Structure-activity relationship studies of the phytotoxic properties of the diterpenic moiety of breviones.
BACKGROUND
Brevianes are a family of bioactive meroterpenoids originally described in fungi of the family Penicillium. These compounds have attracted a great deal of interest not only because of their unusual skeleton, suggesting a mixed mevalonate and polyketide biogenetic pathway, and their unusual oxa-spiro ring fused to an α-pyrone, but also because of the bioactivities shown by many members of this family.


RESULTS
During the course of a project aimed at the total synthesis of natural breviones A to E, the authors were able to synthesise the diterpenic moiety of brevianes and abeo-brevianes. As a result, a collection of 25 compounds were synthesised and tested for bioactivity by two different bioassays. The bioassays used were etiolated wheat coleoptiles (Triticum aestivum) and seedlings in petri dishes. The plant species tested in the seedling bioassay were the commercial dicots lettuce and cress and the monocot weeds Echinochloa crus-galli and Lolium rigidum.


CONCLUSIONS
The results clearly show that expanded phenanthrene-like compounds corresponding to the diterpenic moiety of abeo-brevianes are more selective towards E. crus-galli in comparison with L. rigidum. Such selectivity can reach up to one order of magnitude (200-fold) and makes some of the compounds good candidates as leads for the development of more specific herbicides.
Grupo de Alelopatía, Departamento de Química Orgánica, Facultad de Ciencias, Instituto de Biomoléculas (INBIO), Universidad de Cádiz, Campus de Excelencia Internacional Agroalimentario (ceiA3), Spain.
Ceferino
C
Carrera
Nuria
N
Chinchilla
Frank R
FR
Fronczek
Juan C G
JC
Galindo
Francisco A
FA
Macías
D019607:Brassicaceae / Q000187:drug effects; D004224:Diterpenes / Q000737:chemistry* / Q000494:pharmacology; D031747:Echinochloa / Q000187:drug effects; D006540:Herbicides / Q000737:chemistry* / Q000494:pharmacology; D018545:Lactuca / Q000187:drug effects; D008129:Lolium / Q000187:drug effects; D013141:Spiro Compounds / Q000737:chemistry* / Q000494:pharmacology; D013329:Structure-Activity Relationship; D014908:Triticum / Q000187:drug effects
D004224:Diterpenes; D006540:Herbicides; D013141:Spiro Compounds
breviones; diterpenes; herbicides; structure-activity relationship