Phytotoxicity and ultrastructural effects of gymnopusin from the orchid Maxillaria densa on duckweed (Lemna pausicostata) frond and root tissues
Por:
Valencia-Islas N.A, Paul R.N, Shier W.T, Mata R., Abbas H.K
Publicada:
1 ene 2002
Resumen:
Two phenanthrene derivatives, characterized as erianthridin (9,10-dihydro-2,7-dihydroxy-3,4-dimethoxyphenanthrene) and gymnopusin (2,7-dihydroxy-3,4,9-trimethoxyphenanthrene), were isolated from an extract of the orchid Maxillaria densa, using phytotoxicity with amaranth (Amaranthus hypochondriacus) to guide fractionation. Gymnopusin and erianthridin inhibited radicle elongation of A. hypochondriacus seedlings with IC50 values of 330 and 58.2 ?M, respectively, The phytoxicity of the two phenanthrene derivatives was also assessed on duckweed (Lemna pausicostata), and compared with mammalian toxicity estimated in vitro with four mammalian cell lines. On duckweed, both phenanthrene derivatives caused electrolyte leakage, chlorophyll loss and photobleaching. Ultrastructural examination of duckweed frond and root tissues treated with gymnopusin (100 ?M) revealed membrane damage to the tonoplast after 12 h of exposure. Effects on membrane integrity followed a time course similar to that of electrolyte leakage. Both phenanthrene derivatives exhibited moderate cytotoxicity to all mammalian cells tested, which precludes their use as a bioherbicide. © 2002 Elsevier Science Ltd. All rights reserved.
Filiaciones:
Valencia-Islas N.A:
Facultad de Química, Universidad Nacional Autónoma de México, Coyoacán 04510, Mexico
Paul R.N:
USDA-ARS, Southern Weed Research Unit, Stoneville, MS 38776, United States
Shier W.T:
College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, United States
Mata R.:
Facultad de Química, Universidad Nacional Autónoma de México, Coyoacán 04510, Mexico
Abbas H.K:
USDA-ARS, Crop Genetics and Production Research Unit, PO Box 345, Stoneville, MS 38776, United States
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