Studies with rats suggested that barthrin (6-chloropiperonyl 
chrysanthemumate) was metabolized and execreted in urine as metabolites, 
free and conjugated, having a strong reducing effect on Benedict's 
reagent (19, 930). Residues from urine gave a positive test for 
chrysanthemumic acid, for methylene oxide linkage, and for glucuronic acid 
before and after hydrolysis. Tentatively, it was concluded that barthrin 
in rats was metabolized and excreted in the urine as chrysanthemumic acid 
6-chloropiperonlylic acid, and partly as the 6-chloropiperonyl glucuronide 
or glycine conjugate. Similar results were obtained with Dimethrin 
(2,4-Dimethylbenzyl chrysanthemumate) (20, 930). 
Male Wistar rats were administered phthalthrin orally and intravenously. 
Tissues, blood, feces and urine were processed and thin-layer and column 
chromatography were used to separate the metabolites. Elementary analyses, 
NMR, UV, and IR were used to identify the metabolites. Although residues 
were observed in tissues, only Cyclohexane-1,2-dicarboximide in liver was 
identified. From urine, N-Hydroxymethy1-3,4,5,6-Tetrahydrophthalimide, 
Cyclohexane-1,2-dicarboximide, 3-or-4-hydroxycyclohexane-1 ,2-dicarboximide 
and its glucuronide were obtained and identified. The major metabolite 
from in vivo and in vitro (liver homogenate) studies was N-Hydroxymethyl- 
3,4 as ,o- -Tet rahydrophthalimide (1584). 
The synergist piperonyl cyclonene inhibited the detoxification of 
pyrethrin more than that of allethrin, c-14 labeled allethrin was metabo- 
lized by flies in large part to a polar compound with the same Re as 
allethrolone (690). 
Allethrin exhibited more stability towards ultra-violet light than 
did the natural pyrethrins (119). Studies showed that pyrethrum was sensi- 
tive to ultra-violet in the range of 2200-2300 Angstroms (1054) and under- 
went some decomposition, This effect was independent of oxygen or humidity 
(117, 118). 
In light and air, pyrethrin I was inactivated by conversion to lumi- 
pyrethrin I via pyrethrin I-peroxide, Pyrethrin II was similarly affected. 
Under the influence of heat, pyrethrin I and II were converted to their 
respective isopyrethrins. These were affected by light and air in the same 
manner as pyrethrin I and II (1345). 
Isopyrethrin I Isopyrethrin II 
Pyrethrin I Pyrethrin II. 
Pyrethrin I-peroxide Pyrethrin II-peroxide 
Lumi-pyrethrin I Lumi-pyrethrin II 
34 

