Synthetic Pyrethroids

7 Insecticidal Activities of Synthetic Pyrethroids

Downloaded by UNIV OF CALIFORNIA SAN DIEGO on March 5, 2016 | http://pubs.acs.org Publication Date: June 1, 1977 | doi: 10.1021/bk-1977-0042.ch007

YOSHIYUKI INOUE, SHIGEKI OHONO, TAKAO MIZUNO, YASUO YURA, and KEISUK MURAYAMA Central Research Laboratories, Sankyo Co. Ltd., No. 2-58 Hiromachi 1-chome, Shinagawa-ku, Tokyo 140, Japan

Pyrethroids (natural and synthetic ones) are be coming increasingly important as insect control agents because they possess a unique combination of desirable properties including exceptionally good insecticidal activity, low mammalian toxicity, and rapid bio degradation. These features, c o m b i n e d with their b r o a d spectrum of insecticidal activities, h a v e made t h e m commercially successful, and also environmentally safe. There have been desired synthetic insecticide having higher toxicity on insects, lower cost, lower mammalian toxicity a n d some u n i q u e properties for actual uses. In general, the uses o f pyrethroids are mainly limited by high cost and by their instability for certain possible uses.

RESULTS AND DISCUSSION recognized by Nakada and collaborators (1) t h a t several compounds were isolated by pyrolysis of allethrin heated a t 400°C. Two of t h e compounds obtained by t h e pyrolysis were indanone derivatives as shown in Fig. 1. These indanones showed themselves weak insecticidal activities. The activity was measured by using first instar nymphs of the American cockroach as first screening insect. According to this method, each compounds dissolved in a c e t o n e were deposited into a 20 ml glass vial. After evaporating the solvent, 10 nymphs of the cockroach were introduced into the vial. Then the vial was covered with a plastic lid. Mortality of nymphs after 24 hours was measured. As shown in Fig. 2 the degree of effectiveness against nymphs of the cockroach was presented by using a mark from A to E. In the case of A, 100 per cent kill of nymphs of cockroach was obtained by using 1 ygr of the compound. These indanones obtained by pyrolysis have a It was

72

Elliott; Synthetic Pyrethroids ACS Symposium Series; American Chemical Society: Washington, DC, 1977.


7.

INOUE

E T

AL.

Insecticidal

Figure 1.

Activities

Pyrolysis of allethrin

0 Ε

Β

Degree of effectiveness A

C

Insecticidal effect 1 jjg

100 /o e

kill

Β

1 0 jjg

1 0 0 °/.

C

1 0 0 jjg

1 0 0 7o

kill kill

D

1000

jjg

1 0 0 °/o

Ε

1000

jjg

0 °/o

kill

Dose: j j g / v i a l test insect . f i r s t instar nymphs of the American cockroach. Figure 2.

Degree of effectiveness



74

SYNTHETIC

PYRETHROIDS

s t r u c t u r a l s i m i l a r i t y t o a l l e t h r o l o n e . Thus, i n d a n o l ester of crysanthemic a c i d was s y n t h e s i z e d . This c o m p o u n d d i d n ' t show i n s e c t i c i d a l a c t i v i t y . Therefore, more s i m p l i f i e d d e r i v a t i v e s w e r e s y n t h e s i z e d . As a r e s u l t , 1 - i n d a n y l c h r y s a n t h e m a t e i n d i c a t e d i n s e c t i c i d a l a c t i v i t y t h o u g h t h e a c t i v i t y was l e s s than that of a l l e t h r i n . T h e r e f o r e m o d i f i c a t i o n s o f i n d a n y l and r e l a t e d b e n z o f u r a n y l o r b e n z o t h i o p h e n y l compounds were c a r r i e d out. C h e m i c a l s t r u c t u r e and t h e i r i n s e c t i c i d a l a c t i v i t i e s a r e shown in F i g . 3. The m e t h y l g r o u p a t imp o s i t i o n was effective but benzyl or chloro s u b s t i t u ent were n o t effective. Further introduction of m e t h y l g r o u p was n o t effective. 2,3-Dihydro-7-methyl3-benzofuranyl chrysanthemate which c a l l ES-56, exhibited activity. S y n t h e t i c r o u t e o f t h e ES-56 is shown in F i g . 4. A c c o r d i n g t o o u r s y n t h e t i c r o u t e , t h e f i r s t s t e p is e t h e r f o r m a t i o n w i t h o - c r e s o l and c h l o r o a c e t i c a c i d . Conversion with t h i o n y l c h l o r i d e t o the a c i d c h l o r i d e f o l l o w e d by F r i e d e l - C r a f t c y c l i z a t i o n w i t h a l u m i n i u m c h l o r i d e gave 7 - m e t h y l - 2 , 3 - d i h y d r o b e n z o f u r a n o n e . Reduction o f the ketone leads t o 7-methyl-2,3-dihydrobenzofuranol . E s t e r i f i c a t i o n o f the benzofuranol with c h r y s a n t h e m i c a c i d c h l o r i d e r e s u l t s in f i n a l p r o d u c t . The a c t i v i t i e s o f ES-5 6 w e r e c o m p a r e d w i t h known pyrethroids. Insecticidal a c t i v i t i e s of pyrethroids against nymphs o f t h e c o c k r o a c h a n d t e r m i t e a r e shown in T a b l e 1. U s i n g d r y f i l m m e t h o d , 0.1 y g r o f p e r m e t h r i n killed 10% o f c o c k r o a c h o r 8 5% o f t e r m i t e . P e r m e t h r i n was most effective. The a m o u n t o f 0.1 y g r o f d - t r a n s o f ES-56 k i l l e d 20 p e r c e n t o f c o c k r o a c h . T a b l e 2 shows t h e r e s u l t o f i n s e c t i c i d a l a c t i v i t y o f p y r e t h r o i d s a g a i n s t common h o u s e f l y b y t o p i c a l a p p l i c a t i o n method. LD o f ES-56 was 0.41 y g r p e r f l y . d - t r a n s P h e n o t h r i n a n d r e s m e t h r i n s h o w e d h i g h e r insecticidal activity. T a b l e 3 shows t h a t t h e i n s e c t i c i d a l a c t i v i t y o f p y r e t h r o i d s a g a i n s t t h r e e s p e c i e s o f c o c k r o a c h was examined by t o p i c a l a p p l i c a t i o n method. Only d - t r a n s p h e n o t h r i n a n d r e t h m e t h r i n w e r e more effective than ES-56. The p e r s i s t e n c e o f ES-5 6 a n d r e s m e t h r i n a r e shown in T a b l e 4 u s i n g t e r m i t e , C o p t o t e r m e s f o r m o s a n u s . E a c h amount o f 0.1 mg a n d 1 mg o f p y r e t h r o i d s w e r e a d d e d in a g l a s s v i a l p r e v i o u s l y m e n t i o n e d , a n d mort a l i t y was m e a s u r e d a f t e r 1 t o 12 8 d a y s . I n the case 5 0



1. v

o f

:

:

C

Τ

( f i r s t

(Coptotermes

C o c k r o a c h

T e r m i t e

nymphs

o f

f o r m o s a n u s ) .

i n s t a r

0

85 10

100

P e r i p l a n e t a

a m e r i c a n a ) .

100

100

100

100

P e r m e t h r i n ( d l - c i s , t r a n s = 1

100

0

10

5 100 100

100

100

100

P h e n o t h r i n ( d - t r a n s )

100

30

0 100

100

100

100

100

R e s m e t h r i n

100

0

0 0

0

25

30

100

100

P h t h a l t h r i n

0 0

0

0

0 0

0

0 0

0

85

60

100

100

100

100

A l l e t h r i n

0

0 0

20

100

100

100

100

56)

100

o f

100

( t r a n s

0

τ

yg

0

353

0

0

100

100

c

100

τ

0.01

100

c

yg

100

τ

0.1

100

yg

ES-56

1

c

yg

o f

τ

10

(%)

nymphs

c

yg

a g a i n s t method.

M o r t a l i t y

d r y f i l m

p y r e t h r o i d s by

τ

100

t e r m i t e

e f f e c t

C

:1)

and

I n s e c t i c i d a l

c o c k r o a c h

P y r e t h r o i d s

T a b l e


CO

ο

S* «·».

I

et*

ο

ϊ

I

76

SYNTHETIC

Table

2. I n s e c t i c i d a l a c t i v i t y o f ES-56 a n d o t h e r P y r e t h r o i d s on t h e h o u s e f l y by t o p i c a l a p p l i c a t i o n method. LD50


Compounds ES-56

0.41 1.44

Phthalthrin

1.55

Resmethrin

0.10

PhenothrinC d-trans)

0.09

Furamethrin

0.55

Proparthrin

0.59

Butethrin

0.33

3

T ^

X

CH

3

CH

Substituents none

CH2

C

0

Β

S

Β

Figure

(yg/fly)

Allethrin

X

S.

PYRETHROIDS

1-CH C —

c

3

3

(Y) 4-CH C H

2-CH3

3-CH3

4-CH

c

c

Β

C

c

Β

A

Β

D

Β

Β

3

2

6

5

—

Modifications of indanyl and related benzofuranyl or benzothiophenyl compounds



18.9 31.1 100yg=0 % 7.6 3.5 63.0 49.0 49.0

20.9 49.0 100yg=10% 15. 5 14.4 21.9 24.5 55.9

2.32 4.75 10 .70 1.20 1.23 6.90 4.11 1 1 . 20

ES-56

Allethrin

Phthalthrin

Resmethrin

PhenothrinCd-trans)

Furamethrin

Proparthrin

Butethrin

Ρ.americana

Ρ.fuliginosa

(yg/cockroach)

Β.germanica

5

LD ο

3. I n s e c t i c i d a l a c t i v i t y o f ES-56 a n d o t h e r P y r e t h r o i d s on t h e 3 s p e c i e s o f c o c k r o a c h e s b y t o p i c a l a p p l i c a t i o n method.

Compounds

Table


3

CO

I

Ci

I

Ci*

a

TO

r

>

I

78

SYNTHETIC

ff^,

NaOH γ. 97 ./.

S^O^ CH

2

^OH CH

COOH I

ClCH COOH

3

1) S0C1

*

-QH

>=

^

CH


C H 3

3

^ ^ CH

0

^

3

COCt

Pyridine or CH

1=0

2

2) Al C l Y. 65 ./.

3

Reduction

.

PYRETHROIDS

Et3N

Y. 9 3 ./.

3

/C=CH-CH-CHCO

0 T

-

Compound E S - 5 6 (dl-cis . trans) CH

3

CH

Reduction : Na BH4 H /5%> 2

Figure 4.

Synthesis of

3

in

C

H

3

MeOH-i - Propyl

Rh-C

in

ether

EtOH

Y.

87 ./.

Y.

90 °/o

7-methyl-2,3-dihydro-3-benzofurylchrysanthemate (dl-cis, trans-mixture).

T a b l e 4. T h e p e r s i s t e n c e o f e f f e c t i v e n e s s against termite.

ι

Mortality

Dose

Compounds j ES-56 i 0.1

lday

7

100

i 1.0 R e s m e t h r i n \ 0.1 1.0

(mg)

Dry

film

(%)

14

28

56

64

100

100

100

100

5

0

100

100

100

100

100

100

0

100

55

100

100

0 100

128

0

0

0

0

0

0

0

0

method.

o f 1 mg o f E S - 5 6 , t h e e f f e c t t o k i l l 1 0 0 % o f t e r m i t e s c o n t i n u e d f o r 64 d a y s . Whereas t h e c o r r e s p o n d i n g e f f e c t o f r e s m e t h r i n w a s o n l y 14 d a y s . A l a b o r a t o r y t e r m i t e t e s t was c a r r i e d o u t u s i n g -Coptotermes f o r m o s a n u s . T h e t e s t b l o c k was J a p a n e s e c e d a r a n d t h e s i z e o f t h e b l o c k was l x l x l cm. The b l o c k was t r e a t e d w i t h m e t h a n o l s o l u t i o n o f e a c h com p o u n d s a n d t h e v o l u m e o f a b s o r b e d s o l u t i o n was 300 m l per m . T h e e x p o s u r e t o t e r m i t e was c a r r i e d o u t f o r 15 d a y s w i t h o u t w e a t h e r i n g . Then, w e i g h t l o s s o f t h e b l o c k a n d s u r v i v a l o f t h e t e r m i t e were measured. The r e s u l t s a r e shown in T a b l e 5. P e r m e t h r i n s h o w e d t h e strongest effects against termite. B u t ES-56 was a l s o effective. 2



20.6

10.4

2

100

100 100

0 100

23 . 6 20 . 6

100

100

30 0

100

100

28

Wood p i e c e : J a p a n e s e c e d a r ( C r y p t o m e r i a j a p o n i c a ) 10 χ 10 χ 10 T e r m i t e : C o p t o t e r m e s f o r m o s a n u s j E x p o s u r e p e r i o d : 15 d a y s . Solvent : methanol, S u r f a c e t r e a t m e n t : 30 0 m l / m

Untreated

26.6

18 .2

0

Allethrin

Phthalthrin

14 . 4

4.4

0

Phenothrin (d-trans)

0

9. 9

7.8

0

Resmethrin

100

100

0.002

(%)

22

26

0 0

0 .02

0.2

Surviving

test.

11 . 1

0

0

13 .1

0. 002

Permethrin ( d l - c i s , d l - t r a n s , 1 : 1)

9.4

0.02

l o s s (%)

0

0.2

Weight

ES-56

s=:::::

5. R e s u l t s o f t e r m i t e

^* =^c^r----^ of ^ attack ^ " " ^ ^ ^ t i ^ T ^ — ^^hi^taori Pyrethroids ^^^-^)

Table


mm.

CD

-α

CO

Ci

ϊ

2!

§ M


Temperature(°C) 93

112

120 132

180 136

138

300

140

360

142

420

3.3 0

0

0

0

0

Resmethrin

60

0

0

0

0

0

0

Phthalthrin

(second)

0

0

0

0

0

0

Allethrin

Time

70.0

60.0

46. 7

36.7

23.3

0

ES-56

60

50

40

30

(%)

20

240

Knockdown

10 m i n .

Compounds

Tabe 6. K n o c k d o w n e f f e c t b y v a p o u r o f p y r e t h r o i d s on t h e h o u s e f l y .


ο i

1

3

Ω

ni

CO

ο

00


7.

INOUE

Insecticidal

E T A L .

Activities

81

A new b o x t y p e a p p a r a t u s was d e v i c e d f o r f u m i gation or mist spraying test. T h e s i z e o f t h e b o x was 30 χ 30 χ 30 cm. T e s t i n s e c t s w e r e i n t r o d u c e d i n t o the box a f t e r f u m i g a t i o n o r m i s t s p r a y i n g w i t h o u t leak ing o f the i n s e c t i c i d e . The d i a g r a m is shown in F i g . 5. The k n o c k d o w n e f f e c t b a s e d o n v a p o u r a c t i o n o f p y r e t h r o i d s was m e a s u r e d b y u s i n g common h o u s e f l y . One mg o f e a c h compound was h e a t e d up t o 142°C o f t h e heater during 7 minutes. Then, t h e t e s t i n s e c t s were i n t r o d u c e d i n t o t h e box and t h e percentage o f knock down was d e t e r m i n e d . The r e s u l t s a r e shown in T a b l e 6. ES-56 s h o w e d b e t t e r r e s u l t t h a n a l l e t h r i n , p h t h a l t h r i n and r e s m e t h r i n . The i n s e c t i c i d a l a c t i v i t y o f ES-56 was i n c r e a s e d when c o m b i n e d w i t h s a f r o x a n e o r 1 - d o d e c y l i m i d a z o l e . U s i n g t h e box type apparatus p r e v i o u s l y mentioned, t h e e f f e c t o f m i s t s p r a y i n g t o common h o u s e f l y was t e s t e d u s i n g 0.4% a c e t o n s o l u t i o n . The r e s u l t s a r e shown in T a b l e 7. The k n o c k d o w n e f f e c t was i n c r e a s e d when 1 - d o d e c y l i m i d a z o l e was a d d e d . The i n s e c t i c i d a l e f f e c t o f s a f r o x a n e was s t r o n g e r t h a n t h a t o f 1dodecylimidazole.

Table

7. M i s t s p r a y i n g t e s t a g a i n s t h o u s e f l y b y u s i n g a new b o x a p p a r a t u s .

Compounds

Concentration (%)

KT (min.)

Mortality (%)

5 0

Allethrin

0.4

55.2

2.5

ES-56

0.4

39.8

5.0

ES-5 6 +

Safroxane

0.4 + 2

32.8

50.0

ES-56 +

^Dodecyl imidazole

0.4 + 2

29.1

37.5

Solvent : acetone Amount o f s p r a y : 0 . 6 5 m l / 3 0 x 3 0 x 3 0 c m

I n t h e c a s e o f t h e m i x e d r a t i o , 1 t o 5, b e t t e r s y n e r g i s t i c e f f e c t s were o b s e r v e d . The i n s e c t i c i d a l a c t i v i t y o f t h i n wood t r e a t e d w i t h p y r e t h r o i d s c o n t a i n i n g s y n e r g i s t s was t e s t e d a f t e r exposing t o u l t r a v i o l e t l i g h t . I n t h i s experiment, w e a t h e r - O m e t e r h a v i n g o n e c a r b o n a r c l a m p was u s e d . The i r r a d i a t i o n t i m e was f r o m 3 t o 12 h o u r s . After i r r a d i a t i o n , t h e f i r s t i n s t a r nymphs o f t h e A m e r i c a n



82

SYNTHETIC

PYRETHROIDS

30cm

Insect

•A ο

ο

Fun

CO

Hole for spraying Packing Sample pan

Heater Figure 5.

A diagram of new box-type testing apparatus


7.

INOUE

E T

AL.

Insecticidal

Activities

83

c o c k r o a c h were c o n t a c t e d on t h e s u r f a c e o f t h e t h i n wood a n d t h e m o r t a l i t y was m e a s u r e d . The r e s u l t s a r e shown in T a b l e 8.


Table

Pyrethroids

ES-56

Resmethrin

8.

I n s e c t i c i d a l a c t i v i t y o f wood treated with pyrethroids after exposing to u l t r a v i o l e t l i g h t Mortality

Synergists

(%)

Ohr*

3

6

9

12

100

80

30

0

0

Safroxane

100

100

100

25

0

1-Dodecyl imidazole

100

100

100

60

0

100

0

0

0

0

Safroxane

; loo

0

0

0

0

1-Dodecyl imidazole

J 100

0

0

0

0

* I r r a d i a t i o n time Concentration : 0.2% a c e t o n e Mixed r a t e , 1 : 1 W e a t h e r - 0 m e t e r was u s e d .

solution

ES-56 was w e l l p r o t e c t e d by t h e a d d i t i o n o f s y n e r g i s t s from u l t r a v i o l e t l i g h t . As a p a r t o f t h e t o x i c i t y s t u d i e s o f E S - 5 6 , L D 5 0 (mg/kg) was e x a m i n e d . The r e s u l t s a r e s h o w n in T a b l e 9. The t o x i c i t y o f c o m p o u n d 56 w o u l d be l e s s t h a n that of a l l e t h r i n . I n c o n c l u s i o n , ES-56 h a s b e t t e r i n s e c t i c i d a l a c t i v i t y and r e l a t i v e l y l o n g e r r e s i d u a l e f f e c t . Moreover, l o w e r c o s t is t o be e x p e c t e d . T h e r e is much o f w o r k y e t t o be d o n e in f u n d a m e n t a l t e s t s o n t h i s new pyrethroid. We a r e now m a k i n g e x t e n s i v e e f f o r t f o r f u r t h e r d e v e l o p m e n t o f t h i s compound, e s p e c i a l l y t o x i c o l o g i c a l s t u d i e s o n it. REFERENCES 1. N a k a d a y , Y u r a . Y a n d M u r a y a m a Κ : Bull. Chem. S o c . J a p . ( 1 9 7 1 ) , 4 4 , 1724



3412

3590

661

692

Peroral

5 0

(mg/kg)

1758

1863

334

326

Subcutaneous

LD

ES-56

: m o u s e , m a l e 5 1 3 , f e m a l e 416 r a t , m a l e 1 0 8 4 , f e m a l e 1217

female

Allethrin

(wister)

male

female

(ddy)

Rat

male

sex

Mouse

Animals

T a b l e 9. T o x i c i t y o f compound

/

3 ml 3 ml

>

4000

>

3524

3000 ~

Percutaneous


I

Ο

1

00

Synthetic Pyrethroids

Recommend Documents