Rifamorpholines A–E, potential antibiotics from locust-associated actinobacteria Amycolatopsis sp. Hca4

Abstract

Cultivation of locust associated rare actinobacteria, Amycolatopsis sp. HCa4, has provided five unusual macrolactams rifamorpholines A-E. Their structures were determined by interpretation of spectroscopic and crystallographic data. Rifamorpholines A-E possess an unprecedented 5/6/6/6 ring chromophore, representing a new subclass of rifamycin antibiotics. The biosynthetic pathway for compounds 1-5 involves a key 1,6-cyclization for the formation of the morpholine ring. Compounds 2 and 4 showed potent activities against methicillin-resistant Staphylococcus aureus (MRSA) with MICs of 4.0 and 8.0 μM, respectively.

The secondary metabolites of rare actinomycetes: chemistry and bioactivity

“…Rifamorpholines B and D showed signicant activities towards methicillinresistant Staphylococcus aureus (MRSA) (MICs ¼ 4.0 and 8.0 mM, respectively). 9 Two novel enediyne-derived natural products, amycolamycin A and B (9-10) with a special 2-(cyclopenta[a]-inden-5-yl) oxirane core also were characterized from the same rare actinomycete Amycolatopsis sp. HCa4.…”

Comparative Genomics and Biosynthetic Potential Analysis of Two Lichen-Isolated Amycolatopsis Strains

“…Among Pseudonocardiaceae , members of the genus Amycolatopsis produce several relevant secondary metabolites, such as balhimycin, vancomycin, avoparcin, ristomycin, chelocardin, chloroeremomycin, ECO-0501 and rifamycin (Chen et al, 2016 ; Kumari et al, 2016 ). More recently, other antibiotics have been described from some Amycolatopsis strains such as macrotermycins A–D (Beemelmanns et al, 2017 ), pargamicins B–D (Hashizume et al, 2017 ) and rifamorpholines A–E (Xiao et al, 2017 ). In addition, the importance of Amycolatopsis strains in industrial processes such as bioremediation (heavy metal immobilization, herbicide and polymers biodegradation) and bioconversion (wuxistatin and vanillin production) (Dávila Costa and Amoroso, 2014 ), has been clearly demonstrated.…”

New Antibacterial Phenone Derivatives Asperphenone A–C from Mangrove-Derived Fungus Aspergillus sp. YHZ-1

“…The in vitro antibacterial activity of compounds 1 and 2 were evaluated against four bacteria including Staphylococcus aureus CMCC(B) 26003, Streptococcus pyogenes ATCC19615, Bacillus subtilis CICC 10283 and Micrococcus luteus in accordance with previously reported methods [ 14 , 15 ]. In the assays, the medium used in the test was Müller-Hinton (MH) broth.…”

“…In the past several years, our research group has explored many novel secondary metabolites from mangrove-derived endophytic fungi, such as sesquiterpenoids diaporols A-I, diaporine with regulation activity of macrophage differentiation and other polyketides [ 10 , 11 , 12 ]. As part of our ongoing search for novel biologically active natural products from microbe from special environment [ 13 , 14 ], we chemically investigated an endophytic fungus, Aspergillus sp. YHZ-1, from mangrove plant from Hainan Island, China.…”