scholarly journals SEL1L Protein Critically Determines the Stability of the HRD1-SEL1L Endoplasmic Reticulum-associated Degradation (ERAD) Complex to Optimize the Degradation Kinetics of ERAD Substrates

2011 ◽  
Vol 286 (19) ◽  
pp. 16929-16939 ◽  
Author(s):  
Yasutaka Iida ◽  
Tsutomu Fujimori ◽  
Katsuya Okawa ◽  
Kazuhiro Nagata ◽  
Ikuo Wada ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Degradation Kinetics ◽  
Endoplasmic Reticulum Associated Degradation ◽  
The Stability ◽  
Kinetics Of

scholarly journals Improvement of Anthocyanin Stability in Butterfly Pea Flower Extract by Co-pigmentation with Catechin

2020 ◽  
Vol 141 ◽  
pp. 03008
Author(s):  
Phoomjai Charurungsipong ◽  
Chairath Tangduangdee ◽  
Suksun Amornraksa ◽  
Suvaluk Asavasanti ◽  
Jenshinn Lin
Keyword(s):  
Degradation Kinetics ◽  
Differential Method ◽  
Pigment Ratio ◽  
Flower Extract ◽  
Zero Order Kinetics ◽  
Butterfly Pea ◽  
Anthocyanin Stability ◽  
The Stability ◽  
Stability Enhancement ◽  
Kinetics Of

Most of the food processing operations involve the use of heat which generally causes alteration, and degradation of natural pigments, resulting in lower stability. One of the stability enhancement methods is co-pigmentation. This study aimed to determine effect of catechin co-pigment on stability of anthocyanins in Clitoria ternatea (or butterfly pea flower) extract. Degradation kinetics of anthocyanins in the extract were evaluated at three temperatures (28, 60, and 90℃). The effect of co-pigment ratio (catechin: anthocyanins at 1:1, 50:1 and 100:1 by weight) on the stability of anthocyanin extract at 90℃ was determined by the pH differential method. It was found that anthocyanin degradation followed the zero- order kinetics at all temperatures; the degradation rate increased as the temperature increased. At a lower pH, anthocyanins became more stable. An increase in the co-pigment ratio significantly retarded the degradation anthocyanins at 90℃. In addition, co-pigmentation also intensified the color of butterfly pea extract. The highest anthocyanin stability was obtained at co-pigment ratio of 100:1.

scholarly journals Determination of solubility, stability and degradation kinetics of morin hydrate in physiological solutions

RSC Advances ◽  
2018 ◽  
Vol 8 (50) ◽  
pp. 28836-28842 ◽  
Author(s):  
Ashok Kumar Jangid ◽  
Deep Pooja ◽  
Hitesh Kulhari
Keyword(s):  
Degradation Kinetics ◽  
Morin Hydrate ◽  
The Stability ◽  
Kinetics Of

The stability of morin hydrate depends on pH, temperature, and light.

scholarly journals Kinetics of Lycopene Degradation in Sunflower and Grape Seed Oils

2018 ◽  
Vol 34 (5) ◽  
pp. 2229-2235 ◽  
Author(s):  
Antonio Zuorro ◽  
Roberto Lavecchia ◽  
Erenio González ◽  
Viatcheslav Kafarov
Keyword(s):  
Seed Oil ◽  
Storage Temperature ◽  
Degradation Kinetics ◽  
Grape Seed ◽  
Antioxidant Compounds ◽  
First Order Kinetics ◽  
Grape Seed Oil ◽  
The Stability ◽  
And Storage ◽  
Kinetics Of

The stability of lycopene in two vegetable oils, sunflower seed oil (SSO) and grape seed oil (GSO), was investigated by analysing the carotenoid degradation kinetics in the temperature range of 10–40°C. A tomato oleoresin containing 6% (w/w) of lycopene was used to prepare lycopene-enriched oil samples. Analysis of kinetic data showed that lycopene degradation follows first-order kinetics, with an apparent activation energy of 70.7 kJ mol–1 in SSO and 69 kJ mol–1 in GSO. The estimated half-life of lycopene was found to depend on oil type and storage temperature. At 20°C, it varied between 59 and 122 days, while at 4°C it was comprised between 302 and 650 days. At all temperatures, lycopene was more stable in SSO than in GSO, which is likely due to the higher content of antioxidant compounds in SSO.

scholarly journals LC-UV and UPLC-MS/MS Methods for Analytical Study on Degradation of Three Antihistaminic Drugs, Ketotifen, Epinastine and Emedastine: Percentage Degradation, Degradation Kinetics and Degradation Pathways at Different pH

Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 64
Author(s):  
Anna Gumieniczek ◽  
Izabela Kozak ◽  
Paweł Żmudzki ◽  
Urszula Hubicka
Keyword(s):  
Degradation Products ◽  
Degradation Kinetics ◽  
Imidazole Ring ◽  
Piperidine Ring ◽  
Degradation Pathways ◽  
Pseudo First Order Reaction ◽  
Kinetics Of Degradation ◽  
The Stability ◽  
Antihistaminic Drugs ◽  
Kinetics Of

Evaluation of pH-dependent reactivity of drugs is an essential component in the pharmaceutical industry. Thus, the stability of three antihistaminic drugs, i.e., ketotifen, epinastine and emedastine, was tested, in solutions of five pH values, i.e., 1.0, 3.0, 7.0, 10.0 and 13.0, at high temperature (70 °C). LC-UV isocratic methods were developed to estimate percentage degradation as well as the kinetics of degradation. Generally, epinastine was shown to be the most stable compound with degradation below 14%. Emedastine was labile in all pH conditions, with degradation in the range 29.26–51.88%. Ketotifen was moderately stable at pH 1–7 (degradation ≤ 14.04%). However, at pH ≥ 10, its degradation exceeded 30%. The kinetics of degradation of ketotifen, epinastine and emedastine was shown as a pseudo-first-order reaction with the rate constants in the range 10−4–10−3 min−1 Finally, the UPLC-MS/MS method was applied to identify the main degradants and suggest degradation pathways. Degradation of ketotifen proceeded with oxidation and demethylation in the piperidine ring of the molecule. As far as epinastine was concerned, opening of the imidazole ring with formation of the amide group was observed. Unfortunately, no degradation products for emedastine were detected. The present results complete the literary data and may be important for both manufacturing of these drugs and their administration to patients.

The stability and degradation kinetics of Sulforaphene in microcapsules based on several biopolymers via spray drying

2015 ◽  
Vol 122 ◽  
pp. 5-10 ◽  
Author(s):  
Guifang Tian ◽  
Yuan Li ◽  
Qipeng Yuan ◽  
Li Cheng ◽  
Pengqun Kuang ◽  
...  
Keyword(s):  
Spray Drying ◽  
Degradation Kinetics ◽  
The Stability ◽  
Kinetics Of

Different redox sensitivity of endoplasmic reticulum associated degradation clients suggests a novel role for disulphide bonds in secretory proteins

2014 ◽  
Vol 92 (2) ◽  
pp. 113-118 ◽  
Author(s):  
Iria Medraño-Fernandez ◽  
Claudio Fagioli ◽  
Alexandre Mezghrani ◽  
Mieko Otsu ◽  
Roberto Sitia
Keyword(s):  
Endoplasmic Reticulum ◽  
Reduced Form ◽  
Secretory Proteins ◽  
Endoplasmic Reticulum Associated Degradation ◽  
Disulphide Bonds ◽  
Complex Process ◽  
Cargo Proteins ◽  
Redox Sensitivity ◽  
Partially Unfolded ◽  
The Stability

To maintain proteostasis in the endoplasmic reticulum (ER), terminally misfolded secretory proteins must be recognized, partially unfolded, and dislocated to the cytosol for proteasomal destruction, in a complex process called ER-associated degradation (ERAD). Dislocation implies reduction of inter-chain disulphide bonds. When in its reduced form, protein disulphide isomerase (PDI) can act not only as a reductase but also as an unfoldase, preparing substrates for dislocation. PDI oxidation by Ero1 favours substrate release and transport across the ER membrane. Here we addressed the redox dependency of ERAD and found that DTT stimulates the dislocation of proteins with DTT-resistant disulphide bonds (i.e., orphan Ig-μ chains) but stabilizes a ribophorin mutant (Ri332) devoid of them. DTT promotes the association of Ri332, but not of Ig-µ, with PDI. This discrepancy may suggest that disulphide bonds in cargo proteins can be utilized to oxidize PDI, hence facilitating substrate detachment and degradation also in the absence of Ero1. Accordingly, Ero1 silencing retards Ri332 degradation, but has little if any effect on Ig-µ. Thus, some disulphides can increase the stability and simultaneously favour quality control of secretory proteins.

scholarly journals Degradation Kinetics and Shelf Life of N-acetylneuraminic Acid at Different pH Values

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5141
Author(s):  
Weiwei Zhu ◽  
Xiangsong Chen ◽  
Lixia Yuan ◽  
Jinyong Wu ◽  
Jianming Yao
Keyword(s):  
Shelf Life ◽  
Degradation Kinetics ◽  
Polysialic Acid ◽  
Acetylneuraminic Acid ◽  
Ph Values ◽  
Different Temperatures ◽  
Shelf Life Studies ◽  
The Stability ◽  
Kinetics Of ◽  
Hydrolysis Of

The objective of this study was to investigate the stability and degradation kinetics of N-acetylneuraminic acid (Neu5Ac). The pH of the solution strongly influenced the stability of Neu5Ac, which was more stable at neutral pH and low temperatures. Here, we provide detailed information on the degradation kinetics of Neu5Ac at different pH values (1.0, 2.0, 11.0 and 12.0) and temperatures (60, 70, 80 and 90 °C). The study of the degradation of Neu5Ac under strongly acidic conditions (pH 1.0–2.0) is highly pertinent for the hydrolysis of polysialic acid. The degradation kinetics of alkaline deacetylation were also studied. Neu5Ac was highly stable at pH 3.0–10.0, even at high temperature, but the addition of H2O2 greatly reduced its stability at pH 5.0, 7.0 and 9.0. Although Neu5Ac has a number of applications in products of everyday life, there are no reports of rigorous shelf-life studies. This research provides kinetic data that can be used to predict product shelf lives at different temperatures and pH values.

Kinetics of Various 99mTc-Sn-Pyrophosphate Compounds in the Rat

1977 ◽  
Vol 16 (04) ◽  
pp. 157-162 ◽  
Author(s):  
C. Schümichen ◽  
B. Mackenbrock ◽  
G. Hoffmann
Keyword(s):  
Normal Saline ◽  
Half Life ◽  
Compound A ◽  
Short Half Life ◽  
Low Concentrations ◽  
The Stability ◽  
Kinetics Of ◽  
In Vitro Stability

SummaryThe bone-seeking 99mTc-Sn-pyrophosphate compound (compound A) was diluted both in vitro and in vivo and proved to be unstable both in vitro and in vivo. However, stability was much better in vivo than in vitro and thus the in vitro stability of compound A after dilution in various mediums could be followed up by a consecutive evaluation of the in vivo distribution in the rat. After dilution in neutral normal saline compound A is metastable and after a short half-life it is transformed into the other 99mTc-Sn-pyrophosphate compound A is metastable and after a short half-life in bone but in the kidneys. After dilution in normal saline of low pH and in buffering solutions the stability of compound A is increased. In human plasma compound A is relatively stable but not in plasma water. When compound B is formed in a buffering solution, uptake in the kidneys and excretion in urine is lowered and blood concentration increased.It is assumed that the association of protons to compound A will increase its stability at low concentrations while that to compound B will lead to a strong protein bond in plasma. It is concluded that compound A will not be stable in vivo because of a lack of stability in the extravascular space, and that the protein bond in plasma will be a measure of its in vivo stability.

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