黄素酶的模拟

本综述介绍模拟黄素酶的进展。

Inhibition of human cytochrome CYP1B1 by anthraquinone compounds,chrysophanol and physcion

The in vitro inhibitory effects of chrysophanol and physcion on CYP1B1 were explored,utilizing ethoxyresorufin as the substrate.The inhibition kinetics of CYP1B1 by these compounds were assessed with escalating doses of ethoxyresorufin.Both chrysophanol(IC_(50)(0.47±0.01)μmol·L^(-1))and physcion(IC_(50)(0.35±0.02)μmol·L^(-1))significantly reduce the catalytic efficiency of CYP1B1.The V_(max)and K_(m)values are determined to be(51.9912±10.0547)pmol·μg^(-1)(protein)·min^(-1) and(0.9663±0.2987)nmol·L^(-1)for chrysophanol,and(45.4227±1.9978)pmol·μg^(-1)(protein)·min^(-1) and(0.4367±0.0386)nmol·L^(-1)for physcion,respectively.Kinetic analysis reveals that chrysophanol and physcion exert mixed inhibitory effects on CYP1B1.This mixed inhibition is primarily characterized by the compounds’ability to competitively bind to the active sites of CYP1B1,as well as potentially through non-competitive mechanisms,thereby reducing the enzyme’s catalytic efficiency.Molecular docking studies are conducted to elucidate the interaction between anthraquinone derivatives and CYP1B1,indicating that these compounds may inhibit CYP1B1 activity by binding to their active sites.The demonstrated capacity of chrysophanol and physcion to inhibit CYP1B1 enzymatic function unveils a potential anticancer mechanism,advancing our comprehension of how the structure of anthraquinone derivatives correlates with CYP1B1 inhibition and paving the way for developing innovative cancer treatments.

中国番茄黄化曲叶病毒利用根吸收法诱导基因沉默(VIGS)的初步研究

以含硫黄素酶Su基因的中国番茄黄化曲叶病毒卫星DNA作为载体,通过冻融法将其转化到农杆菌中,利用根部吸收法进行农杆菌侵染,对农杆菌介导的病毒诱导基因沉默体系进行了优化,探讨对病毒诱导基因沉默效率的影响。结果显示以OD600值为1.5的含质粒pBinPLUS-2mβ-Su,pBinPLUS-1.7A的农杆菌菌液1∶1混合进行根部吸收法侵染22-25 d的番茄幼苗,目的基因Su沉默导致番茄幼苗出现光漂白现象,半定量RT-PCR检测目的基因Su mRNA被显著降解,该体系的建立有利于对植物基因进行高通量功能分析。

Xanthophyll Cycle and Its Molecular Mechanism in Photoprotection

When plants absorb more light than that can be used for photosynthesis, the excessive energy can cause photoinhibition and even photooxidation of photosynthetic apparatus. Xanthophyll cycle-dependent photo-protection is believed to be the main mechanism for plants to deal with excessive light energy. This review focuses on molecular biological aspects and regulations of violaxanthin de-epoxidase and zeaxanthin epoxidase involved in xanthophyll cycle. We will summarize the functions of xanthophyll cycle, especially recent advances in its thermal dissipation mechanism of photoprotection. Some interesting issues deserving further study will be discussed.

Application of Cellulase-assisted Method to Extract Flavonoids from Plants

The extraction mechanisms of cellulase-assisted extraction technology in extracting flavonoids were summarized, as wel as its application in extracting flavonoids from the plants of Leguminosae, Ginkgoaceae, Rutaceae and Labiatae. In addition, the progress in the extraction of flavonoids by combining cellulase-assisted extraction technology and other technologies, such as cellulase-ultrasonic assisted extraction and cellulase-microwave assisted extraction, were described.

Cloning and Expression Analysis of Violaxanthin De-Epoxidase (VDE) cDNA in Wheat

Violaxanthin de-epoxidase (VDE) is the key enzyme in the xanthophyll cycle and protects plant photosynthetic apparatus from the damage of excessive light. A wheat (Triticum aestivum L cv. Xiaoyan 54) VDE cDNA was obtained using RT-PCR method. Its deduced protein sequence shares high identity with that of Arabidopsis and rice. Southern blot revealed that there are three copies of VDE gene per haploid genome of wheat. VDE transcript levels were higher in green leaf than in root, seed and etiolated leaf. Northern blotting analysis indicated that VDE mRNA level is induced during greening process of etiolated wheat seedling and increased by intense light illumination.

维生素B2到底有什么样的作用

维生素B2，因其是体内多种黄素辅酶的重要组成成分，所以又被称为核黄素。黄素酶在生物体内的氧化还原反应中起传递氢的作用，当其缺乏时就会影响机体的生物氧化过程，使人体代谢发生障碍。

Changes in Violaxanthin Deepoxidase Activity and Unsaturation of Thylakoid Membrane Lipids in Indica and Japonica Rice Under Chilling Condition and Strong Light

To explore the differences of sensitivities to chilling and strong light in indica and japonica rice (Oryza sativa L), the changes in unsaturation of thylakoid membrane lipids and xanthophyll cycle were studied under chilling condition and strong light. The contents of unsaturated fatty acids of thylakoid membrane lipids decreased and that of the saturated ones increased with the time of chilling and strong light treatment, resulting in the reduction of the index of unsaturation of fatty acids (IUFA). The activity of violaxanthin deepoxidase (VDE), a key enzyme of xanthophyll cycle, also reduced. The content of violaxanthin (V) increased, and the contents of antheraxanthin (A) and zeaxanthin M decreased, the ratio of (A+Z)/ (A+Z+V) decreased correspondingly. Arrhenius analysis showed that VDE was sensitive to both chilling and unsaturation level of thylakoid membrane lipids. Correlation analysis showed that there was distinctly positive relationships between IUFA of thylakoid membrane lipids and the activity of VDE, Fv/Fm, and D, protein content. Lower IUFA values, less fluidity and stability of thylakoid membrane lipids, lower VDE activity and (A+Z)/(A+Z+V) ratio were found in indica rice cv. Shanyou 63 than in japonica rice cv. 9516 under chilling and strong light.

洗维散的制备及对口腔溃疡的应用

口腔溃疡是口腔粘膜病的一种症状,也是全身疾病在口腔粘膜上的反应。患者自觉灼痛,影响进食、说话、睡眠,且不易愈合,常伴口臭,便秘等症状,给病人带来了很大痛苦,临床上除了积极治疗全身疾病外,主要进行局部治疗。以往多在溃疡面上涂三氯醋酸、硝酸银、冰硼散等,方法较多,但效果常不理想,自1990年以来,我院自制了洗维散,对80例门诊患者进行了治疗,效果显著。

Increase of β -1, 3-Glucanase and Chitinase Activities in Cotton Callus Cells Treated by Salicylic Acid and Toxin of Verticillium dahliae

The different resistance of cotton (Gossypium hirsutum L.) cultivars to crude toxin of Verticillium dah/iae(VD) was correlated with the activities of chitinase and β-1, 3-glucanase in callus cells. The activities of chitinase and β-1, 3-glucanase in the callus cells treated with the VD-toxin were increased to the higher level at earlier time point in resistant cultivars than these in the susceptible cultivars. Exogenous salicylic acid (SA) induced the accumulation of chitinase and β -1,3-glucanase, which resulted in the resistance of callus cells to the VD. toxin. Western blot using a polyclonal antibody against β -1,3-glucanase identified 28 kD protein that was induced by VD-toxin, SA, or VD-toxin plus SA.

Cellulase Extraction and Gas Chromatography Detection Technology of Swainsonine from Astragalus strictusin in Tibet

Locoweed is a poisonous plant wildly distributed in most areas of the world,which causes livestock poisoning or death with serious economic loss.The Astragalus strictus belongs to a species of Iocoweed.It is mainly distributed in Tibet of China and is a serious hazard to the local livestock industry.The objective of this study is extracting and purifying condition of Swainsonine from Astragalus strictus with the cellulase extraction method.An optimum extracting technology of SW from Astragalus strictus was investigated through the orthogonal experiment under the cellulose assistance conditions,and then the content of swainsonine was analyzed with gas chromatography （GC） method.The optimized extraction conditions were as follow：The crushed mesh is 40; solid-liquid ratio is 1∶40 （g/ml）; enzyme dosage is 3.5％; enzymatic time is 3 h.Under the above conditions,the extraction percentage of the swainsonine was 0.003 941％.The conditions for extracting swainsonine with cellulase extraction method are mild,it is easy to utilize industrial production.It is benefit for producing swainsonine from Astragalus strictus.

Lipoxygenase Activity and Its Relationship with Traits of Whole-mill Color in Wheat

130 wheat varieties are selected as materials to test the LOX activity, whiteness, yellowness, carotenoids content and RVA parameters, which are to be analyzed by variance analysis, correlation analysis, cluster analysis and classified according to the origins. The result shows there are highly significant variations in LOX activity from varieties; LOX activity is positively correlated with whiteness, and significantly and negatively correlated with yellowness. Cluster analysis applying longest distance method based on LOX activity clusters all the varieties or lines into three major groups. There are great differences between the averages of LOX activity from varieties. LOX activities are discussed in the application of nutritional quality improvement in wheat.

Effect of dietary genistein on growth performance,digestive enzyme activity,and body composition of Nile tilapia Oreochromis niloticus

An 8-week feeding experiment was performed to evaluate the effect of dietary genistein on growth performance,body composition,and digestive enzymes activity of juvenile Nile tilapia(Oreochromis niloticus).Four isonitrogenous and isoenergetic diets were formulated containing four graded supplements of genistein:0,30,300,and 3 000 μg/g.Each diet was randomly assigned in triplicate to tanks stocked with 15 juvenile tilapia(10.47±1.24 g).The results show that 30 and 300 μg/gdietary genistein had no significant effect on growth performance of Nile tilapia,but the higher level of genistein(3 000 μg/g)significantly depressed the final body weight and specific growth rate.There was no significant difference in survival rate,feed intake,feed efficiency ratio or whole body composition among all dietary treatments.An assay of digestive enzymes showed that the diet containing 3 000 μg/ggenistein decreased stomach and hepatopancreas protease activity,and amylase activity in the liver and intestine,while a dietary level of300 μg/g genistein depressed stomach protease and intestine amylase activities.However,no significant difference in stomach amylase activity was found among dietary treatments.Overall,the results of the present study indicate that a high level of dietary genistein(3 000 μg/g,or above) would significantly reduce the growth of Nile tilapia,partly because of its inhibitory effect on the activity of major digestive enzymes.Accordingly,the detrimental effects of genistein,as found in soybean products,should not be ignored when applied as an alternative ingredient source in aquaculture.

Occurrence and Diversity of Candida Genus in Marine Environments

A total of 317 yeast isolates from seawater, sediments, mud of salterns, guts of marine fishes and marine algae were obtained. The results of routine identification and molecular characterization showed that six isolates among these marine yeasts belonged to Candida genus as Candida intermedia for YA01a, Candida parapsilosis for 3eA2, Candida quercitrusa for JHSb, Can- dia rugosa for wlS, Candida zevlanoides for TJY 13a, and Candida membranifaciens for W 14-3. Isolates YA01 a （Candida intermedia）, wl8 （Candida rugosa）, 3eA2 （Candida parapsilosis）, and JHSb （Candida quercitrusa） were found producing cell-bound lipase, while isolate Wl4-3 （Candida membran（faciens） producing riboflavin. These marine yeast Candida spp. seem to have wide potential applications in bioteehnology.

Mycotoxins Incidence in Romanian Malting Barley （Harvest 2009）

The presence of deoxynivalenol （DON）, total aflatoxins, ochratoxin （OTA） and zearalenone （ZEA） was investigated in malting barley samples harvested in Romania using an ELISA method （VERATOX, Neogen）. In 7 out of 14 barley samples the aflatoxins were not found at detectable levels （50%）. In 9 out of 14 barley samples the OTA was not found at detectable levels （64.29%）. In 1 out of 14 barley samples the DON was not found at detectable levels （7.14%）. In 13 out of 14 barley samples （92.86%） the ZEA was above the acceptable limit （100μg/kg）. For all barley samples the aflatoxins, DON and OTA were in line with European Union regulations in force （4.0 μg/kg for aflatoxins, 1,250.0μg/kg for DON, 5.0 μg/kg for OTA, respectively）.

Xanthophyll Cycle and Its Relative Enzymes

Light is a fundamental source of energy but is also potentially harmful to organisms. Plants have evolved a variety of regulatory mechanisms to respond to the naturally varying light conditions. Xanthophyll cycle is now recognized as a key regulator and photoprotective mechanism found ubiquitously in plants. Xanthophyll cycle has multiple functions, such as thermal dissipation, protection against oxidative stress caused by light, modulation of the structure of thylakoid membrane, involving in blue light signal transduction and regulating the synthesis ofABA （Abscisic acid）. VDE （Violaxanth de-epoxidase） and ZE （zeaxanth epoxidase）, are involved in xanthophyll cycle. This paper outlined the functions of xanthophylls cycle and its relative enzymes.

Wastewater Treatment for Removal of Recalcitrant Compounds：A Hybrid Process for Decolorization and Biodegradation of Dyes

While conventional wastewater treatments for urban effluents are fairly routine and have proved highly effective,industrial wastewater requires more complex and specific treatments.This paper provides a technological strategy for removal of recalcitrant contaminants based on a hybrid treatment system.The model effluent containing a binary mixture of synthetic dyes is treated by a combination of a preliminary physicochemical stage followed by a biological stage based on ligninolytic enzymes produced by Phanerochaete chrysosporium.This proposal includes biosorption onto peat as pretreatment,which decreases the volume and concentration to be treated in the biological reactor,thereby obtaining a completely decolorized effluent.The treated wastewater can therefore be reused in the dyeing baths with the consequent saving of water resources.

Ammonium Thiosulfate Ecological Viable Alternative to Replace Sodium Cyanide in Gold and Silver Dissolution Ores

The southern region of the state of Chihuahua is mining by origin, as this has been proved ghost towns of Minas Nuevas, it is also called Villa Escobedo, Emerald and Blue. Minerals are nonrenewable resources. There are only reserves and waste deposited in tailings ponds of low-rade precious metals （gold and silver）. A conventional method for recovering gold and silver ore is low-grade cyanidation and the solvent consider toxic and highly dangerous for the flora, fauna, humans and the environment. The mechanism of cyanide poisoning is inhibition of cytochrome oxidase--an enzyme needed for cell respiration. Without compromising efficiency, sensitivity and cost of the process, the toxic solvent is replaced by a less aggressive one, which helps the environment, public and occupational health. （NH4）2S203 has no appreciable damage to conservative amounts, is a selective aqueous solvent for leaching gold and silver, easy to get and manipulate. This work is done in the Technological Institute of Parral in a low-grade ore from the southern region of the state of Chihuahua. This document has been enriched presented in the IMEC 2014, with the increase of series Ⅴ and Ⅵ.

Emodin promoted pancreatic claudin-5 and occludin expression in experimental acute pancreatitis rats

AIM:To investigate the effect of emodin on pancreatic claudin-5 and occludin expression,and pancreatic paracellular permeability in acute pancreatitis(AP).METHODS:Experimental pancreatitis was induced by retrograde injection of 5% sodium taurocholate into the biliopancreatic duct.Emodin was injected via the external jugular vein 0 or 6 h after induction of AP.Rats from sham operation and AP groups were injected with normal saline at the same time.Samples of pancreas were obtained 6 or 12 h after drug administration.Pancreatic morphology was examined with hematoxylin and eosin staining.Pancreatic edema was estimated by measuring tissue water content.Tumor necrosis factor(TNF)-α and interleukin(IL)-6 level were measured by enzyme-linked immunosorbent assay.Pancreatic paracellular permeability was assessed by tissue dye extravasation.Expression of pancreatic claudin-5 and occludin was examined by immunohistology,quantitative real-time reverse transcriptase polymerase chain reaction and western blotting.RESULTS:Pancreatic TNF-α and IL-6 levels,wet/dry ratio,dye extravasation,and histological score were significantly elevated at 3,6 and 12 h following sodium taurocholate infusion;treatment with emodin prevented these changes at all time points.Immunostaining of claudin-5 and occludin was detected in rat pancreas,which was distributed in pancreatic acinar cells,ductal cells and vascular endothelial cells,respectively.Sodium taurocholate infusion significantly decreased pancreatic claudin-5 and occludin mRNA and protein levels at 3,6 and 12 h,and that could be promoted by intravenous administration of emodin at all time points.CONCLUSION:These results demonstrate that emodin could promote pancreatic claudin-5 and occludin expression,and reduce pancreatic paracellular permeability.

Curcumin induces apoptosis through the mitochondria-mediated apoptotic pathway in HT-29 cells

Objective： To investigate the effects of curcumin on release of cytochrome c and expressions of Bcl-2, Bax, Bad, Bcl-xL, caspase-3, poly ADP-ribose polymerase （PARP）, and survivin of HT-29 cells. Methods： HT-29 cells were treated with curcumin （0-80 μmol/L） for 24 h. The release of cytochrome c from the mitochondria and the apoptosis-related proteins Bax, Bcl-2, Bcl-xL, Bad, caspase-3, PARP, and survivin were determined by Western blot analysis and their mRNA expressions by reverse transcriptase-polymerase chain reaction （RT-PCR）. Results： Curcumin significantly induced the growth inhibition and apoptosis of HT-29 cells. A decrease in expressions of Bcl-2, Bcl-xL and survivin was observed after exposure to 10-80 μmol/L curcumin, while the levels of Bax and Bad increased in the curcumin-treated cells. Curcumin also induced the release of cyto- chrome c, the activation ofcaspase-3, and the cleavage of PARP in a dose-dependent manner. Conclusion： These data suggest that curcumin induced the HT-29 cell apoptosis possibly via the mitoehondria-mediated pathway.