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Mitochondrial dysfunction, which results in the overproduction of oxygen free radicals, is a crucial mechanism underlying cerebral ischemia-reperfusion injury. 4'-Hydroxyl-2-substituted phenylnitronyl nitroxide (HPN), which is an antioxidant and free radical scavenger, can effectively scavenge oxygen free radicals, suggesting its potential as a protective agent against cerebral ischemia-reperfusion injury. In this study, we investigated the effects of HPN on mitochondrial function and apoptosis following cerebral ischemia/reperfusion injury in rats. Healthy adult SD rats were chosen as the experimental subjects, and the rat ischemia/reperfusion injury model was generated using the modified Zea Longa method. The administration of HPN significantly enhanced the activity of endogenous antioxidant enzymes, such as superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT). Additionally, HPN effectively preserved the morphology and function of mitochondria, reduced the protein and gene expression of Caspase-3 and Bax, increased the protein and gene expression of Bcl-2, mitigated neuronal apoptosis, improved neurological deficits, and decreased the volume of cerebral infarction. Of interest, the protective effect on brain tissue was more evident with increasing doses of HPN. These findings indicate that HPN can serve as an effective protective agent against cerebral ischemia-reperfusion injury., (Copyright © 2024 IBRO. Published by Elsevier Inc. All rights reserved.)

Oxidative stress has been considered to be closely related to spaceflight-induced bone loss; however, mechanism is elusive and there are no effective countermeasures. Using cultured rat calvarial osteoblasts exposed to microgravity simulated by a random positioning machine, this study addressed the hypotheses that microgravity-induced shortening of primary cilia leads to oxidative stress and that primary cilium protection prevents oxidative stress and osteogenesis loss. Microgravity was found to induce oxidative stress (as represented by increased levels of reactive oxygen species (ROS) and malondialdehyde production, and decreased activities of antioxidant enzymes), which was perfectly replicated in osteoblasts growing in NG with abrogated primary cilia (created by transfection of an interfering RNA), suggesting the possibility that shortening of primary cilia leads to oxidative stress. Oxidative stress was accompanied by mitochondrial dysfunction (represented by increased mitochondrial ROS and decreased mitochondrial membrane potential) and intracellular Ca 2+ overload, and the latter was found to be caused by increased activity of Ca 2+ channel transient receptor potential vanilloid 4 (TRPV4), as also evidenced by TRPV4 agonist GSK1016790A-elicited Ca 2+ influx. Supplementation of HC-067047, a specific antagonist of TRPV4, attenuated microgravity-induced mitochondrial dysfunction, oxidative stress, and osteogenesis loss. Although TRPV4 was found localized in primary cilia and expressed at low levels in NG, microgravity-induced shortening of primary cilia led to increased TRPV4 levels and Ca 2+ influx. When primary cilia were protected by miR-129-3p overexpression or supplementation with a natural flavonoid moslosooflavone, microgravity-induced increased TRPV4 expression, mitochondrial dysfunction, oxidative stress, and osteogenesis loss were all prevented. Our data revealed a new mechanism that primary cilia function as a controller for TRPV4 expression. Microgravity-induced injury on primary cilia leads to increased expression and overactive channel of TRPV4, causing intracellular Ca 2+ overload and oxidative stress, and primary cilium protection could be an effective countermeasure against microgravity-induced oxidative stress and loss of osteogenic potential of osteoblasts., (© 2023 Wiley Periodicals LLC.)

The dense canopy of rice causes attenuation of droplet dispersion during pesticide application. The canopy-opening device can increase droplet deposition in the middle and lower canopy of rice by causing disturbance to the rice canopy. However, the conditions for use of the canopy-opening device are difficult to determine. Rice morphological structure parameters and material parameters were measured to study the movement mechanism of the rice stems under the action of the canopy-opening device, and the canopy-opening process was then simulated using the explicit dynamic method. The simulation scene of the rice canopy-opening process considered the combination of three different heights and three different driving velocities of the canopy-opening device. The movement mechanism of the rice stems under the operation of the canopy-opening device was investigated, and the entire movement process was separated into two stages: contact and oscillation. The simulation results and high-speed photography experimental results show a strong correlation, with a correlation coefficient of 0.733. The simulation results indicate that when the canopy-opening device is closer to the ground and the driving velocity is higher, the disturbance to the rice stem during the contact stage is stronger. However, for the oscillation stage, there exists a critical value for both the height and driving velocity of the canopy-opening device. During the oscillation stage, there is a critical value for both the height and driving velocity of the canopy-opening device. The numerical-based explicit dynamics approach was employed in this work to investigate the rice canopy motion mechanism, and this study has a definite reference value for the investigation of complicated motion mechanisms in the field crop production process., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Jing, Wei, Song and Wang.)

P-TEFb, a heterodimer of the kinase CDK9 and Cyclin T1, is a critical regulator of promoter-proximal pause release of Pol II in metazoans. It is capable of forming three larger complexes, including the super elongation complex (SEC), the BRD4/P-TEFb complex and the 7SK snRNP. In the SEC or the BRD4/P-TEFb complex, P-TEFb is enzymatically active, while in the 7SK snRNP, its activity is inhibited. The SEC consists of AFF1 or 4, ENL or AF9, ELL1, 2 or 3 and EAF1 or 2 in addition to P-TEFb, the only subunit with catalytic activity, and the noncatalytic subunits have been found to be able to regulate pause release through P-TEFb. We and others recently found that AFF1, ENL and AF9 are capable of regulating transcriptional initiation, but it is unknown yet whether AFF4 is also capable of doing so. With respect to the gene regulation selectivity of the SEC and the BRD4/P-TEFb complex, one recent study showed that in human DLD-1 cells, the SEC only regulates pause release of heat shock (HS) genes, whereas the BRD4/P-TEFb complex regulates pause release of the rest of the genes. However, it is unclear whether those mechanisms are general. In this study for the purpose of further understanding the role of AFF4 in transcriptional regulation, we found that AFF4 knockdown by RNA interference in human HEL cells decreased not only cellular level but also global chromatin occupancy of CTD serine 2 phosphorylated Pol II. Direct target genes of AFF4 were identified by RNA-seq and CUT&Tag. Notably, we found by ChIP-seq and PRO-seq that AFF4 loss also increased promoter-proximal pause of Pol II on several hundred HS and thousands of non-HS genes. Mechanistically, AFF4 promotes pause release likely by facilitating the binding of P-TEFb to Pol II. These results suggest that extent of the impact of AFF4 on pause release is likely to be context-dependent or cell-type dependent.

Two new azaphilone pigments, talaralbols A and B ( 3 and 7 ), along with five known azaphilone metabolites ( 1 , 2 , and 4 - 6 ), were isolated from the culture of Talaromyces albobiverticillius associated with the isopod Armadillidium vulgare . Their structures were elucidated by a combination of 1 D and 2 D NMR data, ECD calculations, chemical transformations, and NMR data analogy with model compounds. Talaralbol A ( 3 ) showed a moderate inhibition on the lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW264.7 cells with the inhibitory rate being 31.0% at the concentration of 10  μ M.[Formula: see text].

microRNAs (miRNAs) have gained more attention due to the biological functions in many cancers, including non-small cell lung cancer (NSCLC). However, the roles and the mechanism of miR-140-3p in NSCLC progression remain poorly understood. In this study, the expression levels of miR-140-3p and Janus kinase 1 (JAK1) were measured in NSCLC tissues and cells by quantitative real-time PCR. Cell viability, apoptosis, migration and invasion were detected by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-trtrazolium bromide, flow cytometry, Western blot or trans-well assay, respectively. Murine xenograft model was conducted to analyze the anti-tumor effect of miR-140-3p in vivo. Interaction between miR-140-3p and JAK1 was probed by luciferase reporter activity and Western blot. We found that miR-140-3p expression was down-regulated and JAK1 expression was increased in NSCLC tissues and cells compared with those in corresponding controls. Moreover, overexpression of miR-140-3p inhibited cell viability, migration and invasion while promoted cell apoptosis in NSCLC cells and suppressed NSCLC xenograft tumor growth in vivo . Besides, JAK1 was proved as a target of miR-140-3p and its restoration reversed miR-140-3p-mediated regulatory effect on progression of NSCLC. We concluded that miR-140-3p inhibited NSCLC progression by targeting JAK1, providing a novel avenue for treatment of NSCLC.

The formation of advanced glycation end-products(AGEs) is an important cause of metabolic memory in diabetic patients and a key factor in the formation of atherosclerosis(AS) plaques in patients with diabetes mellitus. Related studies showed that AGEs could disrupt hemodynamic steady-state and destroy vascular wall integrity through the endothelial barrier damage, foam cell(FC) formation, apoptosis, calcium deposition and other aspects. At the same time, AGEs could initiate oxidative stress and inflammatory response cascade via receptor-depended and non-receptor-dependent pathways, promoting plaques to develop from a steady state to a vulnerable state and eventually tend to rupture and thrombosis. Numerous studies have confirmed that these pathological processes mentioned above could lead to acute coronary heart disease(CHD) and other acute cardiovascular and cerebrovascular events. However, the specific role of AGEs in the progression and regression of AS plaques has not yet been fully elucidated. In this paper, the formation, source, metabolism, physical and chemical properties of AGEs and their role in the migration of FCs and plaque calcification are briefly described, we hope to provide new ideas for the researchers that struggling in this field.

Background: The aim of the present study was to investigate knowledge, attitude, and practice (KAP) associated with medical nutrition therapy (MNT) among Chinese adult patients with diabetes and prediabetes., Methods: From May to August 2014, a cross-sectional study was conducted in 40 hospitals across China. The KAP of respondents was investigated through a pretested structured questionnaire in face-to-face interviews. Anthropometric and biochemical data were collected, and KAP scores were recorded according to patient responses., Results: In all, responses from 7017 of 7508 patients were analyzed. The mean (±SD) overall KAP score was 9.63 ± 3.46, with individual scores for the K, A, and P components being 2.69 ± 1.90, 1.77 ± 1.99, and 5.17 ± 1.99, respectively (out of possible total scores of 19, 6, 3, and 10, respectively). All scores were higher in respondents who received ≥15 min MNT education than in those with shorter sessions. Patients with higher KAP scores exhibited significantly better glycemic control, with a higher proportion achieving target HbA1c, fasting plasma glucose, and 2-h postprandial blood glucose levels (P < 0.05). "Health publicity in hospitals" and "expert outpatient services" were the most favorable means of acquiring MNT information. The two predominant concerns associated with MNT were "the feasibility" and "the authenticity and professionalism of the information"., Conclusions: Patients with diabetes and prediabetes achieved moderate scores for KAP towards MNT. Glycemic control was positively correlated with the KAP score. Thus, MNT education should be improved, with a particular focus on feasibility and authenticity and professionalism, in China., (© 2016 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and John Wiley & Sons Australia, Ltd.)

Background: Fibrinolysis prevents blood clots from growing and becoming problematic. Antifibrinolytics are used as inhibitors of fibrinolysis. Aprotinin was doubted after identification of major side effects, especially on kidney. Lysine analogues has their own defects and whether they are adequate substitutes for aprotinin is still under doubt. Lamiophlomis rotata (Benth.) Kudo. was previous found to have hemostatic activity. But the active compound in L. rotata and its hemostatic mechanism were unknown., Objectives: To find the major hemostatic compound in L. rotata and identify its haemostasis mechanism., Methods: Traumatic hemorrhage model and coagulant activity assays were monitored in mice and platelets in drug treatment group and control group. Hyperfibrinolysis model was established by intravenous administration of urokinase in mice. Capillary blood clotting time (CBCT), activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), fibrinogen and euglobulin clot lysis time (ECLT) were measured., Results: The anti-fibrinolytic activity come from 8-O-Acetyl shanzhiside methylester (ASM) one of the highest iridoid glycosides contents in TIG extracted from L. rotata. ASM significantly (P<0.05) shorten CBCT and reduced blood loss volume in vivo, but did not influence mice APTT, PT or TT. In particular, it significantly prolonged ECLT in hyperfibrinolysis mice. It indicated that ASM could inhibit fibrinolysis. ASM was also effective in CBCT, traumatic bleeding volume and ECLT in hyperfibrinolysis mice model., Conclusions: ASM was the major hemostatic compound in L. rotata. The haemostasis mechanism of ASM was achieved by anti-fibrinolytic activity. ASM was a new fibrinolysis inhibitor as iridoid glycoside compound., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Objective: The present study was designed to explore expression and prognostic value of miR-485-5p in patients with gastric cancer., Patients and Methods: We determined the expression level of miR-485-5p in 132 cases of paired GC and adjacent non-tumor tissues by quantitative real-time PCR (qRT-PCR). The relevance of miR-485-5p expression to the clinicopathological factors was assessed. Overall survival (OS) was examined using Kaplan-Meier curves and the Cox proportional hazards regression model., Results: The expression of miR-485-5p was significantly down-regulated in GC tissues compared with adja-cent normal tissues (p < 0.01). MiR-485-5p expression was positively correlated with larger tumor size (p = 0.003), deeper invasion depth, (p = 0.005), positive lymph node metastasis (p = 0.039), advanced tumor-node-metastasis (TNM) stage (p = 0.017). Patients survival analysis showed that a clear positive correlation between miR-485-5p expression level and survival time of gastric cancer patients (p < 0.001). Multivariate analyses confirmed that a low level of miR-485-5p expression was an independent predictor of poor prognosis in GC patients., Conclusions: Expression level of miR-485-5p serves as a novel biomarker for the overall survival of patients with gastric cancer.

Background: This study aims to evaluate the efficacy of Xiaoyaosan (XYS) for treatment of major depressive disorder (MDD) and to review the studies on antidepressant mechanisms of XYS., Methods: The China Knowledge Resource Integrated Database (1998-2014), VIP Journal Integration Platform (1989-2009), and PubMed (1950-2014) were used to search for and collect scientific publications related to XYS and MDD. Clinical trials for "MDD" and "xiaoyao" were screened. Papers that used the original prescription of XYS for treatment and in combination with Western medicines were included, while papers describing modified XYS were excluded. Four investigators read and screened the resulting publications independently, evaluated the associated scientific results and evidence., Results: There were no conclusive results to support the efficacy of XYS for treatment of MDD, owing to limited sample sizes, flaws in blinding and randomization, and lack of multi-centered clinical trials. Among the experimental studies on the effects of XYS possible involvement of 5-hydroxytryptamine, hypothalamic-pituitary-adrenal axis function, and neuroinflammation were possibly involved demonstrated., Conclusions: The effectiveness of XYS for treatment of MDD is uncertain.

Apigenin (Api), a mainly bioactive component of Apium graveolens L. var. dulce DC. (a traditional Chinese medicinal herb), possesses a wide range of biological activities, including antioxidant effects. It also has been shown to associate with lower prevalence of cardiovascular diseases, but its mechanisms of action remain unclear. The aim of the present study is to investigate the role of Api in isolated rat heart model of ischemia/reperfusion (I/R). Langendorff-perfused isolated rat hearts were used in our study. Api was added to the perfusate before ischemia and during reperfusion in the isolated pulsed rat heart exposed to 30-min ischemia followed by 50-min reperfusion. The treatment with Api conferred a cardioprotective effect, and the treated hearts demonstrated an improved ischemic cardiac functional recovery, a decreased myocardial infarct size, a reduced activities of creatine kinase isoenzyme and lactate dehydrogenase in the coronary flow, a reduced number of apoptotic cardiomyocytes, a reduced activity of caspase-3, up-regulation of the anti-apoptotic protein Bcl-2 and down-regulation of the pro-apoptotic protein Bax. In addition, Api inhibited the phosphorylation of p38 MAPKS during I/R. In conclusion, these observations provide preliminary evidence that Api can protect cardiomyocytes from I-/R-induced injury, at least partially, through the inhibition of p38 MAPKS signaling pathway.

A convergent synthesis route of moslooflavone, isowogonin and norwogoninis reported,starting from chrysin, an easily available flavone, by methylation, bromination, methoxylation and demethylation procedures. This synthetic route is convenient and can give the three rare flavones in good yield.

Nitric oxide (NO) may act as either a pro-oxidant or an antioxidant in biological systems. Previous work has found inhalation of NO improved survival in a high altitude rat model. NO donor isosorbide mononitrate derivants might have a protective effect against hypoxia. We synthesized a series of isosorbide mononitrate derivant compounds to test their anti-hypoxia activities. Normobaric hypoxia and hypobaric hypoxia models were used to study the protective role of NO donor in mice. The results showed isosorbide mononitrate derivants had protective effects in hypoxia mice. Among those compounds, acetyl ferulic isosorbide mononitrate (AFIM) was the most effective. It prolonged the survival time during the normobaric hypoxia test. It decreased malondialdehyde (MDA) and H2O2 in hypobaric hypoxia mice. The antioxidase activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) remained in normal ranges in the AFIM group. As a sign of mitochondrial dysfunction, the activities of ATPase were down regulated in mice under hypobaric hypoxia conditions. AFIM also protected ATPase activities. The protective effects of AFIM might come from a sustained NO supply and the release of acetyl ferulic acid with anti-oxidant activity.

A quantitative analysis method for fudosteine in human serum by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI/MS/MS) was established, which shows high sensitivity and selectivity. The mobile phase composition was 75% 20 mM acetic acid and 25% acetonitril, which was pumped at a flow rate of 0.40 mL/min. The overall chromatographic run time was approximately 7 min. The autosampler was set with an injection volume of 10 μL. The calibration curve was linear in the concentration range of 0.1~15.0 µg/mL. The coefficient of determination (r) was greater than 0.9998. This method has been fully validated and shown to be specific, accurate and precise. The method was simple, rapid and the sample preparation was minimal. It was successfully applied to the analysis of healthy volunteer.

The Title Compound (systematic Name: 5,6-dihy-droxy-7,8-dimeth-oxy-2-phenyl-chromen-4-one), C17H14O6, is a flavone that was isolated from the petroleum ether-soluble fraction of the rare traditional Chinese medicinal herb Saussurea involucrata. The flavone mol-ecule is almost planar, with a dihedral angle between the planes of the benzo-pyran-4-one group and the attached phenyl group of 1.89 (6)°. The 5-hy-droxy group forms a strong intra-molecular hydrogen bond with the carbonyl group, resulting in a six-membered hydrogen-bonded ring. The 6-hy-droxy group also forms an intra-molecular O-H⋯O contact. In the crystal, the molecules are linked by O-H⋯O and C-H⋯O hydrogen bonds and π-π inter-actions [3.37 (2)-3.39 (2) Å], which build up a three-dimensional network.

Acute mountain sickness is caused by sub-acute hypoxia in healthy individuals going rapidly to altitude. Both tissue hypoxia in vitro and whole-body hypoxia in vivo have been found to promote the release of reactive oxygen species. Nitronyl nitroxide can trap free radicals such as ·NO or ·OH, and may therefore be efficient protective agents. This study assessed the ability of nitronyl nitroxide to against acute mountain sickness as a free radical scavenger in acute high-altitude hypoxia mice model. Normobaric hypoxia and hypobaric hypoxia model were used to estimate the protect effects of nitronyl nitroxide against acute mountain sickness. Low pressure oxygen compartment system was used to stimulate high-altitude hypobaric hypoxia environment. Mice in nitronyl nitroxide groups survived longer than acetazolamide group in normobaric hypoxia test. Hydrogen peroxide (H2O2) and malondialdehyde (MDA) increased in both cerebrum and myocardium in vehicle group. The results indicated more radicals were generated during high-altitude hypobaric hypoxia environment. In therapeutic groups H2O2 and MDA were significantly reduced while the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) were similar to normal group. These results demonstrated that nitronyl nitroxide was an efficient tissue radical scavenger and a potential protective agent for acute mountain sickness.

Objective: To assess the practical utility of pleural fluid carbonic anhydrase XII (CAXII) quantification for differential diagnosis of effusions., Materials and Methods: Fluid was collected prospectively from fifty patients presenting with lymphocytic pleural effusions for investigation and CAXII was quantified by ELISA., Results: Pleural fluid CAXII concentrations were significantly higher in lung cancer patients (n=30) than in tuberculous controls (n=20). The sensitivity and specificity of this biomarker were 60%and 75%, respectively. CAXII measurement was not inferior to cytological examination in the diagnosis and exclusion of pleural effusions from lung cancer patients (sensitivity 60% vs. 57%; specificity 75% vs. 100%; positive predictive value 77%; negative predictive value 54%). In patients with negative cytology, it offered a sensitivity of 54%., Conclusions: Pleural fluid CAXII is elevated in pleural effusions from lung cancer patients. Measurement of CAXII may be used in the future as a valuable adjunct to cytology in the diagnostic assessment of patients with pleural effusions related to lung cancer, especially when cytological examination is inconclusive.

A simple and sensitive high-performance liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed and validated for simultaneous determination of shanzhiside methylester and its three derivatives in rabbit plasma. The method showed good linearity and no endogenous material interfered with the marked compounds and internal standard (IS) capatol peaks. Samples were processed by acetonitrile precipitation. Chromatography was performed using a C₁₈ column (150 × 3.9 mm i.d., 4 µm). The mobile phase consisted of methanol and water (60:40, v/v) during a total run time of 7 min. The main mass parent ions and daughter ions pairs (m/z) for monitoring were: shanzhiside methylester, 429.0/267.4; 8-O-acetyl shanzhiside methylester, 470.9/411.3; loganin, 413.2/251.4; phloyoside II, 479.2/281.3; and IS 385.2/203.3. Finally, the method was applied to a pharmacokinetic study of rabbits following intravenous administration of iridoid glycosides extracted from traditional herb Lamiophlomis rotata., (Copyright © 2012 John Wiley & Sons, Ltd.)

Buyang Huanwu decoction (BYHWD) is a well-known and canonical Chinese medicine formula from "Correction on Errors in Medical Classics" in Qing dynasty. Here, we show that BYHWD could alleviate the ventricular remodeling induced by left anterior descending (LAD) artery ligation in rats. BYHWD treatment (18 g/kg/day) decreased heart weight/body weight (HW/BW), left ventricle (LV) dimension at end diastole (LVDd) and increased LV ejection fraction (LVEF) and LV fractional shortening (LVFS) significantly compared to model group at the end of 12 weeks. The collagen volume of BYHWD group was more significantly decreased than that of model group. Proteomic analysis showed that atrial natriuretic factor (ANF) was downregulated; heat shock protein beta-6 (HSPB6) and peroxiredoxin-6 (PRDX6) were upregulated in BYHWD-treated group among successfully identified proteins. The apoptotic index (AI) was reduced by BYHWD accompanied by decreased expression of Bax and caspase 3 activity, increased Bcl-2/Bax ratio, and phosphorylation of HSPB6 compared to that of model group. Taken together, these results suggest that BYHWD can alleviate ventricular remodeling induced by LAD artery ligation. The antiremodeling effects of BYHWD are conferred by decreasing AI through affecting multiple targets including increased Bcl-2/Bax ratio and decreased caspase 3 activity that might be via upregulated PRDX6, phosphorylation of HSPB6 and subsequently reduction of ANF.

In the title compound, C(16)H(21)N(2)O(5), the benzene ring is nearly perpendicular to the imidazole ring, making a torsion angle of 88.6 (8)°·The crystal structure is stabilized by non-classical C-H⋯O and C-H⋯π inter-actions, which build up a three-dimensional network.

In the title compound, C(15)H(21)N(2)O(5), the imidazoline ring displays a twisted conformation. The mean plane of the imidazoline ring makes a dihedral angle of 22.55 (5)° with the benzene ring. In the crystal, O-H⋯O and C-H⋯O hydrogen bonds link the mol-ecules into a layer parallel to the bc plane.

In the title compound, C(15)H(21)N(2)O(4), the imidazoline ring displays a twisted conformation. The dihedral angle between the mean plane of the imidazoline ring and the benzene ring is 33.50 (12)°. In the crystal, mol-ecules are connected by O-H⋯O hydrogen bonds, forming a zigzag chain along the c axis. The chains are linked by C-H⋯O and C-H⋯π inter-actions.

In the title compound, C(15)H(21)N(2)O(4), the nitronyl nitroxide unit displays a twisted conformation. The crystal structure is stabilized by non-classical C-H⋯O and C-H⋯π hydrogen bonds, which build up a three-dimensional network.

Ethnopharmacological Relevance: Rhodiola algida, Saussurea involucrata, and other herbs grown in Qinghai-Tibetan plateau have long been used to prevent and treat acute mountain sickness., Aim of the Study: To screen and identify the anti-hypoxic constituents in the herbs grown in Qinghai-Tibetan plateau of Northwestern China., Materials and Methods: The anti-hypoxic activities of 20 selected plateau herbs were examined against two positive controls, Rhodiola algida and acetazolamide, using the normobaric hypoxia model of mice. The herb with the highest activity was successively extracted with 70% ethanol, petroleum ether, chloroform, ethyl acetate and n-butanol. The extract with the highest activity was identified by comparing the survival time of mice under normobaric hypoxia condition after being subjected to different extracts. The identified extract was further tested by simulating high altitudes through an acute decompression model and a chronic decompression model for mice., Results: The herb found to have the highest anti-hypoxic activity was Saussurea involucrate (Kar. et Kir.) Sch.-Bip, and the most effective fraction was in the petroleum ether extract. Administration of petroleum ether extract of Saussurea involucrata (PESI) to mice at 50mg/kg significantly decreased the mortality of animals under acute decompression conditions. Changes in biochemical indicators for glycometabolism and energy metabolism, including adenosine triphosphate (ATP) content and adenosine triphosphatase (ATPase) activity in brain and cardiac muscle, lactic acid (LAC) and lactate dehydrogenase (LDH) in blood and cardiac muscles, blood sugar, and glycogen content in liver and skeletal muscle were reversed under chronic decompression conditions., Conclusions: Saussurea involucrata (Kar. et Kir.) Sch.-Bip exhibits high anti-hypoxic activity that may be effective in preventing acute mountain sickness, and the active constituents are mainly in the petroleum ether extract., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Three new flavonoid glycosides, kaempferol-3-O-β-D-apiofuranosyl(1 → 2)-β-D-glucopyranosyl-7-O-α-L-rhamnopyranoside (1), kaempferol-4'-O-β-D-apiofuranosyl-3-O-β-D-glucopyranosyl-7-O-α-l-rhamnopyranoside (2), and 5,6,7,4'-tetrahydroxy-flavone-6-O-β-D-arabinopyranosyl-7-O-α-L-rhamnopyranoside (3), were isolated from the aerial parts of Urena lobata L., along with 10 known compounds (4-13). Their structures were determined based on spectroscopic methods including 1D and 2D NMR spectroscopy as well as HR-ESI-MS.

In the title compound, C(21)H(28)Cl(2)N(3)O(6), the nitronyl nitroxide ring displays a half-chair conformation, whereas the pyrrolidine ring has an envelope conformation. These two rings are twisted to each other with N-C-C-N torsion angles around the connecting C-C bond of 48.9 (6) and -127.0 (5)°. The benzene ring is nearly perpendicular to the pyrrolidine ring, with torsion angles around the connecting C-C bond of 86.3 (6) and -97.7 (6)°. The crystal structure is stabilized by C-H⋯O and C-H⋯π hydrogen bonds, which build up a three-dimensional network.

In the title compound, C(18)H(23)ClN(3)O(3), the imidazole ring system has an envelope conformation, whereas the nitronyl nitroxide unit displays a half-chair or twisted conformation. In the crystal, C-H⋯O hydrogen bonds build up a three-dimensional network.

Two new compounds 1 and 2 have been isolated from the aerial parts of Urena lobata L. The structures of the two new compounds were established as ceplignan-4-O-β-d-glucoside (1) and 2,5-dihydroxy benzoic acid-7-(2,6-dimethyl-6-hydroxy-2,7-octadienoic acid) anhydride-5-O-β-d-apiofuranosyl(1 → 2)-β-d-glucoside (urenoside A) (2), on the basis of chemical and spectral evidence, including 1D and 2D NMR spectroscopic data as well as mass spectrometry (HR-ESI-MS).

In the title compound, C(16)H(28)N(3)O(4), the plane of the pyrrolidine ring system is twisted with respect to the plane of the nitronyl nitroxide unit, making a dihedral angle of 79.80 (6)°. The crystal structure is stabilized by C-H⋯O hydrogen bonds.

The title compound, C(13)H(14)N(2)O(2), is a natural product isolated from Cicer arietinum L. (chickpea). The benzene ring and pyrrole rings display planar conformations and the piperidine ring has a half-chair conformation. Inter-molecular C-H⋯π inter-actions between a methyl H atom and the pyrrole ring of an adjacent mol-ecule are present in the crystal structure.

In the title compound, C(15)H(18)N(3)O(2), the plane of the indole ring system is twisted with respect to the plane of the nitronyl nitroxide moiety, exhibiting a dihedral angle of 21.61 (6)°. The crystal packing is stabilized by N-H⋯O hydrogen bonds and weak C-H⋯O inter-actions.

The title nitro-phenyl pyridine compound, C(20)H(22)N(2)O(6) was synthesized as a degradation product of the hypertension medication nisoldipine. The dihedral angle between the nitro-substituted phenyl ring and the pyridine ring is 75.5 (4)°. There are a number of C-H⋯O inter-actions between symmetry-related mol-ecules>.

The title compound, C(18)H(15)OP·C(13)H(17)N(2)O(3), belongs to a series of mol-ecular systems based on triphenyl-phosphine oxide. The O atom of the oxide group acts as an acceptor for hydrogen bonds from -OH groups of the nitronyl nitroxide. The crystal structure is stabilized by O-H⋯O hydrogen bonds.

In the title nitronyl nitroxide radical compound, C(16)C(23)N(2)O(5), the imidazole and benzene rings are twisted with respect to each other, making a dihedral angle of 26.2 (4)°. The imidazole ring adopts a half-chair conformation. Weak C-H⋯π inter-actions are also found.

Compared to conventional C18 phases, polar-modified phases have distinct differences with regards to chromatographic behavior. In the present study, ODS phases and polar-modified phases were synthesized. The columns containing these new packings demonstrated satisfactory stability under both acidic (pH 1.5) and basic (pH 10) conditions. We evaluated the selectivity differences between alkyl and polar-modified alkyl RP columns by using a range of neutral analytes. The polar-modified alkyl phases showed excellent peak shapes for almost all compounds. We also compared the selectivity differences between them for separating nucleotides by using 100% aqueous mobile phase and tricyclic antidepressants in the intermediate pH mobile phases. The results demonstrated that polar-modified phases display a significantly reduced hydrophobic nature and a significantly reduced silanol activity compared to the conventional C18 phases.

Different 1,4-dichlorophthalazine-cinchona alkaloid derivatives have been used to catalyze the asymmetric "interrupted" Feist-Bénary reaction of ethyl bromopyruvate/substituted bromoketoesters and beta-dicarbonyl compounds. The corresponding hydroxydihydrofurans have been obtained in excellent yields and with up to 91%ee.