Specialized metabolites of the endophyte Annulohypoxylon areolatum hosted by Aconitum carmichaelii.

Seven previously undescribed compounds, including one amino acid hybrid sesquiterpene areolatol A (1), two unusual natural sesquiterpenoid skeleton areolatones A-B (2-3) and four benzo[j]fluoranthene areolaranes A-D (4-7) were characterized from Annulohypoxylon areolatum. The structures of the compounds were determined by extensive spectroscopic analysis, X-ray diffraction analysis, and ECD and NMR computational. Notably, areolatol A (1) was the first reported sesquiterpene featuring a 5/7/3-ring system and hybridized with two molecular amino acids. In addition, areolaranes A-D (4-7) were identified as possible chemophenetic markers.

Accumulation of antitumor polyketides by fermentation of Rubus delavayi Franch. with Clonostachys rogersoniana.

The aim of this work is to explore the effects of herbal medicine on secondary metabolites of microorganisms during fermentation. Clonostachys rogersoniana was found to metabolize only small amounts of polyketide glycosides rogerson B and C on fresh potatoes, but after replacing the medium to the medicinal plant Rubus delavayi Franch., the type and content of the metabolized polyketones showed significant changes. The sugars and glycosides in R. delavayi are probably responsible for the changes in secondary metabolites. Six polyketide glycosides including a new metabolite, rogerson F, and two potential antitumor compounds, TMC-151C and TMC-151D, were isolated from the extract of R. delavayi fermented by C. rogersoniana. In addition, 13C labeling experiments were used to trace the biosynthesis process of these compounds. TMC-151C and TMC-151D showed significant cytotoxic activity against PANC-1, K562 and HCT116 cancer cells but had no obvious cytotoxic activity against BEAS-2B human normal lung epithelial cells. The yields of TMC-151C and TMC-151D reached 14.37 ± 1.52 g/kg and 1.98 ± 0.43 g/kg, respectively, after fermentation at 28 °C for 30 days. This is the first study to confirm that herbal medicine can induce microbes to metabolize active compounds. And the technology of fermenting medicinal materials can bring more economic value to medicinal plants.

Efficient peroxymonosulfate activation of immobilized Fe-N-C catalyst on ceramsite for the continuous flow removal of phenol.

Nowadays, developing environmentally friendly catalysts with both low cost and high efficiency was still a challenge in actual organic wastewater purification. Herein, the Fe-N-C catalyst was successfully immobilized on solid waste derived ceramsite for efficient degradation of phenol under continuous flow conditions by activating peroxymonosulfate (PMS). After the introduction of ceramsite, the microstructure of Fe-N-C catalyst was changed from granular structure to worm-like structure, promoting the dispersion of the nanoscale catalyst and providing more reactive sites. Therefore, the phenol removal rate and mineralization rate of the obtained 0.5FNNC within 30 min were up to 96.79% and 71.79%, respectively. In addition, the degradation rate of the optimal composite (0.5FNNC)/PMS system was about 4.06 times higher than that of bare Fe-N-C/PMS system. Intriguingly, the Fe ion leaching from 0.5FNNC during the degradation reaction was significantly lower than bare Fe-N-C owing to the strong catalyst-support chemical bonding. Based on electron paramagnetic resonance, quenching experiments, X-ray photoelectron spectroscopy analysis and electrochemical analysis, it was indicated that the non-radical processes (1O2 and high valent iron-oxo species) should be responsible for the phenol degradation. Meanwhile, the possible phenol degradation pathways were proposed, and the intermediates were evaluated for ecotoxicity by ECOSAR. Finally, a preliminary economic analysis of this process was carried out. Overall, this work would provide a new strategy for the construction of ceramsite based multi-pore composite catalysts and the large-scale application of persulfate oxidation technology in organic wastewater treatment.

Investigations of specialised metabolites of endophyte Diaporthe destruens hosted in Illigera orbiculata C. Y. Wu.

A chemical investigation of the endophytic fungus Diaporthe destruens from the Hernandiaceae plant Illigera orbiculata C. Y. Wu collected from southern Yunnan Province, China, led to the isolation of six undescribed compounds, including two azaphilone analogs, which are a pair of epimers (13R-hydroxy-chermesinone A and 13S-hydroxy-chermesinone A); a pyrrole derivative (1-(4-(methoxymethyl)-1H-pyrrol-3-yl)ethan-1-one); an isoindolone derivative (4-hydroxy-6-methoxyisoindolin-1-one); a benzylbenzene derivative (destruensine A) and a conjectural fragment of polyketide ((2R,4R)-2-(methoxymethyl)pentane-1,4-diol) along with nine known compounds. Their structures were elucidated by spectroscopic methods and HRESIMS, and the absolute configurations were further confirmed by electronic circular dichroism (ECD) and chemical derivatization. The antimicrobial activities, anti-acetylcholinesterase activities, antiproliferation, and NO production inhibitory effects of compounds 1-15 were evaluated.

Biotransformation of α-terpineol by Alternaria alternata.

α-Terpineol (1), the main volatile constituent in some traditional Chinese medicines, has been reported to be metabolized to 4R-oleuropeic acid by the larvae of common cutworms. The present study verified that α-terpineol could be converted to 4R-oleuropeic acid (2) and (1S,2R,4R)-p-menthane-1,2,8-triol (3) by Alternaria alternata fermentation. Using shortened fermentation times, 7-hydroxy-α-terpineol (2a) was identified as an oxidative intermediate, which was consistent with the hypothesis put forward by previous studies. Cytochrome P450 enzymes were also confirmed to catalyze this biotransformation. This is the first study on the biotransformation of α-terpineol by microbial fermentation.

Biotransformation of 1,8-Dihydroxyanthraquinone into Peniphenone under the Fermentation of Aleurodiscus mirabilis.

The present study verified that 1,8-dihydroxyanthraquinone (1), a common component in some industrial raw materials and dyes, could be converted into peniphenone (2), which possesses immunosuppressive activity and other medicinal potential, by Aleurodiscus mirabilis fermentation. The yield of peniphenone (2) after 7 days of fermentation was 11.05 ± 2.19%. To reveal the transformation mechanism, two secondary metabolites, emodin (3) and monodictyphenone (4), were isolated from the fermentation broth of A. mirabilis, implying that polyketide metabolic pathways from emodin (3) to monodictyphenone (4) might exist in A. mirabilis. 1,8-Dihydroxyanthraquinone (1) was suspected to be converted into peniphenone (2) via the same pathway since emodin (3) and 1,8-dihydroxyanthraquinone (1) share very similar skeletons. The P450 enzyme and Baeyer-Villiger oxidase in A. mirabilis were confirmed to catalyze this biotransformation on the basis of ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) analysis. This novel investigation could shed light on the mechanism and therefore development of peniphenone production from 1,8-dihydroxyanthraquinone by microbial fermentation.

A new menthane-type monoterpenoid from fermented Illigera aromatica with Clonostachys rogersoniana 828H2.

A new menthane-type monoterpenoid, illigerate E (1), as well as two known ones, (1R*,3R*,4S*,6R*)-6,8-dihydroxymenthol (2) and cis-4-hydroxy-5-(1-hydroxy-1-methylethyl)-2-methyl-2-cyclohexene-1-one (3), were isolated from fermented Illigera aromatica with Clonostachys rogersoniana 828H2. Their structures were identified by HRESIMS and 1D/2D NMR spectra. Their inhibitory effects of NO production in RAW 264.7 macrophages were estimated.

Improving the acetylcholinesterase inhibitory effect of Illigera henryi by solid-state fermentation with Clonostachys rogersoniana.

Illigera henryi, an endemic traditional Chinese medicine, contains abundant aporphine alkaloids that possess various bioactivities. In the present study, tubers of I. henryi were fermented by several fungi, and the acetylcholinesterase (AChE) inhibitory activities of non-fermented and fermented I. henryi were measured. The results showed that the fermentation of I. henryi with Clonostachys rogersoniana 828H2 is effective for improving the AChE inhibitory activity. A key biotransformation was found during the C. rogersoniana fermentation for clarifying the improvement of the AChE inhibitory activity of I. henryi: (S)-actinodaphnine (1) was converted to a new 4-hydroxyaporphine alkaloid (4R,6aS)-4-hydroxyactinodaphnine (2) that possessed a stronger AChE inhibitory activity, with an IC50 value of 17.66±0.06 µM. This paper is the first to report that the pure strain fermentation processing of I. henryi and indicated C. rogersoniana fermentation might be a potential processing method for I. henryi.

Monoterpene esters and aporphine alkaloids from Illigera aromatica with inhibitory effects against cholinesterase and NO production in LPS-stimulated RAW264.7 macrophages.

Three new monoterpene phenylpropionic acid esters, illigerates A-C (1-3), and one new aporphine alkaloid, illigeranine (4), as well as four known ones, actinodaphnine (5), nordicentrine (6), 8-hydroxy carvacrol (7), and 3-hydroxy-α,4-dimethyl styrene (8), were isolated from the tubers of Illigera aromatica. The structures of 1-4 were identified by HRESIMS, 1D and 2D NMR, and electronic circular dichroism spectra. Compound 1 potently inhibited NO production in LPS-stimulated RAW264.7 cells with an IC50 value of 18.71 ± 0.85 µM; compound 1, 3, and 4 showed moderate butyrylcholinesterase inhibitory activities with the IC50 values of 46.86 ± 0.65, 53.51 ± 0.71, and 31.62 ± 1.15 µM, respectively. Compound 4 showed weak AChE inhibitory activity with an IC50 value of 81.69 ± 2.07 µM, and compounds 5 and 6 possessed moderate AChE inhibitory activities with the IC50 values of 47.74 ± 1.66 and 40.28 ± 2.73 µM, respectively. This paper provides a chemical structure and bioactive foundation for using I. aromatica as an herbal medicine.

A new C20-diterpenoid alkaloid from the lateral roots of Aconitum carmichaeli.

A new C20-diterpenoid alkaloid carmichaedine (1) and six known alkaloids (2-7) were isolated from the lateral roots of Aconitum carmichaeli. Their structures were established on the basis of extensive spectroscopic analyses. Compound 1 exhibited potent antibacterial activity against Bacillus subtilis with minimum inhibitory concentration of 8 µg/mL.

Alkaloids with antioxidant activities from Aconitum handelianum.

A new C20-diterpenoid alkaloid handelidine (1) and twenty-seven known alkaloids (2-28) were isolated from the roots of Aconitum handelianum. Their structures were established on the basis of extensive spectroscopic analyses. The study indicated that denudatine-type C20-diterpenoid alkaloids with vicinal-triol system and benzyltetrahydroisoquinoline alkaloids exhibited significant antioxidant activities measured by three antioxidant test systems. The aconitine-type C19-diterpenoid alkaloids could serve as potential secondary antioxidants for their strong binding effects to metal ions.

Two new peroxy fatty acids with antibacterial activity from Ophioglossum thermale Kom.

Two new peroxy fatty acids, thermalic acids A (1) and B (2), together with eight known compounds, (3ß)-methyl-3-hydroxy-urs-11-en-28 oate (3), luteolin (4), quercetin (5), 3-methoxyquercetin (6), ophioglonol (7), ophioglonol 4'-O-α-D-glucopyranoside (8), pedunculosumoside B (9), syringol (10), were isolated from the herba of Ophioglossum thermale Kom. The structures of 1 and 2 were identified by HRESIMS, EIMS, 1D and 2D NMR, and electronic circular dichroism (ECD) spectra. Both two acids exhibited potential antibacterial activities against Staphylococcus aureus, Bacillus subtilis, and Escherichia coli. This is the first report of peroxy fatty acids isolated from herbaceous plants of Ophioglossaceae.