| Autor: |
Siciliano A; Department of Biology, University of Naples Federico II, Complesso Universitario Monte Sant'Angelo, Via Cintia 4, 80126 Naples, Italy., Zorrilla JG; Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario Monte S. Angelo, Via Cintia, 80126 Naples, Italy.; Allelopathy Group, Department of Organic Chemistry, Facultad de Ciencias, Institute of Biomolecules (INBIO), University of Cadiz, C/Avenida República Saharaui, s/n, 11510 Puerto Real, Spain., Saviano L; Department of Biology, University of Naples Federico II, Complesso Universitario Monte Sant'Angelo, Via Cintia 4, 80126 Naples, Italy., Cimmino A; Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario Monte S. Angelo, Via Cintia, 80126 Naples, Italy., Guida M; Department of Biology, University of Naples Federico II, Complesso Universitario Monte Sant'Angelo, Via Cintia 4, 80126 Naples, Italy., Masi M; Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario Monte S. Angelo, Via Cintia, 80126 Naples, Italy., Meyer S; Shrub Sciences Laboratory, U.S. Forest Service Rocky Mountain Research Station, 369 North 100 West Suite 8, Cedar City, UT 84721, USA. |
| Abstrakt: |
Buffelgrass ( Cenchrus ciliaris L.) is an invasive C4 perennial grass species that substantially reduces native plant diversity of the Sonoran Desert through fire promotion and resource competition. Broad-spectrum herbicides are essentially used for its control, but they have a negative environmental and ecological impact. Recently, phytotoxicity on C. ciliaris has been discovered for two metabolites produced in vitro by the phytopathogenic fungi Cochliobolus australiensis and Pyricularia grisea. They were identified as (10 S ,11 S )-(-)- epi -pyriculol and radicinin and resulted in being potential candidates for the development of bioherbicides for buffelgrass biocontrol. They have already shown promising results, but their ecotoxicological profiles and degradability have been poorly investigated. In this study, ecotoxicological tests against representative organisms from aquatic ecosystems ( Aliivibrio fischeri bacterium, Raphidocelis subcapitata alga, and Daphnia magna crustacean) revealed relatively low toxicity for these compounds, supporting further studies for their practical application. The stability of these metabolites in International Organization for Standardization (ISO) 8692:2012 culture medium under different temperatures and light conditions was also evaluated, revealing that 98.90% of radicinin degraded after 3 days in sunlight. Significant degradation percentages (59.51-73.82%) were also obtained at room temperature, 30 °C or under ultraviolet (254 nm) light exposure. On the other hand, (10 S ,11 S )- epi -pyriculol showed more stability under all the aforementioned conditions (49.26-65.32%). The sunlight treatment was also shown to be most effective for the degradation of this metabolite. These results suggest that radicinin could provide rapid degradability when used in agrochemical formulations, whereas (10 S ,11 S )- epi -pyriculol stands as a notably more stable compound. |
