Gombapyrones E and F, New α-Pyrone Polyenes Produced by Streptomyces sp. KMC-002

Abstract

Microorganism-derived polyene polyketides have been shown to display a variety of biological activities and have attracted great interest due to their structurally intriguing chemical diversity. Two new polyenes were isolated from a culture broth of Streptomyces sp. KMC-002 obtained from a soil sample in an abandoned mine. The structures of these compounds were determined to be α-pyrone-containing polyene analogues through analyses of HRFABMS, UV and NMR data, and were named Gombapyrones E (1) and F (2). Gombapyrone E (1) showed antibacterial activity against Micrococcus luteus, Enterococcus hirae, Staphylococcus aureus and MRSA.

Antibacterial Polyketides from the Marine Alga-Derived Endophitic Streptomyces sundarbansensis: A Study on Hydroxypyrone Tautomerism

“…In a further investigation in order to define MIC values against MRSA, E. coli and P. aeruginosa , interestingly 13 showed selective antimicrobial activities (MIC = 2 μg/mL = 6.0 μM, Table 3) against MRSA, a bacterium responsible for human infections which is difficult to treat, showing resistance to penicillins and cephalosporins and mainly found among people with a greater risk of infection. Current findings are in line with the activities against S. aureus and MRSA bacteria, observed for the 4-hydroxy α-pyronepolyene, gombapyrone E [9]. It is noteworthy that compound 13 showed selective antibacterial activity against MRSA, but no growth inhibition against S. aureus ATCC 25923.…”

“…Polyketides represent a highly diverse structural class of products found also in bacteria, demonstrating varied biological functions [9]. Over the past decades, the isolation and structural characterization of shunt products from act mutants of Streptomyces coelicolor derived by classical mutagenesis led to the elucidation of several compounds, which typically show the presence of: (i) a methyl group, as in mutactin ( 1 ), dehydrated mutactin ( 2 ), SEK34 ( 3 ) and its dehydrated SEK34b ( 4 ) [10,11,12]; (ii) a phenyl group, in wailupemycin F ( 5 ) and G ( 6 ) isolated using mutational analysis [13]; (iii) a propyl chain in metabolites recently isolated from an actinomycete strain Streptomyces phaeochromogenes LL-P018, phaeochromycin A–E ( 7 – 11 ) [14].…”

Screening and Whole-Genome Sequencing of TwoStreptomycesSpecies from the Rhizosphere Soil of Peony Reveal Their Characteristics as Plant Growth-Promoting Rhizobacteria

“…However, up to now, the biocontrol capacities and mechanisms of S. alboflavus as PGPR have not been effectively investigated. For species S. albireticuli , its biological research is even less to date [ 26 ] and its biological control capacity and genetic mechanism as PGPR have not yet been exploited.…”

Epipyrone A, a Broad-Spectrum Antifungal Compound Produced by Epicoccum nigrum ICMP 19927

“…However, compared to the other polyene antifungal drugs, the chemical structure of epipyrone A is significantly different as it is linear and not cyclic like other known antifungal polyene drugs such as amphotericin B and nystatin. Besides, epipyrone A possesses α-pyrone moiety that is glycosylated, which is rare in nature, increasing its solubility in water [ 3 , 34 ]. Several antifungal compounds with structural differences to other members of the same antifungal drug family showed significantly altered biological activities [ 31 , 34 ], with varied spectra of antifungal activity [ 35 , 36 , 37 ], and potentially presented additional modes of action [ 38 , 39 , 40 ].…”