To explore the chemical diversity of metabolites from endophytic fungi, the strain Phomopsis sp. TJ507A, isolated from the medicinal plant Phyllanthus glaucus, was investigated. A 2,3- seco-protoilludane-type sesquiterpenoid (1), eight protoilludane-type sesquiterpenoids (2-9), four illudalane-type sesquiterpenoids (10a/10b, 11, and 12), and a botryane-type sesquiterpenoid (13) in addition to seven known sesquiterpenoids (14-20) were identified from the liquid culture of the fungus. Structures of the isolated compounds, including their absolute configurations, were elucidated based on extensive spectroscopic analyses, a modified Mosher analysis, electronic circular dichroism (ECD) calculations, and [Rh(OCOCF)]-induced ECD spectra as well as X-ray crystallographic analyses. Compound 1 represents the first example of a naturally occurring sesquiterpenoid containing the unusual 2,3- seco-protoilludane scaffold. Compounds 1 ( p < 0.001); 2-6, 15, and 18 ( p < 0.01); and 7, 9, and 20 ( p < 0.05) displayed β-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitory activities ranging from 19.4% to 43.8% at the concentration of 40 μM. LY2811376 was used as the positive control with an inhibitory activity of 38.6% ( p < 0.01). Furthermore, none of these compounds showed obvious hepatotoxicity at concentration of 40 μM.

Rising drug resistance limits the treatment options infected by methicillin-resistant Staphylococcus aureus (MRSA). A promising solution for overcoming the resistance of MRSA is to inhibit the penicillin-binding protein 2a (PBP2a). A novel terpene-polyketide hybrid meroterpenoid, aspermerodione (1), characterized by an unusual 2,6-dioxabicyclo[2.2.1]heptane core skeleton, and a new heptacyclic analogue, andiconin C (2), were isolated and identified from the liquid cultures of endophytic fungus Aspergillus sp. TJ23. The structures and their absolute configurations of all chiral centers were elucidated via extensive spectroscopic analyses and electronic circular dichroism (ECD) calculations and determined via single-crystal X-ray diffraction analysis. Aspemerodione (1) was found to be a potential inhibitor of PBP2a, and work synergistically with the β-lactam antibiotics oxacillin and piperacillin against MRSA.

Eighteen compounds, including eight new cassane-type furanoditerpenoids, 3β-hydroxyphanginin H (1), 3β-acetoxyphanginin H (2), 7β-acetoxyphanginin H (3), 7β-hydroxyphanginin H (4), 4-epi-3β-hydroxycaesalpinilinn (5), 4-epi-3β-acetoxycaesalpinilinn (6), 20-acetoxytaepeenin D (7), and tomocin E (8), along with 10 known compounds (9-18) were isolated from the roots of Caesalpinia decapetala. Compounds 1-13 were isolated from C. decapetala for the first time. The new compounds with their absolute configurations were determined by extensive spectroscopic analysis, single-crystal X-ray diffraction, and electronic circular dichroism calculations. Compounds 1, 4, 5, 7, and 11 exhibited inhibitory activities against the SW1990 human pancreatic cancer cell line with IC values ranging from 2.9 to 8.9 μM.

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Three PPAPs were isolated from H. longistylum Oliv.