Ya-Bin Yang

Antioxidant activity and chemical constituents of edible flower of Sophora viciifolia.

The antioxidant activities of crude extract and its derived soluble fractions from the flower of Sophora viciifolia were evaluated in five different test systems (DPPH, ABTS, FRAP, reducing power and inhibition of lipid peroxidant models) for the first time. The ethylacetate soluble fraction exhibited the highest antioxidant effect. Correlation analysis suggested that the flavonoids might be the major contributors for the high antioxidant activity of this flower. In addition, 11 compounds were isolated from this flower, and the antioxidant capacities of 5 flavonoids were evaluated by DPPH assay. Compound 3 (luteolin) had a significant DPPH radical-scavenging activity, and was also present at the highest concentration (5.56mg/gdrysample), implying an important role of 3 for the antioxidant activity of this flower. The study suggests that the flower of S. viciifolia can provide valuable functional ingredients and can be used for the prevention of diseases related to various oxidant by-products of human metabolism.

Anti-phytopathogen, multi-target acetylcholinesterase inhibitory and antioxidant activities of metabolites from endophytic Chaetomium globosum

Abstract Fourteen metabolites with various structure types were isolated from endophytic Chaetomium globosum. Five compounds were separated from genus Chaetomium for the first time. Some compounds exhibited remarkable inhibition against phytopathogenic fungi causing root rot of Panax notoginseng. Compounds 1–5 had significant DPPH-free radical-scavenging activity. Compounds 3 and 5 indicated significant inhibitions against the acetylcholinesterase (AChE). From preliminary structure–activity relationship, it was found that the oxygenic five-membered ring of 3 and 5 was crucial in the anti-AChE activity. These structures provide new templates for the potential treatment and management of plant diseases and Alzheimer disease.

Two new glucosides from the pellicle of the walnut (Juglans regia)

A new α-tetralonyl glucoside, 6′-O-acetyl-juglanoside E (1), and a new dihydrophaseic acid glucoside, dihydrophaseic acid 1-O-(6-O-acetyl)-glucopyranoside (2), together with two known ones, juglanoside E (3) and dihydrophaseic acid (4), were isolated from the pellicle of the walnut (Juglans regia). The structures of the new compounds were elucidated by comprehensive spectroscopic analysis, including IR, HRESIMS, 1D and 2D NMR data.

Koninginins N-Q, Polyketides from the Endophytic Fungus Trichoderma koningiopsis Harbored in Panax notoginseng.

Four new fungal polyketides named koninginins N-Q (1–4), together with four known analogues (5–8), were isolated from the endophytic fungus Trichoderma koningiopsis YIM PH30002 harbored in Panax notoginseng. Their structures were determined on the basis of spectral data interpretation. These compounds were evaluated for their antifungal activity, nitric oxide inhibition, and anticoagulant activity.Graphical Abstract

A new polyoxygenated farnesylcyclohexenone from Fungus Penicillium sp.

A new polyoxygenated farnesylcyclohexenone, peniginsengin A (1), was isolated from the fermentation of Penicillium sp. YIM PH30003, an endophytic fungus associated with Panax notoginseng (Burk.) F. H. Chen. The structure was assigned based on a combination of 1 D and 2 D NMR and mass spectral data. The cytotoxicity and antimicrobial activities of compound 1 were investigated.

Koninginins R-S from the endophytic fungus Trichoderma koningiopsis

Abstract Two new metabolites named koninginins R-S (1–2) were isolated from the culture of Trichoderma koningiopsis YIM PH30002. Their chemical structures were elucidated by the extensive spectroscopic analysis. These isolated compounds showed certain antifungal activities against phytopathogens, Fusarium flocciferum and Fusarium oxysporum.

Phytotoxic, antibacterial, and antioxidant activities of mycotoxins and other metabolites from Trichoderma sp.

Abstract A new natural mycotoxin was isolated from the fermentation broth of Trichoderma sp. Jing-8 and the structure was determined as alternariol 1′-hydroxy-9-methyl ether (1), together with twelve known compounds. The structures were elucidated on the basis of their 1D, 2D NMR spectra and mass spectrometric data. Compounds 1, 8 and 9 indicated inhibitions against germination of the seeds of cabbage with MICs < 3 μg/mL. The compound 1 showed the antibacterial activity against Bacillus subtilis and Staphylococcus aureus with MICs at 64 μg/mL. Compound 1 and 3 showed significant DPPH radical-scavenging activities with IC50 at 12 μg/mL, respectively. The OH at C-1′ in compound 1 decreased the cytotoxicity of these mycotoxins. A primary structure–activity relationship about the alternariol derivatives was discussed. Compounds 2–7 and 8 were the first time to be isolated from the Trichoderma.

Novel Isochroman Dimers from Stachybotrys sp. PH30583: Fermentation, Isolation, Structural Elucidation and Biological Activities.

The rare anishidiol and five new isochromans, including three novel dimers with unprecedented skeletons, were isolated from Stachybotrys sp. PH30583. Their structures were determined by spectral analyses. The bioactivities of these compounds were also investigated. The dimers (6-10) inhibited acetylcholinesterase at 50u2009µM, but the monomers did not. To investigate the biogenesis of the novel dimers, a time-course investigation of metabolite production was undertaken.

Lovastatin analogues and other metabolites from soil-derived Aspergillus terreus YIM PH30711

Eight previously undescribed metabolites including of lovastatin analogues, a pair of diastereoisomers, a cyclopentenone dimer, and three polyketides were isolated from the culture of Aspergillus terreus YIM PH30711. Two types of unprecedented skeletons, benzene-cyclopentanone complex and linear polyketide, and an unusual dimer structure were determined by spectral analysis. Compound, 3α-hydroxy-3,5-dihydromonacolin L showed moderate activity against HMG-CoA reductase, with an inhibition ratio of 34% at the concentration of 50xa0μM, while lovastatin and dihydromonacolin K ethyl ester presented much stronger activity against HMGR with inhibition rates of 85% and 90% at the concentration of 50xa0μM, respectively. Aspereusin A was active against AChE with a ratio of 62% at the concentration of 50xa0μM, while its stereomers did not showed obvious inhibition (<10%). The configuration at C-4 of these three diastereoisomers was crucial in the inhibition against AChE, and the β-orientation of substituted methoxyl acrylic acid should be beneficial to the combining with AChE.

New bioactive compounds from aquatic endophyte Chaetomium globosum

Abstract Two new oxidation products-related aureonitol and cytochalasan were isolated from Chaetomium globosum fermented in Chinese yam (Dioscorea opposita) and determined as 10,11-dihydroxyl- aureonitol (1) and yamchaetoglobosin A (2). Compound 2 indicated significant inhibitory effect on nitric oxide production in LPS-activated macrophages, anti-acetylcholinesterase activity with the inhibition ratios of 92.5, 38.2% at 50 μM, and cytotoxicity to HL-60, A-549, SMMC-7721, MCF-7 and SW480 with the range of inhibition ratio at 51–96% for a concentration of 40 μM. Compounds 1, 2 showed weak anticoagulant activity with PT at 16.8 s. Few work was reported on the anti-acetylcholinesterase, and anticoagulant activities of aureonitol, and cytochalasan derivatives. The preliminary structure–activity relationship stated that the oxidation ring-opening in yamchaetoglobosin A can retain the inhibitory effect against NO production and tumor cell.