Homoseongomycin, a compound isolated from marine actinomycete bacteria K3-1, is a potent inhibitor of encephalitic alphaviruses

Marine Pharmacology in 2019‐2021: 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

“…Li and colleagues described two novel sesquiterpene-based analogues harzianoic acids A and B (45,46), discovered in the marine sponge-associated fungus Trichoderma harzianum, that inhibited hepatitis C virus (HCV) life cycle in vitro by binding to both the HCV viral envelope E1/E2 glycoproteins as well as the host cells key protein CD81, thus suggesting "potential for development as HCV inhibitors" [57]. Lin and colleagues characterized the polyketide homoseongomycin (47), found in the marine actinomycete bacterium K3-1, that potently inhibited Venezuelan and Eastern equine encephalitis viruses, by affecting both the early and late stages (assembly and budding) of the viral life cycle, with concomitant low toxicity [58]. Tan and colleagues determined that a natural xanthone dimer polyketide penicillixanthone A (48), isolated from a marine jellyfish-derived fungus Aspergillus fumigates, potently inhibited HIV-1 by binding to white blood cell membrane receptors C-C chemokine receptor type 5 (CCR5) and C-C chemokine receptor type 4 (CCR4), thus suggesting that this new type of CCR5/CXCR4 dual-coreceptor antagonist has potential " for the development of anti-HIV therapeutics" [59].…”

“…Wen and colleagues identified the polyketide phenolic aglycone (58), derived from the marine fungus Aspergillus sp., and showed that it decreased LPS-induced NO production and NF-kBregulated cytokines such as IL-1β and IL-6 [72]. Keeler and colleagues investigated the polyketide brevenal (59), isolated from the marine dinoflagellate Karenia brevis, showing that in the context of lung inflammation, it blocked NF-kB activation and development of fully activated macrophages in vitro, which are critical players that promote lung inflammation [73].…”

Advances in the Development of Small Molecule Antivirals against Equine Encephalitic Viruses

“…Homoseongomycin is a marine natural product that was found during a high throughput screen [ 179 ] aimed at identifying compounds with activity against VEEV ( Figure 12 , Table 4 ). In Vero cells, homoseongomycin inhibited VEEV with EC 50 values of 8.6 µM (TC83-luc assay) and 9.1 µM (ZPC738 strain).…”

“…Time of addition studies showed that homoseongomycin significantly inhibited VEEV entry as well as later stages of viral infection. The intermediacy of host factors in the observed antiviral effects of homoseongomycin is undetermined at this time but these experiments and assessments in animal models are proposed [ 179 ].…”

Marine Bacterial Secondary Metabolites: A Treasure House for Structurally Unique and Effective Antimicrobial Compounds

“…In another recent work, a novel antiviral compound, namely homoseongomycin, was isolated from marine sponge-associated actinomycete bacteria K3-1. It showed potent antiviral activity against alphaviruses, such as the eastern and Venezuelan equine encephalitis viruses, with 50% effective concentrations of 1.2 and 8.6 µM, respectively [207]. Mitova et al isolated a novel cyclopeptide compound, namely, cyclo-(glycyl-L-seryl-Lprolyl-L-glutamyl) (Figure 11, Compound 31) from the extract of marine Agrobacterium (Ruegeria strain) associated with the sponge Suberites domuncula.…”