Phytotoxic activity in Flourensia campestris and isolation of [-] hamanasic acid A as its active principle compound
An aqueous extract from Flourensia campestris [Asteraceae] dry aerial parts showed strong inhibition on the germination and growth of Lactuca sativa. Based on bio-guided chromatographic fractionation of aq. extracts from dry and fresh leaves and spectroscopic means, [-]-hamanasic acid A [7-carboxy-8-hydroxy-1[2], 12[13]-dien-bisabolene [1]] was isolated as the most inhibitory active principle on germination [ECg50 = 2.9 mM] and on root [ECr50 = 1.5 mM]/shoot [ECs50 = 2.0 mM] growth. As measured by GC, and correlated with a simple designed 2D-TLC, compound 1 was distributed throughout the plant, with a remarkably high concentration [1.6 percent] in the leaves and the inflorescences. At least a quarter of the amount of 1 was found in aqueous extracts suggesting that leaching would be a key route for its release into the environment. By contrast, leaf essential oils [HD] between 0.5 and 1.5 ul ml-1 did not show herbicidal effects and 1 was not found in them [TLC] nor among volatiles [HS-SPME]. Volatile compositions were assessed by GC-FID and GC-MS and led to the identification of 23 compounds [4 monoterpenes and 19 sesquiterpenes] with a wide seasonal [spring-summer percent] variation, represented principally by bicyclo-germacrene [37-6 percent], spathulenol [4-32 percent], globulol [20-0 percent], beta-caryophyllene [15-6 percent], caryophyllene oxide [1-13 percent] and bicycloelemene [10-1 percent], respectively. The high amount of 1 in F. campestris together with its feasibility of being extracted with water suggest that [-]-hamanasic acid A is an allelochemical in this species. Species-specific studies must be carried out to evaluate the potential of 1 as a natural herbicidal compound.
Main Authors: | , , , , , , , |
---|---|
Format: | Texto biblioteca |
Language: | eng |
Subjects: | [-]-HAMANASIC ACID A, ALLELOPATHIC AGENT, ASTERACEAE, BISABOLANOIDS, ESSENTIAL OILS, FLOURENSIA CAMPESTRIS, PHYTOTOXIC ACTIVITY, SESQUITERPENOIDS, VOLATILES, 7 CARBOXY 8 HYDROXY 1[2],12[13] DIEN BISABOLENE, 7-CARBOXY-8-HYDROXY-1[2],12[13]-DIEN-BISABOLENE, SESQUITERPENE, CHEMISTRY, DRUG EFFECT, FRACTIONATION, GAS CHROMATOGRAPHY, GERMINATION, GROWTH, DEVELOPMENT AND AGING, ISOLATION AND PURIFICATION, LETTUCE, PLANT, PLANT ROOT, CHEMICAL FRACTIONATION, CHROMATOGRAPHY, GAS, PLANT ROOTS, PLANT SHOOTS, SESQUITERPENES, LACTUCA, LACTUCA SATIVA, |
Online Access: | http://ceiba.agro.uba.ar/cgi-bin/koha/opac-detail.pl?biblionumber=46718 |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|