com- 

 pounds upon the pneumococcus. A ten-minute exposure to 

 1/5000 solution in 0.9 NaCl kills the cocci. The streptococcus 

 is less sensitive requiring a 1/1000 solution, but no difference 

 is observable between the two compounds. 



An attempt was made to produce a quinine derivative having 

 a toxicitiy less than quinine. Chitenin, which differs from 

 quinine in having a — COOH group in place of the vinyl 

 — CH=CH 2 group in the side chain was prepared by oxidizing 

 quinine according to the method of Skraup. 3 We have found 

 that this substance is from three to four times less toxic than 

 quinine on subcutaneous injection (minimum lethal dose of 

 Chitenin=2.2 G to 4.2 G per Kg. rat; minimum lethal dose of 

 quinine=0.7 G per Kg. rat). 



The antiseptic actions of ethylhydrocuprein, quinine and 

 Chitenin are shown in the following table : 



TABLE 



+ = growth 



— = 110 growth Pneumococcus (3 separate tests made) 



Ethylhydrocuprein, HCL 1 — — 1 — 



sol. 5 min. -j- 10 min. sol. 5 min. — 



10,000 — — 5000 — 



Quinine. HCL „. 1 — — 1 — 



sol. 5 min. + 10 mm. sol. 5 min. — 



1000 + — 500 — 



Chitenin, HCL 1 + + + 



sol. 5 min. + 10 min. — 1% sol. 5 min. -f- 



200 + — — 



+ 



10 miu. — 



Chitenin, Na salt 1 



sol. 10 min. + 30 min. + 



500 + — 



H acid 1 1 



sol. 5 min. — : 30 min. + (24 hrs. — ) 



500 — 1000 



Streptococcus 



Ethylhydrocuprein, HCL 1 — — 1 4- 



5 min. 4- 10 min. — ; 5 min. -f- 



3000 ++ — 2000 + 



+ 1 + + 



10 min. -j-j 10 min. H 



— 5000 4- 



3 Skraup, Zd., Annalen der Chemie, 1879, cxcix, 344. 



