Metabolites from marine invertebrates and their symbiotic microorganisms: molecular diversity discovery, mining, and application

Abstract

Metabolites from marine organisms have proven to be a rich source for the discovery of multiple potent bioactive molecules with diverse structures. In recent years, we initiated a program to investigate the diversity of the secondary metabolites from marine invertebrates and their symbiotic microorganisms collected from the South China Sea. In this review, representative cases are summarized focusing on molecular diversity, mining, and application of natural products from these marine organisms. To provide a comprehensive introduction to the field of marine natural products, we highlight typical molecules including their structures, chemical synthesis, bioactivities and mechanisms, structure-activity relationships as well as biogenesis. The mining of marine-derived microorganisms to produce novel secondary metabolites is also discussed through the OSMAC strategy and via partial chemical epigenetic modification. A broad prospectus has revealed a plethora of bioactive natural products with novel structures from marine organisms, especially from soft corals, gorgonians, sponges, and their symbiotic fungi and bacteria.

New Thiodiketopiperazine and 3,4-Dihydroisocoumarin Derivatives from the Marine-Derived Fungus Aspergillus terreus

“…It should be noted that the known compound 3 is listed in SciFinder Scholar with the CAS Registry Number 2166398-50-9, but this is the first time that its spectroscopic data have been reported. (3R)-8-methoxy-6-hydroxymellein (8) was obtained as a yellow solid with the molecular formula C11H12O4 determined by the HRESIMS data, with more than 14 Da compared with the co-isolated known compound (3R)-6-hydroxymellein (12). The 1 H NMR data of 8 displayed the presence of the (3R)-8-methoxy-6-hydroxymellein (8) was obtained as a yellow solid with the molecular formula C 11 H 12 O 4 determined by the HRESIMS data, with more than 14 Da compared with the co-isolated known compound (3R)-6-hydroxymellein (12).…”

“…(3R)-8-methoxy-6-hydroxymellein (8) was obtained as a yellow solid with the molecular formula C11H12O4 determined by the HRESIMS data, with more than 14 Da compared with the co-isolated known compound (3R)-6-hydroxymellein (12). The 1 H NMR data of 8 displayed the presence of the (3R)-8-methoxy-6-hydroxymellein (8) was obtained as a yellow solid with the molecular formula C 11 H 12 O 4 determined by the HRESIMS data, with more than 14 Da compared with the co-isolated known compound (3R)-6-hydroxymellein (12). The 1 H NMR data of 8 displayed the presence of the meta-coupled aromatic protons at δ H 5.80 (1H, d, J = 1.9 Hz) and at δ H 5.71 (1H, d, J = 1.9 Hz).…”

“…During our ongoing research for novel bioactive secondary metabolites from marine-derived Aspergillus species, we found a series of bioactive natural products with antifungal, antibacterial, antiviral, antifouling, and cytotoxic activities [12]. In the present study, the chemical investigation of the ethyl acetate (EtOAc) extract of Aspergillus terreus RA2905, isolated from the fresh inner tissue of the sea hare Aplysia pulmonica, resulted in the identification of two new thiodiketopiperazines, emestrins L (1) and M (2), as well as five known analogues (3)(4)(5)(6)(7), and five known dihydroisocoumarins (8)(9)(10)(11)(12) (Figure 1). Herein, we report the isolation, structural determination, and bioactivity evaluation of these compounds.…”

Three nitrogen-containing metabolites from an algicolous isolate of Trichoderma asperellum

“…Marine fungi have proven to be a large reservoir of structurally unique and biologically active compounds (Cao and Wang 2020;Liu et al 2019). So far, over 2000 new natural products have been discovered from marine fungi, such as nitrogen-containing metabolites, sulfur-bearing compounds, and halogenated structures, even some of them with clinically relevant pharmacological activities (Jia et al 2015;Meng et al 2013;Newman and Cragg 2016;Rateb and Ebel 2011;Wang et al 2018).…”

Marine life science and technology (MLST): a new journal highlighting all aspects of marine biology and biotechnology research

“…The secondary metabolites from marine invertebrates and their symbiotic microorganisms represent a promising and valuable source for drug discovery. In our seventh paper, Liu et al (2019b) provide a comprehensive introduction to marine natural products research. Multiple strategies and methods have been applied to find novel marine natural products with diverse structures and promising activities, including OSMAC (one strain many compounds), chemical epigenetic manipulation, co-culture, structural modification, and chemical synthesis.…”