Neuraminidase Inhibitors from marine-derived actinomycete Streptomyces seoulensis

Abstract

Aims: This work was performed to characterize new secondary metabolites with neuraminidase (NA) inhibitory activity from marine actinomycete strains. Methods and Results: An actinomycete strain IFB-A01, capable of producing new NA inhibitors, was isolated from the gut of shrimp Penasus orientalis and identified as Streptomyces seoulensis according to its 16S rRNA sequence (over 99% homology with that of the standard strain). Repeated chromatography of the methanol extract of the solid-substrate culture of S. seoulensis IFB-A01 led to the isolation of streptoseolactone (1), and limazepines G (2) and H (3). The structures of 1-3 were determined by a combination of IR, ESI-MS, 1D ( 1 H and 13 C NMR, and DEPT) and 2D NMR experiments (HMQC, HMBC, 1 H-1 H COSY and NOESY). Compounds 1-3 showed significant inhibition on NA in a dose-dependent manner with IC 50 values of 3Á92, 7Á50 and 7Á37 lmol l À1 , respectively.Conclusions: This is the first report of two new (1 and 2) and known (3, recovered as a natural product for the first time in the work) NA inhibitors from the marine-derived actinomycete S. seoulensis IFB-A01. Significance and Impact of the Study: The three natural NA inhibitors maybe of value for the development of drug(s) necessitated for the treatment of viral infections.

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

“…Ma and colleagues determined that the novel phenylspirodrimane stachybotrin D ( 101 ), isolated from the fungus Stachybotrys chartarum MXH-X73 derived from the Chinese marine sponge Xestospongia testudinaria , inhibited HIV-1 replication of wild-type and five non-nucleoside reverse transcriptase inhibitor (NNRTI)-resistant HIV-1 strains by inhibiting the reverse transcriptase, and thus “provides a new class of chemotype for the search of NNRT inhibitors” [100]. Jiao and colleagues reported that streptoseolactone ( 102 ), derived from the actinomycete Streptomyces seoulensis strain isolated from the shrimp Penasus orientalis , inhibited neuraminidase by a noncompetitive mechanism, a finding “of value in terms of drug discovery for the treatment of influenza” [101]. …”

Dereplication Strategies for Targeted Isolation of New Antitrypanosomal Actinosporins A and B from a Marine Sponge Associated-Actinokineospora sp. EG49

“…Marine actinomycetes are still an underexplored source of secondary metabolites and lead molecules with biotechnological, therapeutic, and industrial applications [20,21]. Metabolites from these microorganisms were shown to exhibit diverse activities, such as antibacterial, antifungal, antiparasitic, immunomodulatory, anti-inflammatory, anti-protease, antioxidant, and anticancer activities [22,23,24,25].…”

Nuclear Magnetic Resonance Spectroscopy for Structural Characterization of Bioactive Compounds

“…The combination of COSY, HMQC, and HMBC confirmed this proposal and led to the exact assignment of all 1 H and 13 C signals. In particular, the key HMBC correlations are: (1) H-6 with C-5 (amide carbonyl) and C-9a and H-7 with methyl and aromatic oxygenated carbons confirmed the substitution pattern of the benzene ring; (2) H-12 with C-1, C-3 and C-14 proves the anchorage of the 1-propenyl group at C-2 [23] (Figure 7.8).…”