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1.
PLoS One ; 15(4): e0232263, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32348369

RESUMO

Gentisic acid (GA), a metabolite of acetylsalicylic acid (ASA), and homogentisic acid (HGA), which is excreted at high levels in alkaptonuria, are divalent phenolic acids with very similar structures. Urine containing HGA is dark brown in color due to its oxidation. We recently reported a new oxidation method of HGA involving the addition of sodium hydroxide (NaOH) with sodium hypochlorite pentahydrate (NaOCl·5H2O), which is a strong oxidant. In the present study, we attempted to oxidize GA, which has a similar structure to HGA, using our method. We herein observed color changes in GA solution and analyzed the absorption spectra of GA after the addition of NaOH with NaOCl·5H2O. We also examined the oxidation reaction of GA using a liquid chromatography time-of-flight mass spectrometer (LC/TOF-MS). The results obtained indicated that GA solution had a unique absorption spectrum with a peak at approximately 500 nm through an oxidation reaction following the addition of NaOH with NaOCl·5H2O. This spectrophotometric method enables GA to be detected in sample solutions without expensive analytical instruments or a complex method.


Assuntos
Gentisatos/química , Espectrofotometria/métodos , Alcaptonúria/urina , Aspirina/metabolismo , Cromatografia Líquida , Gentisatos/metabolismo , Gentisatos/urina , Ácido Homogentísico/química , Humanos , Espectrometria de Massas , Oxidantes , Oxirredução , Hidróxido de Sódio , Hipoclorito de Sódio
2.
Nat Commun ; 10(1): 5056, 2019 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-31699983

RESUMO

Macrophages are one of the most functionally-diverse cell types with roles in innate immunity, homeostasis and disease making them attractive targets for diagnostics and therapy. Photo- or optoacoustics could provide non-invasive, deep tissue imaging with high resolution and allow to visualize the spatiotemporal distribution of macrophages in vivo. However, present macrophage labels focus on synthetic nanomaterials, frequently limiting their ability to combine both host cell viability and functionality with strong signal generation. Here, we present a homogentisic acid-derived pigment (HDP) for biocompatible intracellular labeling of macrophages with strong optoacoustic contrast efficient enough to resolve single cells against a strong blood background. We study pigment formation during macrophage differentiation and activation, and utilize this labeling method to track migration of pro-inflammatory macrophages in vivo with whole-body imaging. We expand the sparse palette of macrophage labels for in vivo optoacoustic imaging and facilitate research on macrophage functionality and behavior.


Assuntos
Ácido Homogentísico/química , Microscopia Intravital/métodos , Ativação de Macrófagos , Macrófagos/citologia , Técnicas Fotoacústicas/métodos , Pigmentos Biológicos/química , Coloração e Rotulagem/métodos , Animais , Materiais Biocompatíveis , Diferenciação Celular , Citocinas/metabolismo , Ouro , Células HEK293 , Células HeLa , Humanos , L-Lactato Desidrogenase/metabolismo , Macrófagos/metabolismo , Melaninas , Camundongos , Nanopartículas , Nanotubos
3.
J Microbiol Biotechnol ; 29(6): 973-983, 2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31216793

RESUMO

It is well known that iron is critical for bacterial growth and pathogenic virulence. Due to chemical similarity, Ga3+ competes with Fe3+ for binding to compounds that usually bind Fe3+, thereby interfering with various essential biological reactions. In our present study, gallium(III) nitrate [Ga(NO3)3] could repress the growth of V. splendidus Vs without complete inhibition. In the presence of Ga(NO3)3, the secretion of homogentisic acid-melanin (HGAmelanin) in V. splendidus Vs cells could be increased by 4.8-fold, compared to that in the absence of Ga(NO3)3. HGA-melanin possessed the ability to reduce Fe3+ to Fe2+. In addition, HGA-melanin increased the mRNA levels of feoA and feoB, genes coding Fe2+ transport system proteins to 1.86- and 6.1-fold, respectively, and promoted bacterial growth to 139.2%. Similarly, the mRNA expression of feoA and feoB was upregulated 4.11-fold and 2.71-fold in the presence of 640 µM Ga(NO3)3, respectively. In conclusion, our study suggested that although Ga(NO3)3 could interfere with the growth of V. splendidus Vs, it could also stimulate both the production of Fe3+-reducing HGA-melanin and the expression of feoA and feoB , which facilitate Fe2+ transport in V. splendidus Vs.


Assuntos
Gálio/farmacologia , Ferro/metabolismo , Vibrio/efeitos dos fármacos , Proteínas de Bactérias/genética , Transporte Biológico/efeitos dos fármacos , Proteínas de Transporte de Cátions/genética , Relação Dose-Resposta a Droga , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Ácido Homogentísico/química , Ácido Homogentísico/metabolismo , Ácido Homogentísico/farmacologia , Melaninas/química , Melaninas/metabolismo , Melaninas/farmacologia , Oxirredução , Sideróforos/metabolismo , Vibrio/crescimento & desenvolvimento , Vibrio/metabolismo
4.
Elife ; 82019 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-31134893

RESUMO

To persist in microbial communities, the bacterial pathogen Legionella pneumophila must withstand competition from neighboring bacteria. Here, we find that L. pneumophila can antagonize the growth of other Legionella species using a secreted inhibitor: HGA (homogentisic acid). Unexpectedly, L. pneumophila can itself be inhibited by HGA secreted from neighboring, isogenic strains. Our genetic approaches further identify lpg1681 as a gene that modulates L. pneumophila susceptibility to HGA. We find that L. pneumophila sensitivity to HGA is density-dependent and cell intrinsic. Resistance is not mediated by the stringent response nor the previously described Legionella quorum-sensing pathway. Instead, L. pneumophila cells secrete HGA only when they are conditionally HGA-resistant, which allows these bacteria to produce a potentially self-toxic molecule while restricting the opportunity for self-harm. We propose that established Legionella communities may deploy molecules such as HGA as an unusual public good that can protect against invasion by low-density competitors.


Assuntos
Antibacterianos/metabolismo , Farmacorresistência Bacteriana , Ácido Homogentísico/metabolismo , Legionella pneumophila/efeitos dos fármacos , Legionella pneumophila/metabolismo , Legionella pneumophila/crescimento & desenvolvimento
5.
Dermatol Online J ; 25(4)2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-31046911

RESUMO

Endogenous ochronosis (EO) or alkaptonuria is an inherited autosomal recessive disease caused by the insufficiency of the enzyme homogentisic acid dioxygenase. This disturbance causes an accumulation and increased renal excretion of homogentisic acid (AHG), which manifests as dark urine when it oxidizes on contact with air. Other clinical manifestations of OE are the result of the deposit of AHG in the form of ochronotic pigment at the level of collagen in the skin and cartilage, where it causes blue-gray cutaneous hyperpigmentation, degenerative arthropathy, valvular disease, and other multisystem effects. Despite the progressive and irreversible nature of OE and the lack of a curative treatment, the life expectancy is preserved. We report a new case of EO with cutaneous and joint involvement, in which a high clinical suspicion, confirmed by elevated AHG in urine was the key in the diagnosis.


Assuntos
Alcaptonúria/diagnóstico , Ácido Homogentísico/urina , Hiperpigmentação/etiologia , Artropatias/etiologia , Ocronose/diagnóstico , Alcaptonúria/complicações , Alcaptonúria/urina , Feminino , Humanos , Pessoa de Meia-Idade , Ocronose/etiologia
6.
FEBS Open Bio ; 9(4): 791-800, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30984552

RESUMO

Melanin-producing Cryptococcus and Aspergillus are highly invasive and can suppress or escape the immune system of the host. Since non-melanin-producing strains do not affect the immune system, melanin may play a role in immune system suppression. Artificial melanin synthesized using conventional methods is insoluble, making structural and functional analysis of this chemical difficult. In this study, we describe a melanin solubilization method based on polymerization of homogentisic acid (solubilizing component) and an equivalent amount of L-DOPA in the presence of laccase. In addition, we investigated the effect of melanin on the immune system. Homogentisic acid and L-DOPA mixed melanin (HALD), the synthetic solubilized melanin, did not exert a cytotoxic effect on mouse macrophages. HALD suppressed cytokine and reactive oxygen species production by macrophages when they were stimulated by fungal components. HALD also suppressed the phagocytosis of fungal components by macrophages. These results suggest that HALD can suppress the function of macrophages without causing cytotoxicity.


Assuntos
Bioquímica/métodos , Ácido Homogentísico/química , Levodopa/química , Macrófagos/imunologia , Melaninas/imunologia , Animais , Lacase/química , Masculino , Melaninas/química , Camundongos , Camundongos Endogâmicos C57BL , Polimerização , Solubilidade
7.
Fitoterapia ; 134: 65-72, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30768952

RESUMO

Chromatographic separation of fruits and flowers of the Thai medicinal plant, Miliusa velutina, resulted in the isolation of five new rare homogentisic acid derivatives, miliusanal (1) and miliusanones A-D (2-5), together with fifteen known secondary metabolites (6-20). Their structures were determined through the use of extensive spectroscopic data. The absolute configurations of homogentisic acid derivatives 2-7 were identified using NOESY data and a comparison of experimental and calculated ECD spectral data. Compounds 2, 3, 6, and 7 showed antimalarial activity with IC50 values in the range of 3.3-5.2 µg/mL. Compound 6 also showed activity against Mycobacterium tuberculosis with an MIC value of 50 µg/mL. Compounds 1-3, 6 and 7 exhibited cytotoxicity againt KB, MCF-7, NCI-H187 and Vero cell lines with IC50 values in the range of 5.8-40.4 µg/mL. In addition, compounds 1, 2 and 6 showed moderate antibacterial activities against three Gram-positive bacteria (Bacillus cereus, Staphylococcus aureus, and Methicillin resistant S. aureus) with MICs in the range of 32-64 µg/mL.


Assuntos
Annonaceae/química , Antibacterianos/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Ácido Homogentísico/farmacologia , Animais , Antibacterianos/isolamento & purificação , Antineoplásicos Fitogênicos/isolamento & purificação , Linhagem Celular Tumoral , Chlorocebus aethiops , Flores/química , Frutas/química , Bactérias Gram-Positivas/efeitos dos fármacos , Ácido Homogentísico/isolamento & purificação , Humanos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Mycobacterium tuberculosis/efeitos dos fármacos , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Tailândia , Células Vero
9.
J Cell Physiol ; 234(5): 6696-6708, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30341892

RESUMO

Alkaptonuria (AKU) is a disease caused by a deficient homogentisate 1,2-dioxygenase activity leading to systemic accumulation of homogentisic acid (HGA), that forms a melanin-like polymer that progressively deposits onto connective tissues causing a pigmentation called "ochronosis" and tissue degeneration. The effects of AKU and ochronotic pigment on the biomechanical properties of articular cartilage need further investigation. To this aim, AKU cartilage was studied using thermal (thermogravimetry and differential scanning calorimetry) and rheological analysis. We found that AKU cartilage had a doubled mesopore radius compared to healthy cartilage. Since the mesoporous structure is the main responsible for maintaining a correct hydrostatic pressure and tissue homoeostasis, drastic changes of thermal and rheological parameters were found in AKU. In particular, AKU tissue lost its capability to enhance chondrocytes metabolism (decreased heat capacity) and hence the production of proteoglycans. A drastic increase in stiffness and decrease in dissipative and lubricant role ensued in AKU cartilage. Multiphoton and scanning electron microscopies revealed destruction of cell-matrix microstructure and disruption of the superficial layer. Such observations on AKU specimens were confirmed in HGA-treated healthy cartilage, indicating that HGA is the toxic responsible of morphological and mechanical alterations of cartilage in AKU.


Assuntos
Alcaptonúria/tratamento farmacológico , Condrócitos/efeitos dos fármacos , Ácido Homogentísico/farmacologia , Ocronose/tratamento farmacológico , Alcaptonúria/metabolismo , Cartilagem Articular/efeitos dos fármacos , Cartilagem Articular/metabolismo , Condrócitos/metabolismo , Humanos , Oxirredução/efeitos dos fármacos , Pigmentação/efeitos dos fármacos
11.
Mol Genet Metab ; 125(1-2): 127-134, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30055994

RESUMO

QUESTION: Does Nitisinone prevent the clinical progression of the Alkaptonuria? FINDINGS: In this observational study on 39 patients, 2 mg of daily nitisinone inhibited ochronosis and significantly slowed the progression of AKU over a three-year period. MEANING: Nitisinone is a beneficial therapy in Alkaptonuria. BACKGROUND: Nitisinone decreases homogentisic acid (HGA), but has not been shown to modify progression of Alkaptonuria (AKU). METHODS: Thirty-nine AKU patients attended the National AKU Centre (NAC) in Liverpool for assessments and treatment. Nitisinone was commenced at V1 or baseline. Thirty nine, 34 and 22 AKU patients completed 1, 2 and 3 years of monitoring respectively (V2, V3 and V4) in the VAR group. Seventeen patients also attended a pre-baseline visit (V0) in the VAR group. Within the 39 patients, a subgroup of the same ten patients attended V0, V1, V2, V3 and V4 visits constituting the SAME Group. Severity of AKU was assessed by calculation of the AKU Severity Score Index (AKUSSI) allowing comparison between the pre-nitisinone and the nitisinone treatment phases. RESULTS: The ALL (sum of clinical, joint and spine AKUSSI features) AKUSSI rate of change of scores/patient/month, in the SAME group, was significantly lower at two (0.32 ±â€¯0.19) and three (0.15 ±â€¯0.13) years post-nitisinone when compared to pre-nitisinone (0.65 ±â€¯0.15) (p < .01 for both comparisons). Similarly, the ALL AKUSSI rate of change of scores/patient/month, in the VAR group, was significantly lower at one (0.16 ±â€¯0.08) and three (0.19 ±â€¯0.06) years post-nitisinone when compared to pre-nitisinone (0.59 ±â€¯0.13) (p < .01 for both comparisons). Combined ear and ocular ochronosis rate of change of scores/patient/month was significantly lower at one, two and three year's post-nitisinone in both VAR and SAME groups compared with pre-nitisinone (p < .05). CONCLUSION: This is the first indication that a 2 mg dose of nitisinone slows down the clinical progression of AKU. Combined ocular and ear ochronosis progression was arrested by nitisinone.


Assuntos
Alcaptonúria/tratamento farmacológico , Cicloexanonas/administração & dosagem , Nitrobenzoatos/administração & dosagem , Ocronose/tratamento farmacológico , 4-Hidroxifenilpiruvato Dioxigenase/metabolismo , Alcaptonúria/epidemiologia , Alcaptonúria/metabolismo , Alcaptonúria/patologia , Progressão da Doença , Feminino , Ácido Homogentísico/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Ocronose/epidemiologia , Ocronose/metabolismo , Ocronose/patologia , Reino Unido
12.
J Phys Chem B ; 122(30): 7514-7521, 2018 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-29986138

RESUMO

Acute, or chronic, ethanol consumption leads to the formation of free radicals in the liver, which is related to hepatic damage. Among these radicals 1-hydroxyethyl, •CH(OH)CH3, is the most abundant one. Thus, efficient •CH(OH)CH3 scavengers are likely candidates to offer liver protection after ethanol consumption. In the present work ergosterol and homogentisic acid (HGA), which are found in edible mushrooms, were investigated as potential candidates to that purpose. The investigation was carried out following the QM-ORSA protocol, and using the density functional theory (DFT). The overall rate constants calculated for the •CH(OH)CH3 radical scavenging activity of ergosterol in lipid and ethanol media are 1.34 × 107 and 1.86 × 107 M-1 s-1, respectively. For homogentisic acid the overall rate constant in lipid, ethanol and aqueous media are 4.33 × 108, 2.74 × 106, and 3.62 × 107 M-1 s-1, respectively. Accordingly, both compounds are predicted to efficiently scavenge the •CH(OH)CH3 radical. Thus, the results from this investigation support the antioxidant capability of edible mushrooms, their potential beneficial effects against ethanol hepatotoxicity, and the nutraceuticals properties of ergosterol and homogentisic acid.


Assuntos
Ergosterol/química , Etanol/química , Depuradores de Radicais Livres/química , Ácido Homogentísico/química , Radical Hidroxila/química , Agaricales/química , Agaricales/metabolismo , Teoria Quântica , Termodinâmica
13.
Nutrients ; 10(5)2018 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-29757931

RESUMO

The ability to orally administer silver nanoparticles (AgNPs) in enteric capsules implies a direct interaction with the colon microbiota. The in vitro effect provides a portrayal of the functional properties under in vivo conditions. The purpose of this study was to describe a green AgNP synthesis process, using aqueous extract from Lactarius piperatus mushroom, and to characterize the nanomaterial. We determined its antimicrobial and antioxidant effects in vitro in the microbiota of healthy individuals via the GIS1 system-a colon transit simulator. Per the quantitative polymerase chain reaction (qPCR) results, the antimicrobial properties of the AgNPs affected the initial share of different enteric species by decreasing the Bacteroides, Enterobacteriaceae, and Lactobacillus populations and favoring the Bifidobacterium group. The association between AgNPs and wild mushroom L. piperatus extract had a synergistic antibacterial activity against various pathogenic microorganisms while the mushroom extract reduced biofilm formation. Administration of AgNP maintained its constant antioxidant status, and it was correlated with a reduction in ammonium compounds. The physicochemical characterization of these NPs complemented their biochemical characterization. The maximum ultraviolet-visible spectroscopy (UV-VIS) absorbance was observed at 440 nm, while the Fourier transform infrared (FT-IR) spectrum reached a peak at 3296 cm⁻1, which was correlated with the high-performance liquid chromatographic analysis (HPLC). The major phenolic compound was homogentisic acid. The size (49 ± 16 nm in diameter) and spherical shape of the NPs were correlated with their biological effects in vitro.


Assuntos
Agaricales/química , Microbioma Gastrointestinal/efeitos dos fármacos , Nanopartículas Metálicas/química , Prata/farmacologia , Anti-Infecciosos/farmacologia , Basidiomycota/química , Biofilmes/efeitos dos fármacos , Sinergismo Farmacológico , Ácido Homogentísico/farmacologia , Humanos , Testes de Sensibilidade Microbiana , Microscopia de Força Atômica , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier
14.
Biomed Chromatogr ; 32(7): e4216, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29461623

RESUMO

Homogentisic acid (HGA) is a diagnostic metabolite that accumulates in the urine and tissues of patients with alkaptonuria which is a rare autosomal recessive disease. HGA is a specific metabolite in urine and serum, which is used for diagnosis of alkaptonuria. This study presents an inexpensive and easy capillary electrophoretic method for the quantitative determination of HGA in urine samples. The method was optimized using full factorial experimental design. The optimal separation electrolyte and separation voltage were revealed as 45 mmol/L phosphate buffer at pH 7.0 and 22 kV, respectively. Under these conditions the presence of HGA was detected in 6 min. Repeatability of migration times and corrected peak areas of HGA (as RSD) were 0.37 and 1.99, respectively. The detection limit was 0.56 µg/mL, 3 times of the average noise, and the quantification limit was 1.85 µg/mL, 10 times the average noise for HGA. Urine samples were directly injected to the capillary without any pretreatment step.


Assuntos
Alcaptonúria/diagnóstico , Eletroforese Capilar/métodos , Ácido Homogentísico/urina , Alcaptonúria/urina , Humanos , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes , Projetos de Pesquisa
15.
J Sep Sci ; 41(3): 740-746, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29152857

RESUMO

Traditional Chinese herbal medicine has long enjoyed the reputation of the world's most advanced system of natural medicine. Pinellia ternata is one of the most commonly used herbs in the traditional Chinese medical science. In this study, five representative ingredients of Pinellia ternata guanosine, methionine, glycine, 3,4-dihydroxybenzaldehyde, and homogentisic acid, were assayed using simple derivatization procedures. Under optimized experimental condition, five analytes in Pinellia ternata were rapidly separated and detected using microchip electrophoresis, affording the benefits of speed, minimal sample requirements, and sensitive on-the-chip electrochemical detection, in 5 min with linearity over a concentration of 20-500 µM (R2  = 0.994) with nearly complete recovery (95.6-98.5%).


Assuntos
Medicamentos de Ervas Chinesas/análise , Eletroforese em Microchip , Pinellia/química , Benzaldeídos/análise , Tampões (Química) , Catecóis/análise , Eletroforese , Glicina/análise , Guanosina/análise , Ácido Homogentísico/análise , Concentração de Íons de Hidrogênio , Modelos Lineares , Metionina/análise , Análise de Sequência com Séries de Oligonucleotídeos
16.
J Trace Elem Med Biol ; 45: 85-92, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29173488

RESUMO

The concentration of 23 major and trace elements, total phenolic content (TPC) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity were determined in nine samples of strawberry tree honey and compared to other types of unifloral honeys. The most abundant elements in strawberry tree honey were potassium, calcium, magnesium and sodium, ranging between 1276 and 2367, 95.2-154, 14.4-74.4 and 13.4-64.3mg/kg, respectively. Strawberry tree honey had generally higher TPC (range: 0.314-0.522g GA/kg) and DPPH (1.94-4.45mM TE/kg) compared to other analysed unifloral honeys. A strong positive relationship was found between TPC and DPPH, TPC and concentration of homogentisic acid (HGA), chemical marker of strawberry tree honey, and between DPPH and HGA. Regarding daily intake of essential elements, strawberry tree honey can be considered nutritionally richer than the majority of unifloral honeys available in Croatia, while contribution to tolerable intake set for potentially toxic elements was very low, corresponding to pristine areas.


Assuntos
Antioxidantes/análise , Mel/análise , Compostos de Bifenilo/análise , Croácia , Ácido Homogentísico/análise , Picratos/análise , Medição de Risco , Oligoelementos/análise
17.
Genome Biol Evol ; 9(9): 2191-2197, 2017 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-28922869

RESUMO

Among sphingomonads, Sphingobium indicum B90A is widely investigated for its ability to degrade a manmade pesticide, γ-hexachlorocyclohexane (γ-HCH) and its isomers (α-, ß-, δ-, and ε-HCH). In this study, complete genome of strain B90A was constructed using Single Molecule Real Time Sequencing (SMRT) and Illumina platform. The complete genome revealed that strain B90A harbors four replicons: one chromosome (3,654,322 bp) and three plasmids designated as pSRL1 (139,218 bp), pSRL2 (108,430 bp) and pSRL3 (43,761 bp). The study determined the precise location of lin genes (genes associated with the degradation of HCH isomers), for example, linA2, linB, linDER, linF, linGHIJ, and linKLMN on the chromosome; linA1, linC, and linF on pSRL1 and linDEbR on pSRL3. Strain B90A contained 26 copies of IS6100 element and most of them (15 copies) was found to be associated with lin genes. Duplication of several lin genes including linA, linDER, linGHIJ, and linF along with two variants of linE, that is, linEa (hydroquinone 1,2-dioxygenase) and linEb (chlorohydroquinone/hydroquinone 1,2-dioxygenase) were identified. This suggests that strain B90A not only possess efficient machinery for upper and lower HCH degradation pathways but it can also act on both hydroquinone and chlorohydroquinone metabolites produced during γ-HCH degradation. Synteny analysis revealed the duplication and transposition of linA gene (HCH dehydrochlorinase) between the chromosome and pSRL1, possibly through homologous recombination between adjacent IS6100 elements. Further, in silico analysis and laboratory experiments revealed that incomplete tyrosine metabolism was responsible for the production of extracellular brown pigment which distinguished strain B90A from other HCH degrading sphingomonads. The precise localization of lin genes, and transposable elements (IS6100) on different replicons now opens up several experimental avenues to elucidate the functions and regulatory mechanism of lin genes acquisition and transfer that were not completely known among the bacterial population inhabiting the HCH contaminated environment.


Assuntos
Genes Bacterianos , Genoma Bacteriano , Hexaclorocicloexano/metabolismo , Sphingomonadaceae/genética , Biodegradação Ambiental , Mapeamento Cromossômico , Cromossomos Bacterianos , Genótipo , Homogentisato 1,2-Dioxigenase/deficiência , Ácido Homogentísico/metabolismo , Plasmídeos , Sphingomonadaceae/crescimento & desenvolvimento , Sphingomonadaceae/metabolismo
18.
Mar Drugs ; 15(9)2017 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-28867763

RESUMO

The supernatants (the solution part received after centrifugation) of squid pens fermented by four species of Paenibacillus showed potent inhibitory activity against α-glucosidases derived from yeast (79-98%) and rats (76-83%). The inhibition of acarbose-a commercial antidiabetic drug, used against yeast and rat α-glucosidases-was tested for comparison; it showed inhibitory activity of 64% and 88%, respectively. Other chitinolytic or proteolytic enzyme-producing bacterial strains were also used to ferment squid pens, but no inhibition activity was detected from the supernatants. Paenibacillus sp. TKU042, the most active α-glucosidase inhibitor (aGI)-producing strain, was selected to determine the optimal cultivation parameters. This bacterium achieved the highest aGI productivity (527 µg/mL) when 1% squid pens were used as the sole carbon/nitrogen source with a medium volume of 130 mL (initial pH 6.85) in a 250 mL flask (48% of air head space), at 30 °C for 3-4 d. The aGI productivity increased 3.1-fold after optimization of the culture conditions. Some valuable characteristics of Paenibacillus aGIs were also studied, including pH and thermal stability and specific inhibitory activity. These microbial aGIs showed efficient inhibition against α-glucosidases from rat, yeast, and bacteria, but weak inhibition against rice α-glucosidase with IC50 values of 362, 252, 189, and 773 µg/mL, respectively. In particular, these aGIs showed highly stable activity over a large pH (2-13) and temperature range (40-100 °C). Various techniques, including: Diaoin, Octadecylsilane opened columns, and preparative HPLC coupled with testing bioactivity resulted in isolating a main active compound; this major inhibitor was identified as homogentisic acid (HGA). Notably, HGA was confirmed as a new inhibitor, a non-sugar-based aGI, and as possessing stronger activity than acarbose with IC50, and maximum inhibition values of 220 µg/mL, 95%, and 1510 µg/mL, 65%, respectively. These results suggest that squid pens, an abundant and low-cost fishery processing by-product, constitute a viable source for the production of antidiabetic materials via fermentation by strains of Paenibacillus. This fermented product shows promising applications in diabetes or diabetes related to obesity treatment due to their stability, potent bioactivity, and efficient inhibition against mammalian enzymes.


Assuntos
Decapodiformes/efeitos dos fármacos , Inibidores de Glicosídeo Hidrolases/farmacologia , Hipoglicemiantes/farmacologia , Paenibacillus/química , Acarbose/farmacologia , Animais , Cromatografia Líquida de Alta Pressão , Diabetes Mellitus Tipo 2/tratamento farmacológico , Carboidratos da Dieta , Fermentação , Inibidores de Glicosídeo Hidrolases/metabolismo , Ácido Homogentísico/farmacologia , Concentração Inibidora 50 , Ratos , Leveduras , alfa-Glucosidases/metabolismo
19.
J Agric Food Chem ; 65(39): 8523-8537, 2017 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-28903556

RESUMO

The development of new herbicides is receiving considerable attention to control weed biotypes resistant to current herbicides. Consequently, new enzymes are always desired as targets for herbicide discovery. 4-Hydroxyphenylpyruvate dioxygenase (HPPD, EC 1.13.11.27) is an enzyme engaged in photosynthetic activity and catalyzes the transformation of 4-hydroxyphenylpyruvic acid (HPPA) into homogentisic acid (HGA). HPPD inhibitors constitute a promising area of discovery and development of innovative herbicides with some advantages, including excellent crop selectivity, low application rates, and broad-spectrum weed control. HPPD inhibitors have been investigated for agrochemical interests, and some of them have already been commercialized as herbicides. In this review, we mainly focus on the chemical biology of HPPD, discovery of new potential inhibitors, and strategies for engineering transgenic crops resistant to current HPPD-inhibiting herbicides. The conclusion raises some relevant gaps for future research directions.


Assuntos
4-Hidroxifenilpiruvato Dioxigenase/antagonistas & inibidores , 4-Hidroxifenilpiruvato Dioxigenase/metabolismo , Agroquímicos , Inibidores Enzimáticos , Herbicidas , 4-Hidroxifenilpiruvato Dioxigenase/química , Agroquímicos/química , Agroquímicos/farmacologia , Arabidopsis/enzimologia , Catálise , Resistência a Medicamentos , Inibidores Enzimáticos/farmacologia , Herbicidas/química , Herbicidas/farmacologia , Ácido Homogentísico/metabolismo , Estrutura Molecular , Ácidos Fenilpirúvicos/metabolismo , Plantas Geneticamente Modificadas/efeitos dos fármacos , Proteínas Recombinantes , Relação Estrutura-Atividade , Controle de Plantas Daninhas
20.
J AOAC Int ; 100(4): 889-892, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-28560954

RESUMO

To confirm the botanical origin of strawberry tree (Arbutus unedo L.) honey, a liquid-liquid extraction followed by GC-MS method was developed for the quantitative determination of homogentisic acid (HGA), the main phenolic compound in this honey. Different parameters affecting extraction, such as the type and volume of extraction solvents, pH of the solution, and amount of salt, were optimized. The method showed good linearity (r2 = 0.9990) over the tested concentration range (50-500 mg/kg) and a low LOD (0.3 mg/kg). Precision expressed as RSD was <7%. The average accuracy was 95%. The optimized method was applied for determining the HGA content in strawberry tree honey samples from Croatia. The HGA content in analyzed samples (n = 7) ranged from 245.1 to 485.9 mg/kg. The proposed method provided reliable performance and can be easily implemented for the routine monitoring of HGA in strawberry tree honey in order to assure honey QC.


Assuntos
Ericaceae , Cromatografia Gasosa-Espectrometria de Massas , Mel/análise , Ácido Homogentísico , Árvores
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