奶油栓孔菌菌丝体多糖的提取工艺优化、结构表征及抗氧化活性

奶油栓孔菌Trametes lactinea是一种生物活性丰富的大型真菌。本研究在单因素试验的基础上,通过响应面法优化其菌丝体多糖的提取工艺,利用DEAE-Cellulose-52阴离子交换柱和Sephadex G-200层析柱对粗多糖进行分离纯化,获得TLMPS-0、TLMPS-1和TLMPS-3均一多糖组分。采用化学组成分析、UV-vis、FTIR、刚果红实验对3种多糖组分进行结构分析,并检测了多糖清除自由基的能力和还原力。结果表明,奶油栓孔菌菌丝体多糖最优提取工艺为：提取温度99℃、料液比1:30 (g/mL)、提取时间5h,提取次数2次。在此工艺条件下,多糖提取率为4.01%。TLMPS-0、TLMPS-1和TLMPS-3的糖醛酸含量分别为12.91%±0.44%、8.24%±0.22%、7.50%±0.66%,硫酸基含量分别为22.24%±1.88%、14.55%±0.56%、18.68%±0.69%,并且证明TLMPS-0是一种α-吡喃型多糖或β-吡喃型多糖,而TLMPS-1是一种β-吡喃型多糖,均不具备三螺旋空间构象,此外,3种多糖组分均具有一定的清除DPPH自由基、ABTS自由基、羟基自由基的能力和铁离子还原能力,其中TLMPS-0抗氧化活性最强。研究结果为奶油栓孔菌多糖的功能研究与挖掘提供了研究基础与理论依据。     

枸杞色素及多糖的不同提取次序对其得率及抗氧化活性的影响

为探究先后提取枸杞多糖及枸杞色素时对各自得率的影响。本研究通过分别考察这两种成分在提取过程中的提取溶剂、提取温度、料液比、提取次数及提取时间等因素对枸杞色素和枸杞多糖的得率影响,确定枸杞色素和枸杞多糖在提取次序不同时,两者的最佳提取工艺以及对DPPH·和·OH自由基清除率。结果表明,首先提取枸杞多糖后,枸杞色素的最佳提取工艺为采用正己烷,80℃时,料液比1∶10,提取2次,每次1 h,枸杞色素得率为2.48%,此时枸杞多糖得率为7.45%;而首先提取枸杞色素后,采用了超声辅助提取的方式提取枸杞多糖,发现超声效率为25%,料液比1∶10,提取20 min,枸杞多糖得率为5.23%,此时枸杞色素得率为3.93%。因此,首先提取枸杞多糖,使其平均得率为7.45%,而后提取枸杞色素,其平均得率为2.48%;总体上,枸杞色素1和枸杞多糖1对DPPH·自由基清除率都较高,枸杞多糖1对·OH自由基清除率较高,其抗氧化活性都接近Vc。     

Abacavir prodrugs: microwave-assisted synthesis and their evaluation of anti-HIV activities

The synthesis of a new series of abacavir prodrugs involving N2-substitution with various substituted benzaldehyde and ketone derivatives is described. The in vitro anti-HIV activities indicated that compound (3-(2-(4-methylaminobenzylideneamino)-6-(cyclopropylamino)-9H-purin-9-yl)cyclopentyl)methanol (3) was found to be most potent compound with EC50 of 0.05 microM and CC50 of >100 microM with selectivity index of >2000. Compound 3 was found to be 32 times more potent than the parent drug (EC50 of 1.6 microM). At pH 7.4, 37 degrees C, the hydrolytic t1/2 ranged between 120 and 240 min.     

Cardioprotective properties of Artemisia herba alba nanoparticles against heart attack in rats: A study of the antioxidant and hypolipidemic activities

Recently, pharmaceutical scientists' interest has increased to find novel pharmaceutical natural substances with potent antioxidant capacity and very low side effects to be used safely in preventive medicine. One of the most common types of diseases with a large spread globally is cardiovascular diseases, which cause a high rate of deaths annually. The present study evaluated the use of Artemisia herba alba leaves’ extract (AHALE) and AHALE zinc oxide nanoparticles (AHALE–ZnONPs) against isoproterenol (ISO) inducing myocardial infarction (MI) in male rats. Several groups of Wistar male rats fed a high-fat diet (HFD) were pretreated with several doses of AHALE or AHALE–ZnONPs for one month followed by exposure to ISO for two days. After treatment, samples of the rats’ heart tissues and blood were collected for several molecular biological and biochemical analyses. Heart enzymes, antioxidant enzymes, lipid peroxidation compounds, lipid markers, activities, ROS generation, apoptosis, DNA damage and expression of lipid metabolism genes were analyzed in rats pretreated with AHALE or AHALE–ZnONPs followed by exposure to ISO. The results showed an increase in the levels of AST, ALT, LDH, CK, CK-MB, and cTnT (heart markers), elevation in TG, TC, and LDL levels (lipid profile markers), levels of TBARS and LOOH (lipid peroxidation products), ROS generation, DNA damage, apoptosis, and upregulation of PPAR-α, ADD1, FASN, and ACC genes in animals exposed to ISO in comparison with the control animals. Moreover, a decrease in antioxidant enzyme activities, including GPx, GRx, and GST, was observed in animals exposed to ISO in comparison with control rats. In male rats pretreated with AHALE or AHALE–ZnONPs followed by exposure to ISO, the oxidative stress induced by ISO was prevented. The results suggest that Artemisia extract could be considered for use as one of the natural compounds for prevention of atherosclerosis and heart diseases due to its high antioxidant and hypolipidemic activities. The reduced oxidative stress of Artemisia extract may be a result of the existence of flavonoids and phenolic substances.     

Effects of Glycyrrhiza glabra polysaccharides on immune and antioxidant activities in high-fat mice

The purpose of this study was to investigate the immune and antioxidant activities of Glycyrrhiza glabra polysaccharides (GGP) in rats fed high-fat diet. The experiment was performed on four groups of growing Kunming mice. The results of the experiment showed a statistically significant decrease in serum antioxidant enzyme activities in high-fat group. Administration of GGP dose-dependently significantly enhanced immune and antioxidant enzyme activities in the GGP-treated mice compared to the high-fat model mice. It is concluded that GGP treatment can enhance immune activities, and reduce oxidative stress in high-fat mice.     

Effect of Aloe vera polysaccharides on immunity and antioxidant activities in oral ulcer animal models

Aloe vera polysaccharides have traditionally been used in Asian cultures as medicinal plants to enhance immunity and reduce oxidative injury. The current investigation was conducted to examine the effects of A. vera polysaccharides on various in vivo parameters of innate immunity and antioxidant enzymes activities in oral ulcer animals. Forty wistar rats were randomly divided into the following 1 control group and 3 experimental groups (each group contained 10 rats). Rats in experimental groups were orally fed by A. vera polysaccharides. Rats in control group were orally fed by same volume of saline. The results showed that A. vera polysaccharides enhanced immunity activity and exerted antioxidant effects compared with vehicle controls. These results demonstrate, for the first time, that A. vera polysaccharides are effective in enhancing innate immunity and suppressing oxidative injury in oral ulcer animals.     

A study on the antioxidant activities of some new benzazole derivatives

The in vitro antioxidant properties of some new benzazole derivatives (1-10) such as benzoxazoles, benzimidazoles, and benzothiazoles were determined by their effects on the rat liver microsomal NADPH-dependent lipid peroxidation (LP) level, the scavenging of superoxide anion and the stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). Compounds 1, 2, 4 and 6, showed potent scavenging effect on superoxide radical at 10(-3) M. Compound 8, 5-nitro-2-(phenoxymethyl)benzimidazole, strongly inhibited lipid peroxidation at 10(-3) M concentration.     

四种多孔菌子实体粗多糖抗肿瘤活性的比较研究

对粗毛纤孔菌、椭圆嗜蓝孢孔菌、火木层孔菌、木蹄层孔菌4种多孔菌子实体粗多糖成分的含量及其体内抗肿瘤活性进行了比较研究。结果表明粗毛纤孔菌子实体中的粗多糖含量为4.1%,高于其他3种多孔菌;同时,4种多孔菌子实体粗多糖对H22荷瘤小鼠均显示出一定的抗肿瘤活性,除木蹄层孔菌外,其他3种多孔菌给药剂量为500mg/mL和1 000mg/mL时抑瘤率均大于40%,其中粗毛纤孔菌子实体粗多糖抑瘤率最高,低剂量组（500mg/kg）为58.12%,高剂量组（1 000mg/kg）为47.75%。     

Basil polysaccharides: A review on extraction,bioactivities and pharmacological applications

Traditional Chinese Medicine has been widely used in China and is regarded as the most commonly used treatment. As a natural plant used in traditional Chinese Medicine, Basil has various functions associated with a number of its components. There are many compositions in basil including polysaccharides, naphtha, steroids, flavone, coumarins, vitamins, and so on. Among these, polysaccharides play a significant role in based therapeutics. The article summarizes that basil polysaccharides have a lot of biological activities and pharmacological applications, such as their antitumor activity, antioxidant activity, anti-aging activity, immunity enhancement effect, hypolipidemic and anti-atherosclerotic effects, antibacterial effect, treatment of diabetes mellitus, and so on. This review summarized the extraction method, purification method, compositions, pharmacological applications, molecular weight, biological activities, and prospects of basil polysaccharides, providing a basis for further study of basil and basil polysaccharides.     

杨梅树皮黄酮的提取及体外抗氧化研究

采用乙醇热回流提取法对杨梅树皮中总黄酮进行提取,通过正交试验确定了杨梅树皮总黄酮乙醇热回流提取法的最佳工艺条件:以28目的杨梅树皮粉为原料,料液比为1∶60,用60%的乙醇溶液在60℃的水浴中提取2.5h,提取率达6.86%。利用清除DPPH自由基的能力和还原力作为指标测定了杨梅树皮总黄酮的抗氧化活性。结果表明,杨梅树皮黄酮有较强的抗氧化能力。     

Effect of steaming process on the structural characteristics and antioxidant activities of polysaccharides from Polygonatum sibiricum rhizomes

Polygonatum sibiricum (P. sibiricum) rhizomes are widely used as a tonic and functional food, and are often processed to enhance their tonic function by repeated steaming and drying. As the most important constituent, the polysaccharide from P. sibiricum rhizomes (PSP) has demonstrated various activities, but the alteration of structural characteristics and activities of the purified PSPs during steaming process was rarely investigated. To well understand the effect of steaming process on the polysaccharides of P. sibiricum, neutral polysaccharides from P. sibiricum rhizomes (PSP0?~?PSP9) after steaming were first isolated and purified, and then the chemical properties and antioxidant activities were determined. The results showed that the molar ratios of monosaccharides in PSPs were different. The molecular weights of PSPs were increased significantly after the fourth steaming. Morphological studies showed that the surface of PSPs became much tighter during the steaming process. Fourier transform infrared spectroscopy spectra displayed the polysaccharides had similar backbones and chemical groups. Furthermore, the antioxidant activity of PSPs was measured through radical scavenging tests. It was found that the radical scavenging activity of PSPs was elevated strikingly after steaming, and increased gradually with numbers of steaming process. The biological and chemical variance of PSPs revealed considerable segregation of PSP0, PSP1?~?PSP4 and PSP5?~?PSP9. In conclusion, our results proposed the fourth time as the optimal number of steaming to extract functional polysaccharide from P. sibiricum rhizomes.

     

MaxBench: evaluation of sequence and structure comparison methods

SUMMARY: MaxBench is a web-based system available for evaluating the results of sequence and structure comparison methods, based on the SCOP protein domain classification. The system makes it easy for developers to both compare the overall performance of their methods to standard algorithms and investigate the results of individual comparisons. AVAILABILITY: http://www.sanger.ac.uk/Users/lp1/MaxBench/     

Effects of extraction methods on physicochemical properties and hypoglycemic activities of polysaccharides from coarse green tea

Glycoconjugate Journal - Coarse tea is made of mature tea plant (Camellia sinensis L.) shoots and is generally discarded as a worthless crop product, but has been proved an excellent material for...     

Vitrification of mouse islets of Langerhans: comparison with a more conventional freezing method

The possibility of cryopreservation of islets of Langerhans by vitrification using a mixture of cryoprotectants was investigated and the results were compared with a more conventional freezing method using Me2SO as cryoprotectant. Isolated mouse islets were divided into three groups: (1) control islets cultured for 6 days, (2) islets which were cryopreserved by vitrification after 2 days of culture, and (3) islets frozen in 1.5 M Me2SO after 2 days of culture. After warming, islets from groups 2 and 3 were cultured for 4 days. The thus treated islets were investigated with respect to insulin secretion in the presence of 2.5 or 25 mM glucose, survival during postwarming culture, morphology, and capability to reverse streptozotocin-induced diabetes. The insulin secretion in islets from all groups could be stimulated by a factor 5 or more by an increase in the concentration of glucose from 2.5 to 25 mM. The secretion of insulin in the presence of 2.5 mM glucose was similar in all groups of islets. The secretion of insulin in the presence of 25 mM glucose was slightly but not significantly lower in the cryopreserved islets than in the control noncryopreserved islets. The survival of islets during postwarming culture was comparable after cryopreservation with both methods, and islets from both groups could lower serum glucose in streptozotocin diabetic mice. We conclude that islets cryopreserved by the vitrification method are functional in vitro and in vivo. This method is quick, simple, and cheap because the use of complicated freezing equipment is avoided.     

Phenolic composition and antioxidant activities of two Phlomis species: A correlation study

Two traditional Chinese medicines (Phlomis umbrosa Turcz. and Phlomis megalantha Diels), as well as five pure phenolic compounds (protocatechic, chlorogenic, benzoic, rosmarinic acid, and rutin) have been studied for antioxidant activities in acetone and methanol extracts from leaves. An HPLC method was developed to quantify the amounts of 14 phenolic compounds in the leaf extracts. The antioxidant capacities of the studied species are high. Almost all samples were capable of directly scavenging DPPH and superoxide free radicals, inhibiting linoleic acid oxidation, acting as reducing agents, and reducing plasmid DNA damage induced by hydroxyl radicals. Among different extracts, the acetone extract of P. megalantha exhibited the highest antioxidant activity. The major phenolic compounds identified were protocatechic, chlorogenic, caffeic, rosmarinic acid, and (−)-epicatechin. Antioxidant activities of pure compounds and correlation analysis indicated that protocatechic and rosmarinic acids were the major contributors to the observed antioxidant activities of the investigated Phlomis extracts. To cite this article: Y. Zhang, Z.-z. Wang, C. R. Biologies 332 (2009).     

Bioactivities of water-soluble polysaccharides from fruit shell of Camellia oleifera Abel: Antitumor and antioxidant activities

Polysaccharides were extracted from fruit shell of Camellia oleifera Abel. Fruit shell of Camellia oleifera Abel polysaccharide (WEP2) was a water-soluble compound. Its molecular weight was about 362 kDa. HPLC analysis showed that this polysaccharide was composed of rhamnose, fucose, arabinose, mannose, galactose and glucose in the molecular ratio of 4.05, 11.62, 1.78, 3.91, 8.76 and 27.06, respectively. The broad intense characteristic peak around 3463 cm⁻¹ due to the hydroxyl stretching vibration of the polysaccharide was observed in the polysaccharide. The characteristic absorption bands at 852 cm⁻¹ and 893 cm⁻¹ indicated that WEP2 contained both α-glycosidic and β-glycosidic linkages. WEP2 exhibited remarkable antitumor activity against Sarcoma180 cell compared to the negative control group. At the highest dose 40 mg/kg days, the tumor inhibition rate reached 65.2%. The scavenging effects of WEP2 to hydroxyl radical and superoxide radical anion were 72.5% and 86.3% at a concentration of 1.0 mg/ml, respectively.     

Computer-assisted primary screening of cervical smears using the PAPNET method: comparison with conventional screening and evaluation of the role of the cytologist

The PAPNET method is an interactive computer-assisted screening procedure. the diagnostician selects the abnormal video tiles out of the 128 and decides which smears need additional light microscopy. the original diagnoses of 1494 archival smears were compared with the PAPNET analysis of the same smears. the general trend observed was that the PAPNET-assisted diagnoses were of a higher grade than those assigned by the primary screener, thus less cases were signed out as negative. In addition, the PAPNET method was used for primary screening of 2971 randomly selected smears, whilst in the same period 5797 smears were conventionally screened. Using the PAPNET method, significantly fewer smears were signed out as negative. Seventy-three percent of the cases were diagnosed on the basis of the information provided by the 128 video tiles, 11% had to be screened completely by the light microscope, and the remaining cases needed additional light microscopy of a part of the smear. As a result, PAPNET-assisted screening was approximately two times faster. the great advantage of the method is that it is much less tiring for the eyes than conventional screening, making fatigue-related errors less likely, and if a smear contains only a few abnormal cells, these are easier to find.     

A combination of ultrasonic-assisted extraction with RRLC-QQQ method for the determination of artemisinin in the Chinese herb Artemisia annua L

Introduction – Artemisinin, the primary active ingredient of the Chinese herb Artemisia annua L., is known to have considerable anti‐malaria properties. However, rapid, sensitive and selective method for the determination of artemisinin in it is not currently available. Objective – To develop and validate an efficient method for extraction and analysis of artemisinin from the plant samples of Artemisia annua L. by rapid resolution liquid chromatography triple quadrupole mass spectrometry (RRLC‐QQQ). Methodology – Following ultrasound‐assisted extraction (USE), RRLC‐QQQ was utilised to separate and determine artemisinin from the plant sample of Artemisia annua L. The LC separation, QQQ‐MS detection and multiple reaction monitoring (MRM) mode were optimised, and the method validation concluding selectivity, calibration, accuracy and precision, and recovery were also evaluated. Results – LC separation was performed with an isocratic elution of 20% of methanol–water (10 mmol/L ammonium acetate, pH 4.0) on a C₁₈ column. The triple quadrupole MS detection was carried out under MRM mode of precursor ion [M + H]⁺ → fragment ions m/z 265.1 and m/z 247.2. The limits of detection and quantitation of artemisinin were 0.20 and 0.75 ng/mL, respectively. The intra‐ and inter‐day precisions did not exceed 3.71%, and the deviation of the intra‐ and inter‐day mean values did not exceed ±7.50. The average recoveries for artemisinin ranged from 92.45 to 103.8% with an RSD from 2.47 to 2.79%. Conclusion – The developed RRLC‐QQQ assay is an efficient method for separation and determination of artemisinin from the plant samples of Artemisia annua L. Copyright © 2011 John Wiley & Sons, Ltd.     

A comparison of antioxidant properties of hypoxen and duroquinone by the method of chemiluminescence

The antioxidant activity of duroquinone and hypoxen was compared with that of alpha-tocopherol and vitamin C in a model system (luminol-peroxidase-H2O2), and their influence on the level of reactive oxygen species in systems containing polymorphonuclear leukocytes of healthy and tumor-bearing animals was studied. It was shown that, in a model chemical system, the concentrations of antioxidants (the inverse of antioxidant activity) necessary to decrease twice the intensity of the chemiluminescence answer (C50%) are arranged in the following order: alpha-tocopherol > duroquinone > hypoxen > ascorbic acid. In this case, the concentrations of the hydrophobic antioxidants (C50% for alpha-tocopherol and duroquinone 10-30 mkM) should be 20-50 times higher than for hydrophilic antioxidants (C50% for vitamin C and hypoxen 0.5-0.6 mkM). It was revealed that the generation of reactive oxygen species by blood phagocytes of tumor-bearing animals is 2-2.5 times higher than by phagocytes of healthy animals. The antioxidant concentration necessary to decrease the chemiluminescence answer in the cellular system should be one order of magnitude higher than in the model chemical system. The distribution of a hydrophobic antioxidant between water/lipid phases promotes an increase in the concentration of the antioxidant necessary to decrease the level of reactive oxygen species twice. Thus, the major factor influencing the antioxidant activity is the constant of distribution of these compounds in a water/lipid system.