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1.
Cureus ; 16(5): e60900, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38910716

RESUMO

Acute bacterial prostatitis (ABP) is a common disease in adults but uncommon in children. Here, we report the case of a pediatric patient without any underlying disease who was diagnosed with ABP while trying to determine the cause of fever refractory to antimicrobial therapy. A previously healthy 12-year-old boy presented with a 13-day history of fever and malaise despite initial antimicrobial treatment. Further tests revealed pyuria and enlarged prostate with possible abscesses, which led to the diagnosis of ABP based on a contrast-enhanced computed tomography (CT) scan. Although initial urine cultures were negative, Corynebacterium pyruviciproducens was detected in subsequent cultures. Antimicrobial therapy for 10 weeks led to improvement without relapse. This case demonstrates that ABP can cause fever in children. Moreover, it shows that contrast-enhanced CT imaging can help identify the cause of fever and that administration of antimicrobials before adequate investigations can confound the diagnosis and complicate the treatment.

2.
J Nat Med ; 78(3): 547-557, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38509426

RESUMO

Photochemical reactions are powerful tools for synthesizing organic molecules. The input of energy provided by light offers a means to produce strained and unique molecules that cannot be assembled using thermal protocols, allowing for the production of immense molecular complexity in a single chemical step. Furthermore, unlike thermal reactions, photochemical reactions do not require active reagents such as acids, bases, metals, or enzymes. Photochemical reactions play a central role in green chemistry. This article reports the isolation and structure determination of four new compounds (1-4) from the photoreaction products of the Polyozellus multiplex MeOH ext. The structures of the new compounds were elucidated using MS, IR, comprehensive NMR measurements and microED. The four compounds were formed by deacetylation of polyozellin, the main secondary metabolite of P. multiplex, and addition of singlet oxygen generated by sunlight. To develop drugs for treating Alzheimer's disease (AD) on the basis of the amyloid cascade hypothesis, the compounds (1-4) obtained by photoreaction were evaluated for BACE1 inhibitory activity. The hydrolysates (5 and 6) of polyozellin, the main secondary metabolites of P. multiplex, were also evaluated. The photoreaction products (3 and 4) and hydrolysates (5 and 6) of polyozellin showed BACE1 inhibitory activity (IC50: 2.2, 16.4, 23.3, and 5.3 µM, respectively).


Assuntos
Carpóforos , Carpóforos/química , Estrutura Molecular , Secretases da Proteína Precursora do Amiloide/metabolismo , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Ácido Aspártico Endopeptidases/metabolismo , Processos Fotoquímicos
3.
Biochem Biophys Res Commun ; 691: 149277, 2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38029543

RESUMO

The human skin microbiome consists of many species of bacteria, including Staphylococcus aureus and S. epidermidis. Individuals with atopic dermatitis (AD) have an increased relative abundance of S. aureus, which exacerbates the inflammation of AD. Although S. epidermidis, a main component of healthy skin microbiota, inhibits the growth of S. aureus, the balance between S. epidermidis and S. aureus is disrupted in the skin of individuals with AD. In this study, we found that Citrobacter koseri isolated from patients with AD produces substances that inhibit the growth of S. epidermidis. Heat-treated culture supernatant (CS) of C. koseri inhibited the growth of S. epidermidis but not S. aureus. The genome of C. koseri has gene clusters related to siderophores and the heat-treated CS of C. koseri contained a high concentration of siderophores compared with the control medium. The inhibitory activity of C. koseri CS against the growth of S. epidermidis was decreased by the addition of iron, but not copper or zinc. Deferoxamine, an iron-chelating agent, also inhibited the growth of S. epidermidis, but not that of S. aureus. These findings suggest that C. koseri inhibits the growth of S. epidermidis by interfering with its iron utilization.


Assuntos
Citrobacter koseri , Dermatite Atópica , Humanos , Staphylococcus epidermidis , Staphylococcus aureus , Ferro , Sideróforos/farmacologia
5.
J Nat Med ; 77(3): 516-522, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37038034

RESUMO

Alzheimer's disease (AD) is an important human disease that mainly causes cognitive impairments. Growing evidence has shown that amyloid-ß (Aß) peptide plays a key role in AD pathogenesis in what is known as the Aß cascade hypothesis. This hypothesis suggests the importance of suppressing Aß aggregation and Aß production. The latter process is governed by ß-site APP Cleaving Enzyme1 (BACE1) and γ-secretase. We, therefore, focused on Aß aggregation inhibitory activity, initially assessing numerous extracts derived from our marine-derived fungus collections. One EtOAc extract derived from an Aspergillus sp. exhibited Aß aggregation inhibitory activity. Eleven known compounds (1-11) were isolated from CHCl3 and EtOAc extracts derived from the fungus, and the structures were identified based on MS, NMR, and ECD spectra. Compounds 2, 6, and 10 inhibited Aß aggregation with IC50 values of 2.8, 3.9, and 8.1 µM, respectively. The protective effect on SH-SY5Y cells against Aß toxicity was also evaluated, and compounds 6 and 10 significantly alleviated Aß toxicity. BACE1 inhibitory activity was also examined, and compounds 4, 5, 7, 10, and 11 inhibited BACE1 activity with IC50 values of 14.9, 70.0, 36.5, 28.0, and 72.8 µM, respectively. These data suggest that compound 10 could be useful in AD treatment.


Assuntos
Doença de Alzheimer , Neuroblastoma , Humanos , Secretases da Proteína Precursora do Amiloide , Pironas/farmacologia , Ácido Aspártico Endopeptidases , Peptídeos beta-Amiloides , Doença de Alzheimer/tratamento farmacológico , Aspergillus , Fungos
6.
J Nat Med ; 77(3): 455-463, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36859622

RESUMO

Candidemia is a life-threatening disease common in immunocompromised patients, and is generally caused by the pathogenic fungus Candida albicans. C. albicans can change morphology from yeast to hyphae, forming biofilms on medical devices. Biofilm formation contributes to the virulence and drug tolerance of C. albicans, and thus compounds that suppress this morphological change and biofilm formation are effective for treating and preventing candidemia. Marine organisms produce biologically active and structurally diverse secondary metabolites that are promising lead compounds for treating numerous diseases. In this study, we explored marine-derived fungus metabolites that can inhibit morphological change and biofilm formation by C. albicans. Enniatin B (1), B1 (2), A1 (3), D (4), and E (5), visoltricin (6), ergosterol peroxide (7), 9,11-dehydroergosterol peroxide (8), and 3ß,5α,9α-trihydroxyergosta-7,22-dien-6-one (9) were isolated from the marine-derived fungus Fusarium sp. Compounds 1-5 and 8 exhibited inhibitory activity against hyphal formation by C. albicans, and compounds 1-3 and 8 inhibited biofilm formation by C. albicans. Furthermore, compounds 1-3 decreased cell surface hydrophobicity and expression of the hypha-specific gene HWP1 in C. albicans. Compound 1 was obtained in the highest yield. An in vivo evaluation system using silkworms pierced with polyurethane fibers (a medical device substrate) showed that compound 1 inhibited biofilm formation by C. albicans in vivo. These results indicate that enniatins could be lead compounds for therapeutic agents for biofilm infections by C. albicans.


Assuntos
Candidemia , Fusarium , Humanos , Candida albicans/genética , Antifúngicos/farmacologia , Biofilmes
7.
J Nat Prod ; 84(6): 1748-1754, 2021 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-34100599

RESUMO

To develop drugs to treat Alzheimer's disease (AD) on the basis of the amyloid cascade hypothesis, the amyloid-ß (Aß) aggregation inhibitory activities of 110 extracts from mushrooms were evaluated by thioflavin T (Th-T) assays. The MeOH extract of Albatrellus yasudae inhibited Aß aggregation, and the bioactivity-guided fractionation of the extract afforded four novel meroterpenoids, named scutigeric acid (1), albatrelactone methyl ester (2), albatrelactone (3), and 10',11'-dihydroxygrifolic acid (4), together with two known compounds, grifolin (5) and grifolic acid (6). The structures of 1-4 were elucidated using NMR, MS, UV, IR, and induced ECD spectral data. The structure of 1 was determined as a methyl ester (1a) by 2D NMR spectroscopy. Th-T assays showed that compounds 1-4 and 1a possessed inhibitory activities against Aß aggregation, with IC50 values of 6.6, 40.7, 51.4, 53.3, and 50.3 µM, respectively. Notably, 1 possessed an inhibitory activity against Aß aggregation comparable to that of myricetin as a positive control. Moreover, 1-6 exhibited inhibitory activities against BACE1, with IC50 values of 1.6, 10.9, 10.5, 34.4, 6.1, and 1.4 µM, respectively.


Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Basidiomycota/química , Terpenos/farmacologia , Agaricales/química , Doença de Alzheimer/tratamento farmacológico , Humanos , Japão , Estrutura Molecular , Terpenos/isolamento & purificação
9.
Chem Pharm Bull (Tokyo) ; 69(2): 199-202, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33518602

RESUMO

The 13C-NMR spectral data for the 15-carbon flavonoid skeleton in eleven methoxyflavones isolated from Kaempferia parviflora (Zingiberaceae) were processed by principal component analysis (PCA). Based on the PCA score plots, the methoxyflavones were categorized into three groups according to their structural features. The cytotoxicities of the methoxyflavones toward 3T3-L1 murine preadipocyte cells were evaluated by 3-(4,5-dimethylthiazole-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTT) assay and found to differ according to structure. The relationship between the 13C-NMR chemical shifts of the methoxyflavones and their cytotoxicities was investigated using Pearson's correlation analysis. The 13C-NMR signal at C-10, a quaternary carbon, was correlated with cytotoxicity. Based on these results, a structural design which lowers the 13C-NMR chemical shift at C-10 would be important for the development of cytotoxic compounds. Although quantitative structure-activity and structure-property relationships are well established paradigms for predicting trends among a series of compounds, quantitative property-activity relationships have been relatively unstudied. This approach offers a new strategy for directing structure-activity relationship research.


Assuntos
Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Flavonas/química , Células 3T3-L1 , Animais , Sobrevivência Celular/efeitos dos fármacos , Flavonas/farmacologia , Camundongos , Extratos Vegetais/química , Análise de Componente Principal , Relação Estrutura-Atividade , Zingiberaceae/química , Zingiberaceae/metabolismo
10.
J Nat Med ; 75(2): 284-298, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33231837

RESUMO

Six new triterpene saponins (1-5,7) and 3 known saponins (6,8,9) were isolated from MeOH extracts of the cactus Stenocereus pruinosus. The structures of the isolated saponins were elucidated using MS, IR, and comprehensive NMR measurements. To develop drugs for treating Alzheimer's disease (AD) on the basis of the amyloid cascade hypothesis, the isolated saponins were evaluated for inhibition of BACE1 activity and amyloid beta (Aß) aggregation using thioflavin-T assay, and triterpenes as an aglycone moiety and an alkaline hydrolysate of the saponins were also evaluated. One saponin, stenoside A (7), exhibited inhibitory activity related to Aß aggregation and its degree of Aß aggregation was 40.6% at 100 µM.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/antagonistas & inibidores , Cactaceae/química , Saponinas/química , Triterpenos/química , Humanos
11.
Sci Rep ; 10(1): 17509, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-33060804

RESUMO

Phytophagous insect larvae feed on plants containing secondary metabolic products with biological activity against other predatory organisms. Phytophagous insects can use their specialised metabolic systems to covert these secondary metabolic products into compounds with therapeutic properties useful to mankind. Some Asians drink tea decoctions made from phytophagous insect frass which is believed to be effective against inflammatory diseases. However, insects that can convert plant-derived secondary metabolic products into useful human therapeutic agents remain poorly studied. Here, we constructed the TUATinsecta database by integrating publicly plant/insect datasets for the purpose of selecting insect species. Using TUAT-insecta we selected the Asian swallowtail butterfly, Papilio xuthus larvae fed on several species of Rutaceous plants and examined whether the plant-derived secondary metabolites, especially those present in frass, were chemically altered or not. We extracted metabolic products from frass using three organic solvents with different polarities, and evaluated solvent fractions for their cytotoxic effects against several human cell lines. We found that chloroform frass extracts from P. xuthus larvae fed on Poncirus trifoliata leaves contained significant cytotoxic activity. Our findings demonstrate that screening of insect species using the 'TUATinsecta' database provides an important pipeline for discovering novel therapeutic agents that might be useful for mankind.


Assuntos
Produtos Biológicos/química , Bases de Dados Factuais , Entomologia/métodos , Insetos/química , Animais , Borboletas , Proliferação de Células , Sobrevivência Celular , Citrus , Descoberta de Drogas , Fezes/química , Células HeLa , Células Hep G2 , Humanos , Inflamação , Concentração Inibidora 50 , Larva , Folhas de Planta/química , Poncirus
12.
Bioorg Med Chem Lett ; 30(2): 126808, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31791817

RESUMO

Alzheimer's disease is a serious neurologic disorder that cannot be cured completely. In this study, we targeted compounds that inhibit amyloid-beta (Aß) aggregation, based on the amyloid cascade hypothesis. Ten compounds (1-10) were isolated from CHCl3 extracts of the mushroom Albatrellus yasudae using Aß-aggregation inhibitory activity-guided separation. The structures of these compounds were elucidated from 1D and 2D NMR and MS spectral data. Compounds 1-3 were novel, whereas 4-10 were identified as the known compounds grifolin, grifolic acid, neogrifolin, confluentin, 2-hydroxyneogrifolin, daurichromenic acid, and a cerebroside derivative. Compounds 1-10 were tested for Aß-aggregation inhibitory activity. Compounds 1, 3, 5, 6, 8, and 9 have potential as Aß-aggregation inhibitory activity.


Assuntos
Peptídeos beta-Amiloides/antagonistas & inibidores , Basidiomycota/química , Resorcinóis/química , Terpenos/química , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Basidiomycota/metabolismo , Humanos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Conformação Molecular , Resorcinóis/metabolismo , Terpenos/metabolismo
13.
J Nat Prod ; 82(7): 1797-1801, 2019 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-31244141

RESUMO

BACE1 inhibitory activity-guided fractionation of an extract of the fruiting body of Boletinus asiaticus yielded five novel meroterpenoids (1-5) and one known compound (6; asiaticusin A). The structures of these compounds were determined by interpretation of NMR, MS, and IR spectral data. The five new compounds contain 4-hydroxybenzoic acid and geranylgeranoic acid units. Compounds 4-6 possessed BACE1 inhibitory activity (IC50 values: 14.7, 11.4, and 2.0 µM, respectively).


Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Basidiomycota/química , Carpóforos/química , Terpenos/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Concentração Inibidora 50 , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Massas por Ionização por Electrospray , Terpenos/farmacologia
14.
Bioorg Med Chem Lett ; 29(15): 1994-1997, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31138471

RESUMO

Amyloid ß (Aß) aggregation plays an essential role in promoting the progression of Alzheimer's disease (AD). Therefore, the inhibition of Aß aggregation is a potential therapeutic approach for AD. Herein, twenty-seven biflavonoids with different inter-flavonyl linkages and methoxy substitution patterns were isolated from several plants, and their Aß40 aggregation inhibitory activity was evaluated by the thioflavin-T fluorescence assay. Amentoflavone (1) and its monomethoxy derivatives (2, 3, and 5) exhibited the most potent inhibitory activity, with IC50 values of approximately 5 µM. It was clarified that increasing the number of methoxy substituents on the biflavonoid structures attenuated the inhibitory activity. Moreover, the linkage and the methoxy substitution pattern had a marked influence on the inhibitory activity. Our investigation strongly supports that biflavonoids can be considered a new type of anti-Alzheimer agents that may be successfully developed for AD patients.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/antagonistas & inibidores , Biflavonoides/química , Doença de Alzheimer/patologia , Humanos
15.
J Nat Prod ; 81(5): 1290-1294, 2018 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-29715021

RESUMO

A chemical investigation of the ascomycetes of Daldinia concentrica was performed using silica gel column chromatography, ODS column chromatography, and preparative HPLC. Two new isoindolinone compounds, daldinans B (1) and C (2), two new phthalide compounds, daldinolides A (3) and B (4), and a new naphthoquinone, daldiquinone (5), were isolated together with two known compounds (6 and 7). The structures of 1, 2, and 5 were established using NMR, MS, and IR methods, and the structures of 3 and 4 were determined by derivatization from known compounds (6 and 7). 5 exhibited antiangiogenesis activity against HUVECs (IC50 = 7.5 µM).


Assuntos
Ascomicetos/química , Benzofuranos/química , Naftoquinonas/química , Ftalimidas/química , Linhagem Celular , Cromatografia Líquida de Alta Pressão/métodos , Células Endoteliais da Veia Umbilical Humana , Humanos , Espectroscopia de Ressonância Magnética/métodos
16.
Bioorg Med Chem ; 26(1): 17-24, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29198893

RESUMO

We are interested in new non-natural glycosides with sialic acid conjugates and their biological activities. We report the synthesis of eleven non-natural occurring glycosides, which are triterpene (glycyrrhetinic acid and its derivatives)-sialic acid conjugates, and their inhibitory activities against influenza virus sialidases and influenza virus multiplication in MDCK host cells. Deoxoglycyrrhetol-sialic acid conjugates (6d and 6e) and oleanolic acid-sialic acid conjugates (7d and 7e) showed strong inhibitory activities against three subtypes of influenza virus sialidases. These four compounds (6d, 6e, 7d and 7e) showed clear inhibition to influenza virus multiplication but not to MDCK host cell survival.


Assuntos
Antivirais/farmacologia , Ácido N-Acetilneuramínico/farmacologia , Orthomyxoviridae/efeitos dos fármacos , Triterpenos/farmacologia , Animais , Antivirais/síntese química , Antivirais/química , Sobrevivência Celular/efeitos dos fármacos , Galinhas , Cães , Relação Dose-Resposta a Droga , Células Madin Darby de Rim Canino , Testes de Sensibilidade Microbiana , Estrutura Molecular , Ácido N-Acetilneuramínico/química , Relação Estrutura-Atividade , Triterpenos/química
17.
Bioorg Med Chem ; 25(13): 3377-3383, 2017 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-28478866

RESUMO

Alzheimer's disease (AD) destroys brain function, especially in the hippocampus, and is a social problem worldwide. A major pathogenesis of AD is related to the accumulation of amyloid beta (Aß) peptides, resulting in neuronal cell death in the brain. Here, we isolated four saponins (1-4) and elucidated their structures from 1D and 2D NMR and HRFABMS spectral data. The structures of 1 and 2 were determined as new saponins which have cochalic acid as the aglycon, and 3 was determined as a new saponin with oleanolic acid as the aglycon. Compound 4 was confirmed as the known saponin chikusetsusaponin V (=ginsenoside R0). Isolated saponins (1-4) and six previously reported saponins (5-10) were tested for their inhibitory effects of Aß aggregation and their protective effects on SH-SY5Y cells against Aß-associated toxicity. As the results, compounds 3 and 4 showed inhibitory effect of Aß aggregation and compounds 5-8 exerted the protective effects on SH-SY5Y cells against Aß-associated toxicity.


Assuntos
Peptídeos beta-Amiloides/antagonistas & inibidores , Cactaceae/química , Saponinas/farmacologia , Peptídeos beta-Amiloides/metabolismo , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Agregados Proteicos/efeitos dos fármacos , Saponinas/química , Saponinas/isolamento & purificação , Relação Estrutura-Atividade
18.
Anal Chem ; 89(12): 6408-6414, 2017 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-28510445

RESUMO

Direct-injection electron ionization-mass spectrometry (DI-EI-MS) is a multivariate analysis method useful for characterizing biological materials. We demonstrated the use of DI-EI-MS for metabolic profiling using several closely related lichen species: Cladonia krempelhuberi, C. gracilis, C. pseudogymnopoda, and C. ramulosa. The methodology involves conversion of total ion chromatograms to integrated chromatograms and assessment of reproducibility. The qualitative DI-EI-MS method was used to profile the major and/or minor constituents in extracts of lichen samples. It was possible to distinguish each lichen sample by altering the electron energy in DI-EI-MS and examining the resulting data using one-way analysis of variance. Previously undetectable peaks, which are easy to fragment could be revealed by varying the electron energy. Our results suggest that metabolic profiling using DI-EI-MS would be useful for discriminating between subgroups within the same species. This is the first study to report the use of DI-EI-MS in a metabolomics application.


Assuntos
Líquens/metabolismo , Metabolômica , Líquens/química , Espectrometria de Massas , Análise Multivariada
19.
J Nat Med ; 71(4): 606-616, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28497306

RESUMO

Five new oleanane-type saponins 1-5 together with a known saponin 6 and a steroidal glycoside 7 were isolated from Polaskia chichipe Backbg., and their structures were determined from their 1D and 2D NMR and HRFABMS spectral data. The six isolated saponins 1-6 were tested for their effects on the melanogenesis of B16 melanoma 4A5 cells. Compound 1 exerted an inhibitory effect at 100 µM whereas compound 3 promoted melanogenesis at the same concentration, even though these two compounds contain the same aglycon structure. The dose-dependent activities of compounds 1 and 3 on melanin synthesis were investigated.


Assuntos
Cactaceae/química , Melaninas/biossíntese , Melanoma Experimental/metabolismo , Ácido Oleanólico/análogos & derivados , Extratos Vegetais/farmacologia , Saponinas/farmacologia , Triterpenos/farmacologia , Animais , Linhagem Celular Tumoral , Glicosídeos/química , Glicosídeos/isolamento & purificação , Estrutura Molecular , Ácido Oleanólico/química , Ácido Oleanólico/isolamento & purificação , Ácido Oleanólico/farmacologia , Extratos Vegetais/química , Saponinas/química , Saponinas/isolamento & purificação , Triterpenos/química , Triterpenos/isolamento & purificação
20.
Bioorg Med Chem Lett ; 26(20): 4911-4914, 2016 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-27641468

RESUMO

Metabolites of marine derived fungus Eurotium rubrum MPUC136 differed between cultivation on wheat medium and Czapek-Dox agar medium. Melanin synthesis inhibitory activity of crude extract of culture on wheat medium showed stronger activity than that of crude extract of culture on Czapek-Dox agar medium. A new diketopiperazine compound isoechinulin D (1) and eight reported diketopiperazines (2-9) were isolated from the crude extract of wheat medium. The structure of 1 was established using NMR, MS and IR methods. 2-5 inhibited melanogenesis using B16 melanoma cells (IC50=68, 2.4, 83, 9.1µM each). Structure-Activity-Relationships of diketopiperazines (1-10) indicated the importance of the prenyl groups at C-2, C-5 and C-7, the vinyl group at C-12 to C-25 and the sp2 carbons at C-8 and C-9. Isolated compounds (1-9) were not or slightly observed from the extracts of Czapek-Dox agar medium by HPLC analysis, suggesting that different cultivation processes could affect metabolism and enhance bioactivities.


Assuntos
Eurotium/química , Biologia Marinha , Animais , Linhagem Celular Tumoral , Cromatografia Líquida de Alta Pressão , Camundongos , Análise Espectral/métodos , Relação Estrutura-Atividade
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