Tenacibactins K–M, cytotoxic siderophores from a coral-associated gliding bacterium of the genus Tenacibaculum

• Yasuhiro Igarashi,
• Yiwei Ge,
• Tao Zhou,
• Amit Raj Sharma,
• Enjuro Harunari,
• Naoya Oku and
• Agus Trianto

Beilstein J. Org. Chem. 2022, 18, 110–119, doi:10.3762/bjoc.18.12

• ). Conclusion Considering the productivity of siderophores to be an essential trait for the virulence of many microbial pathogens [37], compounds 1–3 could also be involved in the pathogenesis of Tenacibaculum maritimum in fish, which is not well understood [38]. Although the genome size of Tenacibaculum varies

Three new O-isocrotonyl-3-hydroxybutyric acid congeners produced by a sea anemone-derived marine bacterium of the genus Vibrio

• Dandan Li,
• Enjuro Harunari,
• Tao Zhou,
• Naoya Oku and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 1869–1874, doi:10.3762/bjoc.16.154

• , Tenacibaculum maritimum NBRC16015. Structural similarities among 1–4, the O-isocrotonylated 3-hydroxybutyrate oligomers 5, and microbial biopolymer polyhydroxyalkanoates (PHA) suggest the presence of a common biosynthetic machinery, and hence a possible dehydrative modification at the hydroxy terminus of PHA

• . Keywords: 3-hydroxybutyric acid; polyhydroxyalkanoate; sea anemone; Tenacibaculum maritimum; Vibrio; Introduction The genus Vibrio, within the class Gammaproteobacteria, are a group of Gram-negative, halophilic, facultatively anaerobic, rod-shaped bacteria, which are motile with sheathed polar flagella [1

• pathogenic Vibrio species, suggesting the application of PHAs as a biocontrol agent [18]. Although the toxicity of 1–4 toward the producing strain was not tested, they weakly inhibited the growth of Tenacibaculum maritimum, a causative agent of skin ulcers in marine fish, at MIC values of 25 (1), 50 (2), 50

4-Hydroxy-3-methyl-2(1H)-quinolone, originally discovered from a Brassicaceae plant, produced by a soil bacterium of the genus Burkholderia sp.: determination of a preferred tautomer and antioxidant activity

• Dandan Li,
• Naoya Oku,
• Yukiko Shinozaki,
• Yoichi Kurokawa and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 1489–1494, doi:10.3762/bjoc.16.124

• aureus FDA209P JC-1 (Gram-positive bacterium), Rhizobium radiobacter NBRC14554, Ralstonia solanacearum SUPP1541, Tenacibaculum maritimum NBRC16015 (Gram-negative bacteria), Candida albicans NBRC0197, and Saccharomyces cerevisiae S100 (yeasts). Oxidative burst, which is a transient production of massive

Two antibacterial and PPARα/γ-agonistic unsaturated keto fatty acids from a coral-associated actinomycete of the genus Micrococcus

• Amit Raj Sharma,
• Enjuro Harunari,
• Naoya Oku,
• Nobuyasu Matsuura,
• Agus Trianto and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 297–304, doi:10.3762/bjoc.16.29

• assignment of an E geometry at C8 in 2. As metabolites of microbes, compounds 1 and 2 are unprecedented in terms of bearing a 2,4-dienone system. Both 1 and 2 showed antibacterial activity against the plant pathogen Rhizobium radiobacter and the fish pathogen Tenacibaculum maritimum, with a contrasting

• comprehensively analyzed [39], but keto fatty acids like compounds 1 and 2, bearing a dienone system, are unprecedented as microbial metabolites. Compounds 1 and 2 inhibited the growth of Tenacibaculum maritimum NBRC16015, a causative agent of skin infection of marine fish [40], and Rhizobium radiobacter

• bacteria, Micrococcus luteus ATCC9341, Staphylococcus aureus FDA209P JC-1, Rhizobium radiobacter NBRC14554, Escherichia coli NIHJ JC-2, Tenacibaculum maritimum NBRC16015, and two yeasts, Candida albicans NBRC0197 and Saccharomyces cerevisiae S100, as indication strains. Mueller–Hinton Broth (Difco

Two new 2-alkylquinolones, inhibitory to the fish skin ulcer pathogen Tenacibaculum maritimum, produced by a rhizobacterium of the genus Burkholderia sp.

• Dandan Li,
• Naoya Oku,
• Atsumi Hasada,
• Masafumi Shimizu and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2018, 14, 1446–1451, doi:10.3762/bjoc.14.122

• inhibited the growth of the marine bacterium Tenacibaculum maritimum, an etiological agent of skin ulcers in marine fish, offering new opportunities to develop antibacterial drugs for fish farming. Keywords: antimicrobial; Burkholderia; quinolone; skin ulcer; Tenacibaculum maritimum; Findings Bacteria of

• -soluble fractions. Antimicrobial testings against Rhizopus oryzae (the fungal pathogen of rice seedling blight), Trichophyton rubrum (dermatophytosis pathogen), and Tenacibaculum maritimum (the causative organism for skin ulcers in marine fish) revealed that the second fraction was the most active. The

• successively partitioned between 60% MeOH (250 mL) and CH2Cl2 (250 mL × 3) and the latter between 90% aqueous MeOH (150 mL) and n-hexane (150 mL × 3). The aqueous MeOH layer, which concentrated the antibacterial activity against Tenacibaculum maritimum, was subjected to ODS flash chromatography (Ø 3 × 7 cm