金月芽期刊網

和“acid”相關的論文

  • 羊耳蒜化學成分的研究 相關:羊耳蒜 蘭科 羊耳蒜屬
  • 目的 研究羊耳蒜(Liparis japonica)全草的化學成分。方法 采用硅膠、ODS、Sephadex LH-20等柱色譜進行分離純化,通過波譜學方法及與文獻對照鑒定化合物結構。結果 分離得到18個化合物,分別鑒定為acortatarin A(1),3β-hydroxy-5α,8α-epidioxyergosta-6,22-diene(2),13-epicupressic acid(3),3β-hydroxyolean-12-en-28-oic acid(4),白樺脂酸(5),gigantol(6),(2S)-3-O-octadeca-9Z,12Z,15Z-trienoylglyceryl-O-β-D-galactopyranoside(7),α-linolenic acid(8),hydroxydihydrobovolide(5-hydroxyl-3,4-dimethy-5-penty-12(5H)-furanone)(9),反式對羥基肉桂酸(10),(+)-丁香脂素(11),β-谷甾醇(12),2,5-二羥基-4-甲氧基-9,10-二氫菲(13),2,7-二羥基-3,4-二甲氧基菲(14),moscatin(15),山藥素Ⅲ(16),亞油酸(17)和對羥基苯甲醛(18)。結論 本實驗首次從羊耳蒜屬植物中分離得到結構獨特的含嗎?片段的螺環生物堿,化合物2~11為首次從該屬植物中分離得到。
  • Effects of Exogenous 5-Aminolevulinic Acid and 24-Epibrassinolide on Cd Accumulation in Rice from Cd-Contaminated Soil 相關:RICE Cd-contaminated soil
  • High grain-Cd-accumulating rice variety Yongyou 9 was planted in Cd-contaminated farmland in Taizhou City,Zhejiang Province,China to study the effects of 5-aminolevulinic acid(ALA)and 24-epibrassinolide(EBR)on Cd accumulation in brown rice.Results showed that the exogenous ALA and EBR had no significant effects on agronomic traits,soil pH and total Cd content in soil,but had some effects on the available Cd content in soil,and significantly influenced the Cd accumulation in the different parts of rice.Results also showed that 100 mg/L exogenous ALA significantly reduced the Cd accumulation in brown rice to blow the food safety standard(0.2 mg/kg),and also significantly reduced the Cd contents in the roots and culm of rice.However,200 mg/L exogenous ALA treatment increased the Cd content in brown rice remarkably.In addition,0.15 mg/L EBR treatment increased Cd accumulation in roots,culm,leaves and brown rice notably,whereas 0.30 mg/L exogenous EBR treatment reduced the Cd accumulation in brown rice properly,but it was not significant.Therefore,proper concentration of ALA can effectively reduce the Cd accumulation in brown rice,which can be used as an effective technical method for the safe production of rice in Cd polluted farmland.
  • γ-Ray radiolysis of acetohydroxamic acid in HNO3 and its radiolytic product 相關:Acetohydroxamic ACID Γ-RAY
  • Acetohydroxamic acid(AHA)is a novel saltfree reagent used for the separation of Pu and Np from U in the advanced Purex process.This paper reports theγ-ray damage of AHA in HNO3and its radiolytic product.For0.2mol L-1AHA in0.2-2.0mol L-1HNO3irradiated at a dose of5-25kGy,the radiolytic rate of AHA is6.63-77.5%,and it increases with the HNO3concentration and absorbed dose.The main radiolytic gases are N2O and H2,with volume fractions of(0.500-16.2)×10-2and(1.30-11.8)×10-3,respectively,and they increase with the absorbed dose;the H2volume fraction decreases with increasing HNO3concentration.The main liquid radiolytic products are CH3COOH and HNO2,and their concentrations are(3.40-19.7)×10-2and(0.200-4.80)×10-3-mol L-1,respectively,which increase with the HNO3concentration.Since a significant concentration of HNO2is present in the irradiated AHA-HNO3solution,a holding reductant must be used to destroy HNO2and stabilize Pu(III)and Np(V)when AHA is applied for the separation of Pu and Np from U.
  • Core-Corona Structure Formed by Hyaluronic Acid and Poly(L-lysine)via Kinetic Path 相關:POLYELECTROLYTE complex Core-corona
  • The structure and kinetics of the complex formed by hyaluronic acid(HA) and poly(L-lysine)(PLL) were studied by timeresolved laser light scattering, TEM, and AFM. Because HA has a hydrophilic backbone, the complexes formed by HA and PLL are different from those formed by oppositely charged polyelectrolytes both having hydrophobic backbones. Instead of forming strong aggregates and even precipitates, the complex in the presence of excess HA is stable in the studied time period. More importantly, the complex spontaneously forms core-corona structure by the rearrangement of HA chains. The core is composed of complex rich of PLL and the corona is mainly HA. Further analysis shows that the hydrogen bond formed by HA creates a barrier hindering the further relaxation of HA chains. The automatic formation of core-corona structure by PLL/HA is helpful not only to understand the relaxation of polyelectrolyte in complex, but also to develop drug carriers with desirable properties.
  • Abscisic acid induces differential expression of genes involved in wound-induced suberization in postharvest tomato fruit 相關:TOMATO abscisic acid
  • Fruit wounding occurred at harvest and transportation requires rapid suberization as a major part of the healing process to prevent infection and desiccation.The focus of this work was to explore the mediation of abscisic acid (ABA)on woundinduced suberization and to determine expression profiles of specific genes involved in wound-induced suberization in tomato fruit.The measurements of weight loss and fruit firmness suggested wound-induced suberization started at 2 d after wounding.The suberization process with the accumulation of suberin polyphenolics (SPP)and polyaliphatics (SPA) observed through autofluorescence microscopy and Sudan Ⅳ staining was accelerated by ABA.Expressions of SIPAL5 and SI4CL involved in the synthesis of SPP reached the highest at 4 and 8 d after wounding following ABA application, respectively.Associated with SPA biosynthesis,SILACS1 and SILACS2 showed the most abundant transcripts at 8 and 6 d in ABA group,respectively.Transcript levels including SIKCSs,SICYP86B1,SIFAR3,and SIGPATs were up-regulated at 2 d after wounding by ABA.Activities of polyphenol oxidase and lipoxygenase were also enhanced during wound-induced suberization following ABA application.The results in this study proved that ABA accelerated the wound-induced suberization progress by increasing the transcript levels of relevant genes in postharvest tomato fruit.
  • Influence of Iactic acid bacteria,cellulase,cellulase-producing Bacillus pumilus and their combinations on alfalfa silage quality 相關:ALFALFA SILAGE CELLULASE
  • This study assessed the effects of lactic acid bacteria (LAB),cellulase,cellulase-producing Bacillus pumilus and their combinations on the fermentation characteristics,chemical composition,bacterial community and in vitro digestibility of alfalfa silage.A completely randomized design involving a 8 (silage additives)×3 or 2 (silage days)factorial arrangement of treatments was adopted in the present study.The 8 silage additive treatments were:untreated alfalfa (control);two commercial additives (GFJ and Chikuso-1);an originally selected LAB (Lactobacillus plantarum a214)isolated from alfalfa silage;a cellulase-producing Bacillus (CB)isolated from fresh alfalfa;cellulase (C);and the combined additives (a214+C and a214+CB).Silage fermentation characteristics,chemical composition and microorganism populations were analysed after 30,60 and 65 days (60 days followed by exposure to air for five additional days).In vitro digestibility was analysed for 30 and 60 days.Compared with the other treatments,selected LAB a214,a214 combined with either C or CB,and Chikuso-1 had the decreased (P<0.001)pH and increased (P<0.001)lactic acid concentrations during the ensiling process, and there were no differences (P>0.05)among them.Fiber degradation was not significant (P?0.054)in any C or CB treatments.The a214 treatment showed the highest (P=0.009)in vitro digestibility of dry matter (595.0 g kg^-1 DM)after ensiling and the highest abundance of Lactobacillus (69.42 and 79.81%,respectively)on days 60 and 65,compared to all of other treatments.Overall,the silage quality of alfalfa was improved with the addition of a214,which indicates its potential as an alfalfa silage inoculant.
  • Regulation of amino acid transporters in the mammary gland from late pregnancy to peak lactation in the sow 相關:AMINO acid TRANSPORTER
  • Background:Milk protein is crucial for milk quality in sows and health of newborn piglets.Plasma amino acids(AA)in sows are important precursors for milk protein synthesis in the mammary gland.In order to study the regulation of AA transported in sow mammary glands and possible underlying mechanisms,we measured the expression of genes coding for milk proteins,AA transporter expressions,and plasma AA concentrations in sows at three different physiological stages(D-17,D1 and D17 of lactation),and then further investigated the regulation of AA transport across the cell membrane by adaptive mechanisms using pig mammary epithelial cells(PMEC)as an in vitro model.PMEC were cultured in DMEM:F12 with 4 amino acid concentrations(0×AA complex,1×AA complex,5×AA complex,and 25×AA complex).Classes of AA complexes evaluated in this study included neutral AAs(L-Ala+L-Ser+L-Cys),acidic AAs(L-Asp,L-Glu)and neutral+basic AAs(L-Ala+L-Ser+L-Cys+L-Lys).Results:Our results indicated that mRNA expression of genes coding for milk protein(αs1-casein,αs2-casein,β-casein andκ-casein)increased significantly with the advance of physiological stage(P<0.05),and plasma concentrations of most AAs including threonine,serine,glutamate,alanine,valine,cysteine,methionine,isoleucine and tyrosine were greater at D1 of lactation compared with D-17 and D17 of lactation(P<0.05).Additionally,protein and gene expressions of AA transporters including excitatory AA transporter 3(EAAT3),alanine/serine/cysteine/threonine transporter(ASCT1)and sodium-coupled neutral AA transporter 1(SNAT2)were greater in lactating sow mammary glands compared with sow mammary glands in late pregnancy(P<0.05).The mRNA expressions of SLC38A2,SLC1A1,SLC6A14 increased significantly in the cell mediums supplemented with 5×and 25×of AA complexes compared with those cells cultured in DMEM/F12 cell medium(P<0.05).The mRNA expressions of SLC38A,SLC1A4,and SLC6A14 also increased in EBSS cell medium compared to DMEM/F12.However,only mRNA e...
  • Fatty Acid Accumulation in Seeds of Three Seed Pumpkin Cultivars 相關:SEED PUMPKIN CUCURBITA
  • In the literature there are many reports on the composition and properties of pumpkin seed oil; however, few is known about the effect of different stages of seed development on various fatty acid profiles in developing seeds. The objective of this study was to provide the changes of various fatty acid accumulations in seed oil obtained from the seeds of three pumpkin varieties belonging to the species Cucurbita maxima and Cucurbita pepo. Unsaturated acids (oleic and linoleic) were dominant in various fatty acids, which constituted 38.9%-49.1% and 29.4%-42.7% of the total fatty acids at seed maturity for three pumpkin varieties, respectively, while other fatty acid concentrations except for palmitic acid all did not reach 10%. Different varieties exhibited greater effect on various fatty acid contents and the total fatty acid contents in the seeds of pumpkin rather than the species. On the whole, palmitic acid profiles of the seed oil in three varieties all followed the fluctuant decrease during all the stages of seed development, but palmitoleic acid and the total fatty acid profiles of the seed oil in three varieties were just the opposite. Stearic, oleic and linoleic acid profiles of the seed oil in three varieties all experienced the third pattern that fluctuated during all the stages of seed development, but no significant differences in these three fatty acid concentrations were found from the beginning to the end. Linolenic acid concentrations of three varieties were on the decline and ultimately close to zero. Myristic and arachidic acid profiles of the seed oil followed different trends in three varieties. Among them, myristic and arachidic acid profiles of the seed oil of Yinhui-1 fluctuated downward all the time until seed maturity, but those of 0238-1 and Jinhui-2 completely changed oppositely.
  • Study on Degradation of Cellulose-rich Substrates by Bacillus licheniformis 相關:BACILLUS lincheniformis CELLULOSE
  • Bacillus lincheniformis is a representative probiotic, widely used in food, medicine and livestock industries and other industries. In this experiment, a strain of Bacillus lincheniformis was isolated and identified, which was used to ferment celluloserich substrate. The effects were analyzed. The experimental results showed that Bacillus lincheniformis had the capacity to degrade cellulose (32.8% was degraded) and less capacity to degrade hemicellulose (7.9% was degraded), which could not degrade ligin. The total protein contents in the products fermented by Bacillus lincheniformis with cellulose-rich substrate riched by 11.6%, compared with the fermented products with no cellulose-rich substrate, furthermore, the contents of Met, Lys and Leu riched by 14%, 17.5% and 4.1%, respectively. These results showed that Bacillus lincheniformis had the ability to degrade cellulose and it provided experimental data for further utilization.
  • UPLC-Q/TOF法同時定性定量分析滇芹藥材中主要化學成分 相關:滇芹 UPLC-Q/TOF 阿魏酸
  • 目的建立UPLC-Q/TOF法同時定性、定量分析滇芹中主要化學成分。方法采用超高效液相色譜串聯飛行時間質譜法進行分析,色譜柱為Agilent Poroshell 120 Hilic,流動相為乙?-0.1%甲酸水溶液,梯度洗脫,體積流量0.3 m L/min;定性、定量采用Q-TOF正負離子全掃描+IDA(信息關聯采集)模式。結果利用已建立的篩查數據庫將滿足質量誤差小于5×10-6、同位素分布正確且含有二級碎片的離子作為分析目標化合物,結合軟件Formula Finder、Mass Calculators等功能、在線數據庫(Human Metabolome Database、Pub Chem、Chemical Book等)及二級碎片裂解規律,共鑒定出23個化合物,滇芹首次發現4個化合物。確定阿魏酸為定量分析指標性成分,其定量、定性離子分別為178和149;阿魏酸檢測質量濃度線性范圍為1.14~1 140 ng/m L(r=1.000),檢測限、定量限分別為0.87、2.91 ng/m L,精密度、穩定性、重復性試驗的RSD〈2%,加樣回收率為98.13%~101.25%(RSD=1.37%,n=5)。結論該方法靈敏度高、重現性好,分析快速、準確、可靠,可用于同時定性、定量檢測滇芹藥材中主要化學成分;云南滇芹中阿魏酸含量要高于西藏滇芹。