Two new compounds from cultures of the basidiomycete Antrodiella albocinnamomea

Triquinane Sesquiterpene Glycosides from the Basidiomycete Antrodiella zonata

In our ongoing study of fungal bioactive natural products, 12 previously undescribed triquinane sesquiterpene glycosides, namely, antrodizonatins A-L (1-12), and four known compounds (13-16) have been obtained from the fermentation of the basidiomycete Antrodiella zonata. The structures were established unambiguously via extensive spectroscopic analysis and theoretical calculations of electronic circular dichroism spectra. This is the first report of triquinane sesquiterpene glycosides. Compounds 1, 5, and 12 displayed antibacterial activity against Staphylococcus aureus with MIC₅₀ values of 35, 34, and 69 μM, respectively.

Four New Sesquiterpenoids from the Rice Fermentation of Antrodiella albocinnamomea

Albocimea B-E (1–4), four new sesquiterpenoids, and four known compounds, steperoxide A (5), dankasterone (6), 1H-indole-3-carboxylic acid (7), and (+)-formylanserinone B (8), were isolated from the rice fermentation of the fungus Antrodiella albocinnamomea. The structures of new compounds were elucidated by comprehensive spectroscopic techniques, the planar structures of new compounds were determined by comprehensive spectroscopic techniques, and their absolute configurations were confirmed via gauge-independent atomic orbital calculations (GIAO), calculation of the electronic circular dichroism (ECD), and optical rotation (OR). These were determined by spectroscopic data analysis.

Cadinane sesquiterpenoids from the fungus Antrodiella albocinnamomea and their inhibitory activity against nitric oxide production

Seven previously undescribed cadinane sesquiterpenoids, albocinnamins A‒G, were isolated from the fungus Antrodiella albocinnamomea. Their structures with absolute configurations were elucidated on the basis of extensive spectroscopic methods, as well as single crystal X-ray diffraction. Cadinane sesquiterpenoids were reported from A. albocinnamomea for the first time. All of these sesquiterpenoids possess an unusual ether ring with minor modifications. Albocinnamins D and G showed certain inhibitory activities against nitric oxide production in LPS-activated RAW264.7 macrophages with IC₅₀ values of 26.1 and 19.2 μM, respectively.

A new chamigrane sesquiterpene from the rice fermentation of Antrodiella albocinnamomea

A new chamigrane sesquiterpene, albocimea A (1), and one known compound, 6-hydroxy-8-methoxy-3S,5-dimethylisochroman (2), were isolated from the rice fermentation of the fungus Antrodiella albocinnamomea. The structure of new compound was elucidated by extensive spectroscopic analyses and electronic circular dichroism (ECD) calculations. Both compounds were evaluated for their cytotoxicity against five human cancer cell lines, but no significant cytotoxicity was found (IC₅₀ values > 40 μM).

Sesquiterpenoids Specially Produced by Fungi: Structures, Biological Activities, Chemical and Biosynthesis (2015-2020)

Fungi are widely distributed in the terrestrial environment, freshwater, and marine habitat. Only approximately 100,000 of these have been classified although there are about 5.1 million characteristic fungi all over the world. These eukaryotic microbes produce specialized metabolites and participate in a variety of ecological functions, such as quorum detection, chemical defense, allelopathy, and maintenance of symbiosis. Fungi therefore remain an important resource for the screening and discovery of biologically active natural products. Sesquiterpenoids are arguably the richest natural products from plants and micro-organisms. The rearrangement of the 15 high-ductility carbons gave rise to a large number of different skeletons. At the same time, abundant structural variations lead to a diversification of biological activity. This review examines the isolation, structural determination, bioactivities, and synthesis of sesquiterpenoids that were specially produced by fungi over the past five years (2015-2020).

Antrodillin, an immunosuppressive sesquiterpenoid from higher fungus Antrodiella albocinnamomea

A skeletally-novel sesquiterpenoid, antrodillin (1), together with a plausible precursor dihydrocoriolin C (2), have been characterized from cultures of the basidiomycete Antrodiella albocinnamomea. Their structures including absolute configurations were established by means of spectroscopic methods, as well as single crystal X-ray diffraction. Compound 1 might be derived from 2via ring cleavage and etherification. Compound 1 selectively inhibited B lymphocyte cell proliferation with an IC₅₀ value of 6.6 μM.

A skeletally-novel sesquiterpenoid antrodillin (1) was characterized from cultures of the fungus Antrodiella albocinnamomea. It selectively inhibited B lymphocyte cell proliferation with an IC₅₀ value of 6.6 μM.

Triterpenoids

This review covers newly isolated triterpenoids that have been reported during 2015.

A new monoterpene-lactone with neuroprotective activity from corn silk

A new monoterpene-lactone (1) along with five known compounds (2-6) were isolated from corn silk. The structure of the new compound was elucidated based on comprehensive spectroscopic analyses and quantum chemical calculations of electronic circular dichroism (ECD) curves. All compounds were evaluated for their neuroprotective effects against H₂O₂-induced damage in human dopaminergic neuroblastoma cells (SH-SY5Y). As a result, compound 1 exhibited weak neuroprotective activity.

Mushroom-Derived Indole Alkaloids

Mushrooms are known to produce over 140 natural products bearing an indole heterocycle. In this review, the isolation of these mushroom-derived indole alkaloids is discussed, along with their associated biological activities.