Neomacrophorin and premacrophorin congeners from Trichoderma sp. 1212-03

Highly Functionalized Spirobisnaphthalenes from Roussoella sp. KT4147

Highly functionalized spirobisnaphthalenes, preussomerins N (1) and O (2), and simpler compounds, such as 2,3-α-epoxypalmarumycin CP18 (3), 3α-hydroxy-CJ-12,372 (4), and 16 known structurally related congeners, were isolated from a culture broth of Roussoella sp. KT4147. Structural analysis revealed that 1 was a dimer of preussomerin G (6), connected by a nitrogen atom, and 2 was a derivative of 6 with a macommelin substructure. Preussomerin N (1) was considered to be biosynthetically derived via the Michael-type 1,4-addition of ammonia to 6, followed by another Michael addition to another molecule of 6. Contrarily, 2 was suggested to be derived through an endo-Diels-Alder cycloaddition between a diene derived from the (E)-enol form of macommelinal via an ene-reaction and dienophile 6. Compounds 1 and 2 exhibited potent cytotoxicity against COLO-201 human colorectal cancer cells.

The cryptic metabolites and anti-phytopathogenic activities from Nigrospora lacticolonia and Penicillium rubens uncovered by the synergism with host Paris polyphylla, monoculture, and co-culture

The synergism of host Paris polyphylla medium, the monoculture, and the coculture led to seventeen new metabolites, including eight sesquiterpenes, 1-7 having uncommon structural motifs compared to similar caryophyllene derivatives, 8 with an unprecedented bicyclic framework, and three xyloketals (13-15) with unprecedented frameworks from Nigrospora lacticolonia; one polyketide, 17 with novel bicyclo [2.2.2] undecane skeleton, and five polyketide-terpenoid hybrids, 20 (one novel sulfated), 21-24 from Penicillium rubens. The structures were determined mainly by the NMR, HRESIMS, ECD calculation, and single-crystal X-ray diffraction. Nine cryptic compounds (2-4, 5, 12-15, 17) were produced by the inductions of host medium and the coculture. The compounds 13 from N. lacticolonia, 24-26, 28, 29, and 31 from P. rubens indicated significant antiphytopathogenic activities against N. lacticolonia with MICs at 2-4 μg/mL. Moreover, compounds 22-26, 28, 29, and 31 from P. rubens showed antifungal activities against P. rubens with MICs at 2-4 μg/mL. The synergistic effects of host medium and the coculture can induce the structural diversity of metabolites.

Natural epoxyquinoids: isolation, biological activity and synthesis. An update

Epoxyquinoids are of continuing interest due to their wide natural distribution and diverse biological activities, including, but not limited to, antibacterial, antifungal, anticancer, enzyme inhibitory, and others. The last review on their total synthesis was published in 2017. Since then, almost 100 articles have been published on their isolation from nature and their biological profile. In addition, the review specifically considers synthesis, including total and enantioselective, as well as the development of shorter approaches for the construction of epoxyquinoids with complex chemical architecture. Thus, this review focuses on progress in this area in order to stimulate further research.

Structures and Biological Activities of Secondary Metabolites from the Trichoderma genus (Covering 2018-2022)

Trichoderma, a genus with more than 400 species, has a long history of use as an industrial bioreactor, biofertilizer, and biocontrol agent. It is considered a significant source of secondary metabolites (SMs) that possess unique structural features and a wide range of bioactivities. In recent years, numerous secondary metabolites of Trichoderma, including terpenoids, polyketides, peptides, alkaloids, and steroids, have been identified. Most of these SMs displayed antimicrobial, cytotoxic, and antifungal effects. This review focuses on the structural diversity, biological activities, and structure-activity relationships (SARs) of the SMs isolated from Trichoderma covered from 2018 to 2022. This study provides insights into the exploration and utilization of bioactive compounds from Trichoderma species in the agriculture or pharmaceutical industry.

Trichoderma species from plant and soil: An excellent resource for biosynthesis of terpenoids with versatile bioactivities

BACKGROUND

Trichoderma species are rich source of bioactive secondary metabolites. In the past decades, a series of secondary metabolites were reported from different Trichoderma fungi, among which terpenoids possessing versatile structural diversities and extensive pharmacological activities are one of the particularly important categories.

AIM OF REVIEW

The review aims to summarize the terpenoids isolated from Trichoderma species regarding their structural diversities, biological activities, and promising biosynthetic potentials.

KEY SCIENTIFIC CONCEPTS OF REVIEW

So far, a total of 253 terpenoids, including 202 sesquiterpenes, 48 diterpenes, 2 monoterpenes and 1 meroterpenoid, were isolated and identified from Trichoderma species between 1948 and 2022. Pharmacological investigations of Trichoderma terpenoids mainly focused on their antibacterial activities, antifungal activities, inhibitory activities on marine plankton species and cytotoxic activities, indicating that Trichoderma species are important microbial agents for drug discovery and environmentally friendly agrochemicals development. Intriguing chemistry and enzymology involved in the biosynthesis of Trichoderma terpenoids were also presented to facilitate further precise genome mining-guided novel structure discovery. Taken together, the abundance of novel skeletons, bioactivities and biosynthetic potentials presents new opportunities for drug and agrochemicals discovery, genome mining and enzymology exploration from Trichoderma species. The work will provide references for the profound study of terpenoids derived from Trichoderma, and facilitate further studies on Trichoderma species in the areas of chemistry, medicine, agriculture and microbiology.

Trichoderma: A Treasure House of Structurally Diverse Secondary Metabolites With Medicinal Importance

Fungi play an irreplaceable role in drug discovery in the course of human history, as they possess unique abilities to synthesize diverse specialized metabolites with significant medicinal potential. Trichoderma are well-studied filamentous fungi generally observed in nature, which are widely marketed as biocontrol agents. The secondary metabolites produced by Trichoderma have gained extensive attention since they possess attractive chemical structures with remarkable biological activities. A large number of metabolites have been isolated from Trichoderma species in recent years. A previous review by Reino et al. summarized 186 compounds isolated from Trichoderma as well as their biological activities up to 2008. To update the relevant list of reviews of secondary metabolites produced from Trichoderma sp., we provide a comprehensive overview in regard to the newly described metabolites of Trichoderma from the beginning of 2009 to the end of 2020, with emphasis on their chemistry and various bioactivities. A total of 203 compounds with considerable bioactivities are included in this review, which is worth expecting for the discovery of new drug leads and agrochemicals in the foreseeable future. Moreover, new strategies for discovering secondary metabolites of Trichoderma in recent years are also discussed herein.

The chemistry and biology of fungal meroterpenoids (2009-2019)

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.

Identification of neomacrophorins isolated from Trichoderma sp. 1212-03 as proteasome inhibitors

Neomacrophorins I-III (1-3) and X have previously been isolated from Trichoderma sp. 1212-03. Their mode of action against cancer cells and the mechanism of biosynthesis of the characteristic [4.4.3] propellane framework in neomacrophorin X have not been reported. The isolation and characterization of neomacrophorins IV (4), V (5), and VI (6) is reported. Epoxyquinones 1, 4, and 6 potently induced apoptotic cell death in human acute promyelocytic leukemia HL60 cells, while epoxysemiquinols 2, 3, and 5 showed weak activity. This indicates that the epoxyquinone moiety is crucial for apoptosis-inducing activities of neomacrophorins. We also found that neomacrophorins inhibit proteasome in vitro, and 1, 4, and 6 induced significant accumulation of ubiquitinated proteins in HL60 cells. These activities were completely suppressed by a nucleophile, N-acetyl-l-cysteine (NAC). The analysis of reaction mechanisms using LC-MS suggested that C2' and C7' of neomacrophorins could be Michael acceptors in the reaction with NAC methyl ester (NACM). These findings indicated that the electrophilic properties of neomacrophorins are responsible for both their potent biological effects and the biosynthesis of unique [4.4.3] propellane framework in neomacrophorin X.