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21.
Johanna Bakker Colin F. Timberlake 《Journal of the science of food and agriculture》1985,36(12):1315-1324
The distribution of anthocyanins in methanolic skin extracts of 16 grape cultivars used for port wine production and grown at five sites in the Douro Valley in Northern Portugal has been assessed by high performance liquid chromatography. Results are confined to the seven most readily separated and identified anthocyanins and are expressed as percentages of their total (88–99% of the total integrated area). Anthocyanins based on malvidin (Mv) predominated. Of these, Mv 3-glucoside was the major pigment (33–60%), being exceeded by Mv 3-p-coumarylglucoside (2–51%) in only two cultivars; Mv 3-acetylglucoside (1–15%) was consistently the lowest. Peonidin 3-glucoside (1–27%) was prominent in four cultivars, but delphinidin 3-glucoside (1–11%), petunidin 3-glucoside (2–11%) and cyanidin 3-glucoside (trace-6%) were of low proportions throughout. The ratio Mv 3-acetylglucoside/total Mv glucosides appeared characteristic of cultivar, independent of site, and a useful aid to identification of grape cultivars. The coloured pulp of some cultivars contained peonidin 3-glucoside as a major component, present in greater proportions than in the skin; the percentage of Mv 3-p-coumarylglucoside was lower in pulp than in skin. The identities of six of the seven anthocyanins were confirmed by fast atom bombardment mass spectrometry and the structures of the Mv derivatives were determined by nuclear magnetic resonance. The formation of formyl and acetyl anthocyanin artefacts is described. 相似文献
22.
基于机器视觉原理,利用s3c2440嵌入式平台,开发出印刷品质量检测系统,为印刷企业解决了人工检测劳动量大、效率低等问题。 相似文献
23.
Ly Thi Thanh Le Lukasz Kotula Kadambot H. M. Siddique Timothy D. Colmer 《International journal of molecular sciences》2021,22(4)
Grain legumes are important crops, but they are salt sensitive. This research dissected the responses of four (sub)tropical grain legumes to ionic components (Na+ and/or Cl−) of salt stress. Soybean, mungbean, cowpea, and common bean were subjected to NaCl, Na+ salts (without Cl−), Cl− salts (without Na+), and a “high cation” negative control for 57 days. Growth, leaf gas exchange, and tissue ion concentrations were assessed at different growing stages. For soybean, NaCl and Na+ salts impaired seed dry mass (30% of control), more so than Cl− salts (60% of control). All treatments impaired mungbean growth, with NaCl and Cl− salt treatments affecting seed dry mass the most (2% of control). For cowpea, NaCl had the greatest adverse impact on seed dry mass (20% of control), while Na+ salts and Cl− salts had similar intermediate effects (~45% of control). For common bean, NaCl had the greatest adverse effect on seed dry mass (4% of control), while Na+ salts and Cl− salts impaired seed dry mass to a lesser extent (~45% of control). NaCl and Na+ salts (without Cl−) affected the photosynthesis (Pn) of soybean more than Cl− salts (without Na+) (50% of control), while the reverse was true for mungbean. Na+ salts (without Cl−), Cl− salts (without Na+), and NaCl had similar adverse effects on Pn of cowpea and common bean (~70% of control). In conclusion, salt sensitivity is predominantly determined by Na+ toxicity in soybean, Cl− toxicity in mungbean, and both Na+ and Cl− toxicity in cowpea and common bean. 相似文献
24.
Luisa Siculella Laura Giannotti Benedetta Di Chiara Stanca Matteo Calcagnile Alessio Rochira Eleonora Stanca Pietro Alifano Fabrizio Damiano 《International journal of molecular sciences》2021,22(8)
Reactive intermediate deaminase (Rid) proteins are enzymes conserved in all domains of life. UK114, a mammalian member of RidA subfamily, has been firstly identified as a component of liver perchloric acid-soluble proteins (L-PSP). Although still poorly defined, several functions have been attributed to the mammalian protein UK114/RIDA, including the reactive intermediate deamination activity. The expression of UK114/RIDA has been observed in some tumors, arousing interest in this protein as an evaluable tumor marker. However, other studies reported a negative correlation between UK114/RIDA expression, tumor differentiation degree and cell proliferation. This work addressed the question of UK114/RIDA expression in human non-tumor HEK293 cell lines and in some human tumor cell lines. Here we reported that human RIDA (hRIDA) was expressed in all the analyzed cell line and subjected to lysine (K-)succinylation. In HEK293, hRIDA K-succinylation was negatively correlated to the cell proliferation rate and was under the control of SIRT5. Moreover, K-succinylation clearly altered hRIDA quantification by immunoblotting, explaining, at least in part, some discrepancies about RIDA expression reported in previous studies. We found that hRIDA was able to deaminate reactive enamine-imine intermediates and that K-succinylation drastically reduced deaminase activity. As predicted by in silico analysis, the observed reduction of deaminase activity has been related to the drastic alterations of hRIDA structure inferred by K-succinylation. The role of hRIDA and the importance of its K-succinylation in cell metabolism, especially in cancer biology, have been discussed. 相似文献
25.
Long Tang Jianchun Jiang Guoqiang Song Yajing Wang Ziheng Zhuang Ying Tan Yan Xia Xianfeng Huang Xiaoqing Feng 《International journal of molecular sciences》2021,22(11)
Urolithins (hydroxylated 6H-benzo[c]chromen-6-ones) are the main bioavailable metabolites of ellagic acid (EA), which was shown to be a cognitive enhancer in the treatment of neurodegenerative diseases. As part of this research, a series of alkoxylated 6H-benzo[c]chromen-6-one derivatives were designed and synthesized. Furthermore, their biological activities were evaluated as potential PDE2 inhibitors, and the alkoxylated 6H-benzo[c]chromen-6-one derivative 1f was found to have the optimal inhibitory potential (IC50: 3.67 ± 0.47 μM). It also exhibited comparable activity in comparison to that of BAY 60-7550 in vitro cell level studies. 相似文献
26.
Sheetal Rani Basundhara Dasgupta Gaurav Kumar Bhati Kalpana Tomar Dr. Sabyasachi Rakshit Dr. Subhabrata Maiti 《Chembiochem : a European journal of chemical biology》2021,22(7):1113-1113
Evolutionarily elderly proteins commonly feature greater catalytic promiscuity. Cytochrome c is among the first set of proteins in evolution to have known prospects in electron transport and peroxidative properties. Here, we report that cyt c is also a proficient proton-transfer catalyst and enhances the Kemp elimination (KE; model reaction to show proton transfer catalytic property) by ∼750-fold on self-organized systems like micelles and vesicles. The self-organized systems mimic the mitochondrial environment in vitro for cyt c. Using an array of biophysical and biochemical mutational assays, both acid–base and redox mechanistic pathways have been explored. The histidine moiety close to hemin group (His18) is mainly responsible for proton abstraction to promote the concerted E2 pathway for KE catalysis when cyt c is in its oxidized form; this has also been confirmed by a H18A mutant of cyt c. However, the redox pathway is predominant under reducing conditions in the presence of dithiothreitol over the pH range 6–7.4. Interestingly, we found almost 750-fold enhanced KE catalysis by cyt c compared to aqueous buffer. Overall, in addition to providing mechanistic insights, the data reveal an unprecedented catalytic property of cyt c that could be of high importance in an evolutionary perspective considering its role in delineating the phylogenic tree and also towards generating programmable designer biocatalysts. 相似文献
27.
通过对有芯工频炉酸性炉衬生产欧元材料出现的问题进行分析,发现在使用有芯工频炉酸性耐火材料时,炉衬寿命大大缩短,并使铜液Si含量超标,造成材料报废。而炉衬材料换成中性耐火材料时,基本上控制了Si含量,达到了欧元材料标准,并使炉衬寿命大大提高。 相似文献
28.
The influence of Glu44 and Glu56 of cytochrome b5 on the protein structure and interaction with cytochrome c 总被引:1,自引:0,他引:1
Sun Yu-Long; Xie Yi; Wang Yun-Hua; Xiao Gu-Tian; Huang Zhong-Xian 《Protein engineering, design & selection : PEDS》1996,9(7):555-558
The gene encoding trypsin-solubilized bovine liver microsomalcytochrome b5 (82 residues in length) has been mutated, in whichthe codons of Glu44 and Glu56 were changed to those of Ala.The mutated genes were expressed in Escherichia coli successfullyand three mutant proteins (E44A, E56A and E44/56A) were obtained.The UV-visible, CD and 1H NMR spectra of proteins have beenstudied. The results show that the mutagenesis at surface residuesdoes not alter the secondary and tertiary structures of cytochromeb5 significantly. The interactions between recombinant cytochromeb5 and its mutants with cytochrome c were studied by using opticaldifference spectra. The results demonstrated that both Glu44and Glu56 of cytochrome b5 participate in the formation of acomplex between cytochrome b5 and cytochrome c. 相似文献
29.
30.
P. Elumalai H.N. Vasan N. Munichandraiah S.A. Shivashankar 《Journal of Applied Electrochemistry》2002,32(9):1005-1010
Submicron size Co, Ni and Co–Ni alloy powders have been synthesized by the polyol method using the corresponding metal malonates and Pd powder by reduction of PdO
x
in methanol. The kinetics of the hydrogen evolution reaction (HER) in 6 M KOH electrolyte have been studied on electrodes made from the pressed powders. The d.c. polarization measurements have resulted in a value close to 120 mV decade–1 for the Tafel slope, suggesting that the HER follows the Volmer–Heyrovsky mechanism. The values of exchange current density (i
o) are in the range 1–10 mA cm–2 for electrodes fabricated in the study. The a.c. impedance spectra measured at several potentials in the HER region showed a single semicircle in the Nyquist plots. Exchange current density (i
o) and energy transfer coefficient () have been calculated by employing a nonlinear least square-fitting program. 相似文献