RESUMO
Myrosinase (Myr) catalyzes the hydrolysis of glucosinolates, yielding biologically active metabolites. In this study, glucoraphanin (GRA) extracted from broccoli seeds was effectively hydrolyzed using a Myr-obtained cabbage aphid (Brevicoryne brassicae) (BbMyr) to produce (R)-sulforaphane (SFN). The gene encoding BbMyr was successfully heterologously expressed in Escherichia coli, resulting in the production of 1.6 g/L (R)-SFN, with a remarkable yield of 20.8 mg/gbroccoli seeds, achieved using recombination E. coli whole-cell catalysis under optimal conditions (pH 4.5, 45 °C). Subsequently, BbMyr underwent combinatorial simulation-driven mutagenesis, yielding a mutant, DE9 (N321D/Y426S), showing a remarkable 2.91-fold increase in the catalytic efficiency (kcat/KM) compared with the original enzyme. Molecular dynamics simulations demonstrated that the N321D mutation in loopA of mutant DE9 enhanced loopA stability by inducing favorable alterations in hydrogen bonds, while the Y426S mutation in loopB decreased spatial resistance. This research lays a foundation for the environmentally sustainable enzymatic (R)-SFN synthesis.
Assuntos
Afídeos , Brassica , Glicosídeo Hidrolases , Isotiocianatos , Sulfóxidos , Sulfóxidos/química , Sulfóxidos/metabolismo , Animais , Isotiocianatos/metabolismo , Isotiocianatos/química , Afídeos/enzimologia , Afídeos/genética , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Glicosídeo Hidrolases/química , Brassica/genética , Brassica/enzimologia , Brassica/química , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Proteínas de Insetos/química , Glucosinolatos/metabolismo , Glucosinolatos/química , Cinética , Simulação de Dinâmica Molecular , Oximas/química , Oximas/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Evolução Molecular Direcionada , Imidoésteres/metabolismo , Imidoésteres/químicaRESUMO
SCOPE: Obesity and its metabolic comorbidities pose a major global challenge for public health. Glucoraphanin (GRN) is a natural bioactive compound enriched in broccoli that is known to have potential health benefits against various human chronic diseases. METHODS AND RESULTS: This study investigats the effects of broccoli GRN supplementation on body weight, metabolic parameters, gut microbiome and metabolome associated with obesity. The study is conducted on an obese-related C57BL/6J mouse model through the treatment of normal control diet, high-fat diet (HFD)and GRN-supplemented HFD (HFD-GRN) to determine the metabolic protection of GRN. The results shows that GRN treatment alleviates obesity-related traits leading to improved glucose metabolism in HFD-fed animals. Mechanically, the study noticed that GRN significantly shifts the gut microbial diversity and composition to an eubiosis status. GRN supplement also significantly alters plasma metabolite profiles. Further integrated analysis reveal a complex interaction between the gut microbes and host metabolism that may contribute to GRN-induced beneficial effects against HFD. CONCLUSION: These results indicate that beneficial effects of broccoli GRN on reversing HFD-induced adverse metabolic parameters may be attributed to its impacts on reprogramming microbial community and metabolites. Identification of the mechanistic functions of GRN further warrants it as a dietary candidate for obesity prevention.
Assuntos
Brassica , Dieta Hiperlipídica , Suplementos Nutricionais , Microbioma Gastrointestinal , Glucosinolatos , Imidoésteres , Metaboloma , Camundongos Endogâmicos C57BL , Obesidade , Oximas , Sulfóxidos , Microbioma Gastrointestinal/efeitos dos fármacos , Animais , Obesidade/microbiologia , Obesidade/tratamento farmacológico , Dieta Hiperlipídica/efeitos adversos , Brassica/química , Glucosinolatos/farmacologia , Masculino , Metaboloma/efeitos dos fármacos , Sulfóxidos/farmacologia , Imidoésteres/farmacologia , Oximas/farmacologia , CamundongosRESUMO
BACKGROUND: Association studies of vitamin D receptor (VDR) polymorphisms with COVID-19 severity have produced inconsistent results in different populations. Herein we examined VDR gene polymorphisms in a Caucasian Greek cohort of COVID-19 patients. METHODS: This was a case-control study in a tertiary university hospital in Greece including 137 COVID-19 patients with varying disease severities and 72 healthy individuals. In total 209 individuals were genotyped for the FokI (rs10735810), ApaI (rs7975232), TaqI (rs731236) and BsmI (rs1544410) single-nucleotide polymorphisms (SNP) of the VDR gene by polymerase chain reaction and restriction fragment length polymorphism analysis (PCR-RFLPs). Statistical analyses were performed to determine the association between genotype and disease severity, adjusting for various confounding factors. RESULTS: Genotype distribution of the studied VDR SNPs in the control group was in Hardy-Weinberg equilibrium. The TaqI variant was differentially distributed between controls and COVID-19 patients according to the additive model (p = 0.009), and the CC genotype was significantly associated with an increased risk for severe COVID-19 according to the recessive model [OR: 2.52, 95%CI:1.2-5.29, p = 0.01]. Multivariate analysis demonstrated a robust association of COVID-19 severity and TaqI polymorphism in the recessive model even after adjusting for multiple confounders, including age, sex and CRP levels [Adj.OR:3.23, 95%CI:1.17-8.86, p = 0.023]. The distribution of FokI, ApaI and BsmI genotypes was similar between COVID-19 patients and controls. CONCLUSIONS: The CC genotype of TaqI polymorphism is significantly associated with an increased risk for severe COVID-19 independently of age, sex or degree of inflammation.
Assuntos
COVID-19 , Imidoésteres , Receptores de Calcitriol , Humanos , Receptores de Calcitriol/genética , Predisposição Genética para Doença , Estudos de Casos e Controles , Genótipo , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Background: Vitamin D receptor (VDR) is a nuclear hormone receptor widely expressed in the substantia nigra. Its association with an increased risk of Parkinson's disease (PD) is based on vitamin D deficiency and/or different polymorphisms in its gene receptor. This fact has been demonstrated by several case-control studies. Materials and Methods: Consequently, we investigated the association between VDR ApaI, BsmI, FokI, and TaqI gene polymorphisms and PD in a Spanish cohort that included 54 cases and 17 healthy controls. The detection of single nucleotide polymorphisms (SNPs) was performed using a polymerase chain reaction-restriction fragment length polymorphism. Results: Our data indicate that the SNPs were not associated with the age of onset of PD, nor with the occurrence of motor symptoms. However, only BsmI polymorphism was significantly associated with PD in this Spanish cohort. In fact, BsmI genotype was five times higher among PD patients than among controls, and the A allele was considered as a genetic risk for PD. Additionally, the combination of FokI and BsmI polymorphisms was significantly associated with PD and could represent a risk factor. Conclusion: We conclude that ApaI, TaqI, and FokI polymorphisms were not associated with PD, but BsmI could be a risk factor for PD in this randomized population.
Assuntos
Imidoésteres , Doença de Parkinson , Receptores de Calcitriol , Humanos , Estudos de Casos e Controles , Predisposição Genética para Doença/genética , Genótipo , Doença de Parkinson/genética , Polimorfismo de Nucleotídeo Único/genética , Receptores de Calcitriol/genética , Vitamina DRESUMO
Objective: Vitamin D is a potent immune modulator and is associated with autoimmune diseases, including type 1 diabetes (T1D). The vitamin D levels and its receptor gene polymorphisms together in T1D are not yet investigated in the South Indian population. The present study focused on exploring the significance of vitamin D levels and vitamin D receptor (VDR) gene polymorphisms with the risk of developing T1D in the South Indian population. Methods: Patients with T1D and unaffected first-degree relatives (FDRs) were included in this study. Genotyping of VDR polymorphisms at four different loci (FokI- F/f, BsmI- B/b, TaqI- T/t, and ApaI- A/a) was assessed through the amplification refractive mutation system-polymerase chain reaction method. Serum vitamin D levels were measured in 98 T1D patients and 75 age- and sex-matched siblings. Results: A total of 120 patients with T1D and 214 FDRs were included. Vitamin D deficiency (VDD) was observed in a higher proportion of T1D patients than in controls (52% vs. 32%; p<0.03). The frequency of the FokI-FF genotype was significantly higher [odds ratio (OR)=1.66; p<0.03] in T1D patients conferring a susceptible association with the disease. Nevertheless, the increased frequency of heterozygous Ff genotype (OR=0.57; p<0.02) among controls may confer a protective association with T1D. Furthermore, the transmission disequilibrium test revealed over-transmission of ApaI-A (T: U=15/5; p<0.006) and BsmI-B alleles (T: U=17/5; p<0.01) and under-transmission of BsmI-b/ApaI-a/TaqI-T haplotype (T: U=5.4/14.4; p=0.04) from parents to T1D patients. Conclusion: The present study concludes that VDD is the major contributing risk factor to T1D development in the South Indian population. Furthermore, the FokI-FF genotype, BsmI-B, and ApaI-A alleles were positively associated with T1D. In contrast, the FokI-Ff genotype and BsmI-b/ApaI-a/TaqI-T haplotype were negatively associated with T1D.
Assuntos
Diabetes Mellitus Tipo 1 , Imidoésteres , Deficiência de Vitamina D , Humanos , Receptores de Calcitriol/genética , Diabetes Mellitus Tipo 1/genética , Genótipo , Polimorfismo Genético , Vitamina D , Deficiência de Vitamina D/epidemiologia , Deficiência de Vitamina D/genética , Vitaminas , Predisposição Genética para Doença , Estudos de Casos e ControlesRESUMO
<b>Background and Objective:</b> Vitamin D Receptor (VDR) regulate several body processes related to metabolism, immunological function and oncogenesis. Low vitamin D levels are recognized as associated with a higher incidence of hematologic malignancies and poor outcomes. This study aims to determine whether vitamin D levels and VDR contribute to multiple myeloma (MM). <b>Materials and Methods:</b> This study enrolled twenty-five patients diagnosed with MM. Ages and gender were matched between patients and healthy groups. Serum Protein Electrophoresis (SPEP) was detected for all patients. Also, serum 25-hydroxy vitamin D levels were recorded. The PCR products were submitted to Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) and Sanger sequencing to detect VDR gene polymorphism including (FokI, ApaI and Tru9I). <b>Results:</b> This study revealed that an M spike was detected in five patients newly diagnosed with MM. According to vitamin D levels 84% of patients had a vitamin D deficiency. In the RFLP technique, FokI CT, ApaI AA and Tru9I GG genotypes were highly distributed in patients. Additionally, the MM group had a significant frequency of the T allele in the FokI (44.0%), the A allele in the ApaI (68.0%) and the A allele in the Tru9I (30.0%). <b>Conclusion:</b> The SPEP is an easy-to-perform laboratory test that can be used to detect and quantify monoclonal proteins. Low vitamin D level of less than 20 ng mL<sup></sup><sup>1</sup> is associated with an increased prevalence of MM and a worse response to treatment. In addition, VDR gene polymorphisms may be a molecular marker of MM risk.
Assuntos
Mieloma Múltiplo , Receptores de Calcitriol , Humanos , Calcifediol , Estudos de Casos e Controles , Predisposição Genética para Doença , Genótipo , Imidoésteres , Mieloma Múltiplo/diagnóstico , Mieloma Múltiplo/genética , Polimorfismo de Nucleotídeo Único , Receptores de Calcitriol/genética , Receptores de Calcitriol/metabolismo , Vitamina D/sangue , Vitamina D/química , Vitamina D/metabolismoRESUMO
OBJECTIVE: Aim: of our study was the analysis of the blood hypercoagulation risk in patients with ischemic atherotrombotic stroke depending of the VDR gene polymorphisms. PATIENTS AND METHODS: Materials and Methods: Blood of 170 patients with ischemic atherothrombotic stroke (IATS) and 124 healthy individuals (control group) was used for genotyping. Four polymorphisms (FokI, BsmI, ApaI, TaqI) of gene VDR were examined with PCR-RFLP methodology. Statistical analysis was performed by using SPSS-17.0 program. RESULTS: Results: Among patients with IATS who are carriers of the f/f genotype, FokI polymorphism of VDR gene by high thrombin time and a decrease in the rate of spontaneous fibrinolysis was registered. In individuals with the B/B genotype homozygous for the polymorphic variant, BsmI had significantly lower mean values of prothrombin and thrombin time and increased the rate of spontaneous fibrinolysis. The homozygotes for the A-allele ApaI polymorphism have 2.7 times higher risk of developing blood hypercoagulation than homozygotes for the a-allele was found. CONCLUSION: Conclusions: Biochemical signs of hypercoagulation syndrome among patients with IATS who are carriers of the f/f genotype of the FokI polymorphic variant and among B/B homozygotes of the BsmI polymorphic variant and homozygotes for the A-allele of the AÑaI polymorphism of the VDR gene were registered.
Assuntos
Imidoésteres , AVC Isquêmico , Humanos , Genótipo , Polimorfismo Genético , Receptores de Calcitriol/genéticaRESUMO
Phenolamides are abundant specialized metabolites found in nature and consist of hydroxycinnamic acids mono- or polyconjugated with polyamines. Their participation in flower development is well-documented, and their presence in pollen raises the question of their role in pollen/pollinator interactions. The structural characterization of phenolamides is complicated by the presence of positional isomers and stereoisomers. Liquid chromatography coupled to tandem mass spectrometry in the positive ionization mode is becoming very popular in phenolamide structural characterization. However, collision-induced transamidation processes that cause the swapping of side chains have been detected, making it difficult to distinguish regioisomers with this technique. In the present report, we explore the dissociation processes undergone by the [M - H]- ions of spermidine-based phenolamides as model compounds. We describe two original competitive dissociation routes, namely, the phenolate and imidate pathways, to account for the observed fragmentation reactions undergone by collisional activated standard phenolamide anions. Whereas the phenolate pathway is regioselective at the central position for spermidine, the imidate pathway, requiring a deprotonated amide, only occurs at the extremities. Tandem mass spectrometry experiments on negatively charged phenolamide ions may then outperform their positive ionization mode counterparts for the distinction between phenolamide regioisomers and globally for the identification of phenolamides in natural extracts.
Assuntos
Espermidina , Espectrometria de Massas em Tandem , Espectrometria de Massas em Tandem/métodos , Íons , Cromatografia Líquida , Imidoésteres , Espectrometria de Massas por Ionização por Electrospray/métodosRESUMO
Ph3P-I2-mediated condensation reactions of isatoic anhydrides and o-phenylenediamines have been developed for the regioselective syntheses of a wide range of linearly and angularly fused benzoimidazoquinazolinones. The selectivity of the products relies on the generation of either highly electrophilic oxyphosphonium or less reactive imidate intermediates. A direct amine attack at the C-2 position of the oxyphosphonium intermediate presumably drives the reaction toward the linearly fused products, whereas an attack of the diamine at the C-4 position of the in situ generated cyclic imidate leads to the angularly fused derivatives. This strategy serves as a practical handle for the efficient synthesis of other related heterocycles.
Assuntos
Aminas , Anidridos , ImidoésteresRESUMO
A base-mediated (3 + 2) cycloaddition of trifluoroacetohydrazonoyl chlorides with imidates for the construction of 3-trifluoromethyl-1,2,4-triazoles has been described. This reaction is characterized by readily starting materials, simple reaction conditions, good yields, a broad substrate scope, and excellent regioselectivity. The utility of this protocol has been validated by the synthesis of a drug-like molecule.
Assuntos
Cloretos , Triazóis , Reação de Cicloadição , Triazóis/química , Cloretos/química , ImidoésteresRESUMO
An aberrant immunologic mechanism and mitochondrial biogenesis have been suggested to be involved in the pathogenesis of endometriosis. Genetic alterations in the vitamin D receptor (VDR) gene and peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α) may lead to important defects in gene activation, which principally affect immune function and normal mitochondrial function. Therefore, we hypothesized a possible role of VDR and PGC-1α genes in the pathogenesis of endometriosis and analyzed the association of genetic variants ApaI A/C (rs7975232) and TaqI T/C (rs731236) of VDR and rs8192678 (G/A), rs13131226 (T/C), and rs2970856 (T/C) of PGC-1α gene. This study included a total of 425 reproductive-age women (cases = 200 and controls = 225). Detection of VDR and PGC-1α gene polymorphism was performed using polymerase chain reaction-restriction fragment length polymorphism and sequencing analysis. The chi-square test was used to compare allele and genotype frequencies between groups, and a p-value of <0.05 was considered statistically significant. The genotype and allele distribution of both the gene polymorphisms did not show statistically significant association with endometriosis. Our result indicated ApaI A and TaqI T of VDR and GTT of PGC-1α gene as the most common haplotype in Indian women. The data suggest that VDR and PGC-1α gene polymorphisms did not play an important role in the pathogenesis of endometriosis in Indian women studied.
Assuntos
Endometriose , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Receptores de Calcitriol , Feminino , Humanos , Povo Asiático , Endometriose/genética , Predisposição Genética para Doença/genética , Genótipo , Imidoésteres , Polimorfismo Genético , Polimorfismo de Nucleotídeo Único , Receptores de Calcitriol/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genéticaRESUMO
The rapid and facile generation of 4'-carbon radicals from oxime imidates of nucleosides via 1,5-hydrogen atom transfer induced by iminyl radicals was developed. The cyclization of 4'-carbon radicals with olefins, followed by the hydrolysis of imidate residues, provided various 2'-O,4'-C- and 3'-O,4'-C-bridged nucleosides. This operationally simple approach can be applied to the few-step syntheses of 6'S-methyl-2'-O,4'-C-ethylene-bridged 5-methyluridine (6'S-Me-ENA-T) and S-constrained ethyl-bridged 5-methyluridine (S-cEt-T).
Assuntos
Hidrogênio , Nucleosídeos , Carbono , Etilenos/química , Alcenos , Oximas , ImidoésteresRESUMO
Diets rich in cruciferous vegetables have been associated with a lower risk of incidence and progression of prostate cancer. Sulforaphane, an isothiocyanate derived from 4-methylsulphinylbutyl glucosinolate (glucoraphanin) that accumulates in certain of these vegetables, notably broccoli, has been implicated in their protective effects. Likewise, the consumption of garlic and its sulphur-containing compounds such as alliin have been associated with a reduction in risk of prostate cancer. In this study, we tested whether consuming glucoraphanin derived from broccoli seeds and alliin derived from garlic resulted in the occurrence of these potential bioactive compounds in the prostate, which may contribute to our understanding of the putative protective effects of these dietary components. We recruited 42 men scheduled for a trans-perineal prostate biopsy into a randomised, double-blinded, 2 × 2-factorial dietary supplement four-week intervention study, and 39 completed the study. The two active interventions were supplements providing glucoraphanin from broccoli (BroccoMax®) and alliin from garlic (Kwai Heartcare®). Following the intervention, prostate biopsy tissue was analysed for the presence of sulforaphane and its thiol conjugates and for alliin and associated metabolites. Sulforaphane occurred in significantly higher levels in the prostate tissue (both within the transition and peripheral zone) of men consuming the glucoraphanin containing supplements (p < 0.0001) compared to men not consuming these supplements. However, while alliin and alliin-derived metabolites were detected within the prostate, there was no significant difference in the concentrations of these compounds in the prostate of men consuming supplements derived from garlic compared to men not consuming these supplements.
Assuntos
Allium , Brassica , Neoplasias da Próstata , Antioxidantes/metabolismo , Brassica/metabolismo , Cisteína/análogos & derivados , Glucosinolatos/metabolismo , Humanos , Imidoésteres/metabolismo , Isotiocianatos/metabolismo , Masculino , Próstata/metabolismo , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/prevenção & controle , SulfóxidosRESUMO
OBJECTIVE: The aim of this study was to investigate whether the gene polymorphisms of vitamin D receptor (VDR) had a genetic effect on the susceptibility of Behcet's disease (BD). MATERIAL AND METHODS: We conducted a meta-analysis emphasizing the association between the VDR gene polymorphisms and the risk of BD. The strength of the association in five genetic models was assessed by pooled odds ratios (OR) with a corresponding 95%confidence interval (CI). RESULTS: A total of seven independent comparisons with 478 cases and 666 healthy controls were included in this meta-analysis. The overall results suggested that a significant association between ApaI polymorphism and BD risk was found in allele comparison, recessive model, and homozygote model among total populations. Subgroup analysis indicated that a significant association of ApaI polymorphism in the development of BD existed under the allelic model among Africans, while for Caucasians, a similar link was identified in the recessive model and homozygote model. Regarding Bsml polymorphism, an obvious relationship was detected to be significant in allele comparison and recessive model in the Caucasian population. Interestingly, the Fokl variant decreased the risk of BD in Africans under five genetic models, while it increased the risk in Caucasians across the recessive model and homozygote model. CONCLUSION: The results of this meta-analysis provide evidence of the link between the four widely studied polymorphisms in the VDR gene and BD, indicating a robust estimate of the genetic risk.
Assuntos
Síndrome de Behçet , Humanos , Síndrome de Behçet/genética , Predisposição Genética para Doença , Imidoésteres , Polimorfismo Genético , Receptores de Calcitriol/genéticaRESUMO
The catalytic allylic substitution is one of the most important tools in asymmetric synthesis to form C-C bonds in an enantioselective way. While high efficiency was previously accomplished in terms of enantio- and regiocontrol using different catalyst types, a strong general limitation is a very pronounced preference for the formation of allylic substitution products with (E)-configured C=C double bonds. Herein, we report that with a planar chiral palladacycle catalyst a diastereospecific reaction outcome is achieved using isoxazolinones and allylic imidates as substrates, thus maintaining the C=C double bond geometry of the allylic substrates in the highly enantioenriched products. DFT calculations show that the reactions proceed via an SN 2 mechanism and not via π-allyl Pd complexes. Crucial for the high control is the stabilization of the allylic fragment in the SN 2 transition state by π-interactions with the phenyl substituents of the pentaphenylferrocenyl catalyst core.
Assuntos
Imidoésteres , Paládio , Catálise , Paládio/química , EstereoisomerismoRESUMO
The reference sequence of structurally complex regions can only be obtained through a highly accurate clone-based approach that we call Single-Haplotype Iterative Mapping and Sequencing (SHIMS). In recent years, improvements to SHIMS have reduced the cost and time required by two orders of magnitude, but internally repetitive clones still require extensive manual effort to transform draft assemblies into reference-quality finished sequences. Here we describe SHIMS 3.0, using ultra-long nanopore reads to augment the Illumina data from SHIMS 2.0 assemblies and resolve internally repetitive structures. This greatly minimizes the need for manual finishing of Illumina-based draft assemblies, allowing a small team with no prior finishing experience to sequence challenging targets with high accuracy. This protocol proceeds from clone-picking to finished assemblies in 2 weeks for about $80 (USD) per clone. We recently used this protocol to produce reference sequence of structurally complex palindromes on chimpanzee and rhesus macaque X chromosomes. Our protocol provides access to structurally complex regions that would otherwise be inaccessible from whole-genome shotgun data or require an impractical amount of manual effort to generate an accurate assembly.
Assuntos
Nanoporos , Animais , Haplótipos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Imidoésteres , Macaca mulatta , Análise de Sequência de DNA/métodosRESUMO
Arylene diimide compounds exhibit thermally activated delayed fluorescence (TADF), but its mechanism remains elusive. Herein we studied the TADF mechanism of a carbazole-substituted pyromellitic diimide derivative (CzPhPmDI) in poly(methyl methacrylate) (PMMA) film by using DFT, TD-DFT, and MS-CASPT2 methods within the QM/MM framework. We found that the TADF mechanism involves three electronic states (i.e., S0, S1, and T1), but the T2 state is not involved because its energy is higher than the S1 state by 6.9 kcal/mol. By contrast, the T1 state is only 3.2 kcal/mol lower than the S1 state and such small energy difference benefits the reverse intersystem crossing (rISC) process from T1 to S1 thereto TADF. This point is seconded by relevant radiative and nonradiative rates calculated. At room temperature, the ISC rate from S1 to T1 is calculated to be 6.1 × 106 s-1, which is larger than the fluorescence emission rate, 2.2 × 105 s-1; thus, the dominant S1 population converts to the T1 state. However, in the T1 state, the rISC process (1.8 × 104 s-1) becomes the most important channel because of the negligible phosphorescence emission rate (3.5 × 10-2 s-1). So, the T1 population is still converted back to the S1 state to fluoresce enabling TADF. Unfortunately, the rISC process is blocked in low temperature. Besides, we found that relevant Huang-Rhys factors have dominant contribution from low-frequency vibrational motion related to the torsional motion of functional groups. These gained insights could provide useful information for the design of organic TADF materials with excellent luminescence efficiency.
Assuntos
Eletrônica , Imidoésteres , Teoria da Densidade Funcional , FluorescênciaRESUMO
Glucoraphanin is a plant specialized metabolite found in cruciferous vegetables that has long been a target for production in a heterologous host because it can subsequently be hydrolyzed to form the chemopreventive compound sulforaphane before and during consumption. However, previous studies have only been able to produce small amounts of glucoraphanin in heterologous plant and microbial systems compared to the levels found in glucoraphanin-producing plants, suggesting that there may be missing auxiliary genes that play a role in improving production in planta. In an effort to identify auxiliary genes required for high glucoraphanin production, we leveraged transient expression in Nicotiana benthamiana to screen a combination of previously uncharacterized coexpressed genes and rationally selected genes alongside the glucoraphanin biosynthetic pathway. This strategy alleviated metabolic bottlenecks, which improved glucoraphanin production by 4.74-fold. Our optimized glucoraphanin biosynthetic pathway provides a pathway amenable for high glucoraphanin production.
Assuntos
Glucosinolatos , Imidoésteres , Oximas , Sulfóxidos , Nicotiana/genéticaRESUMO
In this investigation, the combinations of exogenous pretreatment (melatonin or vitamin C) and contact ultrasound-assisted air drying were utilized to dry broccoli florets. To understand the influences of the studied dehydration methods on the conversion of glucoraphanin to bioactive sulforaphane in broccoli, various components (like glucoraphanin, sulforaphane, myrosinase, etc.) and factors (temperature and moisture) involved in the metabolism pathway were analyzed. The results showed that compared with direct air drying, the sequential exogenous pretreatment and contact ultrasound drying shortened the drying time by 19.0-22.7%. Meanwhile, contact sonication could promote the degradation of glucoraphanin. Both melatonin pretreatment and vitamin C pretreatment showed protective effects on the sulforaphane content and myrosinase activity during the subsequent drying process. At the end of drying, the sulforaphane content in samples dehydrated by the sequential melatonin (or vitamin C) pretreatment and ultrasound-intensified drying was 14.4% (or 26.5%) higher than only air-dried samples. The correlation analysis revealed that the exogenous pretreatment or ultrasound could affect the enzymatic degradation of glucoraphanin and the generation of sulforaphane through weakening the connections of sulforaphane-myrosinase, sulforaphane-VC, and VC-myrosinase. Overall, the reported results can enrich the biochemistry knowledge about the transformation of glucoraphanin to sulforaphane in cruciferous vegetables during drying, and the combined VC/melatonin pretreatment and ultrasound drying is conducive to protect bioactive sulforaphane in dehydrated broccoli.
Assuntos
Brassica , Brassica/química , Glucosinolatos/química , Imidoésteres , Redes e Vias Metabólicas , Oximas/metabolismo , Sulfóxidos/metabolismoRESUMO
Myrosinase is a biotechnological tool for the preparation of sulforaphane and sulforaphene with a variety of excellent biological activities. In this study, a gene encoding the novel glycoside hydrolase family 3 (GH3) myrosinase Rmyr from Rahnella inusitata was heterologously expressed in Escherichia coli BL21 (DE3). The purified Rmyr shows the highest activity at 40 °C and pH 7.0; meanwhile, its half-life at 30 °C reaches 12 days, indicating its excellent stability. Its sinigrin-, glucoraphenin-, and glucoraphanin-hydrolyzing activities were 12.73, 4.81, and 6.99 U/mg, respectively. Rmyr could efficiently degrade the radish seed-derived glucoraphenin and the broccoli seed-derived glucoraphanin into sulforaphene and sulforaphane within 10 min with the highest yields of 5.07 mg/g radish seeds and 9.56 mg/g broccoli seeds, respectively. The highest conversion efficiencies of sulforaphane from glucoraphanin and sulforaphene from glucoraphenin reached up to 92.48 and 97.84%, respectively. Therefore, Rmyr is a promising and potent biocatalyst for efficient and large-scale preparation of sulforaphane and sulforaphene.