AmxayrisP9s.arm'}    Recent  Literature  Relating  to  Pharmacy.  247 
podophyllum  acid,  C^H^O^  of  which  a  crystalline  sodium  salt  was 
obtained,  and  also  silver  and  copper  salts,  which  were  analysed. 
This  acid  very  readily  loses  water,  and  furnishes  the  crystalline 
picropodophyllin  of  Podwyssozki  and  Kursten,  which  is  isomeric  with 
podophyllotoxin.  It  passes  again  into  podophyllic  acid  when 
warmed  with  aqueous  alkalis.  It  melts  at  2270,  and  is  optically 
inactive.  Podophyllotoxin  and  picropodophyllin  furnish  identical 
decomposition  products ;  when  oxidised  with  nitric  acid,  oxalic  acid 
is  the  principal  product ;  when  fused  with  alkalis,  orcinol  and  acetic 
acid  are  produced.  Both  substances  contain  two  methoxyl  groups 
and  no  hydroxy]..  It  is  concluded  that  picropodophyllin  is  the  lac- 
tone of  podophyllic  acid,  which  is  probably  the  hydroxy-carboxylic 
acid  of  dimethoxymethyl-phenylhydro-y-pyrone. 
The  following  formulae  are  assigned  to  these  compounds  : 
OH     CO,H  .  CO, 
II  !  I 
C0<cS,ZcS>°  CO<CR~CH>° 
CH30/\OCH3  CH3O  /\OCH, 
I      J  II 
CH3  CH3 
Podophyllic  acid.  Picropodophyllin. 
The  nature  of  the  isomerism  of  podophyllotoxin  and  picropodo- 
phyllin remains  to  be  determined.  The  latter  substance  is  thera- 
peutically inert. 
The  yellow  coloring  matter  of  podophyllum,  called  by  Podwys- 
sozki podophylloquercetin,  is  proved  by  the  authors  to  be  identical 
with  quercetin,  the  valuable  yellow  coloring  matter  of  quercitron 
bark. 
An  uncrystallisable  resin,  podophylloresin,  was  also  isolated  and 
found  to  exert  a  purgative  action. 
Estimations  have  been  made  of  the  amount  of  "  podophyllin  "  (a 
mixture  of  resins  with  podophyllotoxin  which  is  used  in  medicine) 
contained  in  the  two  plants.  Indian  podophyllum  contains  from  9 
to  12  per  cent.,  and  American  from  4  to  5  per  cent.  The  two  resins 
have  been  proved  to  be  equally  valuable  therapeutic  agents.  The 
amount  of  crystalline  podophyllotoxin  in  the  Indian  plant  varies 
