Maleic Hydrazide (MH) [6-hydroxy-3{2H) pyridazinone ] 
Ultraviolet studies indicated that maleic hydrazide exists as the 
hydroxy pyridazinone (1008). 
c14_MH was administered orally to rats. After three days, very little 
cl4-activity was detected in tissues or blood and CO, accounted for only 0.2% 
of the administered dose. MH was rapidly excreted via the urine unchanged 
(>90%) and as a conjugate (6-82) (948). 
When applied to tea, Camellia sinensis, MH was degraded to lactic acid, 
succinic acid, maleimide and hydrazine (1552). Extracts of treated wheat 
seedlings exhibited two spots on chromatograms, one of which was identified as 
a beta-glycoside of MH. In other studies with c!4-1abeled maleic hydrazide 
and glucose, only B-glucoside was demonstrated (1420, 1484, 1672). 
In the presence of oxygen, MH undergoes photolysis to form succinic, 
maleic and nitric acid; and in the absence of oxygen, to form succinic acid 
(1552). 
Alcaligenes faecalis and Flavobacterium diffusum were isolated from 
Sugar can soil in which the diethanolamine salt of MH was utilized (860). 
B-Glucoside 
Glucose 
Lactic Acid 
OH Hydrazine 
Maleimide 
| | Succinic Acid 
N Maéic Acid ~~ 
{| 
0 Nitrie Acid 
Maleic Hydrazide 
236 
