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1.
J Oleo Sci ; 69(11): 1509-1516, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33055449

RESUMO

Mono-(5Z)-, -(9Z)-, and -(13Z)-lycopenes are found in food containing processed tomato products, while tetra-Z-(7Z, 9Z, 7'Z, 9'Z)-lycopene (prolycopene) is found in tangerine-strain tomatoes. We prepared pure mono-Z-lycopenes from all-E-lycopene via chemical reaction (heating in CH2Cl2 at 80℃ for 1 h) followed by purification using preparative silica gel HPLC, while prolycopene was isolated from tangerine tomatoes by partitioning with n-hexane and 90% MeOH followed by silica gel column chromatography. A simple method of distinguishing the mono-Z-lycopenes using the 13C NMR chemical shifts of their Z-methyl carbons is proposed. Additionally, the 1O2 quenching and 3T3-L1 cell differentiation activities of the compounds were then compared with all-E-lycopene for the first time. All the evaluated Z-isomers showed 1O2 quenching activities that were equal to or slightly lower than that of all-E-lycopene, with the IC50 values for the 1O2 quenching activities of (all-E)-, (5Z)-, (9Z)-, (13Z)-, and (7Z, 9Z, 7'Z, 9'Z)-lycopene being 4.4±0.36, 4.0±1.44, 5.3±1.08, 6.9±1.67, and 8.7±0.34 µM, respectively. The mouse 3T3-L1 cell differentiation activities followed the order: (all-E) > (9Z) > (5Z) ≈ (9Z) ≈ (13Z) ≈ (7Z, 9Z, 7'Z, 9'Z).


Assuntos
Diferenciação Celular/efeitos dos fármacos , Licopeno/isolamento & purificação , Licopeno/farmacologia , Lycopersicon esculentum/química , Células 3T3-L1 , Animais , Cromatografia Líquida de Alta Pressão , Manipulação de Alimentos , Hexanos , Isomerismo , Licopeno/química , Espectroscopia de Ressonância Magnética , Metanol , Camundongos , Relação Estrutura-Atividade , Temperatura
2.
Front Microbiol ; 11: 2024, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32983026

RESUMO

Bacteria must survive harsh environmental fluctuations at times and have evolved several strategies. "Collective" behaviors have been identified due to recent progress in single-cell analysis. Since most bacteria exist as single cells, bacterial populations are often considered clonal. However, accumulated evidence suggests this is not the case. Gene expression and protein expression are often not homogeneous, resulting in phenotypic heterogeneity. In extreme cases, this leads to bistability, the existence of two stable states. In many cases, expression of key master regulators is bimodal via positive feedback loops causing bimodal expression of the target genes. We observed bimodal expression of metabolic genes for alternative carbon sources. Expression profiles of the frlBONMD-yurJ operon driven by the frlB promoter (PfrlB), which encodes degradation enzymes and a transporter for amino sugars including fructoselysine, were investigated using transcriptional lacZ and gfp, and translational fluorescence reporter mCherry fusions. Disruption effects of genes encoding CodY, FrlR, RNaseY, and nucleoid-associated protein YlxR, four known regulatory factors for PfrlB, were examined for expression of each fusion construct. Expression of PfrlB-gfp and PfrlB-mCherry, which were located at amyE and its original locus, respectively, was bimodal; and disruption of ylxR resulted in the disappearance of the clear bimodal expression pattern in flow cytometric analyses. This suggested a role for YlxR on the bimodal expression of PfrlB. The data indicated that YlxR acted on the bimodal expression of PfrlB through both transcription and translation. YlxR regulates many genes, including those related to translation, supporting the above notion. Depletion of RNaseY abolished heterogenous expression of transcriptional PfrlB-gfp but not bimodal expression of translational PfrlB-mCherry, suggesting the role of RNaseY in regulation of the operon through mRNA stability control and regulatory mechanism for PfrlB-mCherry at the translational level. Based on these results, we discuss the meaning and possible cause of bimodal PfrlB expression.

3.
J Oleo Sci ; 69(7): 711-718, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32612020

RESUMO

Angelica keiskei (ashitaba) is an edible plant belonging to the Apiacea family. We focused on sesquiterpenes in the leaves eaten by humans (specifically, in the Japanese population), and confirmed the presence of several sesquiterpenes by GC-MS. Thus, total RNA was extracted from the ashitaba leaves, reverse transcribed, and the resultant cDNAs were used for degenerate PCR followed by rapid amplification of cDNA ends. Consequently, we were able to isolate two full-length Tps genes (designated AkTps1 and AkTps2). Functional analysis of these two genes was carried out with Escherichia coli cells that expressed mevalonate pathway genes to increase the substrate (farnesyl diphosphate) amount of sesquiterpene synthase, revealing that AkTps1 encodes germacrene D synthase, and AkTps2 codes for an enzyme that catalyzes the generation of germacrene B and smaller amounts of germacrene D (a germacrene B and D synthase). We proposed biosynthetic routes of these two sesquiterpenes from farnesyl diphosphate (FPP) via farnesyl cation.


Assuntos
Angelica/genética , Angelica/metabolismo , Clonagem Molecular/métodos , DNA Circular , Glucosiltransferases/isolamento & purificação , Folhas de Planta/química , Folhas de Planta/genética , RNA de Plantas/isolamento & purificação , Sesquiterpenos/análise , Sesquiterpenos/metabolismo , Alquil e Aril Transferases/genética , Alquil e Aril Transferases/metabolismo , Catálise , Escherichia coli , Cromatografia Gasosa-Espectrometria de Massas , Amplificação de Genes , Ácido Mevalônico/metabolismo , Reação em Cadeia da Polimerase , Sesquiterpenos de Germacrano/metabolismo , Transdução de Sinais/genética
4.
Sci Rep ; 8(1): 15372, 2018 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-30337611

RESUMO

Improving and maintaining memory function is effective in preventing cognitive decline and dementia. Previously, we demonstrated that iso-α-acids, the hop-derived bitter components in beer, prevent cognitive impairment in an Alzheimer's disease mouse model. In this report, we investigated the effects of matured hop bitter acids (MHBA) containing components of oxides derived from α- and ß-acids, and structurally similar to iso-α-acids, on cognitive function using behavioral pharmacological procedures. MHBA and the representative components of MHBA, 4'-hydroxyallohumulinone (HAH) and 4'-hydroxy-cis-alloisohumulone (HAIH) improved spatial working memory in scopolamine-induced amnesia mice. MHBA also enhanced episodic memory in the novel object recognition test (NORT). The administration of MHBA increased the amount of norepinephrine (NE) and NE release into cerebrospinal fluid (CSF) in hippocampus. The MHBA activity in improving memory function was attenuated by treatment with a ß-adrenergic receptor inhibitor. In addition, vagotomized mice did not display the memory improvement induced by MHBA. Together, our results suggest that MHBA improves memory function via stimulation of the vagus nerve and enhancement of NE release in the hippocampus. Vagus nerve activation by the intake of food materials including MHBA may be a safe and effective approach for improving cognitive function.


Assuntos
Ácidos/farmacologia , Cerveja , Hipocampo/efeitos dos fármacos , Humulus/química , Memória/efeitos dos fármacos , Nervo Vago/efeitos dos fármacos , Ácidos/isolamento & purificação , Doença de Alzheimer/patologia , Doença de Alzheimer/fisiopatologia , Doença de Alzheimer/psicologia , Animais , Cerveja/análise , Comportamento Animal/efeitos dos fármacos , Cognição/efeitos dos fármacos , Disfunção Cognitiva/fisiopatologia , Disfunção Cognitiva/prevenção & controle , Modelos Animais de Doenças , Hipocampo/fisiologia , Humulus/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Memória Espacial/efeitos dos fármacos , Paladar
5.
J Oleo Sci ; 67(10): 1235-1246, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30305556

RESUMO

Terpene synthase (TPS) genes were isolated and functionally characterized from three traditional edible plants, Acanthopanax sciadophylloides ("Koshiabura") and Acanthopanax sieboldianus ("Himeukogi"), belonging to the family Araliaceae, and Curcuma zedoaria (zedoary, "Gajutsu"), belonging to the family Zingiberaceae. These plants emit characteristic fragrances and are used for traditional foods and folk medicines. From their fragrant tissues, i.e., sprouts of Araliaceae plants and developing rhizomes of zedoary, total RNAs were extracted and reverse transcribed. The resultant cDNAs were used for degenerate PCR followed by rapid amplification of cDNA ends. From the contig sequences obtained, full-length Tps genes were amplified by PCR with newly synthesized primer sets. The isolated full-length genes were introduced into engineered Escherichia coli cells, which can utilize acetoacetate to synthesize farnesyl diphosphate, the substrate for TPSs, through the mevalonate pathway. TPS products synthesized in the transformed E. coli cells were analysed by gas chromatography-mass spectrometry, nuclear magnetic resonance, and optical rotation. Consequently, the isolated Tps genes were found to encode ß-caryophyllene synthase, germacrene D synthase, linalool/(3S)-(+)-nerolidol synthase, ß-eudesmol synthase, and germacrene B synthase. These results lead us to expect that some of the effective ingredients in folk medicines are volatile terpenes and that intake of traditional foods including these edible plants would have some positive effects on our health.


Assuntos
Alquil e Aril Transferases/genética , Alquil e Aril Transferases/isolamento & purificação , Curcuma/enzimologia , Curcuma/genética , Eleutherococcus/enzimologia , Eleutherococcus/genética , Plantas Comestíveis/enzimologia , Plantas Comestíveis/genética , Acetoacetatos/metabolismo , Curcuma/química , DNA Complementar , Eleutherococcus/química , Escherichia coli/metabolismo , Ácido Mevalônico/metabolismo , Plantas Comestíveis/química , Fosfatos de Poli-Isoprenil/metabolismo , Reação em Cadeia da Polimerase , RNA de Plantas/isolamento & purificação , Sesquiterpenos/metabolismo , Terpenos , Compostos Orgânicos Voláteis
6.
Sci Rep ; 8(1): 12474, 2018 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-30127518

RESUMO

Seven cDNA clones encoding terpene synthases (TPSs), their structures closely related to each other, were isolated from the flower of Camellia hiemalis ('Kantsubaki'). Their putative TPS proteins were phylogenetically positioned in a sole clade with the TPSs of other Camellia species. The obtained Tps genes, one of which was designated ChTps1 (ChTps1a), were introduced into mevalonate-pathway-engineered Escherichia coli, which carried the genes for utilizing acetoacetate as a substrate, and cultured in a medium including lithium acetoacetate. Volatile products generated in the E. coli cells transformed with ChTps1 were purified from the cell suspension culture, and analyzed by NMR. Consequently, the predominant product with ChTPS1 was identified as valerianol, indicating that the ChTps1 gene codes for valerianol synthase. This is the first report on a gene that can mediate the synthesis of valerianol. We next synthesized a Tps ortholog encoding ChTPS1variant R477H (named CsiTPS8), whose sequence had been isolated from a tea tree (Camellia sinensis), carried out similar culture experiment with the E. coli transformant including CsiTps8, and consequently found valerianol production equally. Furthermore, GC-MS analysis of several teas revealed that valerianol had been an unknown ingredient in green tea and black tea.


Assuntos
Alquil e Aril Transferases/genética , Camellia/genética , Proteínas de Plantas/genética , Sesquiterpenos/metabolismo , Chá/genética , DNA Complementar/genética , Escherichia coli/genética , Flores/genética , Cromatografia Gasosa-Espectrometria de Massas/métodos , Regulação da Expressão Gênica de Plantas/genética , Filogenia
7.
J Oleo Sci ; 67(8): 977-981, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30068828

RESUMO

In this study, we investigated the antioxidant activities of antheraxanthin-related carotenoids. Antheraxanthin and 9-cis-antheraxanthin were prepared from persimmon and orange fruit, respectively, and converted to other carotenoids under acidic conditions. Resulting carotenoids were purified using preparative silica gel HPLC, and their structures were analyzed in detail by NMR spectra. Both antheraxanthin and 9-cis-antheraxanthin were found to be converted to (8R)- and (8S)-mutatoxanthin at an approximate ratio of 3:2. High antioxidant activities were observed for antheraxanthin, 9-cis-antherxanthin, (8R)-mutatoxanthin, and (8S)-mutatoxanthin, with potent lipid peroxidation inhibitory and moderate 1O2-quenching activities.


Assuntos
Antioxidantes , Carotenoides/farmacologia , Xantofilas/farmacologia , Carotenoides/química , Carotenoides/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Citrus sinensis/química , Depressão Química , Diospyros/química , Peroxidação de Lipídeos/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Conformação Molecular , Relação Estrutura-Atividade , Xantofilas/química , Xantofilas/isolamento & purificação
8.
Biosci Biotechnol Biochem ; 82(6): 978-985, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29161962

RESUMO

A simple method to purify volatile sesquiterpenes from recombinant Escherichia coli was developed using the cells that carried known sesquiterpene synthase (Tps) genes ZzZss2 (ZSS2) and ZoTps1. This method was applied for the purification and structural analyses of volatile sesquiterpenes produced by E. coli cells that carried unidentified Tps genes, which were isolated from the Aralia-genus edible plants belonging to the family Araliaceae. Recombinant cells carrying each Tps gene were cultured in the two-layer medium (n-octane/TB medium), and volatile sesquiterpenes trapped in n-octane were purified through two-phase partition, silica gel column chromatography, and reversed-phase preparative high-performance liquid chromatography, if necessary. Further, their structures were confirmed by nuclear magnetic resonance, [α]D, and gas chromatography-mass spectrometry analyses. Herein, the products of E. coli cells that carried two Tps gene (named AcTps1 and AcTps2) in Araria cordata "Udo" and a Tps gene (named AeTps1) in Aralia elata "Taranoki" were studied resulting in identifying functionalities of these cryptic Tps genes.


Assuntos
Alquil e Aril Transferases/genética , Araliaceae/genética , Escherichia coli/metabolismo , Plantas Comestíveis/genética , Sesquiterpenos/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Cromatografia Líquida/métodos , Meios de Cultura , Escherichia coli/genética , Fermentação , Cromatografia Gasosa-Espectrometria de Massas , Estrutura Molecular , Espectroscopia de Prótons por Ressonância Magnética , Recombinação Genética , Sesquiterpenos/química , Sesquiterpenos/isolamento & purificação , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/isolamento & purificação
9.
Biosci Biotechnol Biochem ; 82(6): 935-939, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29191086

RESUMO

Most volatile sesquiterpenes had been purified from plants using distillation and preparative gas chromatography, which is not applicable to many laboratories that do not possess a needed facility. Thus, this review focuses on a modern purification method for volatile sesquiterpenes using Escherichia coli cells that functionally express terpene synthase (Tps) genes. It was recently developed that recombinant E. coli cells carrying Tps genes were cultured in two-layer media (n-octane/TB medium) without harming the cells, and the volatile hydrophobic compounds trapped in the n-octane were purified by two-phase partition (alkane/alkaline 50% MeOH), silica gel column chromatography, and reversed-phase preparative high-performance liquid chromatography (if necessary). Consequently, it was found that the volatile sesquiterpenes are easily purified, the structures of which can then be determined by nuclear magnetic resonance, [α]D and gas chromatography-mass spectrometry analyses. The antioxidant activities of several volatile sesquiterpenes are also presented in this review.


Assuntos
Alquil e Aril Transferases/genética , Escherichia coli/genética , Recombinação Genética , Sesquiterpenos/isolamento & purificação , Compostos Orgânicos Voláteis/isolamento & purificação , Antioxidantes/farmacologia , Cromatografia Líquida/métodos , Meios de Cultura , Cromatografia Gasosa-Espectrometria de Massas , Espectroscopia de Ressonância Magnética , Sesquiterpenos/metabolismo , Sesquiterpenos/farmacologia , Compostos Orgânicos Voláteis/metabolismo , Compostos Orgânicos Voláteis/farmacologia
10.
Biosci Biotechnol Biochem ; 82(6): 1043-1052, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29191130

RESUMO

There are many reports about carotenoid-producing bacteria and carotenoid biosynthesis genes. In databases for Pseudomonas genome sequences, there are genes homologous to carotenoid biosynthesis genes, but the function of these genes in Pseudomonas has not been elucidated. In this study, we cloned the carotenoid biosynthesis genes from a Pseudomonas sp. strain, named Akiakane, which was isolated from the excrement of the Autumn Darter dragonfly. Using an Escherichia coli functional expression system, we confirmed that the idi, crtE, crtB, crtI, and crtY gene products of the Akiakane strain show predictable catalytic activities. A cluster of six genes was also found, which was comparable to other carotenoid-producing bacteria that belong to the α-Proteobacteria or γ-Proteobacteria class.


Assuntos
Carotenoides/biossíntese , Genes Bacterianos , Pseudomonas/genética , Animais , Cromatografia Líquida de Alta Pressão , Enzimas/metabolismo , Peixes , Família Multigênica , Filogenia , Pseudomonas/classificação , Pseudomonas/enzimologia
11.
Sci Rep ; 7(1): 13903, 2017 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-29066789

RESUMO

Tolerogenic dendritic cells (DCs) have the ability to induce regulatory T cells and play an important role in preventing chronic inflammatory and autoimmune diseases. We have identified a novel compound, 14-dehydroergosterol, from Koji, a Japanese traditional food material fermented with fungi. 14-dehydroergosterol is an ergosterol analogue with a conjugated double bond, but the activity of 14-dehydroergosterol is much higher than that of ergosterol. 14-dehydroergosterol induces the conversion of murine bone marrow (BM)-derived DCs and differentiated DCs into tolerogenic DCs, in which the production of IL-12 is suppressed and that of IL-10 is increased. In a co-culture experiment, DCs treated with 14-dehydroergosterol induced the conversion of naïve CD4-positive T cells into regulatory T cells. In a murine model of multiple sclerosis, experimental autoimmune encephalopathy, 14-dehydroergosterol suppressed the clinical score and inflammatory responses of myeloid DCs and T cells to myelin oligodendrocyte glycoprotein. 14-dehydroergosterol-treated human DCs induced from PBMCs also showed a tolerogenic phenotype. This is the first report to identify a novel compound, 14-dehydroergosterol, that induces DCs to convert to a tolerogenic type. 14-dehydroergosterol is contained in various fermented foods based on Koji, so 14-dehydroergosterol might be a helpful aid to prevent chronic inflammatory and autoimmune diseases.


Assuntos
Anti-Inflamatórios/farmacologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Ergosterol/análogos & derivados , Animais , Anti-Inflamatórios/química , Aspergillus/metabolismo , Células da Medula Óssea/citologia , Células Dendríticas/citologia , Células Dendríticas/metabolismo , Avaliação Pré-Clínica de Medicamentos , Encefalomielite Autoimune Experimental/prevenção & controle , Ergosterol/química , Ergosterol/farmacologia , Feminino , Fermentação , Interleucina-10/metabolismo , Camundongos , Fenótipo , Triticum/química , Triticum/metabolismo , Triticum/microbiologia
12.
J Agric Food Chem ; 64(49): 9352-9355, 2016 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-27960276

RESUMO

Violaxanthin and 9-cis-violaxanthin (major epoxycarotenoids in fruit) were prepared from mango fruit, purified, and converted to other carotenoids under acidic conditions. The resulting carotenoid structures were then analyzed in detail. Not only violaxanthin but also 9-cis-violaxanthin were found to be converted to (8S,8'S)-, (8S,8'R)-, and (8R,8'R)-auroxanthin at an approximate ratio of 4:6:1. Antioxidant activities of violaxanthin, 9-cis-violaxanthin, (8S,8'S)-auroxanthin, and (8S,8'R)-auroxanthin were examined. They possessed potent lipid peroxidation inhibitory and very weak 1O2 quenching activities.


Assuntos
Antioxidantes/química , Mangifera/química , Extratos Vegetais/química , Ácidos/química , Carotenoides/química , Frutas/química , Hidrólise , Isomerismo , Estrutura Molecular , Xantofilas/química
13.
Planta ; 243(4): 959-72, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26744017

RESUMO

MAIN CONCLUSION: A novel terpene synthase (Tps) gene isolated from Camellia brevistyla was identified as hedycaryol synthase, which was shown to be expressed specifically in flowers. Camellia plants are very popular because they bloom in winter when other plants seldom flower. Many ornamental cultivars of Camellia have been bred mainly in Japan, although the fragrance of their flowers has not been studied extensively. We analyzed floral scents of several Camellia cultivars by gas chromatography-mass spectrometry (GC-MS) and found that Camellia brevistyla produced various sesquiterpenes in addition to monoterpenes, whereas Camellia japonica and its cross-lines produced only monoterpenes, including linalool as the main product. From a flower of C. brevistyla, we isolated one cDNA encoding a terpene synthase (TPS) comprised of 554 amino acids, which was phylogenetically positioned to a sole gene clade. The cDNA, designated CbTps1, was expressed in mevalonate-pathway-engineered Escherichia coli, which carried the Streptomyces mevalonate-pathway gene cluster in addition to the acetoacetate-CoA ligase gene. A terpene product was purified from recombinant E. coli cultured with lithium acetoacetate, and analyzed by (1)H-nulcear magnetic resonance spectroscopy ((1)H-NMR) and GC-MS. It was shown that a sesquiterpene hedycaryol was produced, because (1)H-NMR signals of the purified product were very broad, and elemol, a thermal rearrangement product from hedycaryol, was identified by GC-MS analysis. Spectroscopic data of elemol were also determined. These results indicated that the CbTps1 gene encodes hedycaryol synthase. Expression analysis of CbTps1 showed that it was expressed specifically in flowers, and hedycaryol is likely to be one of the terpenes that attract insects for pollination of C. brevistyla. A linalool synthase gene, which was isolated from a flower of Camellia saluenensis, is also described.


Assuntos
Alquil e Aril Transferases/genética , Camellia/fisiologia , Flores/fisiologia , Odorantes/análise , Proteínas de Plantas/genética , Monoterpenos Acíclicos , Alquil e Aril Transferases/metabolismo , Camellia/genética , Coenzima A Ligases/genética , Coenzima A Ligases/metabolismo , Escherichia coli/genética , Flores/genética , Cromatografia Gasosa-Espectrometria de Massas , Regulação da Expressão Gênica de Plantas , Monoterpenos/metabolismo , Filogenia , Proteínas de Plantas/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Sesquiterpenos/análise , Sesquiterpenos/metabolismo
14.
Chembiochem ; 17(3): 247-53, 2016 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-26629877

RESUMO

Bacterial pigments of the aryl polyene type are structurally similar to the well-known carotenoids with respect to their polyene systems. Their biosynthetic gene cluster is widespread in taxonomically distant bacteria, and four classes of such pigments have been found. Here we report the structure elucidation of the aryl polyene/dialkylresorcinol hybrid pigments of Variovorax paradoxus B4 by HPLC-UV-MS, MALDI-MS and NMR. Furthermore, we show for the first time that this pigment class protects the bacterium from reactive oxygen species, similarly to what is known for carotenoids. An analysis of the distribution of biosynthetic genes for aryl polyenes and carotenoids in bacterial genomes is presented; it shows a complementary distribution of these protective pigments in bacteria.


Assuntos
Antioxidantes/metabolismo , Produtos Biológicos/metabolismo , Carotenoides/metabolismo , Comamonadaceae/metabolismo , Polienos/metabolismo , Antioxidantes/química , Proteínas de Bactérias/classificação , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Produtos Biológicos/química , Carotenoides/química , Cromatografia Líquida de Alta Pressão , Comamonadaceae/genética , Genoma Bacteriano , Família Multigênica , Mutagênese , Filogenia , Polienos/química , Espécies Reativas de Oxigênio/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
15.
Zoological Lett ; 1: 3, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26605048

RESUMO

INTRODUCTION: Calcium carbonate biominerals participate in diverse physiological functions. Despite intensive studies, little is known about how mineralization is initiated in organisms. RESULTS: We analyzed the medaka spontaneous mutant, ha, defective in otolith (calcareous ear stone) formation. ha lacks a trigger for otolith mineralization, and the causative gene was found to encode polyketide synthase (pks), a multifunctional enzyme mainly found in bacteria, fungi, and plant. Subsequent experiments demonstrate that the products of medaka PKS, most likely polyketides or their derivatives, act as nucleation facilitators in otolith mineralization. The generality of this novel PKS function is supported by the essential role of echinoderm PKS in calcareous skeleton formation together with the presence of PKSs in a much wider range of animals from coral to vertebrates. CONCLUSION: The present study first links PKS to biomineralization and provides a genetic cue for biogeochemistry of carbon and calcium cycles.

16.
J Agric Food Chem ; 63(46): 10181-91, 2015 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-26507444

RESUMO

The bitter taste of beer originates from resins in hops (Humulus lupulus L.), which are classified into two subtypes (soft and hard). Whereas the nature and reactivity of soft-resin-derived compounds, such as α-, ß-, and iso-α-acids, are well studied, there is only a little information on the compounds in hard resin. For this work, hard resin was prepared from stored hops and investigated for its compositional changes in an experimental model of beer aging. The hard resin contained a series of α-acid oxides. Among them, 4'-hydroxyallohumulinones were unstable under beer storage conditions, and their transformation induced primary compositional changes of the hard resin during beer aging. The chemical structures of the products, including novel polycyclic compounds scorpiohumulinols A and B and dicyclohumulinols A and B, were determined by HRMS and NMR analyses. These compounds were proposed to be produced via proton-catalyzed cyclization reactions of 4'-hydroxyallohumulinones. Furthermore, they were more stable than their precursor 4'-hydroxyallohumulinones during prolonged storage periods.


Assuntos
Cerveja/análise , Humulus/química , Resinas Vegetais/química , Cicloexanos/análise , Cicloexanos/química , Cicloexenos/química , Manipulação de Alimentos/métodos , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Oxirredução , Terpenos/análise , Terpenos/química
17.
J Agric Food Chem ; 62(47): 11602-12, 2014 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-25354357

RESUMO

The resins from hops (Humulus lupulus L.), which add the bitter taste to beer, are classified into two main sub-fractions, namely, soft and hard resins. α- and ß-Acids in soft resin and their transformation during the wort boiling process are well-studied; however, other constituents in resins, especially hard resin, have been unidentified. In this study, we identified humulinones and hulupones as soft-resin components, in addition to 4'-hydroxyallohumulinones and tricyclooxyisohumulones A and B as hard-resin components. These compounds are all oxidation products derived from α- or ß-acids. We also investigated compositional changes in the hard resin during the wort boiling process, which has a significant effect on the taste of the beer, by using model boiling experiments. The major changes were identified to be isomerization of 4'-hydroxyallohumulinones into 4'-hydroxyallo-cis-humulinones, followed by decomposition into cis-oxyhumulinic acids. These findings will be helpful in systematically evaluating and optimizing the effect of the hard resin on beer quality.


Assuntos
Cerveja/análise , Manipulação de Alimentos/métodos , Humulus/química , Resinas Vegetais/química , Cromatografia Líquida de Alta Pressão , Ciclopentanos/química , Concentração de Íons de Hidrogênio , Espectroscopia de Ressonância Magnética , Oxirredução , Paladar
18.
J Nat Prod ; 77(6): 1252-61, 2014 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-24875004

RESUMO

The transformation of α-acids [in hops (Humulus lupulus L.)] to iso-α-acids (in beer) during the brewing process is well known, but the occurrence and structure of the oxidized α-acids during hop storage are not well documented. Because an understanding of these oxidized compounds is essential to optimize the effects of oxidized hops on the quality of beer, we investigated the autoxidation products of humulone (a representative congener of α-acids) using a simplified autoxidation model. Among the oxidation products, tricyclooxyisohumulones A (1) and B (2), tricycloperoxyisohumulone A (3), deisopropyltricycloisohumulone (4), and the hemiacetal 5 of tricycloperoxyhumulone A (5') were isolated, and their structures were elucidated for the first time. The occurrence of compounds 1-4 in stored hops was verified using LC/MS/MS analysis. We also monitored the levels of compounds 1-4 during hop storage using LC/MS/MS analysis.


Assuntos
Cicloexenos/química , Humulus/química , Terpenos/química , Cerveja/análise , Biotransformação , Alemanha , Humulus/metabolismo , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Oxirredução
19.
Mar Drugs ; 12(3): 1690-8, 2014 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-24663119

RESUMO

Marine bacteria have not been examined as extensively as land bacteria. We screened carotenoids from orange or red pigments-producing marine bacteria belonging to rare or novel species. The new acyclic carotenoids with a C30 aglycone, diapolycopenedioc acid xylosylesters A-C and methyl 5-glucosyl-5,6-dihydro-apo-4,4'-lycopenoate, were isolated from the novel Gram-negative bacterium Rubritalea squalenifaciens, which belongs to phylum Verrucomicrobia, as well as the low-GC Gram-positive bacterium Planococcus maritimus strain iso-3 belonging to the class Bacilli, phylum Firmicutes, respectively. The rare monocyclic C40 carotenoids, (3R)-saproxanthin and (3R,2'S)-myxol, were isolated from novel species of Gram-negative bacteria belonging to the family Flavobacteriaceae, phylum Bacteroidetes. In this review, we report the structures and antioxidant activities of these carotenoids, and consider relationships between bacterial phyla and carotenoid structures.


Assuntos
Antioxidantes/farmacologia , Bactérias/química , Carotenoides/farmacologia , Água do Mar/microbiologia , Antioxidantes/química , Carotenoides/química , Sedimentos Geológicos/microbiologia , Bactérias Gram-Negativas/química , Planococcus (Bactéria)/química , Luz Solar , Microbiologia da Água
20.
Arch Biochem Biophys ; 545: 141-7, 2014 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-24486200

RESUMO

Xanthophyllomces dendrorhous (in asexual state named as Phaffia rhodozyma) is a fungus which produces astaxanthin, a high value carotenoid used in aquafarming. Genetic pathway engineering is one of several steps to increase the astaxanthin yield. The limiting enzyme of the carotenoid pathway is phytoene synthase. Integration plasmids were constructed for transformation with up to three copies of the crtYB gene. Upon stepwise transformation, the copy numbers of crtYB was continuously increased leading to an almost saturated level of phytoene synthase as indicated by total carotenoid content. Several carotenoid intermediates accumulated which were absent in the wild type. Some of them are substrates and intermediates of astaxanthin synthase. They could be further converted into astaxanthin by additional transformation with the astaxanthin synthase gene. However, three intermediates exhibited an unusual optical absorbance spectrum not found before. These novel keto carotenoid were identified by HPLC co-chromatography with reference compounds generated in Escherichia coli and one of them 3-HO-4-keto-7',8'-dihydro-ß-carotene additionally by NMR spectroscopy. The others were 4-keto-ß-zeacarotene and 4-keto-7',8'-dihydro-ß-carotene. A biosynthesis pathway with their origin from neurosporene and the reason for their synthesis especially in our transformants has been discussed.


Assuntos
Proteínas Fúngicas/genética , Leveduras/genética , Leveduras/metabolismo , beta Caroteno/metabolismo , Proteínas Fúngicas/metabolismo , Genes Fúngicos , Engenharia Genética , Leveduras/enzimologia , beta Caroteno/análogos & derivados , beta Caroteno/genética
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