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Two new polyketides named rufoolivacin Eand viocristin B, a new natural product named 1-hydroxy-3,6,8-trimethoxyanthraquinone, and 13 known compounds were isolated from edible mushroom Cortinarius purpurascensin this work. Their structures were assigned on the basis of high-resolution electrospray ionization mass spectrometry, 1D and 2D nuclear magnetic resonance, and electronic circular dichroism data. Notably, the enzyme activity test on glutamate dehydrogenase indicated that 1, 3, 4, 5, 6, 10, 11, and 15displayed an excellent inhibition effect. Further kinetic studies showed that the most potent compounds, 4and 10, possess great potential as competitive inhibitors of glutamate dehydrogenase. Molecular docking and computational chemistry were applied to illustrate the binding mechanism in detail. 2,2-Diphenyl-1-picrylhydrazyl and reactive oxygen species assay results showed that compounds 1, 2, 3, and 8exhibited significant antioxidant activities with IC50values of 7.0 ± 0.3, 8.6 ± 0.1, 7.5 ± 0.1, and 2.8 ± 0.2 μg mL–1, respectively. Thus, Cortinarius caerulescensrepresents a novel resource of these polyketides to be utilized in food selection and drug discovery.

Background: Xanthones are a class of heterocyclic natural products, which are promising sources of anti-cancer leads. Phomoxanthone B (PXB) and Phomoxanthone A(PXA)are xanthone dimers. PXA is wellstudied as an anti-cancer agent, but PXB is not. In our study, PXB was isolated from the endophytic fungus Phomopsis sp. By254. Objective: The purpose of this study was to identify the underlying anti-tumor mechanisms of PXB in breast cancer MCF7 cell line. Methods: Apoptosis, cell cycle, proliferation, invasion, and migration assays were used to assess the anti-tumor activity of PXB. RNA sequencing was used to analyze the effect of PXB treatment on gene expression in MCF7 cells. Results: PXB showed cytotoxicity towards a variety of tumor cells, especially MCF7 cells. PXB inhibited the migration and invasion, arrested cell cycle at G2/M phase, and induced apoptosis associated with caspase-3 activation in MCF7 cells. The detailed transcriptome analysis revealed that PXB affected several pathways related to tumorigenesis, metabolisms, and oxidative phosphorylation in MCF7 cells. KEGG transcriptome analysis revealed that PXB upregulated pro-survival signal pathways, such as MAPK, PI3K-AKT, and STAT3 pathways. We found that PXB also significantly upregulated the expression of IL24, DDIT3, and XAF1, which may contribute to PXB-induced apoptosis. We further found that PXB may downregulate oxidative phosphorylation by decreasing the expression of electron transport chain genes, especially MT-ND1, which is a potential unfavorable prognostic marker for ER-positive breast cancer. Conclusion: PXB exerts strong cytotoxicity against human tumor cells and has a potential for ER-positive breast cancer treatment.

Zn(II)2Cys6 proteins constitute the largest group of fungal-specific transcription factors. However, little is known about their functions in the crop killer Botrytis cinerea. In this work, a T-DNA insertion strain M13448 was identified which was inserted into the Zn(II)2Cys6 TF-encoding gene BcTBS1. Knockout of BcTBS1did not affect mycelia growth, appressorium formation, and sclerotium germination, but impaired fungal conidiation, conidial morphogenesis, conidial germination, infection cushion development, and sclerotial formation. Accordingly, ΔBctbs1mutants showed reduced virulence in its host plants. Further study proved that BcTBS1, BCIN_15g03870, and BCIN_12g06630were induced by cellulose. Subsequent cellulase activity assays revealed that the loss of BcTBS1significantly decreased cellulase activity. In addition, we verified that the BCIN_15g03870and BCIN_12g06630genes were positive regulated by BcTBS1by quantitative real-time reverse-transcription-polymerase chain reaction (qRT-PCR). Taken together, these results suggested that BcTBS1can promote pathogenicity by modulating cellulase-encoding genes that participate in host cellulose degradation.

Botrytis cinerea(B. cinerea) and Colletotrichum gloeosporioides(C. gloeosporioides) were isolated from the decaying strawberry tissue. The antifungal properties of Monarda didymaessential oil (MEO) and its nanoemulsion were confirmed, demonstrating complete inhibition of the pathogens at concentrations of 0.45 μL/mL (0.37 mg/mL) and 10 μL/mL, respectively. Thymol, a primary component of MEO, was determined as an antimicrobial agent with IC50values of 34.51 (B. cinerea) and 53.40 (C. gloeosporioides) μg/mL. Hippophae rhamnoidesoil (HEO) was confirmed as a potent antioxidant, leading to the development of a thymol-HEO-chitosan film designed to act as an antistaling agent. The disease index and weight loss rate can be reduced by 90 and 60%, respectively, with nutrients also being well-preserved, offering an innovative approach to preservative development. Studies on the antifungal mechanism revealed that thymol could bind to FKS1 to disrupt the cell wall, causing the collapse of mitochondrial membrane potential and a burst of reactive oxygen species.

Anthocyanins play crucial roles in pollen protection and pollinator attraction in flowering plants. However, the mechanisms underlying flower color determination and whether floral anthocyanin regulators participate in other processes remain largely unresolved in soybeans (Glycine max). In this study, we investigated the genetic components and mechanisms governing anthocyanin biosynthesis in soybean flowers. Molecular and genetic studies have characterized two antagonistic regulators, the positive activator GmMYBA3 and the negative repressor GmMYBR1, that modulate the gene expression of anthocyanin biosynthesis in soybean flowers. Further findings revealed a regulatory interplay between GmMYBA3 and GmMYBR1 bridged by GmTT8a, highlighting the complexity of anthocyanin regulation in different soybean organs. Exploration of additional soybean cultivars demonstrated the universality of GmMYBA3 and GmMYBR1 in regulating floral anthocyanin biosynthesis- related genes, with GmF3′5′Hidentified as a crucial determinant of white flower color. This study provides a molecular mechanism underlying soybean flower color determination, paving the way for the molecular modification of soybean flowers to probably enhance their resistance to abiotic stresses and attractiveness to pollinators.

AbstractThe present study, for the first time, describes the chemical composition, antioxidant, cytotoxic, and protein tyrosine phosphatase 1B (PTP1B) inhibitory activities of essential oil from the seeds of Euryale feroxSalisb. (Gordon euryale). The essential oil was isolated by steam distillation and characterized by gas chromatography-mass spectroscopy. A total of 37 components were identified in the oil, accounting for 100.0 % of the total oil. The main constituents of the oil were butylated hydroxytoluene (38.7 %), palmitic acid (11.0 %), linoleic acid (9.0 %), α-tocopherol (5.2 %), hexanoic acid (3.9 %), π-tocopherol (3.5 %). In brine shrimp bioassay, the oil showed excellent toxicity with LC50value of 11.48 ± 0.51 μg/ml. Significant antioxidant capacity was evident in DPPH (IC50= 6.27 ± 0.31 μg/ml) and ABTS (IC50= 2.19 ± 0.61 μg/ml) assay. Besides, the oil showed moderate inhibitory activity against PTP1B (IC50= 83.34 ± 2.07 μg/ml). It is concluded that the essential oil is an important substance basis for health and medicine potency of Gordon euryale seeds.

In the 1H NMR-guided fractionation of extracts from the edible mushroom Lactarius deliciosus, two new azulene-type sesquiterpenoids, 7-isopropenyl-4-methyl-azulene-1-carboxylic acid (1) and 15-hydroxy-3,6-dihydrolactarazulene (2), together with seven known compounds were characterized. Their structures were determined on basis of spectroscopic evidence, as well as by comparing with literature data. Amongst the known metabolites, the 13C NMR assignment of 15-hydroxy-6,7-dihydrolactarazulene (3) is reported here for the first time. Moreover, 7-acetyl-4-methylazulene-1-carbaldehyde (5) displayed a moderate antibacterial activity against Staphylococcus aureus. *Digital image of L. deliciosus.Retrieved March 17, 2017 from https://upload.wikimedia.org/wikipedia/commons/e/e3/Lactarius_deliciosus_1_(1).jpg.

Isolation and structural determination of five new highly brominated metabolites (I)—(III), as well as their inhibitory effects on protein tyrosine phosphatase 1B are described.