{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T04:54:58Z","timestamp":1787028898002,"version":"build-2736575974"},"reference-count":21,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2019,3,21]],"date-time":"2019-03-21T00:00:00Z","timestamp":1553126400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"the National Key Research and Development Program of China","award":["2018YFC0311002"],"award-info":[{"award-number":["2018YFC0311002"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Marine Drugs"],"abstract":"<jats:p>Two new piperazine-triones lansai E and F (1, 2), together with four known secondary metabolites lansai D (3), 1-N-methyl-(E,Z)-albonoursin (4), imidazo[4,5-e]-1,2,4-triazine (5), and streptonigrin (6) were isolated from a deep-sea-derived Streptomycetes sp. strain SMS636. The structures of the isolated compounds were confirmed by comprehensive spectroscopic analysis, including HRESIMS, 1D and 2D NMR. Compound 4 exhibited moderate antibacterial activities against Staphylococcus aureus and methicillin resistant S. aureus (MRSA) with Minimum Inhibitory Concentration (MIC) values of 12.5 and 25 \u03bcg\/mL, respectively. Compound 6 displayed significant antibacterial activities against S. aureus, MRSA and Bacillus Calmette-Gu\u00e9rin (BCG) with MIC values of 0.78, 0.78 and 1.25 \u03bcg\/mL, respectively.<\/jats:p>","DOI":"10.3390\/md17030186","type":"journal-article","created":{"date-parts":[[2019,3,21]],"date-time":"2019-03-21T12:28:01Z","timestamp":1553171281000},"page":"186","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["Two New Piperazine-Triones from a Marine-Derived Streptomycetes sp. Strain SMS636"],"prefix":"10.3390","volume":"17","author":[{"given":"Xiuli","family":"Xu","sequence":"first","affiliation":[{"name":"School of Ocean Sciences, China University of Geosciences, Beijing 100083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiahui","family":"Han","sequence":"additional","affiliation":[{"name":"School of Ocean Sciences, China University of Geosciences, Beijing 100083, China"},{"name":"CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rui","family":"Lin","sequence":"additional","affiliation":[{"name":"School of Ocean Sciences, China University of Geosciences, Beijing 100083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8458-5194","authenticated-orcid":false,"given":"Steven W.","family":"Polyak","sequence":"additional","affiliation":[{"name":"School of Pharmacy and Medical Sciences, University of South Australia, Adelaide 5000, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9162-3355","authenticated-orcid":false,"given":"Fuhang","family":"Song","sequence":"additional","affiliation":[{"name":"CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2019,3,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"629","DOI":"10.1021\/acs.jnatprod.5b01055","article-title":"Natural products as sources of new drugs from 1981 to 2014","volume":"79","author":"Newman","year":"2016","journal-title":"J. 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