Enantiospecific behaviour of chiral drugs in soil

• Published in: Environmental pollution (1987) Vol. 262; p. 114364
• Main Authors: Bertin, Sophie, Yates, Kyari, Petrie, Bruce
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.07.2020
• Subjects: agricultural soils; amphetamine; biosolids; Enantiomer; enantiomers; ibuprofen; illicit drugs; Inversion; irrigation; medicinal properties; Microcosm; Pharmaceutical; propranolol; risk; risk assessment process; Soil; soil amendments; soil ecology; stereochemistry; wastewater; Soil; Inversion; Pharmaceutical; Enantiomer; Microcosm
• ISSN: 0269-7491; 1873-6424; 1873-6424
• DOI: 10.1016/j.envpol.2020.114364

The importance of stereochemistry on the behaviour and effects of chiral pharmaceutical and illicit drugs in amended agricultural soils has been over looked to date. Therefore, this study was aimed at investigating the enantiospecific behaviour of a chemically diverse range of chiral drugs including naproxen, ibuprofen, salbutamol, bisoprolol, metoprolol, propranolol, acebutolol, atenolol, chlorpheniramine, amphetamine, fluoxetine and citalopram in soil microcosms. Considerable changes of the enantiomeric composition of ibuprofen, naproxen, atenolol, acebutolol and amphetamine were observed within 56 d. This is significant as enantiomer enrichment can favour the pharmacologically active (e.g., S(−)-atenolol) or less/non-active forms of the drug (e.g., R(−)-amphetamine). Single enantiomer microcosms showed enantiospecific degradation was responsible for enantiomer enrichment of atenolol and amphetamine. However, naproxen and ibuprofen enantiomers were subject to chiral inversion whereby one enantiomer converts to its antipode. Interestingly, chiral inversion was bidirectional and this is the first time it is reported in soil. Therefore, introduction of the less active enantiomer to soil through irrigation with reclaimed wastewater or biosolids as fertiliser can result in the formation of its active enantiomer, or vice versa. This phenomenon needs considered in risk assessment frameworks to avoid underestimating the risk posed by chiral drugs in amended soils. [Display omitted] •Enantiospecific behaviour of 12 diverse drugs studied at enantiomeric level in soil.•Atenolol and amphetamine degrade enantioselectively in soil.•Naproxen and ibuprofen subject to bidirectional chiral inversion in soil.•Enrichment in soil can favour pharmacologically active or less active enantiomers.•Temperate soil temperature and drug concentration influence degradation kinetics. Changes to the enantiomeric composition of chiral drugs in soil due to enantiospecific degradation (e.g., atenolol and amphetamine) or chiral inversion (e.g., ibuprofen and naproxen) could result in the underestimation of environmental risk.