462 
A  New  Base  in  Tea. 
Am.  Jour.  Pharm. 
Sept.,  1888. 
small  quantity  of  xanthine  was  deposited  from  the  clear  filtrate/  and 
upon  concentrating  the  liquid  the  new  base  partly  crystallized  out. 
The  mother-liquor  was  then  mixed  with  mercuric  nitrate  solution,  the 
precipitate  collected  by  filtration,  and  the  filtrate  made  alkaline  with 
sodic  carbonate  solution.  A  white  precipitate  was  thus  obtained  in 
both  cases,  which  consisted  almost  entirely  of  a  mercury  compound  of 
the  base. 
Analysis  of  the  new  base,  for  which  I  suggest  the  name  "  the- 
ophylline,'^ gave  the  following  results  : 
Calculated  for 
C  .  .  46-55  46-63  —  46-67 
H  .  .  4-70  4-77  —  4-44 
N    .    .       —  —      31-66  31-11 
The  crystals  contain  one  molecule  of  water,  which  is  given  off  by 
h-ating  to  110°  C. 
The  composition  of  theophylline  is  the  same  as  that  of  theobromine, 
as  well  as  that  of  paraxanthine  obtained  by  Thudichum  and  Salomon 
from  urine,  but  the  characters  of  the  base  are  different  from  those  of 
either  substance.  The  crystals  are  larger  than  those  of  theo- 
bromine, and  the  latter  do  not  contain  water.  Theophylline  is 
much  more  soluble  in  water  than  theobromine,  and  on  the  addition  of 
a  very  small  quantity  of  ammonia  it  dissolves  very  readily  apparently 
in  any  proportion,  while  theobromine  is  but  sparingly  soluble  in 
strongly  ammoniacal  water.  The  crystals  of  paraxanthine  have  been 
examined  by  Arzruni,  and  Dr.  Scheibe  has  compared  the  crystals  of 
theophylline  with  his  description,  with  the  result  that  they  do  not 
correspond.  The  melting  point  of  theophylline  is  about  264°  C, 
while  that  of  paraxanthine  obtained  from  Dr.  Salomon  is  280°. 
^The  occurrence  of  xanthine  in  tea  was  ascertained  some  four  years  ago 
by  Dr.  Adolph  Baginsky,  who  undertook  the  search  for  it  at  the  suggestion  of 
Dr.  Kossel  {Zeits.  f.  Physiol.  Chemie,  viii.,  395).  For  that  purpose  tea  was 
extracted  with  dilute  sulphuric  acid,  the  clear  liquor  mixed  with  excess  of 
baryta  water  and  then  treated  with  carbonic  acid  to  remove  the  excess  of 
baryta.  After  filtering  and  evaporating,  ammonia  and  silver  nitrate  were 
added,  and  the  precipitate  of  xanthine  silver  thus  obtained,  crystallized 
from  solution  in  dilute  nitric  acid  mixed  with  some  urea.  This  salt  con- 
tained 33-6  per  cent,  of  silver,  very  nearly  the  amount  required  by  the 
formula  CjH^Np.^AgNOg.  The  quantity  of  the  silver  compound  obtained 
from  one  pound  of  tea  was  only  01567  gram. — Ed.  Pharm.  Journ. 
