Harzianolides B-G: Undescribed Butenolides isolated from the fungus Trichoderma harzianum ZN-4.

Five undescribed γ-butyrolactones harzianolides BF (1-5), one precursor harzianolide G (6) along with two known analogues, were isolated and identified from the EtOAc extract of the liquid fermentation of Trichoderma harzianum ZN-4, which was obtained from the sediment of Zhoushan coastal area. Notably, compound 1 featured an unusual carbon skeleton with methylene-bridged furan rings system. Their structures were determined by detailed interpretation of NMR and mass spectroscopic data, and the absolute configurations were unambiguously established based on ECD quantum chemical calculations. In bioassay, 1 and 7 showed inhibitory activity against Pestalotiopsis theae, with MIC values of 25 and 50 µg/mL, respectively.

Specialized metabolites of the fungal genus Phomopsis: Structures, bioactivities and biosynthesis.

Fungi are important resources of novel bioactive compounds which have a high potential to be drug leads or candidates for further pharmacological applications. Phomopsis, a genus widely distributed in the environment, can produce various types of compounds including polyketides, alkaloids, terpenoids, cytochalasins, steroids and flavonoids. The metabolites of Phomopsis sp. showed diverse bioactivities such as antibacterial, anti-inflammatory, antimalarial, and so on, many of which may influence the physiological behaviour of the host plants. In this review, we focus on the chemical structures and biological activities of 183 specialized metabolites isolated from Phomopsis sp. in the decade (2013-2022). Moreover, the biosynthetic pathways of some typical components are summarized.

Exploring gabosine and chlorogentisyl alcohol derivatives from a marine-derived fungus as EcGUS inhibitors with informatic assisted approaches.

ß-Glucuronidase catalyzes the cleavage of glucuronosyl-O-bonds, whose inhibitors reduce the level of toxic substances present in the intestine caused by anti-cancer and anti-inflammatory therapies. Herein, we presented a new tool, Bioactive Fractions Filtering Platform (BFFP), which is able to reliably discern active candidate node from crude extracts. The source code for the BFFP is available on GitHub (https://github.com/BioGavin/msbff). With the assistant of BFFP, 25 gabosine and chlorogentisyl alcohol derivatives including 19 new compounds were isolated from a marine-derived fungus Epicoccum sp. GST-5. Compounds 7, 9-15 possessed an unusual hybrid skeleton of gabosine and chlorogentisyl alcohol units. Compounds 9-12, 16 and 17 possessed a novel three-membered spiral ring skeleton with one/two gabosine and one/two chlorogentisyl alcohol units. Compound 25 represented new gabosine-derived skeleton possessing an unusual 6/6/6/5/6 condensed ring system. All isolates were evaluated for in vitro E. coli ß-glucuronidase (EcGUS) inhibitory activity. 14 Compounds demonstrated superior inhibitory activity (IC50 = 0.24-4.61 µM) to that of standard d-saccharic acid 1,4-lactone (DSL, IC50 = 56.74 ± 4.01 µM). Compounds with chlorogentisyl alcohol moiety, such as 17 (IC50 = 0.24 ± 0.02 µM) and 1 (IC50 = 0.74 ± 0.03 µM), exhibited the most potent inhibitory activity. Furthermore, literature based QSAR profiling by applying PCA and OPLS analysis was carried out to analyze the features of compounds against EcGUS, revealing that the introduction of substituents able to form polar interactions with binding sites of receptor would lead to more active structures.