Antifeedant, Antifungal Cryptic Polyketides with Six Structural Frameworks from Tea Endophyte Daldinia eschscholtzii Propelled by the Antagonistic Coculture with Phytopathogen Colletotrichum pseudomajus and Different Culture Methods.

The antagonistic coculture with tea phytopathogen Colletotrichum pseudomajus induces antifungal cryptic metabolites from isogenesis endophyte Daldinia eschscholtzii against tea phytopathogens. Sixteen new polyketides with six structural frameworks including ten cryptic ones, named coldaldols A-C (1-3), collediol (5), and daldinrins A-L (10-20 and 23), were found from the coculture of C. pseudomajus and D. eschscholtzii by different culture methods. The unique framework of compounds 11 and 12 featured a benzopyran-C7 polyketone hybrid, and compounds 13-16 were characterized by the novel benzopyran dimer. The structures were determined mainly by spectroscopic methods, including extensive one-dimensional (1D), two-dimensional (2D) NMR, high resolution electrospray ionisation mass spectroscopy (HRESIMS), ECD calculation, and single-crystal X-ray diffraction. The configuration of acyclic compounds 5 and 18 were determined by application of the universal NMR database. Most compounds showed significant antifungal activities against the tea pathogens C. pseudomajus and Alternaria sp. with MICs of 1-8 µg/mL. Compound 12 had stronger antifungal activity than that of positive drug nystatin. The ether bond at C-4 of the benzopyran derivative increased the antifungal activity. Compounds 4-9 and 11-23 showed antifeedant activities against silkworms with feeding deterrence indices of 15-100% at the concentration of 50 µg/cm2.

(-)-Epigallocatechin-3-gallate, a Polyphenol from Green Tea, Regulates the Liquid-Liquid Phase Separation of Alzheimer's-Related Protein Tau.

The microtubule-associated protein tau is involved in Alzheimer's disease and other tauopathies. Recently, tau has been shown to undergo liquid-liquid phase separation (LLPS), which is implicated in the physiological function and pathological aggregation of tau. In this report, we demonstrate that the green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) promotes the formation of liquid tau droplets at neutral pH by creating a network of hydrophobic interactions and hydrogen bonds, mainly with the proline-rich domain of tau. We further show that EGCG oxidation, tau phosphorylation, and the chemical structure of the polyphenol influence the efficacy of EGCG in facilitating tau LLPS. Complementary to the inhibitory activity of EGCG in tau fibrillization, our findings provide novel insights into the biological activity of EGCG and offer new clues for future studies on the molecular mechanism by which EGCG alleviates neurodegenerative diseases.

The antifeedant and antifungal cryptic metabolites isolated from tobacco endophytes induced by host medium and coculture.

Four new cryptic metabolites including one fumagillol derivative (2), one cyclohexenone derivative (4), one 10-membered lactone (5), and one natural 4-epi-brefeldin C (8), along with seven known compounds were found from isogenesis endophytes Aspergillus fumigatus, Penicillium janthinellum, Nigrospora sp., and Stagonosporopsis sp. induced by host Nicotiana tabacum medium and co-culture. The structures were determined mainly by spectroscopic methods, including extensive 1D, 2D NMR, MS techniques, ECD calculation, and Mosher's method. Compound 2 possessed a novel 1, 3-dioxetane residue and cyclohexane-containing terpenoid skeleton. Compounds 2, 4-7 and 10 showed significant antifungal activities against the plant pathogen Nigrospora sp. with MICs of 1 µg/mL. 2, 4, 5-7, and 10 indicated antifungal activities against Penicillium janthinellum, Aspergillus fumigatus, Phomopsis sp., and Alternaria sp. with MICs ≤8 µg/mL. Compounds 2, 6-8, and 10 (50 µg/cm2) and microbial fermentation extracts (100 µg/cm2) showed antifeedant activities against silkworms with feeding deterrence indices of 21-100%.

The induced cryptic metabolites and antifungal activities from culture of Penicillium chrysogenum by supplementing with host Ziziphus jujuba extract.

The productions of cryptic metabolites including three undescribed drimane sesquiterpenoids, penicichrins A-C, and three known compounds from Penicillium chrysogenum were activated by the host Ziziphus jujuba medium. The structures were established by comprehensive analysis of spectroscopic data. The spiro ß-lactone, and gem-dimethyl dihydroxylation in induced penicichrins A-C were rare in natural products. Cryptic metabolites, monaspurpurone was first found in Penicillium. 4-Methoxy-3-methylgoniothalamin, and 2-hydroxy-l-phenyl-l,4-pentanedione were second example of isolation. Penicichrin A, monaspurpurone, 4-methoxy-3-methylgoniothalamin, physcion, ergosterol, and ergosta-7,22-dien-3ß-ol had antifungal activities against phytopathogens, P. chrysogenum, Alternaria alternata and Aspergillus fumigatus with MICs ≤2 µg/mL, and 2-hydroxy-l-phenyl-l,4-pentanedione had flowering activity. So the chemical constituents from Z. jujuba could induce the productions of cryptic metabolites with plant growth-promoting activity from endophyte P. chrysogenum.

Effects of 1-methylcyclopropene (1-MCP) treatment on ethanol fermentation of Nanguo pear fruit during ripening.

The aim of this study was to analyze the effects of 1-methylcyclopropene (1-MCP) on ethanol fermentation of Nanguo pears during ripening. Pears were exposed to 1 µl/L 1-MCP and stored at 20 ± 2°C. Our data indicated that postharvest application of 1-MCP maintained flesh firmness and reduced ethylene production and respiration rate during storage compared with untreated fruits. 1-MCP treatment delayed the second glucose peak during fruit ripening. The contents of pyruvate and acetyl-CoA were generally reduced by 1-MCP treatment, and at the same time, their peaks were delayed by it during storage compared with controls. The contents of citric acid (CA) and oxaloacetate (OA) were increased by 1-MCP, whereas the contents of acetaldehyde and ethanol were reduced during the whole storage period compared with controls. Activities of alcohol dehydrogenase (ADH) and pyruvate decarboxylase (PDC) were reduced by application of 1-MCP during the early stage of storage, and the appearance of their peak activities was also delayed after treatment with 1-MCP. These data showed that postharvest application of 1-MCP could effectively delay the production of the "alcohol taste" of Nanguo pears during ripening. PRACTICAL APPLICATIONS: Nanguo pear is one of the most common cultivars that widely grow in northeast China. It is preferred by many consumers for its unique "alcohol taste", which is mainly produced through ethanol fermentation during ripening. Until now, the mechanisms for regulating ethanol fermentation in ripening Nanguo pears are still unclear. Our data indicated that postharvest application of the ethylene action inhibitor 1-MCP could effectively delay the production of the "alcohol taste" of Nanguo pears during ripening. The data from this study can provide reference data for maintaining the quality of postharvest Nanguo pears.

The complete chloroplast genome of Clerodendrum lindleyi Decne. ex Planch. (Tubiflorae: Verbenaceae) from nanjing, China.

Clerodendrum lindleyi Decne. ex Planch. is a Chinese medicinal plant in the Lingnan region of China. In this study, the complete chloroplast genome sequence of C. lindleyi was assembled and characterized from high-throughput sequencing data. The chloroplast genome is 151,678 bp in length, consisting of a large single-copy (LSC) and a small single-copy (SSC) regions of 83,043 bp and 17,311 bp, respectively, which are separated by a pair of 25,662 bp inverted repeat (IR) regions. The overall GC content of the genome is 38.18%. The genome contains 133 genes, including 88 protein-coding, 37 tRNA, and 8 rRNA genes. A phylogenetic tree reconstructed by using 16 chloroplast genomes reveals that C. lindleyi is most closely related to C. trichotomum which together forms a group that is a sister to genus Caryopteris. The work reported here is the first complete chloroplast genome of C. lindleyi which will provide useful information to the evolutionary studies on the genus of Clerodendrum.

The complete chloroplast genome of a Chinese medicinal plant, Peristrophe japonica (Thunb.) Bremek. (Lamiales: Acanthaceae) from Nanjing, China.

Peristrophe japonica (Thunb.) Bremek. is a widely distributed medicinal plant species in China and Japan. In this study, the complete chloroplast genome sequence of P. japonica was assembled and characterized from high-throughput sequencing data. The chloroplast genome is 151,374 bp in length, consisting of a large single-copy (LSC) and a small single-copy (SSC) regions of 83,395 bp and 17,073 bp, respectively, which were separated by a pair of 25,453 bp inverted repeat (IR) regions. The overall GC content of the genome is 38.07%. The genome contains 133 genes, including 88 protein-coding, 37 tRNA, and eight rRNA genes. A phylogenetic tree reconstructed using 23 chloroplast genomes reveals that Peristrophe form a separate group which is a sister of the genus Dicliptera. The work reported here is the first complete chloroplast genome of P. japonica which will provide useful information to the evolutionary studies on the genus of Peristrophe.

[A new lignan from Euscaphis konishii].

The chemical constituents from the extract of the twigs of Euscaphis konishii with anti-hepatoma activity were investigated, twelve compounds by repeated chromatography with silica gel, Sephadex LH-20 and preparative-HPLC. The structures of the chemical components were elucidated by spectroscopy methods, as konilignan(1),(7R, 8S)-dihydrodehydrodico-niferylalcohol-9-O-ß-D-glucopyranoside(2),illiciumlignan B(3),threo-1-(4-hydroxy-3-methoxyphenyl)-2-[4-(3-hydroxypropyl)-2-methoxyphenoxy]-1,3-panediol(4),erythro-1-(4-hydroxy-3-methoxyphenyl)-2-[4-(3-hydroxypropyl)-2-methoxyphenoxy]-1,3-panediol(5), matairesinol(6), wikstromol(7), isolariciresinol(8),(+)-lyoniresinol(9), 4-ketopinoresinol(10), syringaresin(11), and vladinol D(12). Among them, compound 1 is a new lignan. Compounds 10 and 12 had moderate inhibitory activity on HepG2 cells, with IC_(50) values of 107.12 µmol·L~(-1) and 183.56 µmol·L~(-1), respectively.

Chemical Constituents and Biological Activity Profiles on Pleione (Orchidaceae).

Pleione (Orchidaceae) is not only famous for the ornamental value in Europe because of its special color, but also endemic in Southern Asia for its use in traditional medicine. A great deal of research about its secondary metabolites and biological activities has been done on only three of 30 species of Pleione. Up to now, 183 chemical compounds, such as phenanthrenes, bibenzyls, glucosyloxybenzyl succinate derivatives, flavonoids, lignans, terpenoids, etc., have been obtained from Pleione. These compounds have been demonstrated to play a significant role in anti-tumor, anti-neurodegenerative and anti-inflammatory biological activities and improve immunity. In order to further develop the drugs and utilize the plants, the chemical structural analysis and biological activities of Pleione are summarized in this review.