Related Experiment Video
Updated: Jul 19, 2026

Split-and-pool Synthesis and Characterization of Peptide Tertiary Amide Library
Published on: June 20, 2014
Kinetics of ptaquiloside hydrolysis in aqueous solution
Karina B Ayala-Luis1, Pernille B Hansen, Lars H Rasmussen
1University of Tübingen, Center for Applied Geoscience, Sigwart Str. 10, 72076 Tübingen, Germany. kalu@kvl.dk
Ptaquiloside (PTA) toxin from bracken fern is a drinking water concern. Its hydrolysis rate is slowest in acidic conditions and low temperatures, increasing leaching risk in certain soils.
Area of Science:
- Environmental Chemistry
- Toxicology
- Analytical Chemistry
Background:
- Ptaquiloside (PTA) is a toxin from bracken fern (Pteridium aquilinum).
- PTA leaching into water reservoirs poses a human health risk.
- Understanding PTA degradation is crucial for predicting its environmental persistence.
Purpose of the Study:
- To investigate the hydrolysis kinetics of Ptaquiloside (PTA) in aqueous solutions.
- To determine the influence of pH and temperature on PTA degradation rates.
- To elucidate the mechanism of PTA hydrolysis and identify potential intermediates.
Main Methods:
- Hydrolysis kinetics of PTA studied in buffered aqueous solutions (pH 2.88-8.93) at 22°C.
- First-order kinetics analysis applied to PTA degradation.
- Temperature dependence and activation energy determined.
- Spectrophotometry and stoichiometric calculations used to identify reaction intermediates.
Main Results:
- PTA hydrolysis follows first-order kinetics across tested pH and temperatures.
- Acid-mediated hydrolysis dominates below pH 4.43, base-mediated above pH 6.39.
- Rate constants for acid, base, and neutral hydrolysis determined; activation energy is 74.4 kJ mol⁻¹.
- An intermediate compound is formed at pH 5.07 and 6.07.
Conclusions:
- PTA hydrolysis is slowest at slightly acidic pH and low temperatures.
- PTA is not sorbed by soil.
- Acidic sandy soils in cold climates are most susceptible to PTA leaching into aquifers.
More Related Videos
09:42Unraveling Entropic Rate Acceleration Induced by Solvent Dynamics in Membrane Enzymes
Published on: January 16, 2016
05:46Identification of Pharmaceuticals in The Aquatic Environment Using HPLC-ESI-Q-TOF-MS and Elimination of Erythromycin Through Photo-Induced Degradation
Published on: August 1, 2018
Related Concept Videos
Acid Halides to Carboxylic Acids: Hydrolysis
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic acid...
Factors Affecting Dissolution: Drug pKa, Lipophilicity and GI pH
A drug's pKa and the pH of the gastrointestinal (GI) tract play crucial roles in drug...
Hydrolysis of ATP
If one phosphate group is removed, a molecule of ADP—adenosine diphosphate—remains, along with inorganic phosphate. ADP can be further hydrolyzed to AMP—adenosine monophosphate—by the removal of a second...
Phase I Reactions: Hydrolytic Reactions
An important hydrolytic reaction is ester hydrolysis. Ester bonds, often found in prodrugs, are broken down, increasing the solubility of drugs like aspirin and lidocaine for more straightforward elimination. Amide hydrolysis is another critical reaction, targeting amide bonds prevalent...
Strong Acid and Base Solutions
Factors Affecting Solubility