Nomimicins B–D, new tetronate-class polyketides from a marine-derived actinomycete of the genus Actinomadura

• Zhiwei Zhang,
• Tao Zhou,
• Taehui Yang,
• Keisuke Fukaya,
• Enjuro Harunari,
• Shun Saito,
• Katsuhisa Yamada,
• Chiaki Imada,
• Daisuke Urabe and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2021, 17, 2194–2202, doi:10.3762/bjoc.17.141

• nomimicin, hereafter named nomimicin A, were isolated from the culture extract of Actinomadura sp. AKA43 collected from floating particles in the deep-sea water of Sagami Bay, Japan. The structures of nomimicins B, C, and D were elucidated through the interpretation of NMR and MS analytical data, and the

• cytotoxicity against P388 murine leukemia cells with IC50 values of 33 and 89 μM, respectively. Keywords: Actinomadura; nomimicin; polyketide; spirotetronate; Introduction Actinomycetes are a valuable source of bioactive compounds, accounting for approximately two thirds of all known antibiotics, and more

• actinomycete of the genus Actinomadura. We herein describe the isolation, structure determination, and biological activities of 1‒3. Results and Discussion The producing strain Actinomadura sp. AKA43 was isolated from DSW collected at a depth of −800 m in Sagami Bay, Japan. Strain AKA43 was cultured in A16

A cyclopeptide and three oligomycin-class polyketides produced by an underexplored actinomycete of the genus Pseudosporangium

• Shun Saito,
• Kota Atsumi,
• Tao Zhou,
• Keisuke Fukaya,
• Daisuke Urabe,
• Naoya Oku,
• Md. Rokon Ul Karim,
• Hisayuki Komaki and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 1100–1110, doi:10.3762/bjoc.16.97

• actinomycetes” refers to non-Streptomyces actinomycetes [12] and the representative genera, such as Micromonospora, Actinomadura, Nocardia, Actinoplanes, and Saccharothrix, which are no longer rare in terms of difficulties in isolation, already provided thousands of new metabolites [13][14]. Meanwhile, the