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.

Marine Pharmacology in 2012–2013: Marine Compounds with Antibacterial, Antidiabetic, Antifungal, Anti-Inflammatory, Antiprotozoal, Antituberculosis, and Antiviral Activities; Affecting the Immune and Nervous Systems, and Other Miscellaneous Mechanisms of Action

“…[40]; new butenolide cadiolides C–F ( 17 – 20 ) from a Korean tunicate Pseudodistoma antinboja [41]; novel tris-aromatic furanones cadiolides G-I ( 21 – 23 ) from the Korean dark red ascidian Synoicum sp. [42]; xanthones citreamicins θ A and B ( 24 , 25 ), isolated from the Red Sea marine Streptomyces caelestis [43]; two new aromatic polyketides, communols A and F ( 26 , 27 ), isolated from the marine Penicillium commune 518, associated with the gorgonian Muricella abnormalis [44]; two dolabellane diterpenes ( 28 , 29 ), isolated from the Greek brown alga Dilophus spiralis [45]; a novel enhygrolide A ( 30 ), isolated from the obligate marine myxobacterium Enhygromyxa salina from a mud sample from Prerow, Germany [46]; a new β-carboline alkaloid eudistomin Y 11 ( 31 ), isolated from a purple-colored ascidian Synoicum sp. [47]; a new capoamycin-type antibiotic fradimycin B ( 32 ), isolated from the marine Streptomyces fradiae strain PTZ0025 [48]; three novel cyclic bis -1,3 dialkylpyridiniums ( 33 – 35 ) from a Korean sponge Halyclona sp.…”

Isolation, antimicrobial and antitumor potential of endolithic actinobacteria inhabiting diorite rocks of South Sinai, Egypt

“…Nevertheless, the current study provides the first recording of the effectiveness of M. citrea against hepatic carcinoma (HepG2) human cell lines. Although the UV and MALDI/TOF-MS analysis revealed 11% of the extract (18 compound masses) to be in the range of citreamicin group (Liu et al, 2012), further investigation is required to elucidate its chemical nature and assess the active fractions.…”

Antimicrobial Secondary Metabolites—Extraction, Isolation, Identification, and Bioassay

“…Citreamicin A, citreamicin B, and citreaglycon A revealed strong activities against MRSA ATCC 43300 with MIC values of 0.25, 0.25, and 8.0 mg/mL, respectively [97]. A dimeric diketopiperazine, brevianamide S ( Figure 23.10), isolated from Aspergillus versicolor (collected from the Bohai Sea, China), exhibited selective antibacterial activity [98] against Bacille Calmette-Guérin, suggesting a new mechanism of action that could be considered as a new lead for antitubercular drugs.…”