Pesticide Residues in the Environment - Pesticides: Evaluation of Environmental Pollution - page 167

R 1 X

Zn

- R 2 X

R 3 X

P

R 1 X
R 2 X
R 3 X

O

X

X

P

Zn

H -

Zn

O

H

Zn

Pesticide PTE

(a)

-

˙˙

X

R 1 X
R 2 X

X

Zn

R 1 X

P

Zn

P

R 2 X

O

R 3 X

-

HO H

O

Zn

Zn

H

-

O

H

(c) (b)

FIGURE 6.3
(a-c)Initialstepsoftheproposedmechanismofactionof Flavobacterium sp.PTE,naturallycontainingtwoatoms
ofzincattheactivesite,forhydrolyzingorganophosphatepesticides.(FromOrtiz-Hernández,M.L.,Quintero-
Ramírez, R., Nava-Ocampo, A. A., and Bello-Ramírez, A. M., Study of the mechanism of Flavobacterium sp.
forhydrolyzingorganophosphatepesticides. Fundam. Clin. Pharmacol., 2003,17:717-723.CopyrightWiley-VCH
VerlagGmbH&Co.KGaA.Reproducedwithpermission.)

-

R 1 X

R 1 X

X

R 2 X

X

R 1 X

P Zn

P

R 2 X X Zn

P

HO

HO

O

Zn

HO -

-

HO

H

O

O

Zn

Zn

H

H

Zn

-

O

H

(a)

R 1 X

HO
HO

-

P

X X

X

R 1 X

HO

Zn

Zn

P Zn

P

-

HO

HO

O

O

O

HO

H

H

H

Zn

Zn

Zn

-

O

H

(c) (b)

FIGURE 6.4
(a-c)Intermediatestepsofthehydrolysisoforganophosphatepesticidesby Flavobacterium sp.PTE.Thesubstit-
uentsatthephosphoricacidareeliminatedbyhydrolysis.(FromOrtiz-Hernández,M.L.,Quintero-Ramírez,R.,
Nava-Ocampo,A.A.,andBello-Ramírez,A.M.,Studyofthemechanismof Flavobacterium sp.forhydrolyzing
organophosphatepesticides. Fundam. Clin. Pharmacol., 2003,17:717-723.CopyrightWiley-VCHVerlagGmbH&
Co.KGaA.Reproducedwithpermission.)