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ABSTRACT
Background: Antifungal activity of slender amaranth (Amaranthus viridis
L.) is well documented but such studies are scarce in Pakistan, especially
against plant pathogens. It was hypothesized that A. viridis has antifungal
activity against fungal phyto-pathogens also.
Objective: Identification of antifungal constituents from leaf extracts of
A. viridis.
Methods: Different organic solvent extracts of A. viridis leaves were
evaluated against 5 plant pathogenic fungal species viz. Alternaria
alternata, Aspergillus flavus, Drechslera australiensis, Fusarium
oxysporum and Macrophomina phaseolina. Antifungal activity of A. viridis
was determined by serial dilution method. Six levels (0, 5, 10, 15, 20 and
25 mg mL-1) of treatments of each n-hexane, chloroform and ethyl acetate
were employed against all fungal species in a Completely Randomised
Design (CRD).
Results: Generally, all organic solvent extracts reduced the fungal
biomass significantly with the increase in extract concentration but
ethyl acetate leaf fraction exhibited pronounced activity and reduced
the fungal growth up to 44% in A. alternata, 39% in A. flavus, 48% in
D. australiensis, 48% in F. oxysporum and 45% in M. phaseolina.
Gas Chromatography Mass Spectrometry (GCMS) analysis of ethyl
acetate leaf fraction revealed 09 compounds. Out of these 9 compounds,
one compound identified as 1,2- Benzenedicarboxylic acid, mono
(2-ethylhexyl) ester) showed 58.5% peak value.
Conclusions: It was concluded that 1,2- Benzenedicarboxylic acid, mono
(2-ethylhexyl) ester) being in the highest concentration in the ethyl
acetate leaf fraction of A. viridis may be responsible for antifungal activity.
This compound can serve as structural analog to develop ecofriendly
fungicides.

Keywords:
Amaranthus viridis
antifungal
GC-MS
plant pathogenic
slender amaranth