Anthraquinone pigment with herbicidal potential from Phoma herbarum FGCC#54

Abstract

UDC 547.972Metabolites from Phoma sp., a phytopathogenic fungus, were exploited for their herbicidal potential. The phytotoxic compound isolated was identified as anhydropseudophlegmacin-9,10-quinone-3c-amino-8c-Omethyl ether on the basis of spectral data. The isolated pigment was tested for its herbicidal potential against the prominent weeds of Central India, where a positive result was obtained.Weeds are important pests, which cause economic losses in agricultural and forestry systems and serious ecological problems, and which are capable of altering the ecosystem, displacing native flora and fauna [1]. Plant pathogenic microbes have been a novel and lucrative source of a wide range of bioactive compounds with herbicidal potential. Phoma is a well-known phytopathogen responsible for many diseases in plants and is known to produce an array of bioactive extracellular phytotoxic compounds [2,3]. Anthraquinones have also been isolated from Phoma foveata [4], while other fungi too have been reported to exhibit biological activity [5]. As part of our search for potential herbicidal agents, presently we describe the isolation, purification, and characterization of a pigment exhibiting herbicidal potential against, the prominent weeds of Central India. This is the first report where a pigment, i.e., anhydropseudophlegmacin-quinone, exhibits herbicidal potential against the target weeds.The red pigment, R f 0.30, was obtained as an optically active light yellow powder, mp 232qC, [D] D 25 + 33.14q (c 0.91;MeOH), in a yield of 2 u 10 -2 % of fresh weight of the fungus. The electron spray ionization mass spectrum (ESI-MS) displayed a molecular ion peak at m/z 523 corresponding to the molecular formula C 30 H 21 O 8 N. This formula suggests the presence of a dimeric octaketide structure, whereas the long-wavelength absorption at 500 nm in the electronic spectrum suggested the presence of an anthraquinone chromophore. The IR absorption bands at 3482, 3208, and 1610 cm -1 indicated the presence of hydroxyl, amino, and quinone carbonyl groups in the compound. The 1 H NMR spectrum of the pigment revealed the presence of seven aromatic protons, four of which showed a doublet at G 6.91, 6.85, 6.66, and 6.94 ppm, whereas the remaining three showed a sharp aromatic proton singlet at G 7.26, 7.10, and 7.25 ppm. Comparison of these data with those reported in the literature revealed that the new anthraquinone corresponds to a combination of subunits -A (torosachrysone-8-O-methylether) and B (emodin-1-O-methyl ether) joined at the C-10c and C-5 position, respectively [6][7][8].

Multifaceted Applications of Microbial Pigments: Current Knowledge, Challenges and Future Directions for Public Health Implications

“…exigua, Phoma foveata, P. glomerata, P. herbarum, P. macdonaldii, P. macrostoma, P. multirostrata, P. proboscis, P. sorghina , and P. tracheiphila possess herbicidal activities [103]. Quereshi et al (2011) [104] isolated a pigment compound—anhydropseudophlegmacin-9,10-quinone-3′-amino-8′- O -methyl ether—from Phoma herbarum FGCC#54 that showed potential herbicidal activity against prominent weeds Hyptis suaveolens , Lantana camara , Parthenium hysterophorus , and Sida acuta .…”

Controlling weeds with fungi, bacteria and viruses: a review

“…Despite this, macrocidins and other molecules within the tetramic acid family have received significant attention as templates for the development of novel synthetic herbicides ( Barnickel and Schobert, 2010 ; Yoshinari et al, 2010 ; Zhao et al, 2011 ). Additionally, an anthraquinone pigment has been isolated from a P. macrostoma strain and shown to have herbicidal effects on several prominent weeds of Central India ( Quereshi et al, 2011 ). Anthraquinone pigments produced by other fungi have also been demonstrated to cause necrosis on wheat leaf blades ( Bouras and Strelkov, 2008 ) and a variety of cultivated legumes ( Andolfi et al, 2013 ).…”

Fungal Bioactive Anthraquinones and Analogues

“…Furthermore, a phytotoxic anthraquinone, which was identified as anhydropseudophlegmacin-9,10-quinone-3′-amino-8′- O -methyl ether ( 53 , Figure 5 , Table 1 ), was isolated from Phoma herbarum FGCC#54, a phytopathogenic fungus, investigated for herbicidal potential. Compound 53 showed phytotoxic activity against the prominent weeds of Central India [ 46 ].…”