ASSESSMENT OF GEOMORPHIC PROCESSES AND ACTIVE TECTONICS IN CON VOI MOUNTAIN RANGE AREA (NORTHERN VIETNAM) USING THE HYPSOMETRIC CURVE ANALYSIS METHOD

the Day Nui Con Voi (DNCV) area of Vietnam. For this purpose, a spatial database was collected and constructed, including DEM (Digital Elevation Model) and a geological map. The hypsometric curve (HC) analysis method and its statistical moments were adopted to use for the assessment. These methods have been widely used for the assessment of geomorphic processes and active tectonics in many areas in the world showing promising results. A total of 44 sub-basins of the Red River and the Chay river were analyzed. The result shows that 3 curve-types such as "straight- shape", "S- shape", and concave were found; with the concave curve being the dominant and widely distributed in the northeast side and in the south of the southwestern side of the study area. The hypsometric integral (HI) values are rather small with the largest value is 0.37 and the smallest one is 0.128. Other statistical moments of the hypsometric curve, i.e. skew (SK), kurtosis (KUR), and the density function (density skew - DSK and density kurtosis-DKUR) show great values, which increased in the south direction of the area study. Accordingly, recent active tectonics (uplift-lower) in the study area is generally weak; however, they are also not completely homogeneous and can be distinguished by different levels. The southwestern side is being lifted higher than the northeastern side. The northern part is being lifted larger than the southern part. In the region, the uplift activities were increased gradually in the Pliocene-Quaternary and could have stopped at certain time in the past. The current geomorphic processes are mainly headward erosion in the upstream.References Allen, C.R., Gillepie, A.R., Han, Y., Sieh, K.E., Zhu, C., 1984. 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Hepatoprotection and Phytochemistry of the Vietnamese Herbs Cleome chelidonii and Cleome viscosa Stems

The study aims to determine the hepatoprotective effect of n-hexane, ethyl acetate, and methanol extracts of the leaves and stems of two Cleome species against carbon tetrachloride- (CCl4-) induced liver toxicity both in vitro using human hepatoma (HepG2) cells and in vivo in rats as well as the hepatoprotective property of all isolated compounds on HepG2. After 72 h of treatment, at the concentrations of 25, 50, and 100 μg/mL, the methanol of C. chelidonii stems (CCSM) ranged from 18.6% to 20.8%, whereas the methanol of C. chelidonii stems (CVSM) increased from 12.3% to 17.2% cell viability. The results show that CCSM and CVSM significantly expressed in vitro hepaprotective activity on HepG2. Therefore, the animals were daily treated with these extracts at the doses of 15, 30, and 45 mg/kg body weight for 5 days, and CCl4 was injected (2 ml/kg body weight, i.p.) on the 2nd and 3rd days. Levels of aspartate aminotransferase (ALT) and alanine aminotransferase (AST) in the blood were measured and compared to the silymarin control. The treatments with CCSM and CVSM (30, and 45 mg/kg) possessed significant hepatoprotection and were comparable with the activity of silymarin. Further, phytochemical studies of these ones were conducted and led to the identification of eight flavonoids: visconoside A (1), visconoside B (2), quercetin 3-O-β-D-glucopyranoside 7-O-α-L-rhamnopyranoside (3), kaempferol 3-O-β-D-glucopyranoside 7-O-α-L-rhamnopyranoside (4), cleomeside A (5), cleomeside B (6), cleomeside C (7), and quercetin-3-O-[β-D-glucopyranosyl-(1⟶2)]-α-L-rhamnopyranoside 7-O-α-L-rhamnopyranoside (8). Two major flavonoids (1 and 4) displayed significant hepatoprotective property (at the concentration of 100 μM, the prevention percentage values were 66.5% and 74.2%, respectively, compared to the quercetin control, with value of 80.3%)

Triterpene saponins with <i>α</i>-glucosidase inhibition and cytotoxic activity from the leaves of <i>Schefflera sessiliflora</i>

<p>From the leaves of <i>Schefflera sessiliflora</i> De P. V., two new triterpene saponins including one oleanane-type saponin, named scheffleraside C (<b>1</b>) and one lupane-type saponin scheffleraside D (<b>2</b>), together with six known triterpene saponins (<b>3–8</b>), were isolated by various chromatography methods. Among them, <b>3</b> was found for the first time from natural sources, while <b>6–8</b> were isolated for the first time from the genus <i>Schefflera</i>. Their structures were elucidated by IR, UV, HR-ESI-MS, NMR 1D and 2D experiments, and comparison of their NMR data with previously reported data. Their <i>α</i>-glucosidase inhibition and cytotoxic activity against MCF-7 human breast cancer cell lines were evaluated. The isolates (<b>1</b>, <b>3–5, 8</b>) showed stronger <i>α</i>-glucosidase inhibitory activity (IC₅₀ = 5.99–76.58 μM) than the standard drug acarbose (IC₅₀ = 214.50 μM). At the concentration of 100 μg/ml, the isolates (<b>1</b>, <b>2</b>) showed appreciable cytotoxic activity (67.92, 63.83%, respectively).</p

New C₂₀-gibberellin diterpene from the leaves of <i>Schefflera sessiliflora</i> De P. V.

<div><p>From the leaves of <i>Schefflera sessiliflora</i> De P. V., one new C₂₀-gibberellin diterpene 2β,12β-dihydroxygibberellin (12β-hydroxy-GA₁₁₀ or 2β-hydroxy-GA₁₁₂) (<b>1</b>), together with three known compounds, <i>trans</i>-tiliroside (<b>2</b>), kaempferol 3-<i>O</i>-β-d-glucuronopyranoside (<b>3</b>), 5-<i>p</i>-<i>trans</i>-coumaroylquinic acid (<b>4</b>), was isolated for the first time from the genus <i>Schefflera</i> by various chromatography methods. Their structures were elucidated by IR, UV, HR-ESI-MS, NMR 1D and 2D experiments and comparison with previous reported data. The α-glucosidase inhibitory activity of all compounds was measured. The isolates (<b>2</b>, <b>3</b>) showed better α-glucosidase inhibitory activity (IC₅₀ = 134.60, 147.10 μM, respectively) than the standard drug acarbose (IC₅₀ = 214.50 μM).</p></div

Markhacanasin C, cycloartane triterpenoid from the leaves of <i>Markhamia stipulata</i> var. <i>canaense</i> V.S. Dang

<p>One new cycloartane triterpenoid, named markhacanasin C (<b>1</b>), together with three known triterpenoids, oleanolic acid (<b>2</b>), ursolic acid (<b>3</b>) and 6<i>β</i>,19<i>α</i>-dihydroxyursolic acid (<b>4</b>) were isolated by various chromatographic methods from the most cytotoxic fraction of the ethyl acetate extract of <i>Markhamia stipulata</i> var. <i>canaense</i> V.S. Dang leaves. Among them, <b>4</b> was reported for the first time from the genus <i>Markhamia</i>, while <b>2</b> and <b>3</b> were found for the first time from this species. Their structures were elucidated by IR, UV, HR-ESI-MS and NMR experiments. The cytotoxicity of isolated compounds (<b>3</b> and <b>4)</b> against three human cancer cell lines (HeLa, HepG2, and MCF-7) were evaluated. At the concentration of 100 μg/mL, <b>3</b> exhibited significant cytotoxic activity (86.36 ± 3.69%).</p

Limonoid from the rhizomes of <i>Luvunga scandens</i> (Roxb.) Buch. Ham

<p>For first time, the chemical constituents of the rhizomes of <i>Luvunga scandens</i> (Roxb.) Buch. Ham. were investigated and led to the isolation of one new limonoid named Luvunga A (<b>1</b>), together with seven known compounds, including one limonoid (<b>2</b>) and six coumarins (<b>3</b>–<b>8</b>) were isolated for the first time from the species <i>L. scandens</i> by various chromatography methods. Their chemical structures were elucidated by IR, UV, HR-ESI-MS, NMR 1D and 2D experiments and compared with literatures.</p

Antiproliferative, Anti-Inflammatory Activities, and Molecular Docking Studies of Secondary Metabolites from Macrosolen tricolor

In Vietnam, Macrosolen tricolor is used for the treatment of bloating, broken bones, cough, diarrhea, diuretic, rheumatism, and laxative effects. The study aimed to identify the in vitro antiproliferation and anti-inflammation of all fractions and purified compounds from the M. tricolor whole plants, as well as the in silico molecular docking of the potentially cytotoxic compounds. As the results, fractions (MTH.I, MTH.II, MTE.I, and MTE.II) strongly demonstrated antiproliferative properties against three tested cells, MDA-MB-231, RD, and HepG2 (IC50 values ranged from 4.00 ± 0.20 to 70.60 ± 1.44 μg/mL), as well as anti-inflammatory effects (IC50 values ranged from 4.45 ± 0.08 to 23.00 ± 1.18 μg/mL), whereas other fractions meaningfully evidenced selective cytotoxicity and/or anti-inflammation. Therefore, the phytochemical compositions of the active fractions were illuminated, leading to the characterization of eighteen compounds. Compounds (3–5) revealed the most cytotoxic effects towards all examined cells (IC50 values ranged from 6.88 ± 0.12 to 71.64 ± 1.17 μM) and the strongest anti-inflammatory properties (IC50 values of 16.30 ± 0.92, 7.31 ± 0.55, and 9.23 ± 0.60 μM, respectively). Compound 11 showed potential cytotoxicity against MDA-MB-231, RD, and HepG2 cells (IC50 values of 24.42 ± 0.28, 20.60 ± 0.25, and 3.20 ± 0.02 μM, respectively). Furthermore, compounds (4, 5, and 11) interacted with the active site of the apoptosis regulator Bcl-2 protein (PDB ID: 2O2F), were comparable to PAC, and were compatible with their anticancer activity. This project suggests that M. tricolor is a good source of natural antiproliferative and anti-inflammatory agents and contributes to understanding the biological activities of Macrosolen species in traditional Vietnamese medicine