{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,14]],"date-time":"2026-05-14T03:48:43Z","timestamp":1778730523017,"version":"3.51.4"},"reference-count":21,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2023,5,5]],"date-time":"2023-05-05T00:00:00Z","timestamp":1683244800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Microbiol."],"abstract":"<jats:sec><jats:title>Background<\/jats:title><jats:p>The antibiotic resistance in various bacteria is consistently increasing and is posing a serious threat to human health, prompting the need for the discovery of novel structurally featured natural products with promising biological activities in drug research and development. Endolichenic microbes have been proven to be a fertile source to produce various chemical components, and therefore these microbes have been on a prime focus for exploring natural products. In this study, to explore potential biological resources and antibacterial natural products, the secondary metabolites of an endolichenic fungus have been investigated.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>The antimicrobial products were isolated from the endolichenic fungus using various chromatographic methods, and the antibacterial and antifungal activities of the compounds were evaluated by the broth microdilution method under <jats:italic>in vitro<\/jats:italic> conditions. The antimicrobial mechanism has been discussed with measuring the dissolution of nucleic acid and protein, as well as the activity of alkaline phosphatase (AKP) in preliminary manner. Chemical synthesis of the active product compound 5 was also performed, starting from commercially available 2,6-dihydroxybenzaldehyde through a sequence of transformations that included methylation, the addition of propylmagnesium bromide on formyl group, the oxidation of secondary alcohol, and the deprotection of methyl ether motif.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Among the 19 secondary metabolites of the endolichenic fungus, <jats:italic>Daldinia childiae<\/jats:italic> (compound 5) showed attractive antimicrobial activities on 10 of the 15 tested pathogenic strains, including Gram-positive bacteria, Gram-negative bacteria, and fungus. The Minimum Inhibitory Concentration (MIC) of compound 5 for <jats:italic>Candida albicans<\/jats:italic> 10213, <jats:italic>Micrococcus luteus<\/jats:italic> 261, <jats:italic>Proteus vulgaris<\/jats:italic> Z12, <jats:italic>Shigella sonnet<\/jats:italic>, and <jats:italic>Staphylococcus aureus<\/jats:italic> 6538 was identified as 16 \u03bcg\/ml, whereas the Minimum Bactericidal Concentration (MBC) of other strains was identified as 64 \u03bcg\/ml. Compound 5 could dramatically inhibit the growth of <jats:italic>S. aureus<\/jats:italic> 6538, <jats:italic>P. vulgaris<\/jats:italic> Z12, and <jats:italic>C. albicans<\/jats:italic> 10213 at the MBC, likely affecting the permeability of the cell wall and cell membrane. These results enriched the library of active strains and metabolites resources of endolichenic microorganisms. The chemical synthesis of the active compound was also performed in four steps, providing an alternative pathway to explore antimicrobial agents.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fmicb.2023.1168386","type":"journal-article","created":{"date-parts":[[2023,5,5]],"date-time":"2023-05-05T06:11:10Z","timestamp":1683267070000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":3,"title":["Chemical synthesis and mechanism of a natural product from endolichenic fungus with a broad-spectrum anti microorganism activity"],"prefix":"10.3389","volume":"14","author":[{"given":"Xuan","family":"Zhou","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ming-Yi","family":"Wang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qian-Ping","family":"Cao","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ze","family":"Yang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qing-Feng","family":"Meng","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shao-Bin","family":"Fu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2023,5,5]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"1079","DOI":"10.1021\/acs.jnatprod.1c01197","article-title":"Assessing microbial metabolic and biological diversity to natural product library assembly.","volume":"85","author":"Anderson","year":"2022","journal-title":"J. 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