522 



5. QUINONES 



tent as some naphtho- and anthraquinones. In fact, 9,10-anthraqiiinone 

 is not antimitotic, whereas 1,2-anthraquinone is quite potent, indicating 

 that neither the quinone structure nor a polycyclic system is sufficient 

 for activity. It is also remarkable that the addition of a ring onto 1,2- 

 anthraquinone to form 5,6-benzanthraquinone increases the antimitotic 



Colchicine 

 (0.083) 



Diethylstilbeslrol 

 ( 0.0074 ) 



,2 " Anfhraquinone 

 (0.00048) 



9,10 " Anthraqulnone 



1,4 "Naphthoquinone 

 (0.00063) 



c§ 



p-Benzoquinone 

 (0.00046) 



9,10- Phenonthra- 

 quinone 

 ( 0.0002 ) 







5,6-Benzanfhra- 

 quinone 

 (0.000013) 



Limit of solubility. 



Concentration (mM) *- 



Fig. 5-7. Effects of various quinones on the cleavage of Tubifex 

 eggs. The ranges of effects are indicated as follows: diagonally 

 lined area — development disturbed; clear area — mitosis 

 inhibited; and black areas — cytolysis produced. The figures 

 give the minimal antimitotic concentrations (mM). (From 

 Lehmann, 1947.) 



