粘烟草蔗糖酯的分离鉴定及其抑菌和抗TMV活性OA

This study investigated the potential application of sucrose esters(SEs)derived from Nicotiana glutinosa for biopesticide development.SEs were extracted using solvent extraction,purified by normal-phase silica gel column chromatography,followed by identification and quantification using GC/MS analysis.The antifungal properties against phytopathogenic fungi was evaluated through the mycelial growth rate method,and the anti-tobacco mosaic virus(TMV)activity using the half-leaf lesion assay.Two distinct SEs configurations were isolated and identified from N.glutinosa:SE-Ⅱ(acetylated at fructose C-3')and SE-Ⅲ(non-acetylated at fructose C-3').SEs contents varied significantly among tissues,with the highest levels observed in upper leaves(3.56 mg/g fresh weight)and flowers(3.21 mg/g),substantially exceeding those in middle leaves,lower leaves,and stems.The ratio of SE-Ⅱ to SE-Ⅲ in various organs decreases with the rising position on the tobacco plant.The crude SEs extract,SE-Ⅱ,and SE-Ⅲexhibited broad-spectrum antifungal activity,with notably strong inhibition observed against Botrytis cinerea.At a concentration of 20 μg/mL,three SEs forms achieved inhibition rates of 57.75%,65.58%,and 84.73%,respectively.The antifungal activity of the crude SEs extract against B.cinerea was superior to the botanical fungicides eugenol and osthole.SE-Ⅱ showed comparable activity to the synthetic fungicide pyrimethanil,whereas SE-Ⅲ exhibited significantly stronger inhibitory effects than pyrimethanil.In anti-TMV assays at 200 μg/mL,inhibition rates were 36.33%(crude extract),69.09%(SE-Ⅱ),and 64.41%(SE-Ⅲ).The antiviral activity of the crude SEs extract matched that of oligosaccharins,while SE-Ⅱ and SE-Ⅲ showed efficacy comparable to that of ningnanmycin.These findings identify N.glutinosa represents a valuable source of diverse and bioactive SEs showing promising potential for the management of biofungicides against gray mold and antiviral agents for crop protection.