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1.
Commun Chem ; 7(1): 64, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38538750

RESUMO

Norcoclaurine synthase from Thalictrum flavum (TfNCS) demonstrated high stereospecificity and yield in catalyzing the Pictet-Spengler reaction of dopamine with chiral aldehydes, achieving kinetic resolution of aldehydes. However, the mechanism and the factors contributing to the stereoselectivity remain unclear. Herein, by using quantum chemical calculations, the mechanisms of TfNCS-catalyzed reactions of dopamine with both enantiomers of α-methyl-phenylacetaldehyde are studied. The calculations reveal a mechanism mirroring the reaction of natural substrates, for which the deprotonation of the C5-H of the cyclized intermediate is rate-limiting. The calculated overall barriers are 20.1 kcal mol-1 and 21.6 kcal mol-1 for the reactions of (R)- and (S)-α-methyl-phenylacetaldehyde, respectively. The M97 and L72 residues are proposed to be the key residues contributing to the stereospecificity. The obtained detailed information is helpful for designing new variants of TfNCS with extended substrate scope, and also advancing our understanding of TfNCS reactions for potential applications.

2.
Angew Chem Int Ed Engl ; 63(7): e202318550, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38155101

RESUMO

Noncanonical amino acids (ncAAs) containing tertiary alcohols are valuable as precursors of natural products and active pharmaceutical ingredients. However, the assembly of such ncAA scaffolds from simple material by C-C bond formation remains a challenging task due to the presence of multiple stereocenters and large steric hindrance. In this study, we present a novel solution to this problem through highly selective enzymatic decarboxylative aldol addition. This method allows for the streamlined assembly of multifunctionalized ncAAs with γ-tertiary alcohols from readily available materials, such as L -aspartatic acid and isatins, vicinal diones and keto esters. The modularity of electrophiles furnished four classes of ncAAs with decent efficiency as well as excellent site and stereocontrol. Computational modeling was employed to gain detailed insight into the catalytic mechanism and to provide a rationale for the observed selectivities. The method offers a single-step approach to producing multifunctionalized ncAAs, which can be directly utilized in peptide synthesis and bioactivity assessment.


Assuntos
Álcoois , Aminoácidos , Aminoácidos/química , Catálise
3.
Phys Chem Chem Phys ; 25(38): 26308-26315, 2023 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-37747304

RESUMO

SARS-CoV-2 main protease, Mpro, plays a crucial role in the virus replication cycle, making it an important target for antiviral research. In this study, a simplified model obtained through truncation is used to explore the reaction mechanism of aldehyde warhead compounds inhibiting Mpro at the level of density functional theory. According to the calculation results, proton transfer (P_T)-nucleophilic attack (N_A) is the rate-determining step in the entire reaction pathway. The water molecule that plays a catalytic role occupies the oxyanion hole, which is unfavorable for the aldehyde warhead to approach the Cys145 SH. Through a hypothetical study of substituting the main chain NH with methylene, it is further confirmed that the P_T-N_A is a proton transfer-dominated process accompanied by a nucleophilic attack reaction. In this process, the oxyanion hole serves only to stabilize the aldehyde oxygen anion and therefore does not have a significant impact on the activation free energy barrier of the step. Our research results provide a unique perspective for understanding the covalent inhibition reaction of the Mpro active site. This study also offers theoretical guidance for the design of new Mpro covalent inhibitors.


Assuntos
Aldeídos , Antivirais , Proteases 3C de Coronavírus , SARS-CoV-2 , Humanos , Aldeídos/química , Aldeídos/farmacologia , Antivirais/química , Antivirais/farmacologia , Simulação de Acoplamento Molecular , Prótons , SARS-CoV-2/enzimologia , Proteases 3C de Coronavírus/antagonistas & inibidores , Proteases 3C de Coronavírus/química
4.
ChemistryOpen ; 12(6): e202300043, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37248801

RESUMO

Strictosidine synthase (STR) catalyzes the Pictet-Spengler (PS) reaction of tryptamine and secologanin to produce strictosidine. Recent studies demonstrated that the enzyme can also catalyze the reaction of non-natural substrates to form new alkaloid skeletons. For example, the PS condensation of 1H-indole-4-ethanamine with secologanin could be promoted by the STR from Rauvolfia serpentina (RsSTR) to generate a rare class of skeletons with a seven-membered ring, namely azepino-[3,4,5-cd]-indoles, which are precursors for the synthesis of new compounds displaying antimalarial activity. In the present study, the detailed reaction mechanism of RsSTR-catalyzed formation of the rare seven-membered azepino-indole skeleton through the PS reaction was revealed at the atomic level by quantum chemical calculations. The structures of the transition states and intermediates involved in the reaction pathway were optimized, and the energetics of the complete reaction were analyzed. Based on our calculation results, the most likely pathway of the enzyme-catalyzed reaction was determined, and the rate-determining step of the reaction was clarified. The mechanistic details obtained in the present study are important in understanding the promiscuous activity of RsSTR in the formation of the rare azepino-indole skeleton molecule and are also helpful in designing STR enzymes for the synthesis of other new alkaloid skeleton molecules.


Assuntos
Alcaloides , Alcaloides de Vinca , Alcaloides de Vinca/química , Esqueleto
5.
Physiol Mol Biol Plants ; 29(3): 435-445, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37033769

RESUMO

Low-phosphorus stress significantly impacts the development of maize kernels. In this study, the phosphor efficient maize genotype 082 and phosphor deficient maize genotype Ye107, were used to construct an F2:3 population. QTL mapping was then employed to determine the genetic basis of differences in the maize kernel traits of the two parents in a low-phosphorus environment. This analysis revealed several major QTL that control environmental impacts on kernel length, width, thickness, and weight. These QTL were detected in all three environments and were distributed on five genome segments of chromosomes 3, 5, 6, and 9, and some new kernel-trait QTL were also detected (eg: Qkwid6, Qkthi3, Qkwei9, and Qklen3-1). These environmentally insensitive QTL can be stably expressed in low phosphorus environments, indicating that they can lay a foundation for the breeding of high phosphorus utilization efficiency germplasm. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-023-01300-0.

6.
Molecules ; 27(23)2022 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-36500432

RESUMO

Aminopeptidase N (APN) was closely associated with cancer invasion, metastasis, and angiogenesis. Therefore, APN inhibitors have attracted more and more attention of scientists as antitumor agents. In the current study, we designed, synthesized, and evaluated one new series of pyrazoline-based hydroxamate derivatives as APN inhibitors. Moreover, the structure-activity relationships of those were discussed in detail. 2,6-Dichloro substituted compound 14o with R1 = CH3, showed the best capacity for inhibiting APN with an IC50 value of 0.0062 ± 0.0004 µM, which was three orders of magnitude better than that of the positive control bestatin. Compound 14o possessed both potent anti-proliferative activities against tumor cells and potent anti-angiogenic activity. At the same concentration of 50 µM, compound 14o exhibited much better capacity for inhibiting the micro-vessel growth relative to bestatin in the rat thoracic aorta ring model. Additionally, the putative interactions of 14o with the active site of APN are also discussed. The hydroxamate moiety chelated the zinc ion and formed four hydrogen bonds with His297, Glu298 and His301. Meanwhile, the terminal phenyl group and another phenyl group of 14o interacted with S2' and S1 pockets via hydrophobic effects, respectively.


Assuntos
Antineoplásicos , Antígenos CD13 , Ratos , Animais , Inibidores de Proteases/química , Ácidos Hidroxâmicos/farmacologia , Antineoplásicos/farmacologia , Relação Estrutura-Atividade
7.
Front Nutr ; 9: 1038740, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36407511

RESUMO

Obesity has caused serious health and economic problems in the world. Cordyceps guangdongensis is a high-value macrofungus with broad application potential in the food and bio-medicine industry. This current study aimed to estimate the role of C. guangdongensis lipid-lowering compound formula (CGLC) in regulating fat and lipid accumulation, gut microbiota balance, short-chain fatty acid (SCFA) contents, and expression levels of genes involved in fat and lipid metabolism in high-fat diet (HFD) mice. The results showed that CGLC intervention markedly reduced body weights and fat accumulation in HFD mice, improved glucose tolerance and blood lipid levels, and decreased lipid droplet accumulation and fat vacuole levels in the liver. CGLC decreased the ratio of Firmicutes and Bacteroidetes and increased the relative abundances of Bacteroides (B. acidifaciens) and Bifidobacterium (B. pseudolongum). In addition, CGLC treatment significantly promoted the production of SCFAs and regulated the relative expression levels of genes involved in fat and lipid metabolism in liver. Association analysis showed that several species of Bacteroides and most of SCFAs were significantly associated with serum lipid indicators. These results suggested that CGLC is a novel candidate formulation for treating obesity and non-alcohol fatty liver by regulating gut microbiota, SCFAs, and genes involved in fat and lipid metabolism.

8.
Phys Chem Chem Phys ; 24(39): 24447-24456, 2022 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-36190779

RESUMO

Searching for materials with a high thermoelectric figure of merit (ZT) has always been the goal of scientific researchers in the energy field. Here, we combine first-principles calculations to obtain the thermoelectric characteristics of Tl3XSe4 (X = V, Nb, or Ta). First, we compared the phonon thermal transport characteristics of Tl3XSe4 by solving the Boltzmann transport equation and calculated the thermal conductivity. After that, we obtained the thermoelectric properties of Tl3XSe4 through the relaxation time approximation theory. The results show that Tl3XSe4 has a high Seebeck coefficient, high electrical conductivity, high power factor (PF) and low thermal conductivity contributed by both phonons and electrons. At the same time, the ZT value of Tl3XSe4 shows that it is a potential thermoelectric material with excellent performance. This work demonstrates the thermoelectric transport characteristics of Tl3XSe4 to explore its potential applications in many other fields of thermoelectricity and energy.

9.
Front Microbiol ; 13: 964112, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35992691

RESUMO

Acute lung injury (ALI) with uncontrolled inflammatory response has high morbidity and mortality rates in critically ill patients. Pathogen-associated molecular patterns (PAMPs) are involved in the development of uncontrolled inflammatory response injury and associated lethality. In this study, we investigated the inhibit effect of MS19, a microsatellite DNA-derived oligodeoxynucleotide (ODN) with AAAG repeats, on the inflammatory response induced by various PAMPs in vitro and in vivo. In parallel, a microsatellite DNA with AAAC repeats, named as MS19-C, was used as controls. We found that MS19 extensively inhibited the expression of inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α induced by various PAMPs stimulation, including DNA viruses, RNA viruses, bacterial components lipopolysaccharide (LPS), and curdlan, as well as the dsDNA and dsRNA mimics, in primed bone marrow-derived macrophage (BMDM). Other than various PAMPs, MS19 also demonstrated obvious effects on blocking the high mobility group box1 (HMGB1), a representative damage-associated-molecular pattern (DAMP), nuclear translocation and secretion. With the base substitution from G to C, MS19-C has been proved that it has lost the inhibitory effect. The inhibition is associated with nuclear factor kappa B (NF-κB) signaling but not the mitogen-activated protein kinase (MAPK) transduction. Moreover, MS19 capable of inhibiting the IL-6 and TNF-α production and blocking the HMGB1 nuclear translocation and secretion in LPS-stimulated cells was used to treat mice ALI induced by LPS in vivo. In the ALI mice model, MS19 significantly inhibited the weight loss and displayed the dramatic effect on lessening the ALI by reducing consolidation, hemorrhage, intra-alveolar edema in lungs of the mice. Meanwhile, MS19 could increase the survival rate of ALI by downregulating the inflammation cytokines HMGB1, TNF-a, and IL-6 production in the bronchoalveolar lavage fluid (BALF). The data suggest that MS19 might display its therapeutic role on ALI by inhibiting the HMGB1-TLR4-NF-κB signaling pathway.

10.
Front Microbiol ; 13: 948171, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36033898

RESUMO

Kasugamycin (KSM), an aminoglycoside antibiotic, has been widely used for the management of plant diseases, especially for the control of rice blast in Asia. However, its uptake mechanism and transport in plants are still obscure. The castor bean (Ricinus communis L.) seeding, a model plant for phloem transport, was used to study the mechanism of uptake and transport of KSM. Results showed that cotyledon-applied KSM could transport into the phloem and distributed in root and shoot of plant. The temperature, concentration, and pH had significant effects on the uptake of KSM, indicating that the uptake of KSM was mediated by an active carrier system. Compared with the control, competitive inhibitors of sugar transporters D-glucose, D-chiro-inositol, and phloridzin inhibited 71.03%, 67.95%, and 61.73% uptake of KSM, respectively. Energy inhibitor dinitrophenol (DNP) and carbonyl cyanide chlorophenylhydrazone (CCCP) also affected the uptake of KSM, and the inhibition rates were 34.23% and 48.06%. All the results showed that the uptake of KSM was mediated by a sugar transporter, and it could transport from shoot to root in plants via the phloem. The study preliminary elucidated the plant-microbe interactions in the context of the transport of microbial secondary metabolites in plants. It has certain significance for scientific application of antibiotics and biological control of plant diseases and provides theoretical basis for the development of bidirectional transport pesticides.

11.
Front Cardiovasc Med ; 9: 904400, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35783831

RESUMO

Background: Severely burned children are at high risk of secondary intraabdominal hypertension and abdominal compartment syndrome (ACS). ACS is a life-threatening condition with high mortality and requires an effective, minimally invasive treatment to improve the prognosis when the condition is refractory to conventional therapy. Case presentation: A 4.5-year-old girl was admitted to our hospital 30 h after a severe burn injury. Her symptoms of burn shock were relieved after fluid resuscitation. However, her bloating was aggravated, and ACS developed on Day 5, manifesting as tachycardia, hypoxemia, shock, and oliguria. Invasive mechanical ventilation, vasopressors, and percutaneous catheter drainage were applied in addition to medical treatments (such as gastrointestinal decompression, diuresis, sedation, and neuromuscular blockade). These treatments did not improve the patient's condition until she received continuous renal replacement therapy. Subsequently, her vital signs and laboratory data improved, which were accompanied by decreased intra-abdominal pressure, and she was discharged after nutrition support, antibiotic therapy, and skin grafting. Conclusion: ACS can occur in severely burned children, leading to rapid deterioration of cardiopulmonary function. Patients who fail to respond to conventional medical management should be considered for continuous renal replacement therapy.

12.
Drug Dev Res ; 83(4): 952-960, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35132666

RESUMO

Evidence has demonstrated that Daphnetin has antiangiogenesis activity, indicating it might be a new multi-targeted medication for cancer therapy. Here, we aimed to reveal Daphnetin role in hepatocellular carcinoma (HCC) progression and the underlying mechanism. Huh7 and SK-HEP-1, two human HCC cell lines were used in this study. MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), colony formation, flow cytometry, and tumor-bearing experiments were applied to evaluate the effects of different concentrations of Daphnetin on cell viability, apoptosis, cell cycle, and in vivo tumor formation, respectively. Real-time PCR (Polymerase Chain Reaction)and western blotting were applied to measure the mRNA and protein levels of ß-catenin. We observed that Daphnetin inhibited cell viability and tumorigenesis, promoted cell apoptosis, and induced a G1 phase arrest in a dose-dependent manner in both Huh7 and SK-HEP-1 cells, which were rescued by SKL2001, an activator of the Wnt/ß-catenin signaling. Taken together, this study reveals that Daphnetin exerts an antitumor role in HCC through the inactivation of Wnt/ß-catenin signaling.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Apoptose , Carcinoma Hepatocelular/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Umbeliferonas , Via de Sinalização Wnt/genética , beta Catenina/genética , beta Catenina/metabolismo , beta Catenina/farmacologia
13.
ACS Chem Biol ; 17(1): 187-197, 2022 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-34994203

RESUMO

Strictosidine synthase (STR), the gate enzyme for monoterpenoid indole alkaloid biosynthesis, catalyzes the Pictet-Spengler reaction (PSR) of various tryptamine derivatives with secologanin assisted by "indole sandwich" stabilization. Continuous exploration with ß-methyltryptamine (IPA) stereoselectively delivered the C6-methylstrictosidines and C6-methylvincosides by enzymatic and nonenzymatic PSR, respectively. Unexpectedly, the first "nonindole sandwich" binding mode was witnessed by the X-ray structures of STR1-ligand complexes. Site-directed mutagenesis revealed the critical cryptic role of the hydroxyl group of Tyr151 in IPA biotransformation. Further computational calculations demonstrated the adjustable IPA position in STR1 upon the binding of secologanin, and Tyr151-OH facilitates the productive PSR binding mode via an advantageous hydrogen-bond network. Further chemo-enzymatic manipulation of C6-methylvincosides successfully resulted in the discovered antimalarial framework (IC50 = 0.92 µM).


Assuntos
Alcaloides , Carbolinas , Carbono-Nitrogênio Liases , Triptaminas , Humanos , Alcaloides/química , Alcaloides/metabolismo , Antineoplásicos/química , Antineoplásicos/farmacologia , Carbolinas/química , Carbolinas/metabolismo , Carbono-Nitrogênio Liases/genética , Carbono-Nitrogênio Liases/metabolismo , Domínio Catalítico , Sobrevivência Celular/efeitos dos fármacos , Células HL-60 , Modelos Moleculares , Estrutura Molecular , p-Hidroxianfetamina , Ligação Proteica , Conformação Proteica , Triptaminas/química , Triptaminas/metabolismo
14.
J Mol Neurosci ; 72(3): 482-495, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34623606

RESUMO

Mesenchymal stem cells (MSCs)-derived exosomes play significant roles in alleviating spinal cord injury (SCI). Previous study showed that long non-coding RNA tectonic family member 2 (TCTN2) was able to relieve SCI. Herein, whether TCTN2 exerted its roles in functional recovery after SCI via exosomes derived from MSCs was explored. The SCI model was established in rats, and the neurological function was evaluated using the Basso, Beattie, and Bresnahan (BBB) scoring. Lipopolysaccharide (LPS)-induced differentiated PC12 cells were used as an in vitro model for neurotoxicity research. The expression of genes and proteins was detected by qRT-PCR and Western blot. Exosomes were isolated by ultracentrifugation and qualified by TEM and Western blot. In vitro assays were performed using CCK-8 assay, EdU assay, and flow cytometry, respectively. Dual-luciferase reporter assay and RIP assay were used to confirm the target relationship between miR-329-3p and TCTN2 or insulin-like growth factor1 receptor (IGF1R). TCTN2 expression was down-regulated in SCI model rat and lipopolysaccharide (LPS)-stimulated PC12 cells. MSCs produced exosomes and could package TCTN2 into secreted exosomes. Tail vein injection of TCTN2 exosomes into rats significantly improved functional recovery of SCI. Meanwhile, TCTN2 exosomes treatment alleviated LPS-induced neuronal apoptosis, inflammation, and oxidative stress in vitro. Additionally, TCTN2 targeted miR-329-3p and subsequently regulated the expression of its target IGF1R. Rescue assays suggested that miR-329-3p/IGF1R axis mediated the beneficial effects of TCTN2 exosomes on LPS-treated PC12 cells. In all, exosomes derived from TCTN2-modified MSCs could improve functional recovery of SCI in vivo and attenuate LPS-induced neuronal apoptosis, inflammation, and oxidative stress in vitro via miR-329-3p/IGF1R axis, suggesting a novel insight into the development of MSC-exosomes-based therapy for SCI.


Assuntos
Exossomos , Células-Tronco Mesenquimais , MicroRNAs , RNA Longo não Codificante , Traumatismos da Medula Espinal , Animais , Apoptose/genética , Exossomos/metabolismo , Células-Tronco Mesenquimais/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Ratos , Receptor IGF Tipo 1 , Medula Espinal/metabolismo , Traumatismos da Medula Espinal/genética , Traumatismos da Medula Espinal/metabolismo , Traumatismos da Medula Espinal/terapia
15.
Curr Issues Mol Biol ; 45(1): 212-222, 2022 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-36661502

RESUMO

Virus infestation can seriously harm the host plant's growth and development. Turnip yellows virus (TuYV) infestation of host plants can cause symptoms, such as yellowing and curling of leaves and root chlorosis. However, the regulatory mechanisms by which TuYV affects host growth and development are unclear. Hence, it is essential to mine small RNA (sRNA) and explore the regulation of sRNAs on plant hosts for disease control. In this study, we analyzed high-throughput data before and after TuYV infestation in Arabidopsis using combined genetics, statistics, and machine learning to identify 108 specifically expressed and critical functional sRNAs after TuYV infection. First, comparing the expression levels of sRNAs before and after infestation, 508 specific sRNAs were significantly up-regulated in Arabidopsis after infestation. In addition, the results show that AI models, including SVM, RF, XGBoost, and CNN using two-dimensional convolution, have robust classification features at the sequence level, with a prediction accuracy of about 96.8%. A comparison of specific sRNAs with genome sequences revealed that 247 matched precisely with the TuYV genome sequence but not with the Arabidopsis genome, suggesting that TuYV viruses may be their source. The 247 sRNAs predicted target genes and enrichment analysis, which identified 206 Arabidopsis genes involved in nine biological processes and three KEGG pathways associated with plant growth and viral stress tolerance, corresponding to 108 sRNAs. These findings provide a reference for studying sRNA-mediated interactions in pathogen infection and are essential for establishing a vital resource of regulation network for the virus infecting plants and deepening the understanding of TuYV virus infection patterns. However, further validation of these sRNAs is needed to gain a new understanding.

16.
Front Microbiol ; 12: 746141, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34690994

RESUMO

Melatonin, a bioactive compound and an important signaling molecule produced in plants and animals, is involved in many biological processes. However, its function and synthetic pathways in fungi are poorly understood. Here, the samples from Tolypocladium guangdongense, a highly valued edible fungus with functional food properties, were collected under different experimental conditions to quantify the levels of melatonin and its intermediates. The results showed that the intracellular melatonin content was markedly improved by Congo red (CR), cold, and heat stresses; the levels of intracellular melatonin and its intermediates increased at the primordial (P) and fruiting body (FB) stages. However, the levels of most intermediates exhibited a notable decrease under CR stress. Several genes related to melatonin synthesis, excluding AADC (aromatic-L-amino-acid decarboxylase), were markedly upregulated at an early stage of CR stress but downregulated later. Compared to the mycelial stage, those genes were significantly upregulated at the P and FB stages. Additionally, exogenous melatonin promoted resistance to several abiotic stressors and P formation in T. guangdongense. This study is the first to report melatonin biosynthesis pathway in macro-fungi. Our results should help in studying the diversity of melatonin function and melatonin-synthesis pathways and provide a new viewpoint for melatonin applications in the edible-medicinal fungus.

17.
mBio ; 12(2)2021 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-33758088

RESUMO

In filamentous fungi, 1,8-dihydroxynaphthalene (DHN) melanin is a major component of the extracellular matrix, endowing fungi with environmental tolerance and some pathogenic species with pathogenicity. However, the subcellular location of the melanin biosynthesis pathway components remains obscure. Using the gray mold pathogen Botrytis cinerea, the DHN melanin intermediate scytalone was characterized via phenotypic and chemical analysis of mutants, and the key enzymes participating in melanin synthesis were fused with fluorescent proteins to observe their subcellular localizations. The Δbcscd1 mutant accumulated scytalone in the culture filtrate rather than in mycelium. Excessive scytalone appears to be self-inhibitory to the fungus, leading to repressed sclerotial germination and sporulation in the Δbcscd1 mutant. The BcBRN1/2 enzymes responsible for synthesizing scytalone were localized in endosomes and found to be trafficked to the cell surface, accompanied by the accumulation of BcSCD1 proteins in the cell wall. In contrast, the early-stage melanin synthesis enzymes BcPKS12/13 and BcYGH1 were localized in peroxisomes. Taken together, the results of this study revealed the subcellular distribution of melanin biosynthetic enzymes in B. cinerea, indicating that the encapsulation and externalization of the melanin synthetic enzymes need to be delicately orchestrated to ensure enzymatic efficiency and protect itself from the adverse effect of the toxic intermediate metabolite.IMPORTANCE The devastating gray mold pathogen Botrytis cinerea propagates via melanized conidia and sclerotia. This study reveals that the sclerotial germination of B. cinerea is differentially affected by different enzymes in the melanin synthesis pathway. Using gene knockout mutants and chemical analysis, we found that excessive accumulation of the melanin intermediate scytalone is inhibitory to B. cinerea. Subcellular localization analysis of the melanin synthesis enzymes of B. cinerea suggested two-stage partitioning of the melanogenesis pathway: the intracellular stage involves the steps until the intermediate scytalone was translocated to the cell surface, whereas the extracellular stage comprises all the steps occurring in the wall from scytalone to final melanin formation. These strategies make the fungus avert self-poisoning during melanin production. This study opens avenues for better understanding the mechanisms of secondary metabolite production in filamentous fungi.


Assuntos
Vias Biossintéticas/genética , Botrytis/genética , Melaninas/biossíntese , Melaninas/genética , Naftóis/metabolismo , Vias Biossintéticas/fisiologia , Botrytis/enzimologia , Botrytis/metabolismo , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Mutação , Naftóis/análise , Metabolismo Secundário
18.
Biomed Pharmacother ; 137: 111393, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33761610

RESUMO

The leaves of Ficus carica Linn. (FC) have been widely used for medicine purposes since ancient times, and its decoction is consumed as tea. Many scientific papers have been published in the literature and the researchers across the world are still exploring the health benefits of FC leaves. In this review, we have collected the literature published since 2010 in the databases: Pubmed, Scopus, Web of Science, SciFinder, Google Scholar, Baidu Scholar and local classic herbal literature. The summary of the chemical constituents in FC leaves, biological activities, toxicity studies, and clinical studies carried out on FC leaves is provided in this review. In addition, the molecular mechanisms of the active constituents in FC leaves are also comprehended. FC leaves are reported to 126 constituents out of which the polyphenolic compounds are predominant. Many scientific studies have proven the antidiabetic, antioxidant, anti-inflammatory, anticancer, anticholinesterase, antimicrobial, hepatoprotective, and renoprotective activities. Many studies have carried out to provide the insights on molecular pathways involved in the biological activities of FC leaves. The toxicity studies have suggested that FC leaves exhibit toxicity only at very high doses. We believe this review serve as a comprehensive resource for those who are interested to understand the scientific evidence that support the medicinal values of FC leaves and also the research gaps to further improve the commercial value and health benefits of FC leaves.


Assuntos
Ficus/química , Fitoterapia , Folhas de Planta/química , Animais , Etnofarmacologia , Ficus/toxicidade , Humanos , Medicina Tradicional , Folhas de Planta/toxicidade , Plantas Medicinais/química , Plantas Medicinais/toxicidade
19.
Fungal Genet Biol ; 147: 103505, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33347973

RESUMO

Cordyceps guangdongensis is a well-known fungus with high nutritional and medicinal value. The metabolite profile of C. guangdongensis is similar to that of Ophiocordyceps sinensis. In plants and animals, microRNAs play important roles in regulating gene expression at the post-transcriptional level. MicroRNA-like RNAs (milRNAs) have been documented in several macro-fungi. To comprehensively investigate the milRNAs in C. guangdongensis, three small RNA libraries from the differentially developmental stages were constructed. Twenty-six conserved milRNAs were identified, and 19 novel milRNA candidates were predicted. Among them, 20 milRNAs were differentially expressed across the developmental processes, and 12 milRNAs were verified using stem-loop quantitative real-time reverse transcription polymerase chain reaction. In addition, the potential target genes of milRNA were predicted to be involved in the development of fruiting bodies and metabolite biosynthesis. This study is the first to report the milRNAs of C. guangdongensis, and provides important insights into studies of milRNA regulation pathways in ascomycete fungi.


Assuntos
Cordyceps/crescimento & desenvolvimento , Cordyceps/genética , Regulação Fúngica da Expressão Gênica , MicroRNAs/genética , RNA Fúngico/genética , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Redes e Vias Metabólicas/genética , MicroRNAs/isolamento & purificação
20.
Front Aging Neurosci ; 12: 601603, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33192493

RESUMO

Alzheimer's disease (AD) is a neurodegenerative disease with a high incidence rate and complicated pathogenesis. Currently, all anti-AD drugs treat the symptoms of the disease, and with currently no cure for AD. Flavonoid containing natural products, Myricetin (MYR) and Dihydromyricetin (DMY), are abundant in fruits and vegetables, and have been approved as food supplements in some countries. Interestingly, MYR and DMY have been reported to have anti-AD effects. However, the underlying anti-AD mechanism of action of MYR and DMY is complex with many facets being identified. In this review, we explore the benefit of MYR and DMY in AD patients from a molecular level. Their mechanism of action are discussed from various aspects including amyloid ß-protein (Aß) imbalance, neuroinflammation, dyshomeostasis of metal ions, autophagy disorder, and oxidative stress.

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