title: Four new antibacterial xanthones from the marine-derived actinomycetes Streptomyces caelestis.
abstract: Four new polycyclic antibiotics, citreamicin θ A (1), citreamicin θ B (2), citreaglycon A (3), and dehydrocitreaglycon A (4), were isolated from marine-derived Streptomyces caelestis. The structures of these compounds were elucidated by 1D and 2D NMR spectra. All four compounds displayed antibacterial activity against Staphylococcus haemolyticus, Staphylococcus aureus, and Bacillus subtillis. Citreamicin θ A (1), citreamicin θ B (2) and citreaglycon A (3) also exhibited low MIC values of 0.25, 0.25, and 8.0 μg/mL, respectively, against methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300.
authors.affiliation: Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China.
authors.forename: Ling-Li
authors.initials: LL
authors.lastname: Liu
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
authors.forename: Zhuang
authors.initials: Z
authors.lastname: Han
authors.forename: Yong-Xin
authors.initials: YX
authors.lastname: Li
authors.forename: Liang
authors.initials: L
authors.lastname: Lu
authors.forename: Pok-Yui
authors.initials: PY
authors.lastname: Lai
authors.forename: Jia-Liang
authors.initials: JL
authors.lastname: Zhong
authors.forename: Xian-Rong
authors.initials: XR
authors.lastname: Guo
authors.forename: Xi-Xiang
authors.initials: XX
authors.lastname: Zhang
authors.forename: Pei-Yuan
authors.initials: PY
authors.lastname: Qian
mesh_terms: D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000187:drug effects; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D013211:Staphylococcus aureus / Q000187:drug effects; D041162:Staphylococcus haemolyticus / Q000187:drug effects; D013302:Streptomyces / Q000737:chemistry*; D044004:Xanthones / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D044004:Xanthones