Fungal meroterpenoids are secondary metabolites from mixed terpene-biosynthetic origins. Their intriguing chemical structural diversification and complexity, potential bioactivities, and pharmacological significance make them attractive targets in natural product chemistry, organic synthesis, and biosynthesis. This review provides a systematic overview of the isolation, chemical structural features, biological activities, and fungal biodiversity of 1585 novel meroterpenoids from 79 genera terrestrial and marine-derived fungi including macrofungi, Basidiomycetes, in 441 research papers in 2009–2019. Based on the nonterpenoid starting moiety in their biosynthesis pathway, meroterpenoids were classified into four categories (polyketide–terpenoid, indole-, shikimate-, and miscellaneous-) with polyketide–terpenoids (mainly tetraketide-) and shikimate–terpenoids as the primary source. Basidiomycota produced 37.5% of meroterpenoids, mostly shikimate–terpenoids. The genera of Ganoderma, Penicillium, Aspergillus, and Stachybotrys are the four dominant producers. Moreover, about 56% of meroterpenoids display various pronounced bioactivities, including cytotoxicity, enzyme inhibition, antibacterial, anti-inflammatory, antiviral, antifungal activities. It's exciting that several meroterpenoids including antroquinonol and 4-acetyl antroquinonol B were developed into phase II clinically used drugs. We assume that the chemical diversity and therapeutic potential of these fungal meroterpenoids will provide biologists and medicinal chemists with a large promising sustainable treasure-trove for drug discovery.

Marine-derived fungi are a significant source of pharmacologically active metabolites with interesting structural properties, especially terpenoids with biological and chemical diversity. In the past five years, there has been a tremendous increase in the rate of new terpenoids from marine-derived fungi being discovered. In this updated review, we examine the chemical structures and bioactive properties of new terpenes from marine-derived fungi, and the biodiversity of these fungi from 2015 to 2019. A total of 140 research papers describing 471 new terpenoids of six groups (monoterpenes, sesquiterpenes, diterpenes, sesterterpenes, triterpenes, and meroterpenes) from 133 marine fungal strains belonging to 34 genera were included. Among them, sesquiterpenes, meroterpenes, and diterpenes comprise the largest proportions of terpenes, and the fungi genera of Penicillium, Aspergillus, and Trichoderma are the dominant producers of terpenoids. The majority of the marine-derived fungi are isolated from live marine matter: marine animals and aquatic plants (including mangrove plants and algae). Moreover, many terpenoids display various bioactivities, including cytotoxicity, antibacterial activity, lethal toxicity, anti-inflammatory activity, enzyme inhibitor activity, etc. In our opinion, the chemical diversity and biological activities of these novel terpenoids will provide medical and chemical researchers with a plenty variety of promising lead compounds for the development of marine drugs.

Tetramic acid (pyrrolidine-2,4-dione) compounds, isolated from a variety of marine and terrestrial organisms, have attracted considerable attention for their diverse, challenging structural complexity and promising bioactivities. In the past decade, marine-derived microorganisms have become great repositories of novel tetramic acids. Here, we discuss the biological activities of 277 tetramic acids of eight classifications (simple 3-acyl tetramic acids, 3-oligoenoyltetramic acids, 3-decalinoyltetramic acid, 3-spirotetramic acids, macrocyclic tetramic acids, N-acylated tetramic acids, α-cyclopiazonic acid-type tetramic acids, and other tetramic acids) from marine-derived microbes, including fungi, actinobacteria, bacteria, and cyanobacteria, as reported in 195 research studies up to 2019.

Three new isocoumarins—dichlorodiaportintone (1), desmethyldichlorodiaportintone (2) and desmethyldichlorodiaportinol (3)—as well as six known analogues (4–9) were isolated from the culture of the mangrove endophytic fungus Ascomycota sp. CYSK-4 from Pluchea indica. Their structures were elucidated by analysis of spectroscopic data. The absolute configuration of compounds 1 and 2 were determined by the modified Mosher’s method. Compound 2 showed significant anti-inflammatory activity by inhibiting the production of NO in LPS-induced RAW 264.7 cells with IC₅₀ value of 15.8 μM, while compounds 1, 5, and 6 exhibited weak activities with IC₅₀ values of 41.5, 33.6, and 67.2 μM, respectively. In addition, compounds 1, 5, and 6 showed antibacterial effects against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, and Acinetobacter calcoaceticus with the MIC values in the range of 25–50 μg·mL⁻¹.

Two new sesquiterpenes, microsphaeropsisin B (1) and C (2), and two new de-O-methyllasiodiplodins, (3R, 7R)-7-hydroxy-de-O-methyllasiodiplodin (4) and (3R)-5-oxo-de-O-methyllasiodiplodin (5), together with one new natural product (6) and twelve known compounds (3, 7–17), were isolated from the co-cultivation of mangrove endophytic fungus Trichoderma sp. 307 and aquatic pathogenic bacterium Acinetobacter johnsonii B2. Their structures, including absolute configurations, were elucidated by extensive analysis of spectroscopic data, electronic circular dichroism, Mo₂(AcO)₄-induced circular dichroism, and comparison with reported data. All of the isolated compounds were tested for their α-glucosidase inhibitory activity and cytotoxicity. New compounds 4 and 5 exhibited potent α-glucosidase inhibitory activity with IC₅₀ values of 25.8 and 54.6 µM, respectively, which were more potent than the positive control (acarbose, IC₅₀ = 703.8 µM). The good results of the tested bioactivity allowed us to explore α-glucosidase inhibitors in lasiodiplodins.