Controlled Release of 2,4-D from Granule Matrix Formulations Based on Six Lignins

Ferraz, André; Souza, Josefina Aparecida de; Silva, Flávio T.; Gonçalves, Adilson R.; Bruns, Roy E.; Cotrim, André R.; Wilkins, Richard M.

doi:10.1021/jf960487o

Cited by 39 publications

(29 citation statements)

References 5 publications

(1 reference statement)

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“…A few approaches were taken to prepare controlled release formulations: formulations based on alginate (9), cyclodextrin complexes (10), formulations based on lignin (11), polymer encapsulation (12), formulations based on starch (13), and formulations based on organo-clays (14,15). These formulations were designed for hydrophobic herbicides.…”

Section: Introductionmentioning

confidence: 99%

Slow-Release Formulations of Sulfometuron Incorporated in Micelles Adsorbed on Montmorillonite

Mishael

Undabeytia

Rabinovitz

et al. 2002

J. Agric. Food Chem.

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The design and tests of slow-release formulations of sulfometuron (SFM), an anionic sulfonylurea herbicide, are described. The formulations are based on incorporation of the herbicide in octadecyltrimethylammonium (ODTMA) micelles, which adsorb on a clay mineral, montmorillonite. An optimization of herbicide/micelle clay ratios yielded high adsorption of SFM (95%), and at a 1% (w/ w) water suspension only 0.5% of the adsorbed SFM was released at times varying from hours to 9 days. An analytical test in Seville soil showed that under excessive irrigation (400 mm) 100% of the commercial formulation leached, whereas the micelle-clay formulations showed only 50-65% elution. A plant bioassay in Rehovot soil showed that the commercial dispersible granule formulation (Oust, 75% ai sulfometuron methyl) yielded only 23% root elongation inhibition at the top 5 cm of the soil, whereas complete inhibition was achieved with the micelle-clay formulation. The detected concentration of SFM for the micelle-clay formulation at a depth of 15-20 cm was half of that detected for the commercial one, indicating a reduction in leaching when applying the micelle-clay formulation. A 10-fold reduction in the applied dose of SFM in the micelle-clay formulations resulted in good herbicidal activity of 60-87% inhibition. These characteristics make the new formulation promising from the environmental and economic points of view.

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Section: Introductionmentioning

confidence: 99%

Slow-Release Formulations of Sulfometuron Incorporated in Micelles Adsorbed on Montmorillonite

Mishael

Undabeytia

Rabinovitz

et al. 2002

J. Agric. Food Chem.

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“…Several approaches have been employed to obtain CRFs: alginate encapsulation (Gerstl et al, 1998), cyclodextrin complexation (Loukas et al, 1994), polymeric microcapsules (Dailey et al, 1993), lignin entrapment (Ferraz et al, 1997), and starch encapsulation (Mervosh et al, 1995). This latter was essayed for norflurazon (Boydston, 1992).…”

Section: Introductionmentioning

confidence: 99%

Organo-Clay Formulations of the Hydrophobic Herbicide Norflurazon Yield Reduced Leaching

Undabeytia

Nir

Rubin

2000

J. Agric. Food Chem.

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The study aimed to reduce leaching of the hydrophobic herbicide norflurazon (4-chloro-5-methylamino-2-(R,R,R)-trifluoro-m-tolylpyridazin-3-(2H)-one) by adsorbing it on clays or organoclays. The surface of the clay mineral montmorillonite was modified from hydrophilic to hydrophobic by preadsorbing it with organic cations, of which thioflavin-T (TFT) at a loading corresponding to 5 / 8 of the cation-exchange capacity of the clay mineral yielded the highest affinity of adsorption of norflurazon. Pillared clay (PC) used without organic cations exhibited enhanced affinity for norflurazon adsorption, much higher than that of montmorillonite or sepiolite. Fourier transform infrared (FTIR) results showed interactions between aromatic moieties of preadsorbed TFT and the herbicide. Stronger interaction of the herbicide with a clay mineral or organo-clay corresponded to its slower release. Formulations prepared on the basis of montmorillonite-TFT and PC were more effective in reducing herbicide leaching in soil columns in comparison to the commercial formulation, whereas the herbicidal efficiencies were comparable.

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“…DFRC was performed as described by Lu and Ralph (25,26). 4-Acetoxy-3-methoxycinnamyl acetates (DFRC monomers, both cis and trans isomers) were separated by gas chromatography-mass spectrometry (GC-MS) and identified based on their mass spectra, which were identical to those from authentic compounds, including coniferyl diacetate (m/z [relative intensity] ϭ 264 [9], 222 [100], 179 [50], 163 [11], 151 [14], 131 [20], 119 [12], 91 [9]). The amounts of each monomer were determined by GC and flame ionization detection by using a response factor (1.40) derived from pure monomer standards, with 4,4Ј-ethylene bisphenol as the internal standard.…”

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confidence: 99%

“…Fourier transform infrared (FTIR) spectra were obtained with a Nicolet 520 FTIR spectrophotometer and a KBr disk containing 0.5% of the sample. The elemental analysis and methoxyl contents were determined by following methods previously described (11). 1 H, 13 C, distortionless enhancement by polarization transfer with a of 135°( DEPT-135), and heteronuclear multiple quantum coherence (HMQC) spectra were obtained with a Bruker DRX-360 instrument.…”

mentioning

confidence: 99%

Structural Characterization of Lignin during Pinus taeda Wood Treatment with Ceriporiopsis subvermispora

Guerra¹,

Mendonça²,

Ferraz³

et al. 2004

Appl Environ Microbiol

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Although lignin is recalcitrant, some specialized fungi developed the ability to degrade this complex molecule. Most of these fungi belong to the basidiomycetes and are responsible for the white-rot decay process (19). White-rot fungi use an intricate oxidative complex to degrade lignin, which is based on oxidative enzymes and low-molecular-mass mediators (28). Several white-rot fungi produce a lignin peroxidase (LiP) that can initiate one-electron oxidation of nonphenolic arylglycerol-␤-O-aryl ether units. This oxidation is followed by C␣-C␤ or ␤-O-aryl cleavage to give aromatic aldehydes or phenylglycerols, respectively, as primary products (19). On the other hand, some white-rot fungi degrade lignin efficiently without producing LiP (20). One of them, Ceriporiopsis subvermispora, has been extensively studied (15,16,17,31,32), owing to its suitability for biopulping (1,27). Although the industrial applicability of this fungus has been recognized, its ligninolytic strategies are not completely understood. It has often been assumed that lignin degradation by C. subvermispora is dependent on manganese-dependent peroxidases and laccases (28). The occurrence of lignin degradation inside the wood matrix during the first stages of wood decay, when low cell wall permeability does not permit enzyme diffusion, has clearly indicated that some low-molecular-mass agents also act in the early stages of lignin biodegradation (2). Lipid peroxidation induced by manganese-dependent peroxidase has been proposed for lignin biodegradation by C. subvermispora (6,17,18,32). Studies with lignin model compounds have shown that nonphenolic arylglycerol-␤-O-aryl units are disrupted by means of one-electron oxidation mechanisms similar to the routes proposed for basidiomycetes that produce LiP (18,32).Under solid-state fermentation of wood, C. subvermispora extensively depolymerizes lignin. Lignin depolymerization has been demonstrated in studies based on the molecular mass distribution of milled wood lignins (MWLs) recovered from biotreated wood samples (15) and in studies using in situ derivatization followed by reductive cleavage (DFRC) of lignin in biotreated wood, which indicates lignin depolymerization as a consequence of aryl-ether degradation (16).The present study provides additional data for evaluating lignin biodegradation by C. subvermispora during solid-state fermentation of Pinus taeda wood. The structural characteristics of MWLs extracted from sound (untreated) and biotreated wood samples were elucidated using wet-chemical and spectroscopic analyses. MATERIALS AND METHODSFungus, inoculum preparation, and wood biodegradation. C. subvermispora (Pilat) Gilbertson et Ryvarden cultures were maintained on 2% (wt/vol) malt extract agar plates at 4°C. The wood chips (approximately 2.5 by 1.2 by 0.2 cm) used in this work came from a single log of a 28-year-old P. taeda tree.Biodegradation experiments were carried out in 20-liter polypropylene bioreactors. Precolonized wood chips were used as inoculum seed to start the colonization ...

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Controlled Release of 2,4-D from Granule Matrix Formulations Based on Six Lignins

Cited by 39 publications

References 5 publications

Slow-Release Formulations of Sulfometuron Incorporated in Micelles Adsorbed on Montmorillonite

Slow-Release Formulations of Sulfometuron Incorporated in Micelles Adsorbed on Montmorillonite

Organo-Clay Formulations of the Hydrophobic Herbicide Norflurazon Yield Reduced Leaching

Structural Characterization of Lignin during Pinus taeda Wood Treatment with Ceriporiopsis subvermispora

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