Engineering Chitosan Using <i>α</i>, <i>ω</i>-Dicarboxylic Acids—An Approach to Improve the Mechanical Strength and Thermal Stability

The current scenario in tissue engineering research demands materials of requisite properties, viz., high porosity, mechanical stability, thermal stability, biocompatibility and biodegradability for clinical applications. However, bringing these properties in single biomaterial is a challenging task, which needs intensive research on suitable cross-linking agents. In the present study, 3D scaffold was prepared with above said properties using chitosan and oxalic (O), malonic (M), succinic (S), glutaric (G), adipic (A), pimelic (P), suberic (SU), azelaic (AZ) and sebacic (SE) acid (OMS- GAP-SAS) individually as a non covalent cross-linkers as well as the solvent for chitosan. Assessment on degree of cross-linking, mechanical strength, FT-IR analysis, morphological observation, thermal stability, binding interactions (molecular docking), in vitro biocompatibility and its efficacy as a wound dressing material were performed. Results revealed the degree of cross-linking for OMSGAP-SAS engineered chitosan were in the range between ≈55% - 65% and the biomaterial demonstrated thermal stability more than 300°C and also exhibited ≥3 - 4 fold increase in mechanical strength compared to chitosan alone. The bioinformatics studies evidently proved the chemistry behind the interaction of OMSGAP-SAS with chitosan. OMSGAP-SAS played dual role to develop the chitosan biomaterial with above said properties, thus matching the requirements needed for various applications.

Effect of different drying methods on the amino acids,α-dicarbonyls and volatile compounds of rape bee pollen

The significant demand for high quality food has motivated us to adopt appropriate processing methods to improve the food nutritional quality and flavors.In this study,the effects of five drying methods,namely,pulsed vacuum drying(PVD),freeze drying(FD),infrared drying(IRD),hot-air drying(HAD)and sun drying(SD)on free amino acids(FAAs),α-dicarbonyl compounds(α-DCs)and volatile compounds(VOCs)in rape bee pollen(RBP)were determined.The results showed that FD significantly released the essential amino acids(EAAs)compared with fresh samples while SD caused the highest loss.Glucosone was the dominantα-DCs in RBP and the highest loss was observed after PVD.Aldehydes were the dominant volatiles of RBP and SD samples contained more new volatile substances(especially aldehydes)than the other four drying methods.Comprehensively,FD and PVD would be potential methods to effectively reduce the quality deterioration of RBP in the drying process.

Eicosapentaenoic acid代谢产物促进胰岛α细胞转分化为胰岛β细胞的作用研究

目的 探讨eicosapentaenoic acid(EPA)代谢产物促进胰岛α细胞向β细胞转分化的作用。方法 雄性C57BL/6J小鼠连续5 d腹腔注射60 mg/kg链脲佐霉素(streptozocin, STZ)构建1型糖尿病(T1DM)小鼠模型,2周后随机分为模型组、97%EPA饮食干预组、75%鱼油(50%EPA+25%DHA)饮食干预组,每周检测随机血糖;模型到期后,通过免疫荧光染色观察小鼠胰腺中胰岛β细胞再生情况。提取tdTomato荧光蛋白特意标记α细胞的小鼠(GCGicre小鼠与Rosa26tdTomato小鼠杂交获得)胰岛,加入1 mmol·L^(-1)STZ诱导β细胞凋亡,添加EPA代谢产物,培养48 h后,利用荧光染色观察胰岛素和tdTomato荧光的表达。在小鼠胰岛α细胞系αTC1培养基中添加EPA代谢产物,48 h后,利用荧光染色观察胰岛素和胰高血糖素的表达。结果 EPA和鱼油饮食干预均可明显降低T1DM小鼠的血糖水平,改善葡萄糖稳态,且胰腺中出现胰岛素和胰高血糖素共定位细胞;EPA代谢产物引起已发生β细胞凋亡的小鼠胰岛中发生tdTomato荧光蛋白和胰岛素共定位;EPA代谢产物可促进胰岛αTC1细胞系细胞分泌胰岛素。结论 EPA及其代谢产物可通过促进胰岛α细胞转分化为β细胞,进而增加胰岛素的分泌,缓解T1DM小鼠的高血糖症状。

Analysis of Toxin β-N-Oxalyl-α, β-diaminopropionic Acid (β-ODAP),its Isomer α-ODAP and Other Free Amino Acids in Lathyrus sativus

A method has been presented for the simultaneous analysis of neurotoxin β-N-oxalyl-α, β-diaminopropionic acid (β-ODAP) and its non- or low-toxic isomer α-ODAP as well as other amino acids in Lathyrus sativus extracts after derivatization with para-nitrobenzyloxycarbonyl chloride (PNZ-Cl) by reversed-phase (C18 column) high performance liquid chromatography (RP-HPLC). Detection limits of isomers were 0.08 μg/mL for both β-, α-ODAP, for homoarginine 0.09 μg/ mL at a signal-to-noise ratio of 3:1.

γ-亚麻酸对α-亚麻酸转化为DHA的影响

为了明确γ-亚麻酸(GLA)对α-亚麻酸(ALA)转化为二十二碳六烯酸(DHA)效率的影响,以SPF级雌性ICR小鼠为研究对象,给其喂食缺乏n-3多不饱和脂肪酸(n-3 PUFA)饲料8周构建n-3 PUFA缺乏小鼠模型,再将其分为3组,分别为对照组、 ALA组和ALA+GLA组,3组小鼠分别单次灌胃生理盐水、300 mg/kg ALA和300 mg/kg ALA+30 mg/kg GLA,灌胃24 h后,提取各组小鼠血清、肝脏、小肠壁、脑中脂质,测定血清和肝脏甘油三酯(TG)含量,以及血清、肝脏、小肠壁、脑脂质脂肪酸组成及DHA含量。结果表明:相比对照组,ALA组和ALA+GLA组小鼠血清TG浓度降低,ALA组小鼠肝脏TG含量增加,ALA+GLA组小鼠肝脏TG含量降低;3组小鼠血清、肝脏、小肠壁、脑脂肪酸组成均无显著差异,相比血清、肝脏,小肠壁中脂肪酸种类较多,且检出ALA;相比ALA组,ALA+GLA组小鼠肝脏和小肠壁中的DHA含量显著下降,且肝脏中DHA含量显著降低主要体现在TG型DHA的降低上,但两组小鼠脑中DHA含量以及血清DHA浓度无显著差异。综上,补充ALA可提高小鼠外周组织DHA含量,GLA对ALA向DHA的转化具有抑制作用。

α-Vitamin E derivative, RRR-α-tocopheryloxybutyric acid inhibits the proliferation of prostate cancer cells

Aim： To investigate the activity of RRR-α-tocopheryloxybutyric acid （TOB）, an ether analog of RRR-α-tocopheryl succinate （VES）, in prostate cancer cells. Methods： VES and TOB were used to treat prostate cancer LNCaP, PC3, and 22Rvl cells and primary-cultured prostate fibroblasts. The proliferation rates were determined by MTT assay, the cell viabilities were determined by trypan blue exclusion assay, and the cell deaths were evaluated by using Cell Death Detection ELISA kit. The protein expression levels were determined by Western blot analysis. Results： The MTT growth assay demonstrated that TOB could effectively suppress the proliferation of prostate cancer cells, but not normal prostate fibroblasts. Mechanism dissections revealed that TOB reduced cell viability and induced apoptosis in prostate cancer cells similar to VES. In addition, both TOB and VES suppressed prostate-specific antigen （PSA） at the transcriptional level leading to reduced PSA protein expression. Furthermore, vitamin D receptor （VDR） expression increased after the addition of TOB. Conclusion： Our data suggests that the VES derivative, TOB, is effective in inhibiting prostate cancer cell proliferation, suggesting that TOB could be used for both chemopreventive and chemotherapeutic purposes in the future.

α-亚麻酸通过TLR4/MyD88/NF-κB信号通路抑制脂多糖诱导的巨噬细胞炎症

ω-3脂肪酸具有自然的抗炎属性,而α-亚麻酸(ALA)是一种人体必需的ω-3脂肪酸,为了阐明其体外抗炎机制,本实验采用脂多糖(LPS)刺激巨噬细胞构建炎症模型,通过测定单核细胞趋化蛋白(MCP-1)、白细胞介素4(IL-4)、白细胞介素13(IL-13)等炎症因子的水平、活性氧(ROS)生成量和炎症信号通路相关蛋白表达情况探讨α-亚麻酸减轻脂多糖诱导的炎症反应的机制。结果表明,α-亚麻酸能显著抑制MCP-1的释放,提高抗炎细胞因子IL-13的分泌水平;同时,α-亚麻酸还可以降低ROS生成量,缓解ROS介导的炎性损伤。此外,α-亚麻酸可以通过增加抗氧化酶SOD的表达,减少MDA的堆积,从而减轻炎症反应中氧化应激的伴随性危害。蛋白印迹分析进一步证实,α-亚麻酸可抑制TLR4、MyD88的表达以及下游p65和IκBα的磷酸化水平。以上结果表明,α-亚麻酸可明显抑制LPS诱导的RAW264.7细胞炎症反应,其机制可能与抑制TLR4/MyD88/NF-κB信号通路激活有关。

VOLTAMMETRIC BEHAVIOR OF ASCORBIC ACID AT α-CYCLODEXTRIN INCORPORATED CARBON NANOTUBES-COATED ELECTRODE

制备了α -环糊精掺杂纳米碳管涂层电极并应用于抗坏血酸的电催化氧化 ,结果表明 ,氧化电位降低了 2 80mV ,电流响应明显增加。我们首次结合两种物质的特性 :纳米碳管的导电性及催化性能、α -环糊精的分子认知能力 ,对电极表面进行修饰。实验了抗坏血酸与α -环糊精超分子络合物的特性。差示脉冲技术用于定量分析抗坏血酸 ,线性范围为 2 .5× 10 -6～ 1.0× 10

Alpiniae oxyphyllae Fructus ameliorates renal lipid accumulation in diabetic kidney disease via activating PPARα

Objective:To investigate the effects of Alpiniae oxyphyllae Fructus(AOF)on renal lipid deposition in diabetic kidney disease(DKD)and elucidate its molecular mechanisms.Methods:The mechanism of AOF in treating DKD was explored by network pharmacological enrichment analysis,molecular docking,and molecular dynamics simulation.The effects of AOF on renal function and lipid deposition were assessed in a mouse model of DKD and high glucose-stressed HK-2 cells.Cell viability and lipid accumulation were detected by CCK8 and oil red O staining.The expressions of PPARαand fatty acid oxidation-related genes(ACOX1 and CPT1A)were detected by quantitative RT-PCR,Western blot,and immunofluorescence.Furthermore,PPARαknockdown was performed to examine the molecular mechanism of AOF in treating DKD.Results:Network pharmacological enrichment analysis,molecular docking,and molecular dynamics simulation showed that the active compounds in AOF targeted PPARαand thus transcriptionally regulated ACOX1 and CPT1A.AOF lowered blood glucose,improved dyslipidemia,and attenuated renal injury in DKD mice.AOF-containing serum accentuated high glucose-induced decrease in cell viability and ameliorated lipid accumulation.Additionally,it significantly upregulated the expression of PPARα,ACOX1,and CPT1A in both in vivo and in vitro experiments,which was reversed by PPARαknockdown.Conclusions:AOF may promote fatty acid oxidation via PPARαto ameliorate renal lipid deposition in DKD.

Concentration of α-Linoleic Acid of Perilla Oil by Gradient Cooling Urea Inclusion

In this study, production of ct-linoleic acid concentrated from crude perilla oil by gradient cooling urea inclusion was optimized. The fatty acid composition was determined after ethyl esterification by gas chromatography （GC）. In this process, orthogonal experiment was carried out. Under optimum conditions, the maximum amount of α-linoleic acid （91.5%） was obtained at a urea to fatty acid ratio of 3, a solvent to fatty acids ratio of 7, a reaction temperature of 348 K and a crystallization time of 690 min. A simple method of gradient cooling urea inclusion was used to purify α-linolenic acid by using urea to form inclusion complexes with the saturated and the less unsaturated fatty acids, which enhanced the purity of α-linoleic acid ethyl ester by above 90%.

Retinoic acid receptor α promotes autophagy to alleviate liver ischemia and reperfusion injury

AIM: To study the role of autophagy and the relationship between retinoic acid receptor α(RARα) and autophagy in liver ischemia and reperfusion(IR) injury.METHODS: All-trans retinoic acid(ATRA) was administered to mice for two weeks before operation. Reverse transcription-polymerase chain reaction and Western blot were used to detect the expression levels of related factors. To demonstrate the role of RARα,LE540,a RARα inhibitor,was used to treat hepatocytes injured by H2O2 in vitro.RESULTS: ATRA pretreatment noticeably diminished levels of serum alanine aminotransferase and as-partate aminotransferase as well as the degree of histopathological changes. Apoptosis was also inhibited,whereas autophagy was promoted. In vitro,RARα was inhibited by LE540,which resulted in decreased autophagy and increased apoptosis. Similarly,the expression of Foxo3 a and p-Akt was downregulated,but Foxo1 expression was upregulated.CONCLUSION: This research provides evidence that ATRA can protect the liver from IR injury by promoting autophagy,which is dependent on Foxo3/p-Akt/Foxo1 signaling.

Influence of gallic acid on porcine neutrophils phosphodiesterase 4,IL-6,TNF-α and rat arthritis model

Our previous studies showed that the anti-inflammatory effects of Paeonia lactiflora roots extract may be mediated, at least in part, through its gallic acid content, and this effect may be regulated in part by an inhibition on c AMP-phosphodiesterase（PDE）. To explore the anti-inflammatory effect and mechanism, the influence of gallic acid on neutrophils PDE4 activity and expression, TNF-α and IL-6 content and rat arthritis model were further studied. PDE4 activity and gene express were calculated respectively by substrate c AMP change examined with HPLC and real-time RT-PCR. The concentration of IL-6 and TNF-α in supernatant were assayed by ELISA method. Model of rat arthritis was caused by complete Freund＇s adjuvant. Results showed that gallic acid had a dose-dependent restraint on PDE4 activity of neutrophils in vitro, promoted significantly PDE4 A expression（P〈0.01）, and had no influence on the expressions of PDE4 B and 4D. However, PDE4 C expression was not detected. Gallic acid could promote IL-6 release（P〈0.05）, and inhibit TNF-α release of neutrophils（P〈0.05）. The experiment in vivo showed that gallic acid had obvious restraint on local inflammation of animal model（P〈0.05）. Therefore, the anti-inflammatory effect of gallic acid may be mediated in part through an inhibition on PDE4 activity and further an increase of IL-6 and a decrease of TNF-α of neutrophils, and this effect seemed to have no relationship with PDE4 expression.

Modulating Effects of Chlorogenic Acid on Lipids and Glucose Metabolism and Expression of Hepatic Peroxisome Proliferator-activated Receptor-α in Golden Hamsters Fed on High Fat Diet

Objective To examine the effects of chlorogenic acid （CGA） on lipid and glucose metabolism under a high dietary fat burden and to explore the possible role of peroxisome proliferator-activated receptor-α （PPAR-α） in these effects. Methods Twenty male golden hamsters were randomly divided into CGA treatment group （n=10, given peritoneal injection of CGA solution prepared with PBS, 80 mg CGA/kg body weight daily）, and control group （n=10, given PBS i.p. at the average volume of the treatment group）. Animals in both groups were given 15% high fat diet. Eight weeks after treatment with CGA, the level of biochemical parameters in fasting serum and tissues and the expression of hepatic mRNA and protein PPAR-α were determined. Results Eight weeks after treatment with CGA, the levels of fasting serum triglyceride （TG）, free fatty acid （FFA）, total cholesterol （TC）, low density lipoprotein cholesterol （LDL-C）, high density lipoprotein cholesterol （HDL-C）, glucose （FSG）, and insulin （FSI） were significantly lower in the GGA treatment group than in the control group. CGA also led to higher activity of hepatic lipase （HL） lower contents of TG and FFA in liver, and lower activity of lipoprotein lipase （LPL） in skeletal muscle. Furthermore, CGA significantly elevated significantly elevated the expression level of mRNA and protein expression in hepatic PPAR-α. Conclusion CGA can modify lipids and glucose metabolism, which may be attributed to PPAR-α facilitated lipid clearance in liver and improved insulin sensitivity.

Corrosion inhibition of α,β-unsaturated carbonyl compounds on steel in acid medium

Corrosion inhibition of three α,β-unsaturated carbonyl compounds on N80 steel at high temperature and in concentrated acid medium was evaluated, and the inhibition mechanism was investigated. The results proved that both cinnamaldehyde and benzalacetone had an evident anticorrosion effect and could reduce the corrosion of steel effectively in acid medium, α,β-unsaturated carbonyl compounds with a benzene ring structure had good adsorption on steel surface. The experiments proved that polymerization of α,β-unsaturated carbonyl compounds on the steel surface at a high temperature and in concentrated acid medium resulted in a good corrosion inhibiting effect, which was attributed to the structures of α,β-unsaturated carbonyl compounds.

Synthesis of d,l-α-Tocopherol Catalyzed by Heteropoly Acids

,d,l-a-Tocopherol (vitamin E) isfound to be synthesized by condensingtrimethylhydroquinone with isophytol catalyzed by heteropoly acids (HPA) H3:PW12O40 andH3PMo12O40 at room temperature. These HPA are efficient catalysts for the synthesis of d l-a-Tocopherol and can easily be separated from the reaction mixture and roused,

Formulation ofα-linolenic acid microemulsion free of co-surfactant

A novel class ofα-linolenic acid-in-water microemulsion free of co-surfactant was investigated as potential food delivery systems.Rough demarcation within the transparent region was deduced from the results of conductivity and polarizing optical microscopy.The microemulsion mean hydrodynamic diameter and characterization were determined by dynamic light scattering and negative-staining TEM.The location of ALA molecules in the microemulsion formulations was determined by ~1H NMR spectroscopy.

Protective Roles of α-lipoic Acid in Rat Model of Mitochondrial DNA4834bp Deletion in Inner Ear

The protective roles of α-lipoic acid in the rat model of mitochondrial DNA (mtDNA) 4834bp deletion in inner ear were investigated. Forty female Wistar rats at 4 weeks of age were divided into four groups: group A (D-galactose group, n=10), group B (D-galactose+α-lipoic acid group, n=10), group C (α-lipoic acid group, n=10), and group D (control group, n=10). Auditory brainstem response (ABR) was used to detect the hearing threshold. Colorimetry was used to analyze activity of superoxide dismutase (SOD) and concentration of malondialdehyde (MDA). The percentage of mtDNA4834bp deletion in inner ear was identified by real-time PCR. There was no significant difference in ABR threshold shift among all groups. The percentage of mtDNA4834bp deletion in group A was higher than that in other groups, but there was no significant difference in percentage of mtDNA4834bp deletion among groups B, C, and D. The activity of SOD in group A was lower than that in other groups. The concentration of MDA in group A was higher than that in other groups. It was concluded that there was no significant hearing loss when the percentage of mtDNA4834bp deletion was lower than 12.5%. α-Lipoic acid could prevent the reactive oxygen species (ROS)-induced mtDNA4834bp deletion in inner ear of rats.

Preparation and Crystal Structure of 15α-Hydroxyl-oleanolic Acid

The compound 15α-hydroxyl-oleanolic acid was biotransformed from oleanolic acid with Colletotrichum lini AS3.4486,and its structure was characterized by 1H NMR,13C NMR,HR-ESI-MS and single-crystal X-ray diffraction.The crystal of the title compound belongs to monoclinic,space group R3 with a=34.255（5）,b=34.255（5）,c=6.8671（14）,β=90°,Z=9,V=6978（2）3,Mr=490.70,Dc=1.051 mg/m3,μ=0.069 mm-1,F（000）=2430,R=0.0375 and wR=0.0808.The title compound is stacked into a three-dimensional network through hydrogen bonds.

Identification and Mutagenesis of a New Isolated Strain Bacillus sp.B26 for Producing （R）-α-Hydroxyphenylacetic Acid

A bacterium strain B26 capable of producing(R)-α-hydroxyphenylacetic acid [(R)-HPA](yield,47.5%;enantiomeric excess,99.1%) from phenylglyoxylic acid(PGA) with high optical purity was isolated and identified as Bacillus sp.B26 by 16S rDNA(ribosomal DNA) sequencing.Phylogenic analysis showed that the strain was most similar to Bacillus sp.enrichment culture clone SYW5(FJ601635.1) and Bacillus cereus strain FM-4(EU794727.1).Efforts were made to further improve HPA-production and PGA-tolerance by UV irradiation and UV-LiCl cooperative mutagenesis.Among viable mutants,B.sp.UV-38 and B.sp.ULi-11 exhibited better productivities than the wild type.Comparisons of HPA production and time course among wild strain and two mutants showed that B.sp.ULi-11 was more competent than B.sp.UV-38.HPA production was increased by 39.1% with B.sp.ULi-11(yield,65.4%) compared to that with B.sp.B26(yield,47.0%) when cultured in fermentation broth(pH 7.2) at 32℃ with an agitation speed of 180 r·min-1 and PGA final concentration of 15 mmol·L-1 for 25 h.

Fatty Acid Synthase and Hormone-sensitive Lipase Expression in Liver Are Involved in Zinc-α2-glycoprotein-induced Body Fat Loss in Obese Mice

Objective To explore the effects of zinc-0t2-glycoprotein （ZAG） on body weight and body fat in high-fat-diet （HF1））-induced obesity in mice and the possible mechanism. Methods Thirty-six male mice were fed with standard food （SF） （n=9） and HFD （n=27）, respectively. Five weeks later, 9 mice fed with HFD were subjected to ZAG expression plasmid DNA transfection by liposome transfection method, and another 9 mice to negative control plasmid transfection. Two weeks later, serum ZAG level in the mice was assayed by Western blot, and the effects of ZAG over-expression on body weight, body fat, serum biochemical indexes, and adipose tissue of obese mice were evaluated. The mRNA expressions of fatty acid synthase （FAS） and hormone sensitive lipase （HSL） in liver tissue were deterlnined by reverse transcription-polymerase chain reaction. Results Serum ZAG level significantly lowered in simple HFD-fed mice in comparison to SF-fed mice （0.51±0.10 AU vs. 0.75±0.07 AU, P〈0.01）. Further statistical analysis demonstrated that ZAG level was negatively correlated with body weight （r =-0.56, P〈0.001）, epididymal fat mass （r=-0.67, P〈O. 001）, percentage of epididymal fat （r= 0.65, P〈0.001）, and increased weight （r= 0.57, P〈0.001） in simple SF- and HFD fed mice. ZAG over-expression in obese mice reduced body weight and the percentage of epididyreal fat. Furthermore, FAS mRNA expression decreased （P〈0.01） and HSL mRNA expression increased （P〈0.001） in the liver in ZAG over-expressing mice. Conclusions ZAG is closely related to obesity. Serum ZAG level is inversely correlated with body weight and percentage of body fat. The action of ZAG is associated with reduced FAS expression and increased HSL expression in the liver of obese mice.