Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
1.
Molecules ; 27(9)2022 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-35566220

RESUMO

Lichen-derived monoaromatic compounds are bioactive compounds, associated with various pharmacological properties: antioxidant, antifungal, antiviral, cytotoxicity, and enzyme inhibition. However, little is known about data regarding alpha-glucosidase inhibition and antimicrobial activity. Very few compounds were reported to have these activities. In this paper, a series of monoaromatic compounds from a lichen source were isolated and structurally elucidated. They are 3,5-dihydroxybenzoic acid (1), 3,5-dihydroxybenzoate methyl (2), 3,5-dihydroxy-4-methylbenzoic acid (3), 3,5-dihydroxy-4-methoxylbenzoic acid (4), 3-hydroxyorcinol (5), atranol (6), and methyl hematommate (7). To obtain more derivatives, available compounds from the previous reports such as methyl ß-orsellinate (8), methyl orsellinate (9), and D-montagnetol (10) were selected for bromination. Electrophilic bromination was applied to 8-10 using NaBr/H2O2 reagents to yield products methyl 5-bromo-ß-orsellinate (8a), methyl 3,5-dibromo-orsellinate (9a), 3-bromo-D-montagnetol (10a), and 3,5-dibromo-D-montagnetol (10b). Compounds were evaluated for alpha-glucosidase inhibition and antimicrobial activity against antibiotic-resistant, pathogenic bacteria Enterococcus faecium, Staphylococcus aureus, and Acinetobacter baumannii. Compound 4 showed stronger alpha-glucosidase inhibition than others with an IC50 value of 24.0 µg/mL. Synthetic compound 9a exhibited remarkable activity against Staphylococcus aureus with a MIC value of 4 µg/mL. Molecular docking studies were performed to confirm the consistency between in vitro and in silico studies.


Assuntos
Líquens , alfa-Glucosidases , Antibacterianos/farmacologia , Peróxido de Hidrogênio , Simulação de Acoplamento Molecular , Staphylococcus aureus
2.
Molecules ; 27(8)2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35458771

RESUMO

α-Glucosidase plays a role in hydrolyzing complex carbohydrates into glucose, which is easily absorbed, causing postprandial hyperglycemia. Inhibition of α-glucosidase is therefore an ideal approach to preventing this condition. A novel polyprenylated benzoylphloroglucinol, which we named schomburgkianone I (1), was isolated from the fruit of Garcinia schomburgkiana, along with an already-reported compound, guttiferone K (2). The structures of the two compounds were determined using NMR and HRESIMS analysis, and comparisons were made with previous studies. Compounds 1 and 2 exhibited potent α-glucosidase inhibition (IC50s of 21.2 and 34.8 µM, respectively), outperforming the acarbose positive control. Compound 1 produced wide zones of inhibition against Staphylococcus aureus and Enterococcus faecium (of 21 and 20 mm, respectively), compared with the 19 and 20 mm zones of compound 2, at a concentration of 50 µg/mL. The MIC value of compound 1 against S. aureus was 13.32 µM. An in silico molecular docking model suggested that both compounds are potent inhibitors of enzyme α-glucosidase and are therefore leading candidates as therapies for diabetes mellitus.


Assuntos
Anti-Infecciosos , Garcinia , Frutas , Garcinia/química , Inibidores de Glicosídeo Hidrolases/química , Simulação de Acoplamento Molecular , Staphylococcus aureus , alfa-Glucosidases
3.
Chem Biodivers ; 18(12): e2100499, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34761862

RESUMO

A new natural Diels-Alder adduct (3) was isolated from the leaves and stem bark of Artocarpus integer, along with seventeen known compounds (1, 2, and 4-18). Structural elucidation was conducted using NMR and HR-ESI-MS data, and comparisons were made with previous studies. Deoxyartonin I (3) exhibited the most potent α-glucosidase inhibition (IC50 7.80±0.1 µM), outperforming the acarbose positive control. This was mixed-mode inhibition, as indicated by the intersect in the second quadrant of each respective plot. An in silico molecular docking model and the pharmacokinetic features of 3 suggest that it is a potential inhibitor of enzyme α-glucosidase, and is therefore a lead candidate as a drug against diabetes mellitus.


Assuntos
Artocarpus/química , Inibidores de Glicosídeo Hidrolases/farmacologia , Simulação de Acoplamento Molecular , Extratos Vegetais/farmacologia , alfa-Glucosidases/metabolismo , Relação Dose-Resposta a Droga , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/isolamento & purificação , Humanos , Componentes Aéreos da Planta/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação
4.
Molecules ; 26(9)2021 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-33926133

RESUMO

Combretum quadrangulare Kurz is widely used in folk medicine in Eastern Asia and is associated with various ethnopharmacological properties including hepatoprotective, antipyretic, analgesic, antidysenteric, and anthelmintic activities. Previous phytochemical investigations reported the presence of numerous triterpenes (mostly cycloartanes, ursanes, lupanes, and oleananes) along with dozens of flavonoids. However, the extracts of C. quadrangulare and isolated flavonoids have not been evaluated for their alpha-glucosidase inhibition. In the frame of our efforts dedicated to the chemical investigation of Vietnamese medicinal plants and their biological activities, a phytochemical study of the MeOH extract of the leaves of C. quadrangulare using bioactive guided isolation was undertaken. In this paper, the isolation and structure elucidation of twelve known compounds, 5-hydroxy-3,7,4'-trimethoxyflavone (1), ayanin (2), kumatakenin (3), rhamnocitrin (4), ombuin (5), myricetin-3,7,3',5'-tetramethyl ether (6), gardenin D (7), luteolin (12), apigenin (13), mearnsetin (14), isoorientin (15), and vitexin (16) were reported. Bromination was applied to compounds 2 and 3 to provide four new synthetic analogues 8-11. All isolated and synthesized compounds were evaluated for alpha-glucosidase inhibition and antibacterial activity. Compounds 4 and 5 showed moderate antibacterial activity against methicillin-resistant Staphylococcus aureus while others were inactive. All compounds failed to reveal any activity toward extended spectrum beta-lactamase-producing Escherichia coli. Compounds 2, 4, 6-9, and 11-14 showed good alpha-glucosidase inhibition with IC50 values in the range of 30.5-282.0 µM. The kinetic of enzyme inhibition showed that 8 and 11 were noncompetitive type inhibition against alpha-glucosidase. In silico molecular docking model indicated that compounds 8 and 11 were potential inhibitors against enzyme α-glucosidase.


Assuntos
Combretum/química , Flavonas/química , Flavonas/farmacologia , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Relação Dose-Resposta a Droga , Flavonas/isolamento & purificação , Inibidores de Glicosídeo Hidrolases/isolamento & purificação , Ligação de Hidrogênio , Ligantes , Modelos Moleculares , Conformação Molecular , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Molecular , Compostos Fitoquímicos/química , Extratos Vegetais/isolamento & purificação , Relação Estrutura-Atividade
5.
Nat Prod Res ; 37(21): 3563-3571, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35749654

RESUMO

Tecoma stans is a tropical plant that is widely used in folk medicine. Little is known about the chemical constituents of flowers of this plant. From flowers of the native plant in Vietnam, 12 compounds were isolated and elucidated, including one new compound tecomastane (1) and eleven known compounds, (3S,5R,6S,7E)-5,6-epoxy-3-hydroxy-7-megastigmane-9-one (2), bosciallin (3), chakyunglupulin B (4), (2S,6R)-2,6-dimethyloctane-1,8-diol (5), cleroindicin F (6), rengyoxide (7), 3,4-dihydroxybenzoic acid (8), methyl 3,4-dihydrobenzoate (9), 3,5-dihydroxybenzoic acid (10), luteolin (11), and indole-3-carboxylic acid (12). Compound 5 was a new natural product. The chemical structures of isolated compounds were identified by interpretation of their spectroscopic data (1D, 2D NMR, and HRESIMS) and by comparison with the literature. Compounds 1-7 and 10-12 were evaluated for alpha-glucosidase inhibition and antimicrobial activity against antibiotic-resistant, pathogenic bacteria Enterococcus faecium, Staphylococcus aureus, and Acinetobacter baumannii.

6.
Data Brief ; 30: 105497, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32300629

RESUMO

We report in this article the cytotoxicity of Streptomyces sp. SS1-1 against the human lung cancer A549 cell line, its draft genome sequence and a total of 20 predicted secondary metabolite biosynthetic gene clusters. Streptomyces sp. SS1-1 was an endophytic bacterial strain isolated from the plant Catharanthus roseus in Ho Chi Minh City, Vietnam. When cultured in the PY medium, this strain shows a cytotoxic effect on the A549 cell line. The draft genome of Streptomyces sp. SS1-1 has four contigs of total 7,815,656 bp and the GC content of this genome is 72.2%. AntiSMASH analysis reveals 20 putative biosynthetic gene clusters for the largest contig. The genome sequencing of Streptomyces sp. SS1-1 is essential for the molecular identification of gene cluster(s) responsible for secondary metabolite(s) with cytotoxic activity.

7.
Data Brief ; 27: 104746, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31763402

RESUMO

We report here the biosynthesis of daidzein in Streptomyces sp. SS52, its genome sequence and the analysis of its genome for finding putative genes involved in daidzein biosynthesis. The Streptomyces sp. SS52 strain was isolated from the plant Phyllanthus urinaria in Tra Vinh province, Vietnam. This endophytic strain is capable of producing the isoflavone daidzein in the culture medium. Streptomyces sp. SS52 possesses a linear genome of 8,184,045 bp and the GC content of this genome is 72.5%. The preliminary genome analysis identified homologs of genes involved in the de novo biosynthesis of daidzein in the genome of Streptomyces sp. SS52. The genome sequencing of Streptomyces sp. SS52 was essential for the study of the biosynthesis of daidzein in Streptomyces bacteria.

8.
Braz Oral Res ; 32: e126, 2018 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-30569973

RESUMO

Novel biomarkers for screening, diagnosis and monitoring the treatment of nasopharyngeal carcinoma (NPC), one of the most common cancers in Vietnam, are urgently required. Increasing evidence suggests that microRNA-141 (miR-141) is associated with NPC, owing to its ability to affect the expression of genes that modulate tumorigenesis. Unfortunately, research on miR-141 expression in Vietnamese patients is limited. Therefore, the objective of the current study was to evaluate miR-141 expression and assess whether miR-141 might be a potential biomarker for diagnosis of NPC in Vietnamese patients. Total RNA isolated from 40 NPC biopsy samples and 37 non-cancerous samples was analyzed by quantitative reverse-transcription PCR. The miR-141 expression levels were compared between NPC biopsy and non-cancerous samples. The frequency of miR-141 detection was 37.50% and 10.80% in the NPC and non-cancerous samples, respectively (p = 0.0143). The miR-141 expression was 5.27 times higher in tumor samples than non-cancerous samples. Additionally, the RR (Relative risk) and OR (Odds ratio) were 1.83 (95%CI = 1.2576-2.6675, p = 0.0016) and 4.95 (95%CI = 1.4625-16.7541, p = 0.01), respectively. In conclusion, miR-141 was up-regulated in the biopsy samples and thus may be a potential biomarker for NPC in the Vietnamese population.


Assuntos
MicroRNAs/análise , Carcinoma Nasofaríngeo/genética , Neoplasias Nasofaríngeas/genética , Adolescente , Adulto , Idoso , Povo Asiático , Biomarcadores Tumorais/análise , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo/patologia , Neoplasias Nasofaríngeas/patologia , Reação em Cadeia da Polimerase em Tempo Real , Valores de Referência , Regulação para Cima , Vietnã , Adulto Jovem
9.
Braz. oral res. (Online) ; 32: e126, 2018. graf
Artigo em Inglês | LILACS | ID: biblio-974437

RESUMO

Abstract: Novel biomarkers for screening, diagnosis and monitoring the treatment of nasopharyngeal carcinoma (NPC), one of the most common cancers in Vietnam, are urgently required. Increasing evidence suggests that microRNA-141 (miR-141) is associated with NPC, owing to its ability to affect the expression of genes that modulate tumorigenesis. Unfortunately, research on miR-141 expression in Vietnamese patients is limited. Therefore, the objective of the current study was to evaluate miR-141 expression and assess whether miR-141 might be a potential biomarker for diagnosis of NPC in Vietnamese patients. Total RNA isolated from 40 NPC biopsy samples and 37 non-cancerous samples was analyzed by quantitative reverse-transcription PCR. The miR-141 expression levels were compared between NPC biopsy and non-cancerous samples. The frequency of miR-141 detection was 37.50% and 10.80% in the NPC and non-cancerous samples, respectively (p = 0.0143). The miR-141 expression was 5.27 times higher in tumor samples than non-cancerous samples. Additionally, the RR (Relative risk) and OR (Odds ratio) were 1.83 (95%CI = 1.2576-2.6675, p = 0.0016) and 4.95 (95%CI = 1.4625-16.7541, p = 0.01), respectively. In conclusion, miR-141 was up-regulated in the biopsy samples and thus may be a potential biomarker for NPC in the Vietnamese population.


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Adulto Jovem , Neoplasias Nasofaríngeas/genética , MicroRNAs/análise , Carcinoma Nasofaríngeo/genética , Valores de Referência , Vietnã , Biomarcadores Tumorais/análise , Estudos de Casos e Controles , Regulação para Cima , Neoplasias Nasofaríngeas/patologia , Povo Asiático , Reação em Cadeia da Polimerase em Tempo Real , Carcinoma Nasofaríngeo/patologia , Pessoa de Meia-Idade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA