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Asperphenol A (1), a new isoprenyl-phenol-type meroterpenoid, was isolated from the mangrove endophytic fungus Aspergillus sp. GXNU-Y65 together with five known compounds (2-6). All structures were assigned using extensive NMR spectroscopic data and electronic circular dichroism (ECD) calculations. Compounds 1-6 were evaluated for their cytotoxic activity against A549 and T24 human cancer cell lines. Among them, compounds 1 and 5 exhibited moderate inhibitory activities against T24 cancer cell lines with the IC50 values of 26.71 and 43.50 µM, respectively.
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Endophytic fungus Serendipita indica can bolster plant growth and confer protection against various biotic and abiotic stresses. However, S. indica-reshaped rhizosphere microecology interactions and root-soil interface processes in situ at the submicrometer scale remain poorly understood. We combined amplicon sequencing and high-resolution nano X-ray fluorescence (nano-XRF) imaging of the root-soil interface to reveal cadmium (Cd) rhizosphere processes. S. indica can successfully colonize the roots of Sedum alfredii Hance, which induces a remarkable increase in shoot biomass by 211.32% and Cd accumulation by 235.72%. Nano-XRF images showed that S. indica colonization altered the Cd distribution in the rhizosphere and facilitated the proximity of more Cd and sulfur (S) to enter the roots and transport to the shoot. Furthermore, the rhizosphere-enriched microbiota demonstrated a more stable network structure after the S. indica inoculation. Keystone species were strongly associated with growth promotion and Cd absorption. For example, Comamonadaceae are closely related to the organic acid cycle and S bioavailability, which could facilitate Cd and S accumulation in plants. Meanwhile, Sphingomonadaceae could release auxin and boost plant biomass. In summary, we construct a mutualism system for beneficial fungi and hyperaccumulation plants, which facilitates high-efficient remediation of Cd-contaminated soils by restructuring the rhizosphere microbiota.
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An OSMAC strategy was used to study secondary metabolites and anti-inflammatory activities of the endophytic fungus Penicillium herquei JX4 hosted in Ceriops tagal. The PDB ferment of fungus P. herquei JX4 was isolated, purified, and identified by using silica gel column chromatography, gel column chromatography, octadecylsilyl(ODS) column chromatography, and semi-preparative high-performance liquid chromatography. Two new pinophol derivatives, pinophol H(1) and pinophol I(2) were isolated and identified, and they were evaluated in terms of the inhibitory activities against the nitric oxide(NO) production induced by lipopolysaccharide(LPS) in mouse macrophage RAW264.7 cells. The results showed that compound 1 had significant inhibitory activity on NO production, with an IC_(50) value of 8.12 µmol·L~(-1).
Assuntos
Óxido Nítrico , Penicillium , Penicillium/química , Camundongos , Animais , Células RAW 264.7 , Macrófagos/efeitos dos fármacos , Endófitos/química , Estrutura Molecular , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/químicaRESUMO
Different bioproducts can be obtained by changing operative condition of biotechnological process, and this bioprocess aspect is a significant approach to be adopted on industrial scale leading to the creation of new natural aroma. Thus, this study aimed to investigate the culture conditions and optimization of the biotransformation of limonene into limonene-1,2-diol using Pestalotiopsis mangiferae LaBMicrA-505 obtained from the Brazilian Amazon. The study started with the investigation of the establishment of culture, followed by optimization of the conditions for biotransformation of R-(+)-limonene to limonene-1,2-diol, using shake flasks. The fresh biomass of P. mangiferae LaBMicrA-505 obtained in liquid media supplemented with yeast-malt extract under with 72 h (stationary phase) performed better diol productivity when compared to other biomasses. Finally, in the modeling of contour plots and surface responses of a central composite design, the use of 4 g l- 1 biomass, 2% of the substrate at 24 °C, 120 rpm, and pH of 6.0 could maximize the production of limonene-1,2-diol, accumulated up to 98.34 ± 1.53% after 96 h of reaction. This study contributed to identified operational condition for the R-(+)-limonene bioconversion scale-up. The endophytic fungus P. mangiferae LaBMicrA-505 proved to be a potent biocatalyst to biotechnologically produce limonene-1,2-diol, an aroma compounds with interesting bioactive features that up to now has been manufactured by extraction from plants with long and not environmentally friendly procedures.
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Five new diterpenes including four diterpenes with 1,2,3,4,4a,5,6,8a-octalin skeleton talaroacids A-D (1-4) and an isopimarane diterpenoid talaromarane A (5) were isolated from the mangrove endophytic fungus Talaromyces sp. JNQQJ-4. Their structures and absolute configurations were determined by analysis of high-resolution electrospray ionization mass spectroscopy (HRESIMS), 1D/2D Nuclear Magnetic Resonance (NMR) spectra, single-crystal X-ray diffraction, quantum chemical calculation, and electronic circular dichroism (ECD). Talaromarane A (5) contains a rare 2-oxabicyclo [3.2.1] octan moiety in isopimarane diterpenoids. In bioassays, compounds 1, 2, 4, and 5 displayed significant anti-inflammatory activities with the IC50 value from 4.59 to 21.60 µM.
Assuntos
Anti-Inflamatórios , Diterpenos , Talaromyces , Talaromyces/química , Diterpenos/farmacologia , Diterpenos/química , Diterpenos/isolamento & purificação , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/isolamento & purificação , Animais , Camundongos , Estrutura Molecular , Células RAW 264.7 , Espectroscopia de Ressonância MagnéticaRESUMO
Five new naphthalene derivatives dalesconosides A-D, F (1-4, 6), a known synthetic analogue named dalesconoside E (5), and eighteen known compounds (7-24) were isolated from Daldinia eschscholzii MCZ-18, which is an endophytic fungus obtained from the Chinese mangrove plant Ceriops tagal. Differing from previously reported naphthalenes, compounds 1 and 2 were bearing a rare ribofuranoside substituted at C-1 and the 5-methyltetrahydrofuran-2,3-diol moiety, respectively. Their structures were determined by detailed nuclear magnetic resonance (NMR) and mass spectroscopic (MS) analyses, while the absolute configurations were established by theoretical electronic circular dichroism (ECD) calculation. Compounds 1, 3, 13-17 and 19 showed broad ranges of antimicrobial spectrum against five indicator test microorganisms (Enterococcus faecalis, Methicillin-resistant Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans); especially, 1, 16 and 17 were most potent. The variations in structure and attendant biological activities provided fresh insights concerning structure-activity relationships for the naphthalene derivatives.
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Testes de Sensibilidade Microbiana , Naftalenos , Naftalenos/farmacologia , Naftalenos/química , Naftalenos/isolamento & purificação , Relação Estrutura-Atividade , Espectroscopia de Ressonância Magnética , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/isolamento & purificação , Candida albicans/efeitos dos fármacos , Estrutura Molecular , Rhizophoraceae/microbiologia , Endófitos/química , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Anti-Infecciosos/isolamento & purificaçãoRESUMO
Overwhelming evidence points to an aberrant Wnt/ß-catenin signaling as a critical factor in hepatocellular carcinoma (HCC) and cervical cancer (CC) pathogenesis. Dicerandrol C (DD-9), a dimeric tetrahydroxanthenone isolated from the endophytic fungus Phomopsis asparagi DHS-48 obtained from mangrove plant Rhizophora mangle via chemical epigenetic manipulation of the culture, has demonstrated effective anti-tumor properties, with an obscure action mechanism. The objective of the current study was to explore the efficacy of DD-9 on HepG2 and HeLa cancer cells and its functional mechanism amid the Wnt/ß catenin signaling cascade. Isolation of DD-9 was carried out using various column chromatographic methods, and its structure was elucidated with 1D NMR. The cytotoxicity of DD-9 on HepG2 and HeLa cells was observed with respect to the proliferation, clonality, migration, invasion, apoptosis, cell cycle, and Wnt/ß-catenin signaling cascade. We found that DD-9 treatment significantly reduced tumor cell proliferation in dose- and time-dependent manners in HepG2 and HeLa cells. The subsequent experiments in vitro implied that DD-63 could significantly suppress the tumor clonality, metastases, and induced apoptosis, and that it arrested the cell cycle at the G0/G1 phase of HepG2 and HeLa cells. Dual luciferase assay, Western blot, and immunofluorescence assay showed that DD-9 could dose-dependently attenuate the Wnt/ß-catenin signaling by inhibiting ß-catenin transcriptional activity and abrogating ß-catenin translocated to the nucleus; down-regulating the transcription level of ß-catenin-stimulated Wnt target gene and the expression of related proteins including p-GSK3-ß, ß-catenin, LEF1, Axin1, c-Myc, and CyclinD1; and up-regulating GSK3-ß expression, which indicates that DD-9 stabilized the ß-catenin degradation complex, thereby inducing ß-catenin degradation and inactivation of the Wnt/ß-catenin pathway. The possible interaction between DD-9 and ß-catenin and GSK3-ß protein was further confirmed by molecular docking studies. Collectively, DD-9 may suppress proliferation and induce apoptosis of liver and cervical cancer cells, possibly at least in part via GSK3-ß-mediated crosstalk with the Wnt/ß-catenin signaling axis, providing insights into the mechanism for the potency of DD-9 on hepatocellular and cervical cancer.
Assuntos
Apoptose , Proliferação de Células , Via de Sinalização Wnt , Humanos , Células HeLa , Apoptose/efeitos dos fármacos , Via de Sinalização Wnt/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Hep G2 , beta Catenina/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Neoplasias Hepáticas/tratamento farmacológico , Xantonas/farmacologia , Xantonas/química , Xantonas/isolamento & purificação , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/patologia , Movimento Celular/efeitos dos fármacos , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/patologiaRESUMO
Chemical investigation of the fungal endophyte Xylaria sp. isolated from leaves of Moringa oleifera, collected in Cameroon, resulted in the previously undescribed 10-membered macrolide, and two known natural products. The structures of the xylatolides A and B were unambiguously identified by their mass spectra and by extensive 1D and 2D NMR spectroscopic analysis, featuring a 10-membered lactone core structure with oxygenated substituents and an unsubstituted 10-alkyl chain presenting seven carbon atoms. Compounds were screened for their cytotoxic potential against the human HepG2 hepatocellular carcinoma cells and HCT-116 cells (human colon carcinoma cell line). Moreover, the isolated compounds were also assayed against a small panel of sensitive strains including the bacterial species Escherichia coli, Staphylococcus aureus, and Mycobacterium tuberculosis as well as against the fungal species Candida albicans. However, no significant activities were found.
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In our continuous work on the isolation of endophytes, the endophytic fungal strain YIMF00209 was obtained from the roots of Gmelina arborea, which is an ethnic medicinal plant mainly distributed in Southeast Asia. The fermentation extracts of the strain exhibited significant antimicrobial activities against Staphylococcus aureus, Fusarium solani, and Escherichia coli. Based on morphological characteristics and phylogenetic analysis, it was identified as Talaromyces muroii. Four new polyketides, talaromurolides A-D (1-4), along with 26 known compounds (5-30), were isolated from the culture broth of the strain in two different media. Their structures were identified based on HRESIMS, NMR, and CD spectral data. Among them, compounds 2, 4-6, 19, 22, 24, 27, 28, and 30 were isolated from the fermentation broth in CYM medium; compounds 1, 3, 7-18, 20, 21, 23, 25, 26, and 29 were obtained from the fermentation broth in PDB medium; and compounds 2, 5, and 30 were existed in both two media. Compounds 6-9, 12, 16, 20, 21, 23, 25, and 29 were obtained from the genus Talaromyces for the first time. The antimicrobial activities of several compounds were assayed against six pathogens. Compound 1 exhibited inhibitory activities against S. aureus, E. coli, Candida albicans, Salmonella typhimurium, and Botrytis cinerea with MIC value of 64 µg/mL. Compound 25 exhibited antibacterial activity against E. coli with MIC value of 32 µg/mL.
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Endófitos , Policetídeos , Staphylococcus aureus , Talaromyces , Policetídeos/farmacologia , Policetídeos/isolamento & purificação , Policetídeos/química , Endófitos/química , Estrutura Molecular , Staphylococcus aureus/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Fusarium/efeitos dos fármacos , Raízes de Plantas/microbiologia , Filogenia , Antibacterianos/farmacologia , Antibacterianos/isolamento & purificaçãoRESUMO
Three new meroterpenoids (1-3) and ten known ones (4-13) were obtained from the endophytic fungus Talaromyces primulinus H21 isolated from the plant of Euphorbia sikkimensis. Their structures including their absolute configurations were elucidated by extensive analysis of spectroscopic data such as HR-ESI-MS, 1D/2D NMR, and X-ray diffraction of single crystal together with comparison of experimental ECD with calculated ECD. All compounds were examined for their inhibitory effects on nitric oxide (NO) production induced by lipopolysaccharide (LPS) in RAW264.7 cells, and compounds 3, 9, 12, and 13 exhibited certain inhibition on NO production, with IC50 values of 27.19, 41.55, 25.23, and 24.71 µM, respectively.
Assuntos
Óxido Nítrico , Talaromyces , Terpenos , Talaromyces/química , Camundongos , Estrutura Molecular , Óxido Nítrico/metabolismo , Animais , Terpenos/isolamento & purificação , Terpenos/farmacologia , Células RAW 264.7 , Endófitos/química , ChinaRESUMO
Investigation of secondary metabolites from the mangrove endophytic fungus Talaromyces sp. SAF14 led to the isolation of two new polyketides, methyl (R)-3-(6,8-dihydroxy-7-methoxy-1-oxoisochroman-3-yl)propanoate (1), (R)-3-(5,8- dihydroxy-1-oxoisochroman-3-yl)propanoic acid (2), together with four known alkaloids (3-6). The planar structures of new compounds were elucidated by comprehensive analysis of HR-ESI-MS and NMR data. The absolute configurations were determined by comparison of the calculated ECD spectrum with the measured one. All the isolated compounds were tested for cytotoxic activities against three human cancer cell lines. The known beauvericin (3) exhibited strong cytotoxic activity against A549, MCF-7, and KB cell lines with IC50 values of 5.36 ± 2.49, 1.96 ± 1.09 and 4.46 ± 0.68 µM, respectively.
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This study investigated the chemical and biological activity of the secondary metabolites from an endophytic fungus Fusa-rium solani MBM-5 of Datura arborea. A total of six alkenoic acid compounds, including a new compound and five known ones, were isolated from the ethyl acetate extract of F. solani MBM-5 by using the chromatographic methods(open ODS column chromatography, silica gel column chromatography, Sephadex LH-20, and semi-preparative HPLC). The structures of the compounds were identified by using their physical and chemical data, spectroscopic methods(UV, IR, NMR, and HR-ESI-MS), and Mosher's reaction, which were fusaridioic acid E(1), fusaridioic acid C(2), fusaridioic acid A(3), L660282(4), hymeglusin(5), and hymeglnone(6). Compound 1 is new. MTT assay and Griss method were used to evaluate the growth inhibition of all the compounds against two tumor cells, as well as their influence and anti-inflammatory action on the release of NO from LPS-induced RAW264.7 cells. The results showed that compound 5 had strong growth inhibition activity against A549 and HepG2 cell lines, with IC_(50) values of 4.70 and 13.57 µmol·L~(-1), respectively. Compounds 1 and 6 significantly inhibited the release of NO from LPS-induced RAW264.7 cells, with IC_(50) values of 77.00 and 70.33 µmol·L~(-1), respectively.
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Endófitos , Fusarium , Metabolismo Secundário , Fusarium/efeitos dos fármacos , Fusarium/química , Camundongos , Humanos , Animais , Endófitos/química , Linhagem Celular Tumoral , Células RAW 264.7 , Estrutura Molecular , Óxido Nítrico/metabolismo , Proliferação de Células/efeitos dos fármacosRESUMO
Tanshinones are bioactive ingredients derived from the herbal plant Salvia miltiorrhiza and are used for treating diseases of the heart and brain, thus ensuring quality of S. miltiorrhiza is paramount. Applying the endophytic fungus Trichoderma atroviride D16 can significantly increase the content of tanshinones in S. miltiorrhiza, but the potential mechanism remains unknown. In the present study, the colonization of D16 effectively enhanced the levels of Ca2+ and H2O2 in the roots of S. miltiorrhiza, which is positively correlated with increased tanshinones accumulation. Further experiments found that the treatment of plantlets with Ca2+ channel blocker (LaCl3) or H2O2 scavenger (DMTU) blocked D16-promoted tanshinones production. LaCl3 suppressed not only the D16-induced tanshinones accumulation but also the induced Ca2+ and H2O2 generation; nevertheless, DMTU did not significantly inhibit the induced Ca2+ biosynthesis, implying that Ca2+ acted upstream in H2O2 production. These results were confirmed by observations that S. miltiorrhiza treated with D16, CaCl2, and D16+LaCl3 exhibit H2O2 accumulation and influx in the roots. Moreover, H2O2 as a downstream signal of Ca2+ is involved in D16 enhanced tanshinones synthesis by inducing the expression of genes related to the biosynthesis of tanshinones, such as DXR, HMGR, GGPPS, CPS, KSL and CYP76AH1 genes. Transcriptomic analysis further supported that D16 activated the transcriptional responses related to Ca2+ and H2O2 production and tanshinones synthesis in S. miltiorrhiza seedlings. This is the first report that Ca2+ and H2O2 play important roles in regulating fungal-plant interactions thus improving the quality in the D16-S. miltiorrhiza system.
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Abietanos , Cálcio , Endófitos , Peróxido de Hidrogênio , Raízes de Plantas , Salvia miltiorrhiza , Salvia miltiorrhiza/metabolismo , Salvia miltiorrhiza/microbiologia , Peróxido de Hidrogênio/metabolismo , Abietanos/biossíntese , Abietanos/metabolismo , Endófitos/metabolismo , Endófitos/genética , Raízes de Plantas/microbiologia , Raízes de Plantas/metabolismo , Cálcio/metabolismo , Sinalização do Cálcio/efeitos dos fármacos , Lantânio/farmacologia , Lantânio/metabolismo , Regulação da Expressão Gênica de Plantas , Hypocreales/metabolismo , Hypocreales/genéticaRESUMO
Talaromyces sp. DC2 is an endophytic fungus that was isolated from the stem of Catharanthus roseus (L.) G. Don in Hanoi, Vietnam and is capable of producing vinca alkaloids. This study utilizes the PacBio Sequel technology to completely sequence the whole genome of Talaromyces sp. DC2The genome study revealed that DC2 contains a total of 34.58 Mb spanned by 156 contigs, with a GC content of 46.5%. The identification and prediction of functional protein-coding genes, tRNA, and rRNA were comprehensively predicted and highly annotated using various BLAST databases, including non-redundant (Nr) protein sequence, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Clusters of Orthologous Groups (COG), and Carbohydrate-Active Enzymes (CAZy) databases. The genome of DC2 has a total of 149, 227, 65, 153, 53, and 6 genes responsible for cellulose, hemicellulose, lignin, pectin, chitin, starch, and inulin degradation, respectively. The Antibiotics and Secondary Metabolites Analysis Shell (AntiSMASH) analyses revealed that strain DC2 possesses 20 biosynthetic gene clusters responsible for producing secondary metabolites. The strain DC2 has also been found to harbor the DDC gene encoding aromatic L-amino acid decarboxylase enzyme. Conclusively, this study has provided a comprehensive understanding of the processes involved in secondary metabolites and the ability of the Talaromyces sp. DC2 strain to degrade plant cell walls.
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Medicinal plants, as medicinal materials and important drug components, have been used in traditional and folk medicine for ages. However, being sessile organisms, they are seriously affected by extreme environmental conditions and abiotic stresses such as salt, heavy metal, temperature, and water stresses. Medicinal plants usually produce specific secondary metabolites to survive such stresses, and these metabolites can often be used for treating human diseases. Recently, medicinal plants have been found to partner with endophytic fungi to form a long-term, stable, and win-win symbiotic relationship. Endophytic fungi can promote secondary metabolite accumulation in medicinal plants. The close relationship can improve host plant resistance to the abiotic stresses of soil salinity, drought, and extreme temperatures. Their symbiosis also sheds light on plant growth and active compound production. Here, we show that endophytic fungi can improve the host medicinal plant resistance to abiotic stress by regulating active compounds, reducing oxidative stress, and regulating the cell ion balance. We also identify the deficiencies and burning issues of available studies and present promising research topics for the future. This review provides guidance for endophytic fungi research to improve the ability of medicinal plants to resist abiotic stress. It also suggests ideas and methods for active compound accumulation in medicinal plants and medicinal material development during the response to abiotic stress.
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Objective: To study secondary metabolites from endophytic fungus Colletotruchum sp. HK-08 originated from the leaves of Nerium indicum. Methods: The compounds were isolated by various column chromatographic techniques, and their structures were elucidated by spectroscopic techniques [high resolution electrospray ionization mass spectroscopy (HRESIMS), one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance spectroscopy (NMR)], as well as comparison with literature data. The Ellman method was used to determine the acetylcholinesterase (AChE) inhibitory activity. Results: Four indole derivatives were identified from Colletotruchum sp. HK-08, including 6'-hydroxymonaspiloindole (1), 2-(2-oxoindolin-3-yl)ethyl 2-(4-hydroxyphenyl) acetate (2), 2-(2-oxoindolin-3-yl)ethyl 2-(2-hydroxyphenyl)acetate (3), and monaspiloindole (4). Compound 4 presented weak AChE inhibitory activity with IC50 value of (69.30 ± 6.27) µmol/L [tacrine as the positive control, with IC50 value of (0.61 ± 0.07) µmol/L]. Conclusion: Compounds 1-3 were new compounds, and compound 4 had weak AChE inhibitory activity.
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In this study, we have investigated the effect of carbon quantum dots (FM-CQDs) synthesized from marine fungal extract on Curcuma longa to improve the plant growth and curcumin production. The isolated fungus, Aspergillus flavus has produced a high amount of indole-3-acetic acid (IAA) (0.025 mg g-1), when treated with tryptophan. CQDs were synthesized from the A. flavus extract and it was characterized using ultraviolet visible spectrophotometer (UV-Vis) and high-resolution transmission electron microscopy (HR-TEM). The synthesized CQDs were excited at 365 nm in an UV-Vis and the HR-TEM analysis showed approximately 7.4 nm in size with a spherical shape. Both fungal crude extract (FCE) at 0-100 mg L-1 and FM-CQDs 0-5 mg L-1 concentrations were tested on C. longa. About 80 mg L-1 concentration FCE treated plants has shown a maximum height of 21 cm and FM-CQDs at 4 mg L-1 exhibited a maximum height of 25 cm compared to control. The FM-CQDs significantly increased the photosynthetic pigments such as total chlorophyll (1.08 mg g-1 FW) and carotenoids (17.32 mg g-1 FW) in C. longa. Further, antioxidant enzyme analysis confirmed that the optimum concentrations of both extracts did not have any toxic effects on the plants. FM-CQDs treated plants increased the curcumin content up to 0.060 mg g-1 by HPLC analysis. Semi quantitative analysis revealed that FCE and FM-CQDs significantly upregulated ClCURS1 gene expression in curcumin production.
Assuntos
Aspergillus flavus , Carbono , Curcuma , Curcumina , Pontos Quânticos , Pontos Quânticos/química , Curcuma/metabolismo , Curcuma/microbiologia , Carbono/metabolismo , Carbono/farmacologia , Curcumina/metabolismo , Curcumina/farmacologia , Aspergillus flavus/metabolismo , Aspergillus flavus/crescimento & desenvolvimento , Ácidos Indolacéticos/metabolismo , Endófitos/metabolismoRESUMO
Four new monoterpene rhamnosides, graphiumisides A-D (1-4), along with four known steroid compounds (5-8) were isolated from the fermentation extract of animal-derived endophytic fungus, Graphium sp. GD-11. The chemical structures of all compounds were elucidated using 1D and 2D NMR, HRESIMS spectroscopic analyses, and other spectroscopic methods. Compounds 1-4 exhibit a distinctive structure connected by one p-menthane type monoterpene and one L-rhamnose. This is the first report of monoterpene glycosides from Graphium sp. All compounds (1-8) were tested for cytotoxic activities against four cancer cell lines (HepG2, SMMC7721, SW480, and A549), and only compound 1 showed weak anti-tumor activity against SMMC7721 cells.
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Bacillus cereus, a common food-borne pathogen, forms biofilms and generates virulence factors through a quorum sensing (QS) mechanism. In this study, six compounds (dankasterone A, demethylincisterol A3, zinnimidine, cyclo-(L-Val-L-Pro), cyclo-(L-Ile-L-Pro), and cyclo-(L-Leu-L-Pro)) were isolated from the endophytic fungus Pithomyces sacchari of the Laurencia sp. in the South China Sea. Among them, demethylincisterol A3, a sterol derivative, exhibited strong QS inhibitory activity against B. cereus. The QS inhibitory activity of demethylincisterol A3 was evaluated through experiments. The minimum inhibitory concentration (MIC) of demethylincisterol A3 against B. cereus was 6.25 µg/mL. At sub-MIC concentrations, it significantly decreased biofilm formation, hindered mobility, and diminished the production of protease and hemolysin activity. Moreover, RT-qPCR results demonstrated that demethylincisterol A3 markedly inhibited the expression of QS-related genes (plcR and papR) in B. cereus. The exposure to demethylincisterol A3 resulted in the downregulation of genes (comER, tasA, rpoN, sinR, codY, nheA, hblD, and cytK) associated with biofilm formation, mobility, and virulence factors. Hence, demethylincisterol A3 is a potentially effective compound in the pipeline of innovative antimicrobial therapies.
Assuntos
Antibacterianos , Bacillus cereus , Biofilmes , Testes de Sensibilidade Microbiana , Percepção de Quorum , Percepção de Quorum/efeitos dos fármacos , Bacillus cereus/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Antibacterianos/farmacologia , Laurencia/microbiologia , Fatores de Virulência , China , EndófitosRESUMO
A new 14-membered resorcylic acid lactone (RAL14), chaetolactone A (1), along with three known ones (2-4), was obtained from the fermentation of the soil-derived fungus Chaetosphaeronema sp. SSJZ001. Their structures were established based on extensive spectroscopic data analyses (UV, IR, HRESIMS, 1D, and 2D NMR),13C NMR chemical shifts calculations coupled with the DP4+ probability method, theoretical calculations of ECD spectra, as well as X-ray diffraction analysis. All compounds were evaluated for their cytotoxic effects against A549, HO-8910, and MCF-7 cell lines.