478 
Peptone  Salts  from  Glutin. 
(  Am.  Jour.  Pharm, 
t       Sept.,  1892. 
PEPTONE  SALTS  FROM  GLUTIN.1 
By  C.  Paal. 
Mineral  acids  act  on  glutin  in  a  similar  manner  to  pepsin  and 
trypsin,  yielding  peptones,  which  combine  with  the  acid  present  to 
form  salts  ;  these  dissolve  not  only  in  water,  but  also,  unlike  the 
free  peptones,  in  absolute  ethyl  and  methyl  alcohol.  For  their  pre- 
paration, ioo  parts  of  purest  commercial  gelatin  are  warmed  on  the 
water-bath  with  160  parts  of  water  and  40  parts  of  concentrated 
hydrochloric  acid  until  a  portion  of  the  product  is  completely  solu- 
ble in  a  large  quantity  of  absolute  alcohol,  and  the  whole  is  then 
poured  into  4-5  vols,  of  absolute  alcohol.  After  filtering  off  the 
inorganic  salts,  the  solution  is  precipitated  with  ether,  the  residue 
redissolved  in  alcohol,  and  the  solution  evaporated  under  dimin- 
ished pressure.  The  gultin  peptone  hydrochloride  thus  obtained 
forms  a  brittle,  white,  vesicular  mass,  and  is  readily  soluble  in  water, 
methyl  alcohol,  ethyl  alcohol,  and  acetic  acid,  somewhat  less  easily 
in  propyl  alcohol,  sparingly  in  amyl  alcohol,  and  insoluble  in  ether, 
carbon  bisulphide,  and  benzene.  It  is  very  hygroscopic,  remains 
unchanged  at  1300,  and  gives  the  characteristic  peptone  reaction 
with  biuret;  it  is  laevorotatory  in  aqueous  solution  [«]D  being  about 
—  6o°.  The  quantity  of  hydrochloric  acid  found  in  the  different 
preparations  varied  from  10-5-12-5  per  cent.,  whilst  the  ash  is  only 
about  0  5  per  cent.  Jf  stronger  hydrochloric  acid  than  that  men- 
tioned above  is  employed,  or  if  the  heating  be  continued  for  a 
longer  time,  salts  containing  a  larger  percentage  of  acid  can  be 
obtained. 
The  quantity  of  carbon  and  hydrogen  varies  considerably  in  the 
different  preparations,  the  former  being  in  some  cases  higher  than 
that  of  glutin  (for  which  the  author  finds  C  =  50-1,  H  =  6  68),  and 
in  others  less ;  this  is  due  to  the  fact  that  in  most  cases  more  or 
less  etherification  has  taken  place  during  the  treatment  with  alco- 
hol ;  the  compounds  formed  may,  however,  be  hydrolyzed  by  long- 
continued  boiling  with  water.  The  salts  were  found  to  be  almost 
free  from  sulphur. 
The  fact  that  by  varying  the  strength  of  the  hydrochloric  acid, 
and  the  time  allowed  for  the  reaction,  compounds  containing  a 
varying  amount  of  acid  are  obtained,  tends  to  show  that  these  salts 
1  Berichte,  25,  1202-1236;  Jour.  Chem.  Soc,  1892,  p.  895. 
