Three New Isoflavonoid Glycosides from the Mangrove-Derived Actinomycete Micromonospora aurantiaca 110B

Abstract

The mangrove ecosystem is a rich resource for the discovery of actinomycetes with potential applications in pharmaceutical science. Besides the genus Streptomyces, Micromonospora is also a source of new bioactive agents. We screened Micromonospora from the rhizosphere soil of mangrove plants in Fujian province, China, and 51 strains were obtained. Among them, the extracts of 12 isolates inhibited the growth of human lung carcinoma A549 cells. Strain 110B exhibited better cytotoxic activity, and its bioactive constituents were investigated. Consequently, three new isoflavonoid glycosides, daidzein-4′-(2-deoxy-α-l-fucopyranoside) (1), daidzein-7-(2-deoxy-α-l-fucopyranoside) (2), and daidzein-4′,7-di-(2-deoxy-α-l-fucopyranoside) (3) were isolated from the fermentation broth of strain 110B. The structures of the new compounds were determined by spectroscopic methods, including 1D and 2D nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectrometry (HR-ESIMS). The result of medium-changing experiments implicated that these new compounds were microbial biotransformation products of strain M. aurantiaca 110B. The three compounds displayed moderate cytotoxic activity to the human lung carcinoma cell line A549, hepatocellular liver carcinoma cell line HepG2, and the human colon tumor cell line HCT116, whereas none of them showed antifungal or antibacterial activities.

Secondary Metabolites from Marine Micromonospora: Chemistry and Bioactivities

“…The fermentation of Micromonospora aurantiaca 110B, which was isolated from mangrove plants in China, led to the discovery of three new isoflavonoid glycosides, daidzein‐4′‐(2‐deoxy‐ α ‐ l ‐fucopyranoside) ( 112 ), daidzein‐7‐(2‐deoxy‐ α ‐ l ‐fucopyranoside) ( 113 ), and daidzein‐4,7‐di‐(2‐deoxy‐ α ‐ l ‐fucopyranoside) ( 114 ). These compounds exhibited moderate cytotoxic activities to A549, HepG2, and HCT‐116 cell lines …”

Naturally Occurring Flavonoids and Isoflavonoids and Their Microbial Transformation: A Review

“…Three novel isoflavonoid glycosides, daidzein-4 -(2-deoxy-α-L-fucopyranoside) (20), daidzein-7-(2-deoxy-α-L-fucopyranoside) (21) and daidzein-4 ,7-di-(2-deoxy-α-L-fucopyranoside) (71) were obtained from the culture broth of mangrove-derived actinomycete Micromonospora aurantiaca 110B. Though the new compounds were unable to inhibit pathogenic fungus or bacteria, they exhibited moderate cytotoxic activities to the human colon tumor cell line HCT116, the human lung carcinoma cell line A549, and hepatocellular liver carcinoma cell line HepG2 [43]. Four isoflavone glycosides were obtained from S. xanthophaeus.…”

“…[58]. A flavonoid glycoside, daidzein-4′,7-di-(2-deoxy-α-L-fucopyranoside) (71), was obtained from actinomycetes, which showed moderate activity against tumor cells of A549, HepG2, and HCT116 [43].…”

“…Four compounds, luteone hydrate (39), luteone metabolite AF-2 (40), BC-1 (41), and BC-2 (42), were obtained from the cocultures of A. flavus and B. cinerea. Five isoflavonoids, M-1-1 (44), M-1-2 (45), M-2 (46), M-3-1 (47), and M-3-2 (48) were isolated from the fungus A. flavus or B. cinereal by converting licoisoflavone A (43). When their inhibitory ability to grow Cladosporium herbarum was tested, compounds 38 and 43 were found to completely inhibit growth at the level of 25-100 μg/cm 2 , while compound 44 had only a small inhibition zone at the level of 100 μg/cm 2 [45].…”

Discovery of Three 22-Membered Macrolides by Deciphering the Streamlined Genome of Mangrove-Derived Streptomyces sp. HM190

“…The antimicrobial activities of compounds 1-3 against pathogenic bacteria Klebsiella pneumoniae, methicillin-resistant Staphylococcus aureus, and pathogenic fungus Candida albicans were detected with the minimum inhibitory concentrations (MICs) method recommended by the Clinical and Laboratory Standards Institute (Wang et al, 2019). Amphotericin B (an antifungal antibiotic) and gentamicin (an antibacterial antibiotic) were used as a positive control.…”