ABSTRACT
This work aimed to classify Aspergillus (8 species, 28 strains) by using a secondary metabolite profile-based chemotaxonomic classification technique. Secondary metabolites were analyzed by liquid chromatography ion-trap mass spectrometry (LC-IT-MS) and multivariate statistical analysis. Most strains were generally well separated from each section. A. lentulus was discriminated from the other seven species (A. fumigatus, A. fennelliae, A. niger, A. kawachii, A. flavus, A. oryzae, and A. sojae) with partial least-squares discriminate analysis (PLS-DA) with five discriminate metabolites, including 4,6-dihydroxymellein, fumigatin, 5,8-dihydroxy-9- octadecenoic acid, cyclopiazonic acid, and neosartorin. Among them, neosartorin was identified as an A. lentulus-specific compound that showed anticancer activity, as well as antibacterial effects on Staphylococcus epidermidis. This study showed that metabolite-based chemotaxonomic classification is an effective tool for the classification of Aspergillus spp. with species-specific activity.
Subject(s)
Aspergillus/chemistry , Aspergillus/classification , Biological Products/isolation & purification , Biological Products/pharmacology , Anti-Bacterial Agents/isolation & purification , Anti-Bacterial Agents/pharmacology , Antineoplastic Agents/isolation & purification , Antineoplastic Agents/pharmacology , Aspergillus/metabolism , Cell Line, Tumor , Cell Survival/drug effects , Chromatography, Liquid , Epithelial Cells/drug effects , Humans , Mass Spectrometry , Microbial Sensitivity Tests , Secondary Metabolism , Staphylococcus epidermidis/drug effectsABSTRACT
Three sections of Aspergillus (five species, 21 strains) were classified according to culture medium-dependent and time-dependent secondary metabolite profile-based chemotaxonomy. Secondary metabolites were analysed by liquid chromatography-electrospray ionisation tandem mass spectrometry (LC-ESI-MS-MS) and multivariate statistical methods. From the Aspergillus sections that were cultured on malt extract agar (MEA) and Czapek yeast extract agar (CYA) for 7, 12, and 16 d, Aspergillus sections Fumigati (A. fumigatus), Nigri (A. niger), and Flavi (A. flavus, A. oryzae, and A. sojae) clustered separately on the basis of the results of the secondary metabolite analyses at 16 d regardless of culture medium. Based on orthogonal projection to latent structures discriminant analysis by partial least squares discriminant analysis (PLS-DA), we identified the secondary metabolites that helped differentiate sections between A. fumigatus and Aspergillus section Flavi to be gliotoxin G, fumigatin oxide, fumigatin, pseurotin A or D, fumiquinazoline D, fumagillin, helvolic acid, 1,2-dihydrohelvolic acid, and 5,8-dihydroxy-9,12-octadecadienoic acid (5,8-diHODE). Among these compounds, fumagillin, helvolic acid, and 1,2-dihydrohelvolic acid of A. fumigatus showed antifungal activities against Malassezia furfur, which is lipophilic yeast that causes epidermal skin disorders.
Subject(s)
Antifungal Agents/metabolism , Aspergillus fumigatus/metabolism , Antifungal Agents/analysis , Antifungal Agents/pharmacology , Aspergillus fumigatus/chemistry , Culture Media/analysis , Culture Media/metabolism , Cyclohexanes/analysis , Cyclohexanes/metabolism , Cyclohexanes/pharmacology , Fatty Acids, Unsaturated/analysis , Fatty Acids, Unsaturated/metabolism , Fatty Acids, Unsaturated/pharmacology , Fusidic Acid/analogs & derivatives , Fusidic Acid/analysis , Fusidic Acid/metabolism , Fusidic Acid/pharmacology , Malassezia/drug effects , Sesquiterpenes/analysis , Sesquiterpenes/metabolism , Sesquiterpenes/pharmacologyABSTRACT
Xanthomonas oryzae causes rice bacterial blight, which has been reported as one of the most destructive diseases of rice. Metabolites were identified through cheonggukjang, a traditional Korean fermented soybean product fermented by the Bacillus spp., to control the bacteria. HPLC, MS, and UPLC-Q-TOF-MS analyses were performed to identify metabolites responsible for antimicrobial activity. In this analysis, the m/z values of 253.0498, 283.0600, 269.0455, 992.6287, and 1,006.6436 were identified as daidzein, glycitein, genistein, surfactin B, and surfactin A, respectively. The levels of surfactin B and surfactin A were found to be high at 24 h (4.35 µg/ml) and 36 h (3.43 µg/ml) of fermentation, respectively.
Subject(s)
Anti-Bacterial Agents/isolation & purification , Anti-Bacterial Agents/metabolism , Bacillus/metabolism , Food Microbiology , Xanthomonas/drug effects , Anti-Bacterial Agents/chemistry , Bacillus/growth & development , Chromatography, High Pressure Liquid , Fermentation , Mass Spectrometry , Models, Molecular , Molecular Structure , Molecular Weight , Oryza/microbiology , Glycine max/microbiology , Xanthomonas/growth & developmentABSTRACT
Liquid chromatography mass spectrometry and multivariate analysis were employed to investigate the correlation between fermentation time-dependent metabolite changes in cheonggukjang, a traditional fermented soybean product, and changes in its antioxidant activity over 72 h. The metabolite patterns were clearly distinguished not by strains but by fermentation time, into patterns I (0-12 h), II (12-24 h), and III (24-72 h), which appeared as distinct clusters on principal component analysis. The compounds that significantly contributed to patterns I, II, and III were soyasaponins, isoflavonoid derivatives, and isoflavonoid aglycons respectively. Partial least square analysis for metabolite to antioxidant effects showed correlations between the ferric reducing/antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay during 24-36 h, and 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) test and total phenol content (TPC) during 36-72 h. Compared with the strong negative correlations of glucosylated-isoflavonoids with DPPH, ABTS and TPC during fermentation, the isoflavonoid aglycon displayed strong positive correlations with these compounds during fermentation.
