Synthesis and evaluation of effectiveness of a controlled release preparation 2,4-d: a reduction of risk of pollution and exposure of workers

Abstract

Keywords: Acid, 2,4-dichlorophenoxy acetic acid (2,4-D), controlled release, ring-opening polymerization of β-butyrolactone, SEC, 1 H-NMR, ESI-MS characterization of oligomers, assessment of the herbicide effectiveness.Abstract: A novel herbicidal controlled release formulation composed of (2,4-dichlorophenoxy) acetic acid (2,4-D) chemically bonded to biodegradable (R,S)-3-hydroxybutyric acid oligomers was investigated. The synthesis of (R,S)-3-hydroxy butyric acid oligomers was carried out via the ring opening polymerization of β-butyrolactone initiated by 2,4-dichlorophenoxy acetic potassium salt in the presence of complexing agents. The formed oligomers were characterized by size exclusion chromatography, proton magnetic resonance and electrospray mass spectrometry in order to fi nd out their molar mass distribution and molecular structures. An assessment of biological effectiveness of the obtained herbicidal formulation was carried out in the greenhouse vs. Sinapis alba var. Nakielska. A promotion of the controlled release formulation with decreased water solubility and with low vapor pressure of the active ingredient, instead of traditional formulations of 2,4-dichlorophenoxy acetic acid may help to ensure a greater safety for workers and reduce the risk of dissemination of the active ingredient in the soil profi le.

Transesterification of PHA to Oligomers Covalently Bonded with (Bio)Active Compounds Containing Either Carboxyl or Hydroxyl Functionalities

“…The presence of (3HB- co -4HB) oligomers terminated by the crotonate end groups can be explained by the partial thermal degradation of P(3HB- co -4HB), which mainly occurs through a random chain scission mechanism due to the β -CH hydrogen transfer at the 3-hydroxybutyrate units [ 28 ]. Earlier studies indicated that the presence of these types of side products do not negatively affect crops during greenhouse and field bioassays [ 14 , 15 ].…”

“…The one-pot transesterification method led to a small amount of (3HB- co -4HB) oligomers that were terminated by hydroxyl and carboxyl, as well as with unsaturated and carboxyl end groups, in addition to the desired conjugates of (3HB- co -4HB). However, previous studies indicated that the presence of these types of side products did not affect crops during greenhouse and field bioassays [ 14 , 15 ].…”

“…conjugates of (4-chloro-2-methylphenoxy)acetic acid (MCPA) or (2,4-dichlorophenoxy)acetic acid (2,4-D) with atactic oligo(3-hydroxybutyrate) (OHB)) via the anionic ring-opening oligomerisation of β-butyrolactone [ 13 ]. The effectiveness of selected conjugates obtained through ring-opening oligomerisation of racemic β-butyrolactone was confirmed using greenhouse tests [ 14 , 15 ]. The herbicidal effectiveness of the amorphous 3-HBA oligomers was comparable to that of DMA salts of 2,4-D and dicamba in greenhouse and field bioassays.…”

Molecular architecture of novel potentially bioactive (co)oligoesters containing pesticide moieties established by electrospray ionization multistage mass spectrometry

“…Recently, we reported the synthesis of pesticide‐oligomer conjugates, such as the conjugates of (4‐chloro‐2‐methylphenoxy)acetic acid (MCPA) or (2,4‐dichlorophenoxy)acetic acid (2,4‐D) with atactic oligo(3‐hydroxybutyrate) via anionic ring‐opening oligomerization of β‐butyrolactone initiated by the salt of selected pesticides . The effectiveness of selected pesticide‐oligomer conjugates obtained using this method was confirmed during greenhouse and field bioassays . Moreover, during these bioassays only statistically insignificant transient phytotoxicity levels were found, with no difference between pesticide‐oligomer conjugates and conventional formulations.…”

“…[20] The effectiveness of selected pesticide-oligomer conjugates obtained using this method was confirmed during greenhouse and field bioassays. [21,22] Moreover, during these bioassays only statistically insignificant transient phytotoxicity levels were found, with no difference between pesticide-oligomer conjugates and conventional formulations. In our current research the focus was shifted toward the synthesis of potentially bioactive (co)oligoesters with an increased amount of biological active moieties along the oligomer chain in comparison to previously reported pesticide-oligomer conjugates.…”