title: Structure-activity relationship of citrus polymethoxylated flavones and their inhibitory effects on Aspergillus niger.
abstract: Citrus peels are rich in polymethoxylated flavones (PMFs) and are potential sources of natural preservatives. Six PMFs extracts, isolated and purified from the peels of three mandarins (Citrus reticulata) and three sweet oranges (Citrus sinensis), were identified and quantitated. Their inhibitory effects on Aspergillus niger were evaluated using a microbroth dilution assay. The Red tangerine variety exhibited the greatest antifungal activity (MIC = 0.2 mg/mL), while Jincheng showed the lowest activity (MIC = 1.8 mg/mL). An analysis of principal components was applied to the results in order to elucidate the structure-activity relationships of the citrus PMFs. The structure-activity relationship analysis revealed that, for good inhibitory effect, the 5-OH, 3-OCH₃, and 8-OCH₃ functionalities were essential, while the presence of 3-OH and 3'-OCH₃ greatly reduced inhibition. The findings of this study provide important information for the exploitation and utilization of citrus PMFs as natural biopreservatives.
authors.affiliation: College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P. R. China.
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Xu
authors.forename: Dan
authors.initials: D
authors.lastname: Cheng
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Yao
authors.forename: Siyi
authors.initials: S
authors.lastname: Pan
mesh_terms: D001234:Aspergillus niger / Q000187:drug effects*; D002957:Citrus / Q000737:chemistry*; D047309:Flavones / Q000737:chemistry* / Q000494:pharmacology*; D005516:Food Microbiology; D005520:Food Preservatives; D005638:Fruit / Q000737:chemistry*; D005659:Fungicides, Industrial / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D013329:Structure-Activity Relationship
chemical_list: D047309:Flavones; D005520:Food Preservatives; D005659:Fungicides, Industrial