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Chemical Composition and Antimigraine Activity of Essential Oil of Angelicae dahuricae Radix
Jingbo Sun,He Li,Jinghui Sun,Huimin Liu,JianGuang Chen,Chunmei Wang 한국식품영양과학회 2017 Journal of medicinal food Vol.20 No.8
The aim of this study was to explore the chemical composition and the effect of essential oil of Angelicae dahuricae radix on a nitroglycerin (NTG)-induced rat model of migraine. The CO2 supercritical fluid extraction method was optimized for the extraction of essential oil of A. dahuricae radix (EOAD) and its chemical composition was determined. The migraine model was established by subcutaneous injection of NTG (10 mg/kg) 1 h after the last administration of EOAD. The therapeutic effect of EOAD and its underlying mechanism were assessed by monitoring behavioral changes, levels of nitric oxide (NO) in serum and brain tissues, plasma levels of calcitonin gene-related peptide (CGRP) and endothelin (ET), and ET/NO ratio. The optimal conditions for CO2 supercritical fluid extraction of EOAD, as determined by orthogonal test [L9(34)], were as follows: 2 h extraction time, 20 MPa pressure, 40°C temperature, and 30 mesh. The yield of EOAD was 1.8%. On gas chromatography–mass spectrometry, 45 peaks were found in EOAD, and 22 compounds were identified and quantified. The main constituents of EOAD were 1-dodecanol (13.71%), elemene (7.54%), palmitic acid ethyl ester (7.32%), α-pinene (6.25%), and 1-pentadecanol (6.08%). Compared with rat migraine model controls, EOAD (35, 70, and 140 mg/kg) significantly reduced the number of head shaking, head scratching, and hind leg shooting events, decreased serum and brain NO levels, decreased plasma CGRP, and increased ET levels in rats. ET/NO ratio was elevated to 28.68 in the EOAD high-dose group. EOAD ameliorates NTG-induced migraine in rats likely by modulating the levels of vasoactive substances.
Biocatalysis for the synthesis of pharmaceuticals and pharmaceutical intermediates
Sun, Huihua,Zhang, Hongfang,Ang, Ee Lui,Zhao, Huimin Elsevier 2018 Bioorganic & medicinal chemistry Vol.26 No.7
<P><B>Abstract</B></P> <P>Biocatalysis has been increasingly used for pharmaceutical synthesis in an effort to make manufacturing processes greener and more sustainable. Biocatalysts that possess excellent activity, specificity, thermostability and solvent-tolerance are highly sought after to meet the requirements of practical applications. Generating biocatalysts with these specific properties can be achieved by either discovery of novel biocatalysts or protein engineering. Meanwhile, chemoenzymatic routes have also been designed and developed for pharmaceutical synthesis on an industrial scale. This review discusses the recent discoveries, engineering, and applications of biocatalysts for the synthesis of pharmaceuticals and pharmaceutical intermediates. Key classes of biocatalysts include reductases, oxidases, hydrolases, lyases, isomerases, and transaminases.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Stability of Switching Linear Uncertain Systems via switching time-varying Lyapunov functions
Huimin Zheng,Yuangong Sun 제어로봇시스템학회 2022 제어로봇시스템학회 국제학술대회 논문집 Vol.2022 No.11
In this article, the global asymptotic stability of switching linear uncertain systems with all subsystems unstable is investigated. By introducing a switching time-varying Lyapunov function, new criteria are proposed to ensure that the involved system is globally uniformly asymptotically stable (GUAS) under the mode-dependent range dwell time (MDRDT) frame by using the stability of switching behavior to counteract the state divergence generated by unstable subsystems and using linear matrix inequality to deal with uncertainty. Finally, a numerical example is worked out to illustrate the feasibility of the method.
Yidong Wang,Huimin Wang,Zeqing Ma,Wuefa Wen,Qingkang Li,Yunfen Liu,Wiaomin Sun,Guirui Yu 한국기상학회 2009 Asia-Pacific Journal of Atmospheric Sciences Vol.45 No.2
Soil CO₂ efflux (RS) was monitored in a 23-year-old subtropical coniferous plantation in southern China from January 2004 to December 2006. Field measurements of RS with litterfall (CK) and without litterfall (NL) were conducted to evaluate the contribution of aboveground litter decomposition to RS. The results indicated that annual RS from CK ranged from 11.5 mg (C) m<SUP>-2</SUP>h<SUP>-1</SUP> in 2004 to 186.2 ㎎ (C) m<SUP>-2</SUP>h<SUP>-1</SUP> in 2006. The RS of NL was significantly lower than the RS of CK. RS was mainly determined by soil temperature (TS), but it was also affected by soil moisture. Together, both factors explained > 70%of the observed variations in RS. The temperature sensitivity (Q<SUB>10</SUB>) of RS from NLwas lower than that from CK by considering the soil moisture effect. On average, the annual RS of the coniferous plantation was estimated to be 669 g (C)m<SUP>-2</SUP>yr<SUP>-1</SUP> over the study period. The litterfall greatly enhanced the RS, and the respiration from aboveground litter accounted for about 33% of the total RS, in which the fresh litterfall decomposition accounted for a large proportion. The carbon pool of aboveground litter in this young conifer forest is expected to increase continuously.
Shenghan Su,Qingrui Zhao,Lingfeng Dan,Yuqing Lin,Xuebei Li,Yunjin Zhang,Chunxiao Yang,Yimeng Dong,Xiaohan Li,Romano Regazzi,Changhao Sun,Xia Chu,Huimin Lu 대한내분비학회 2022 Endocrinology and metabolism Vol.37 No.6
Background: Chronic exposure to elevated levels of saturated fatty acids results in pancreatic β-cell senescence. However, targets and effective agents for preventing stearic acid-induced β-cell senescence are still lacking. Although melatonin administration can protect β-cells against lipotoxicity through anti-senescence processes, the precise underlying mechanisms still need to be explored. Therefore, we investigated the anti-senescence effect of melatonin on stearic acid-treated mouse β-cells and elucidated the possible role of microRNAs in this process. Methods: β-Cell senescence was identified by measuring the expression of senescence-related genes and senescence-associated β-galactosidase staining. Gain- and loss-of-function approaches were used to investigate the involvement of microRNAs in stearic acid-evoked β-cell senescence and dysfunction. Bioinformatics analyses and luciferase reporter activity assays were applied to predict the direct targets of microRNAs. Results: Long-term exposure to a high concentration of stearic acid-induced senescence and upregulated miR-146a-5p and miR-8114 expression in both mouse islets and β-TC6 cell lines. Melatonin effectively suppressed this process and reduced the levels of these two miRNAs. A remarkable reversibility of stearic acid-induced β-cell senescence and dysfunction was observed after silencing miR-146a-5p and miR-8114. Moreover, V-maf musculoaponeurotic fibrosarcoma oncogene homolog A (Mafa) was verified as a direct target of miR-146a-5p and miR-8114. Melatonin also significantly ameliorated senescence and dysfunction in miR-146a-5pand miR-8114-transfected β-cells. Conclusion: These data demonstrate that melatonin protects against stearic acid-induced β-cell senescence by inhibiting miR-146a-5p and miR-8114 and upregulating Mafa expression. This not only provides novel targets for preventing stearic acid-induced β-cell dysfunction, but also points to melatonin as a promising drug to combat type 2 diabetes progression.