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Yim N.,Chungnam National University | Ha D.T.,Chungnam National University | Ha D.T.,National Institute of Medicinal Materials | Trung T.N.,Chungnam National University | And 7 more authors.
Bioorganic and Medicinal Chemistry Letters | Year: 2010

Nine compounds isolated from the leaf and stem of Vitis amurensis Rupr. (Vitaceae) were evaluated for their antimicrobial activity against two oral pathogens, Streptococcus mutans and Streptococcus sanguis, which are associated with caries and periodontal disease, respectively. The results of several antimicrobial tests, including MIC, MBC, and TBAI, showed that three compounds inhibited the growth of the test bacteria at concentrations ranging from 12.5 to 50 μg/mL. Among these compounds, compound 5, trans-ε-viniferin, displayed the strongest activity against S. mutans and S. sanguis with MIC values of 25 and 12.5 μg/mL, respectively. This is the first report on the antimicrobial activity of stilbenes and oligostilbenes isolated from the leaf and stem of V. amurensis. Thus, this result suggests that natural antimicrobial compounds derived from V. amurensis may benefit oral health as plaque-control agents for the prevention of dental caries and periodontal disease. © 2009 Elsevier Ltd. All rights reserved.

Cuong T.D.,Catholic University of Daegu | Hung T.M.,Catholic University of Daegu | Na M.,Yeungnam University | Ha D.T.,National Institute of Medicinal Materials | And 6 more authors.
Bioorganic and Medicinal Chemistry Letters | Year: 2011

Three new phenolics: ((7S)-8′-(benzo[3′,4′]dioxol- 1′-yl)-7-hydroxypropyl)benzene-2,4-diol (1), ((7S)-8′-(4′- hydroxy-3′-methoxyphenyl)-7-hydroxypropyl)benzene-2,4-diol (2) and ((8R,8′S)-7-(4-hydroxy-3-methoxyphenyl)-8′-methylbutan-8-yl) -3′-methoxybenzene-4′,5′-diol (3), along with four known compounds (4-7) were isolated from the seeds of Myristica fragrans. Their chemical structures were established mainly by 1D and 2D NMR techniques and mass spectrometry. Their anti-inflammatory activity was evaluated against LPS-induced NO production in macrophage RAW264.7 cells. © 2011 Elsevier Ltd. All rights reserved.

Ha D.T.,Chungnam National University | Ha D.T.,National Institute of Medicinal Materials | Trung T.N.,Chungnam National University | Trung T.N.,Hanoi Medical University | And 4 more authors.
Bioorganic and Medicinal Chemistry Letters | Year: 2010

Among nine flavonols (1-9) obtained from Sophorae Flos, we first isolated compounds 4, 5, 8, and 9. These isolates (1-9) were evaluated for the phosphorylation of AMPK and ACC. Administered at 10 μM, 9 possessed high potent activity. Compound 9 displayed a dose-dependent stimulation of glucose uptake in 3T3-L1 cells, and this increase was obviously attenuated by compound C, an AMPK inhibitor. In addition, 9 also phosphorylated AMPK and its downstream substrate ACC in 3T3-L1 cells in a time- and dose-dependent manner. Moreover, we discovered that compound C inhibits 9-stimulated ACC phosphorylation and motivated the 9-inhibited C/EBPα and PPARγ, and FAS gene expression, significantly. These results revealed the role of the AMPK downstream signaling pathway in 9-improved glucose metabolism in 3T3-L1 cells and 9-inhibited adipocyte differentiation. Differentiation was investigated by Oil Red O staining activity after 9 administration (0-20 μM) in 6 days. Compound 9 decreased mean droplet size in a dose-dependent manner. The results revealed that 9 blocked adipogenic conversion in 3T3-L1 cells together with several significant downregulating adipocyte-specific transcription factors, including PPARγ, C/EBPα, and SREBP1. It also reduced FAS gene expression in a dose-dependent manner, which is crucial for adipogenesis in vitro. © 2010 Elsevier Ltd. All rights reserved.

Le H.T.,National Institute of Medicinal Materials | Ha D.T.,National Institute of Medicinal Materials | Minh C.T.A.,Yeungnam University | Kim T.H.,Yeungnam University | And 3 more authors.
Archives of Pharmacal Research | Year: 2012

Phytochemical investigation of the stem barks of Canarium bengalense (Burseraceace) resulted in the isolation of a new flavone glycoside (5) together with six known compounds (1-4, 6, and 7). The chemical structure of the new compound was elucidated as 3′-hydroxy-7,4′-dimethoxyflavone-5-O- α-L-arabinofuranosyl-(1→6)-β-D-glucopyranoside by means of 1D and 2D NMR ( 1H- 1H COSY, HMQC, and HMBC) and MS analyses. To evaluate the in vitro cytoprotective effect, the isolates (1-7) were tested against hydrogen peroxide (H 2O 2)-induced damage in primary cultured hepatocytes. The viability of hepatocytes was increased by treatment with each compound, except compound 1. Compounds 3, 4, and 7 exerted cytoprotective effects comparable to curcumin, the positive control. Our results suggest that the cytoprotective constituents of C. bengalense may contribute to its traditional use in the treatment of tumor and liver damage. © 2012 The Pharmaceutical Society of Korea and Springer Netherlands.

Duong Q.H.T.,Hospital of Traditional Medicine at Ho Chi Minh City | Nguyen P.T.V.,The University of Medicine & Pharmacy at Ho Chi Minh City | Nguyen H.T.T.,National Institute of Medicinal Materials | Nguyen D.M.,Ton Duc Thang University
International Journal of Applied Research in Natural Products | Year: 2016

Majonoside-R1 (MR1), majonoside-R2 (MR2) and vina-ginsenoside-R2 (VR2) are ocotillol-type saponins which were isolated from Vietnamese ginseng (Panax vietnamensis Ha et Grushv.). In this study, tail suspension test (TST) and forced swimming test (FST) were used to assess antidepressant properties of MR1 and VR2. Additionally, the stress model caused an increase of malondialdehyde (MDA) and a decrease of glutathione (GSH) levels in the mouse brain. MR2 was used as a reference one in these experiments. The findings revealed that MR1 and VR2 reduced significantly the immobility time of stressed mice in dose-dependent manner, indicating antidepression-like effect. VR2 (10 mg/kg) as well as MR2 (10 mg/kg) induced dramatically a reduction of MDA levels while VR2 (5 mg/kg) or MR2 (5 mg/kg) had no effect. MR1 did not affect MDA level in neither dose of 10 mg/kg nor 5 mg/kg. MR1 (5-10 mg/kg), VR2 (5-10 mg/kg), and MR2 (5-10 mg/kg) as well as fluoxetine significantly increased GSH levels in mice brain (p<0.05). The findings were that MR1 and VR2 have anti-depression effects in a dose-independent manner. VR2 had a neuroprotective effect on brain by increasing GSH and decreasing MDA. However, MR1 did not show any effect on MDA levels. Industrial relevance: The study provided the first information of biological activites of MR1 and VR2, ocotillol-type saponins isolated from the underground part of cultivated Vietnamese ginseng. MR1 and VR2 might be promising compounds which could be useful for the treatment of neuropathological disorders caused by stress. © 2008-2016. IJARNP-HS Publication.

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