Structurally Various Sorbicillinoids From an Endophytic Fungus Acremonium citrinum SS-g13

The fungal natural product class of the sorbicillinoids: structures, bioactivities, biosynthesis, and synthesis

Covering 1948 up to October 2024Sorbicillinoids are a growing class of natural products (NPs) that stem from a variety of fungi including members of the orders Hypocreales and Eurotiales. This compound class is unique in its combination of structural complexity and pharmaceutically relevant biological activities. The majority of the sorbicillinoids, which are named after the common hexaketide precursor sorbicillin, exhibit anti-inflammatory, antimicrobial, cytotoxic, phytotoxic, and other selective enzyme inhibitory activities. Over the last eight decades, more than 170 sorbicillinoids, many with strong pharmaceutical potential, have been isolated and described in the literature. This review aims to provide an overview of the structural diversity, biosynthetic pathways, and synthetic studies of this exceptional NP class.

Bioactive sorbicillinoid derivatives from an endophytic fungus Trichoderma citrinoviride

Three new sorbicillinoid derivatives, citrinsorbicillinol A-C (1-3), along with three known compounds, such as trichosorbicillin G (4), dibutyl phthalate (5), and 3-(4-methoxyphenyl) propanoic acid (6), were isolated from the endophyte Trichoderma citrinoviride of Coptis chinensis. Their structures were elucidated through extensive analyses of spectroscopic data, computer-assisted structure elucidation (ACD/Structure Elucidator), density functional theory (DFT) calculations of the nuclear magnetic resonance (NMR) spectra, and electronic circular dichroism (ECD). Biologically, compounds 1-4 exhibited potential antioxidant activity, as assessed using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, with IC50 values ranging from 27.8 to 89.6 μM. In particular, compounds 2 and 3 demonstrated radical scavenging activity comparable to that of the positive control, ascorbic acid, with IC50 values of 27.8 and 31.2 μM, respectively. Moreover, compound 1 exhibited potential anti-inflammatory activity by inhibiting nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages, with an IC50 value of 52.7 μM. These findings underscore the therapeutic potential of the new sorbicillinoid derivatives for antioxidant and anti-inflammatory applications.

MFS Transporter as the Molecular Switch Unlocking the Production of Cage-Like Acresorbicillinol C

Sorbicillinoids are a class of fungal polyketides with diverse structures and distinguished bioactivities. Although remarkable progress has been achieved in their chemistry and biosynthesis, the efflux of sorbicillinoids is poorly understood. Here, we found MFS transporter AcsorT was responsible for the biosynthesis of sorbicillinoids in Acremonium chrysogenum. Combinatorial knockout and subcellular location demonstrated that the plasma membrane-associated AcsorT was responsible for the transportation of sorbicillinol and subsequent formation of oxosorbicillinol and acresorbicillinol C via the berberine bridge enzyme-like oxidase AcsorD in the periplasm. Homology modeling and site-directed mutation revealed that Tyr303 and Arg436 were the key residues of AcsorT, which was further explained by molecular dynamics simulation. Based on our study, it was suggested that AcsorT modulates sorbicillinoid production by coordinating its biosynthesis and export, and a transport model of sorbicillinoids was proposed in A. chrysogenum.

Anti-inflammatory monomeric sorbicillinoids from the marine-fish-derived fungus Trichoderma sp. G13

Four new monomeric sorbicillinoids, trichillinoids A - D (1-4), along with two known dimeric sorbicillinoids (5 and 6), and five known monomeric sorbicillinoids (7-11), were obtained from the marine-fish-derived fungus Trichoderma sp. G13. They were structurally characterized on the basis of comprehensive spectroscopic investigations (NMR, HRESIMS, and ECD). Compounds 1-4 displayed moderate anti-inflammatory activities, according to inhibiting the production of NO in RAW264.7 cells activated with IC50 values ranging from 14 to 20 μM.

Recent Advances in Chemistry and Bioactivities of Secondary Metabolites from the Genus Acremonium

Acremonium fungi is one of the greatest and most complex genera in Hyphomycetes, comprising 130 species of marine and terrestrial sources. The past decades have witnessed substantial chemical and biological investigations on the diverse secondary metabolites from the Acremonium species. To date, over 600 compounds with abundant chemical types as well as a wide range of bioactivities have been obtained from this genus, attracting considerable attention from chemists and pharmacologists. This review mainly summarizes the sources, chemical structures, and biological activities of 115 recently reported new compounds from the genus Acremonium from December 2016 to September 2023. They are structurally classified into terpenoids (42%), peptides (29%), polyketides (20%), and others (9%), among which marine sources are predominant (68%). Notably, these compounds were primarily screened with cytotoxic, antibacterial, and anti-inflammatory activities. This paper provides insights into the exploration and utilization of bioactive compounds in this genus, both within the scientific field and pharmaceutical industry.

Major Facilitator Superfamily Transporter Participates in the Formation of Dimeric Sorbicillinoids Pigments

Understanding the biosynthetic pathways of fungal pigments can help elucidate their roles in fungal growth processes. Trichodimerol is a unique cage-like dimeric sorbicillinoids pigment that is commonly isolated from many fungi, however, its biosynthesis is just partially clarified. In this study, we report that a biosynthetic gene cluster encoded major facilitator superfamily transporter (StaE) from the fungus Stagonospora sp. SYSU-MS7888 is involved in the formation of trichodimerol, together with several other dimeric sorbicillinoids. Using Aspergillus oryzae NSARI as a heterologous host, we demonstrated that the formation of dimeric sorbicillinoids required co-expression of the transporter StaE with biosynthetic genes (two PKSs and one monooxygenase) that are responsible for constructing the monomer precursor sorbicillinol. Fluorescence microscopy results showed that eGFP-tagged StaE is localized on the endoplasmic reticulum, suggesting that sorbicillinoid dimerizations might be compartmentalized in this organelle.