Heterologous production of bioactive xenoacremone analogs in Aspergillus nidulans.

Tyrosine-decahydrofluorene derivatives are a class of hybrid compounds that integrate the properties of polyketides and nonribosomal peptides. These compounds feature a [6.5.6] tricarbocyclic core and a para-cyclophane ether moiety in their structures and exhibit anti-tumor and anti-microbial activities. In this study, we constructed the biosynthetic pathway of xenoacremones from Xenoacremonium sinensis ML-31 in the Aspergillus nidulans host, resulting in the identification of four novel tyrosine-decahydrofluorene analogs, xenoacremones I-L (1-4), along with two known analogs, xenoacremones A and B. Remarkably, compounds 3 and 4 contained a 12-membered para-cyclophane ring system, which is unprecedented among tyrosine-decahydrofluorene analogs in X. sinensis. The successful reconstruction of the biosynthetic pathway and the discovery of novel analogs demonstrate the utility of heterologous expression strategy for the generation of structurally diverse natural products with potential biological activities.

Recent advances in gut microbiota-associated natural products: structures, bioactivities, and mechanisms.

Covering: 2014 to June 2022The gut microbiota has attracted increasing attention from researchers due to its critical role in regulating human physiology and pathophysiology. Natural products (NPs) produced or transformed by gut microbes are key signalling mediators for a variety of physiological functions. On the other hand, NPs from ethnomedicines have also been found to generate health benefits through modulation of the gut microbiota. In this highlight, we review the most recent studies related to gut microbiota-derived NPs and bioactive NPs that regulate physiological and pathological processes via gut microbiota-associated mechanisms. We also outline the strategies for the discovery of gut microbiota-derived NPs and the methodologies of how to elucidate the crosstalk between bioactive NPs and the gut microbiota.

Farming of a defensive fungal mutualist by an attelabid weevil.

The mutualism between fungus-growing animals and fungi is a classic example of a complex interspecies association. A handful of insects, notably the well-recognized fungus-farming ants, termites and beetles, have developed advanced agriculture, which includes seeding new gardens with crop propagules, improving growth conditions and protecting and harvesting the fungal crop. More examples, which could be called 'proto-fungiculture', involve fewer adaptations, as exemplified by marine snails that farm intertidal fungi on marsh grass. Recent work has indicated that the solitary leaf-rolling weevil Euops chinensis (family Attelabidae) has a protofarming symbiosis with the mycangial fungus Penicillium herquei (family Trichocomaceae). In this study, we investigated how the weevils create cradles (leaf-rolls) for their offspring and protect the fungal garden. We describe new specialized structures and behaviors that E. chinensis females use for leaf-rolling and fungus inoculation. The fungus P. herquei produces the antibiotic (+)-scleroderolide in laboratory culture and in leaf-rolls, which can serve to inhibit microbial 'weeds' and pests, thus protecting the fungal garden against potential infection. The fungiculture of E. chinensis differs from other advanced insect fungiculture systems because female weevils do not continuously tend the inoculated microbe and do not depend nutritionally on the fungus. The defensive role of the cultivated fungus makes the attelabid weevils exceptional in 'proto-fungiculture' animals.