Antifungal Activities of Isoflavonoids from Uromyces striatus Infected Alfalfa

Abstract

Fungal pathogens constitute a severe yield‐limiting factor for the pasture crop alfalfa (Medicago sativa L.). Eleven phenolic compounds, including a new isoflavane, were isolated from the Uromyces striatus Schroet. infected alfalfa. The effect of infection with U. striatus Schroet. on the phytochemical profile of alfalfa was investigated using ultra‐performance liquid chromatography (UPLC), and the antifungal properties of isolated compounds against a range of pathogens were tested. It was found that the contents of most of the isolated compounds in U. striatus infected alfalfa were higher than those in healthy alfalfa. Compounds 1–5 exhibited a moderate inhibitory activity against Curvularia lunata with 40.14±1.63 %, 48.03±1.22 %, 57.54±1.18 %, 50.10±1.56 %, and 61.54±2.14 % inhibition ratio at the concentration of 50 μg/mL. Compounds 3 and 5 showed a weak inhibitory activity against Fusarium graminearum with the EC50 values of 104.2±2.66 and 123.0±1.23 μg/mL, and a moderate inhibitory activity against Bipolaris sorokinianum with the EC50 values of 39.1±2.05 and 95.0±1.01 μg/mL, respectively. In pot experiments with wheat, compounds 1–5 possessed desirable protective efficacy of over 80 % and curative effectiveness of over 50 % against Puccinia striiformis f. sp. tritici at a concentration of 0.5 mg/mL

New Isoflavanes from Spatholobus suberectus and Their Cytotoxicity against Human Breast Cancer Cell Lines

“…The 13 C-NMR and distortionless enhancement by polarization transfer (DEPT) spectra of 1 showed 18 carbon signals (Table 2) attributed to 3 × OCH 3 , 2 × CH 2 (one oxygen-bearing), 6 × CH (five aromatic methines), and 7 × C (five oxygenated aromatic carbons). These spectroscopic data indicated that compound 1 was an isoflavane possessing a hydroxy and three methoxy groups [18,19,20]. Comparison of the 1 H and 13 C-NMR data of 1 and sativan [18] suggested that an additional methoxy group was substituted at C-8 in 1 .…”

Molecular Mechanism Underlying Pathogenicity Inhibition by Chitosan in Cochliobolus heterostrophus

“…In addition, the top 10 upregulated metabolites in the treatment group were homogentisic acid, N-feruloylagmatine, icariside B2, 3,4-dihydroxybenzeneacetic acid, 4-O-glucosyl-4-hydroxybenzoic acid, 1-O-salicyloyl-β- d -glucose, 1-O-galloyl-β- d -glucose, 3-O-galloyl- d -glucose, and medicarpin-3-O-glucoside (Figure D). We focused on the 100 metabolites upregulated by chitosan, and most of them were categorized as phenolic acids, alkaloids, flavonoids, lignans, and coumarins (Table S2), which were extensively involved in fungal resistance and plant immunity. − These findings hinted that chitosan could induce the production of antifungal compounds to control the C. heterostrophus infection and development in maize.…”

“…28 In addition, the contents of several phenolic compounds in Uromyces striatus-infected alfalfa were higher than those in healthy alfalfa, and these phenolic compounds exhibited a moderate inhibitory activity against fungal pathogens. 29 Moreover, coumarins also exhibited excellent inhibitory activity against phytopathogens. 31,32 All these results would better explain why chitosan has such strong disease resistance activity.…”

Crude Extracts and Secondary Metabolites of Epichloë bromicola against Phytophthora infestans

“…The spectral data (MS, 1 H, and 13 C‐NMR spectra) of compounds 1 – 13 were identical to those reported in the previous literature. Consequently, their structures were identified as those of 5α,8α‐epidioxy‐(22E,22R)‐ergosta‐6,22‐dien‐3β‐ol ( 1 ), [34] gigantenol ( 2 ), [35] (3β,22E)‐ergosta‐5,7,22‐trien‐3‐ol ( 3 ), [36] 5,6‐epoxy‐(3β,5α,6α,7α,22E)‐ergosta‐8,22‐diene‐3,7‐diol ( 4 ), [37] 5α,6α‐epoxyergosta‐8(14),22‐diene‐3β,7α‐diol ( 5 ), [38] 5,6‐epoxy‐3‐hydroxy‐(3β,5α,6α,22E)‐ergost‐22‐en‐7‐one ( 6 ), [39] 7α‐methoxy‐5α,6α‐epoxyergosta‐8(14),22‐dien‐3β‐ol ( 7 ), [40] isolumichrome ( 8 ), [41] adenosine ( 9 ), [42] palmitic acid ( 10 ), [42] n‐octacos‐9‐enyl propionate ( 11 ), [43] n‐eicosanoic‐9‐enoic acid ( 12 ), [44] and 5,8,11‐hexacosatrienoic acid ( 13 ) [44] . Among these isolated compounds, a large amount of them ( 1 ‐ 4 , 6 , 8 , 9 , and 12 ) were tested for their antifungal activity against P. infestans .…”