Chemical constituents from whole herbs of Azolla imbricata / 中草药

Objective: To investigate the chemical constituents from whole herbs of Azolla imbricata. Methods: The chemical constituents were separated and purified by various chromatographic techniques of silica gel, ODS, Sephadex LH-20 gel, and semi-preparative HPLC. Their structures were identified by NMR and MS spectroscopic methods. Results: Twenty compounds were isolated from A. imbricata and identified as chlorogenic acid methyl ester (1), 4-O-caffeoylquinic acid (2), 3,4-O-dicaffeoylquinic acid methyl ester (3), 3,4,5-O-tricaffeoylquinic acid methyl ester (4), (-)-N-[3',4'-dihydroxy-(E)-cinnamoyl]-3-hydroxy-L-tyrosine (5), (-)-N-[3',4'-dihydroxy-(E)-cinnamoyl]-L-tyrosine (6), (-)-N-[3',4'-dihydroxy-(E)-cinnamoyl]-L-tyrosine methyl ester (7), (-)-N- [4'-hydroxy-(E)-cinnamoyl)]-L-tyrosine (8), brainicin (9), quercetin-3-O-β-D-glucoside (10), naringenin-7-O-β-D-glucoside (11), kaempferol-3-O-(6″-O-caffeoyl)-β-D-glucoside (12), caffeic acid (13), epirhododendrin (14), myzodendrone (15), trans-ferulic acid-β-D-glucoside (16), 5,7-dihydroxychromone-2-carboxylic acid (17), pinoresinol-4-O-β-D-glucoside (18), phytol (19) and trans-12-oxo-(10Z,15Z)-phytodienoic acid (20). Conclusion: Compounds 1-12, 14-18, and 20 are isolated from the genus Azolla for the first time and compound 19 is isolated from A. imbricata for the first time. Compounds 1-7, 10, 12, and 13 exhibit good antioxidant activity.

[Mineral Characteristics of Arsenic in the Active Area of the Banbishan Gold Mine and Its Effect on Arsenic Accumulation in Farmland Soil].

To explore the source and pollution characteristics of soil arsenic, mineralogy and chemical analysis methods were used to analyze the ore, waste rock, sediment, and river and soil samples around the mining area. Under a polarized light microscope, As-bearing mineral-arsenopyrite was found in the soil, ore, and waste rock around the Banbishan gold mine. Moreover, arsenopyrite in the waste rock has already experienced weathering and oxidation, and the oxidized arsenopyrite easily migrates and is released in the soil, which is potentially harmful. Because of the effect of mining transportation activities and indigenous smelting, arsenic was mainly distributed in the topsoil, at a depth of 0-20 cm, in the farmland on both sides of the road and in the places where villagers were gathered. The soil arsenic content in Xiaowulan Village and Gaozhangzi Village ranged from 7.2 to 196.2 mg·kg-1 and exceeded the rate of arsenic by 45.9% and 82.1%. According to the assessment by the RAC method, the farmland soil in Xiaowulan Village and Gaozhangzi Village were mainly at low to medium risk, although some soil points in Xiaowulan Village were at high risk. In general, the effects of the mining activities of the surrounding environment were not optimistic. As-bearing minerals in the oxidation of long-term weathering can cause much arsenic to be activated, which in turn, affects the local crops and long-term residents living around the mining area. It is suggested to carry out risk assessments for arsenic in the soil-crop-atmospheric-human system, and further study the conversion rules and mechanisms of arsenopyrite during weathering, to provide scientific guidance for the environmental protection of cultivated land.

[Adsorption and Mechanism of Arsenic by Natural Iron-containing Minerals].

Natural iron-containing minerals present in the geosphere in the form of crystalline minerals can be used as adsorption material for removal of arsenic from wastewater and remediation of arsenic-contaminated soils. In this paper, the adsorption and desorption of arsenic onto different iron-containing materials including hematite, limonite, siderite, ilmenite, magnetite, Fe2O3, Fe3O4, and Fe-Mn binary oxide (FMBO) were studied in laboratory experiments. The mechanism of arsenic adsorption was analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), and fourier transform infrared spectroscopy (FTIR). The results showed that arsenic adsorption is fitted by pseudo-second-order kinetics and the Langmuir isotherm model for almost all adsorbents, suggesting monolayer adsorption of arsenic onto the minerals. The sorption efficiency and capacity of arsenic by FMBO are much higher than those of other materials. Furthermore, limonite has high sorption efficiencies for both As(Ⅲ) and As(Ⅴ) among the natural iron-containing minerals, and their adsorption capacities are 3.96 mg·g-1 and 2.99 mg·g-1, respectively. The XRD results showed that natural limonite contains a large number of weak crystalline mineral components such as goethite, which can provide relatively abundant arsenic adsorption sites. Thus, limonite appears to be the most suitable natural mineral for arsenic adsorption.

Prevalence and risk factors of asymptomatic intracranial vascular stenosis in patients with essential hypertension / 中华心血管病杂志

<p><b>OBJECTIVE</b>The aim of the study was to determine the prevalence and the distribution pattern of lesion site of intracranial vascular stenosis and to identify risk factors for the stenosis in patients with essential hypertension.</p><p><b>METHODS</b>A total of 231 consecutive inpatients with essential hypertension were included in this study. Patients with the history of cerebrovascular diseases and relevant neurological symptoms were excluded. Intracranial vascular stenosis (>50% diameter reduction) was detected using CT angiography (CTA).</p><p><b>RESULTS</b>Of 231 patients, 69 (29.87%) had intracranial artery stenosis. The most common stenosis site is middle cerebral artery (43.69%), followed by carotid siphon (20.39%). The stenosis in internal carotid arterial system (78.64%) was more common than in vertebrobasilar arterial system (21.56%, P < 0.05). The patients with intracranial vascular stenosis were older, had longer history of hypertension, higher levels of systolic blood pressure, higher plasma cholesterol, higher LDL-C. Lp (a), higher urinary microalbumin excretion, thicker ventricular septum, and lower levels of HDL-C than the patients without stenosis. Logistic analysis showed that systolic blood pressure (OR 1.650, 95% CI 1.134 - 2.400, P = 0.023), course of hypertension (OR 1.238, 95% CI 1.072 - 1.429, P = 0.006), LDL-C (OR 2.103, 95% CI 1.157 - 3.823, P = 0.014) and type 2 diabetes (OR 2.325, 95% CI 1.161 - 4.341, P = 0.011) were the independent risk factors of asymptomatic intracranial arterial stenosis.</p><p><b>CONCLUSIONS</b>Nearly 30% inpatients with essential hypertension had asymptomatic intracranial artery stenosis. The most common site of stenosis was middle cerebral artery. Hypertension, dyslipidemia and diabetes were risk factors for the development of intracranial arterial stenosis.</p>