**5. Acknowledgments**

The authors thank FAPESP, CNPq and Fundunesp for financial support.

#### **6. References**

Ahmadi, A. & Ahmadi, A. (2007). Preparation and characterization of chemical structure composition of polyurethane's microcapsules pesticides. *Asian Journal of Chemistry*, Vol.19, No.1, pp. 187-194.

Preparation and Characterization

coatings. *Int J Pharm.,* Vol.112; pp. 47-54.

*Polymer Chemistry,* Vol.48, pp. 3217-3228.

studies. *Polym. Bull.* Vol.67, pp. 479–495.

*Agric. Food Chem*, Vol.57, pp. 3273-3278.

block. *Pharm. Res.,* Vol.12, pp. 1997-2002.

*Pharmaceutical Sciences*, Vol.41 No.5, pp.644-649.

*Anal*. , Vol.47, No. 4-5, pp. 865-869.

*Microencap,* Vol. 22, pp. 633–641.

of Polymeric Microparticles Used for Controlled Release of Ametryn Herbicide 15

Hariharam, D.; Peppas, N.A.; Bettini, R. & Colombo, P. (1994) Mathematical analysis of drug

Hirech, K,; Payan, S.; Carnelle, G.; Brujes, L. & Legrand, J. (2003). Microencapsulation of an insecticide by interfacial polymerization. *Powder Technol*., Vol.130, pp. 324-330. Kilic, A.C.; Capan, Y.; Vural, I.; Gursoy, R.N.; Dalkara, T.; Cuine, A. & Hincal, A.A. J. (2005).

Korsmeyer, R.W. & Peppas, N.A. Macromolecular and modeling aspects of swelling-

Korsmeyer, R.W.; Gurny, R.; Doelker, E.; Buri, P. & Peppas, N.A. (1983). Mechanisms of Solute Release from Porous Hydrophilic Polymers, *Int. J. Pharm.*, Vol.15, pp. 25-35.

Li, J.Y.; Zu, B.Y.; Zhang, Y.; Guo, X.Z. & Zhang, H.Q. One-Pot Synthesis of Surface-

Lionzo, M.I.Z.; Ré, M.I., Guterres, S.S. & Pohlmann, A.R. J. (2007). Microparticles prepared

control the release of a drug model. *Microencapsulation*, Vol.24, pp. 175-186. Lobo, F.A.; Aguirre C.L.; Silva, M.S.; Grillo, R.; Melo, N.F.S.; Oliveira, L.K.; Morais, L.C.;

Maqueda, C.; Villaverde, J.; Sopeña, F.; Undabevtia, T. & Morillo, E. (2009). Effects of soil

Melo, N.F.; Grillo, R.; Rosa, A.H&; Fraceto L.F.J (2008). Interaction between nitroheterocyclic

Moraes, C.M.; De Paula, E.; Rosa, A.H. & Fraceto, L.F. Physicochemical stability of

Bupivacaine. *Journal of the Brazilian Chemical Society*, v.21, p. 995-1000, 2010. Natarajan, V.; Krithica, N.; Madhan, B. & Sehgal, P.K. (2011). Formulation and evaluation of

Parajo, Y.; d'Angelo, I.; Horvath, A.; Vantus, T.; Gyorgy, K.; Welle, A.; Garcia-Fuentes, M. &

delivery systems. New York, USA: Marcel Dekker Inc, 1991.

delivery from swellable systems with parcial physical restrictions or impermeable

Preparation and characterization of PLGA nanospheres for the targeted delivery of NR2B-specific antisense oligonucleotides to the NMDA receptors in the brain.

controlled systems. In: Roseman TJ, Mansdorf SZ (Eds.). Controlled release

Functionalized Molecularly Imprinted Polymer Microspheres by Iniferter-Induced "Living" Radical Precipitation Polymerization *Journal Of Polymer Science Part A-*

with poly(hydroxybutyrate-co-hydroxyvalerate) and poly(ε-caprolactone) blends to

Campos, V.; Rosa, A.H. & Fraceto, L.F.; (2011). Poly(hydroxybutyrate-cohydroxyvalerate) microspheres loaded with atrazine herbicide: screening of conditions for preparation, physico-chemical characterization and *in vitro* release

characteristics on metribuzin dissipation using clay-gel-based formulations. *J.* 

compounds with β-cyclodextrins: Phase solubility and HPLC studies. *Pharm Biomed* 

poly(lactide-co-glycolide) nanocapsules containing the local anesthetic

quercetin polycaprolactone microspheres for the treatment of rheumatoidaArthritis. *Journal of pharmaceutical sciences*, Vol.100, No.1, pp.195-205. Paavola, A.; Yliruusi, J.; Kajimoto, Y.; Kalso, E.; Wahlström, T. & Rosenberg, P. (1995).

Controlled release of lidocaine from injectable gels and efficacy in rat sciatic nerve

Alonso, M.J. (2010). PLGA:poloxamer blend micro- and nanoparticles as controlled release systems for synthetic proangiogenic factors. *European Journal of* 


Amass, W. & Tighe, B. (1998). A review of biodegradable polymers: uses, current

Aulton, M. (2002). Dissolution and Solubility. Pharmaceutics: the science of dosage from

Bazzo, G.C.; Lemos-Senna, E. & Pires, A.T.N. (2009). Poly(3-hydroxybutyrate)/chitosan/

Bin Hussein, M.Z.; Hashim, N.; Yahaya, A.H. & Zainal, Z. (2009). Controlled Release

Colombo, G.; Padera, R.; Langer, R. & Kohane, D.S. (2005). Prolonged duration anesthesia

Colombo, P.; Bettini, R.; Massimo, G.; Catellani, P.L.; Santi, P. & Peppas, N.A. (1995). Drug

Conti, B.; Genta, I.; Modena, T. & Pavanetto, F. (1995). Testing of In Vitro Dissolution

Costa, P. & Lobo, J.M.S. (2001). Modeling and comparison of dissolution profiles. *Eur J* 

De Araújo, D.R.; Cereda, C.M.S.; Brunetto, G.B.; Pinto, L.M.A.; Santana, M.H.A. & De Paula,

El Bahri, Z. & Tavedert, J.L. (2007). Elaboration and characterisation of microparticles loaded

El Bahri, Z. & Taverdet, J.L. (2005). Optimization of an herbicide release from ethylcellulose

Ferrero, C.; Muñoz-Ruiz, A. & Jiménez-Castellanos, M.R. (2000) Fronts movement as a

Friedmann, A.S. (2002) *Atrazine inhibition of testosterone production in rat males following peripubertal exposure.* Johns Hopkins University, Baltimore, MD, USA. Grillo, R.; Melo, N.F.S.; Lima, R.; Lourenço, R.; Rosa, A.H. & Fraceto, L.F. (2010).

Grillo, R.; Melo, N.F.; Moraes, C.M.; De Lima, R.; Menezes, C.M.; Ferreira, E.I.; Rosa, A.H. &

hydroxyvalerate) microspheres. *J Polym Environ*., Vol.18, pp. 26-32.

design. 2 ed. Edinburgh: Churchill Livingstone, cap. 2, p. 15-32,

release evaluation, *Carbohydr. Polym*., Vol.77, pp. 839–844.

*Polym. Int*., Vol.47, pp. 89-144.

*J Microencapsul* ., Vol. 25; pp.170-178.

Vol.21, pp. 1223-1233.

Vol.202, pp. 21-28.

*Pharm Sci,* Vol.13, pp. 123-133.

*Biomed Mater Res Part A* , Vol.75; pp. 458-464.

matrix tablets. *J Biomed Mater Res.,* Vol.84, pp. 991-997.

nerve blockade in mice. *Can. J. Anesth*., Vol.51, pp. 566-572.

by pesticide model. *Powder Technol*., Vol.172, pp. 30-40.

Microspheres. *Polymer Bulletin*., Vol.54, pp. 97-103.

developments in the synthesis and characterization of biodegradable polyesters, blends of biodegradable polymer and recent advances in biodegradation studies.

ketoprofen or piroxicam composite microparticles: Preparation and controlled drug

Formulation of Agrochemical Pesticide Based on 4-(2,4-dichlorophenoxy)butyrate Nanohybrid*. Journal of nanoscience and nanotechnology,* Vol.9, No. 3, pp. 2140-2147. Coimbra, P.A.; De Sousa, H.C. & Gil, M.H. (2008). Preparation and characterization of

flurbiprofen-loaded poly(3-hydroxybutyrate-co-3- hydroxyvalerate) microspheres.

with lipid-protein-sugar particles containing bupivacaine and dexamethasone*. J* 

diffusion front movement is important in drug release control from swellable

Behaviour of Microparticulate Drug Delivery Systems. *Drug Dev. Ind. Pharm.,* 

E. (2004). Encapsulation of mepivacaine prolongs the analgesia provided by sciatic

useful tool for hydrophilic matrix release mechanism elucidation. *Int J Pharm.*,

Characterization of atrazine-loaded biodegradable poly(hydroxybutyrate-co-

Fraceto, L.F. (2008). Study of the interaction between hydroxymethylnitrofurazone and 2-hydroxypropyl-beta-cyclodextrin. *Pharm Biomed Anal*., Vol. 47, pp. 295-302.


**2** 

**Benzoxazolinone Detoxification and** 

**Degradation – A Molecule´s Journey** 

Heinrich W. Scherer4 and Felix Martin Ritter1 *1University of Bonn, Institute of Molecular Physiology* 

*2University of Leipzig, Institute of Organic Chemistry 3Institute of Cellular and Molecular Botany (IZMB)* 

*and Biotechnology of Plants (IMBIO)* 

*Plant Nutrition Germany* 

Margot Schulz1, Dieter Sicker2, František Baluška3, Tina Sablofski1,3,

*4Institut für Nutzpflanzenwissenschaften und Ressourcenschutz(INRES)* 

Benzoxazinoids are important secondary products of maize, several other Poaceae and a few dicotyledonous species belonging to the Acanthaceae, Lamiaceae, Scrophulariaceae and Ranuculaceae. The synthesis which was investigated in maize by the group of Gierl and Frey starts with the conversion of indole-3-glycerol phosphate to indole. The following steps involve four cytochrome P450 dependent monooxygenases (*BX2-BX5*) that convert indole to benzoxazinone by incorporation of oxygen. Glucosylation at the 2-position of DIBOA results in DIBOA-glucoside, an intermediate of the final product DIMBOA-glucoside (Frey et al., 1997; Glawischnig et al., 1999; von Rad et al., 2001; Jonczyk et al., 2008; Schuhlehner et al., 2008). Whereas the benzoxazinoid acetal glucosides are stable under neutral conditions, the aglycones with the 2,4-dihydroxy-*2H*-1,4-benzoxazin-3(4*H*)-one skeleton underlay a degradation by ring contraction and release of formic acid which yields the benzoxazolinones BOA or MBOA (Sicker et al., 2000; Sicker & Schulz, 2002). These derivatives are more stable and can be detected in the soil of rye or wheat fields over a period of several weeks until they are absorbed by other plants or they are converted by microorganisms. The release of benzoxazinoids into the environment and their final degradation are cornerstones within the lifetime of these molecules. In between, a complex set of (re)-modulations and conversions take place due to the activities of a variety of organisms, such as higher plants, fungi and bacteria. Our contribution will give an impression of shuttles between those organisms that end up in the degradation of phenoxazinone(s) as the final conversion products with a limited life time but will also

present several reactions of maize to the treatment with benzoxazolinone BOA.

Investigations of weed specific and of benzoxazinoid producing crops specific reactions, reactions of microorganisms, effects on the biodiversity of soil organisms and the elucidation of degradation processes are unequivocally necessary before bioherbicides can

**1. Introduction** 

be used.

