Effects of the pH and Concentration on the Stability of Standard Solutions of Proteinogenic Amino Acid Mixtures

Kato, Megumi; Yamazaki, Taichi; Kato, Hisashi; Yamanaka, Noriko; Takatsu, Akiko; Ihara, Toshihide

doi:10.2116/analsci.33.1241

Cited by 7 publications

(5 citation statements)

References 19 publications

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“…Thanks to the development of mass spectrometry (MS) technologies, especially coupling it to high-performance liquid chromatography (LC-MS) and tandem MS (MS/MS) in the recent years, researchers can successfully determine various analytes in different samples. [8][9][10][11] For the oxidized phospholipids, there have been reports on the determination of different kinds of oxidized phospholipids in various biological samples, including the hydroperoxides of phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylserine (PS), and cardiolipin (CL), as well as PC aldehydes (PC-CHO). [12][13][14][15][16][17][18] Nevertheless, with regard to lipidomics in diabetes, although there have been studies on lipidomics via LC-MS, 19 there are seldom reports concerning on the changes of these oxidized phospholipids.…”

Section: Introductionmentioning

confidence: 99%

Lipidomic Profiling on Oxidized Phospholipids in Type 2 Diabetes Mellitus Model Zebrafish

Chen

Zang

et al. 2018

ANAL. SCI.

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Type 2 diabetes mellitus is a serious metabolic disorder in the world. Oxidative stress, as a key role on the pathogenesis of diabetes, also results in the oxidation of phospholipids. However, studies on phospholipid oxidation in diabetes, especially directly focusing on oxidized and degraded phospholipid species, are quite limited. In this study, phospholipid profiles of diabetic zebrafish plasma were characterized by LC-HRMS and MS/MS, and the total amounts of each lipid class were compared. Furthermore, the key molecular species as biomarkers in distinguishing control and diabetic samples were investigated by orthogonal partial least squares discriminant analysis. Among the identified 114 phospholipid species in total, there were 11 hydroperoxides, 7 aldehydes, and 19 lysophospholipids found significantly elevated along with the increasing blood glucose, which were known as oxidation or degradation products. Furthermore, lysophosphatidylcholine 20:5 and lysophosphatidylcholine 22:6 were assessed as potential biomarkers in diabetic zebrafish. The current work would not only help to gain further insights into diabetes, but also contribute to find new clinical parameters for the screening of the promising antioxidant agents for its therapies.

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Section: Introductionmentioning

confidence: 99%

Lipidomic Profiling on Oxidized Phospholipids in Type 2 Diabetes Mellitus Model Zebrafish

Chen

Zang

et al. 2018

ANAL. SCI.

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“…The most frequently applied methodology is high-performance liquid chromatography (HPLC). A cation exchange column [ 28 ], reverse-phase column [ 29 , 30 , 31 , 32 ], hydrophilic interaction liquid chromatography (HILIC)-mode column [ 33 , 34 ], and mix-mode column [ 35 ] are used for HPLC separation. In addition, ion-pair mobile phases are applied to detect amino acid impurities with a reverse-phase column [ 36 , 37 , 38 , 39 ] or HILIC-mode column [ 40 ].…”

Section: Analytical Methods To Determine Impurities In Amino Acidsmentioning

confidence: 99%

“…Holzgrabe et al reported that PFHA forms an ion pair with an amino group to enable the retention of amino acids in reverse-phase columns [ 38 , 39 ]. Recently, the HILIC mode, a mode that retains more hydrophilic compounds, has been increasingly used for amino acids and small peptides [ 33 , 34 , 40 ].…”

Section: Analytical Methods To Determine Impurities In Amino Acidsmentioning

confidence: 99%

Analytical Chemistry of Impurities in Amino Acids Used as Nutrients: Recommendations for Regulatory Risk Management

et al. 2022

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Proteinogenic amino acids are natural nutrients ingested daily from standard foods. Commercially manufactured amino acids are added to a wide range of nutritional products, including dietary supplements and regular foods. Currently, the regulatory risk management of amino acids is conducted by means of setting daily maximum limits of intake. However, there have been no reported adverse effects of amino acid overdosing, while impurities in low-quality amino acids have been identified as causative agents in several health hazard events. This paper reviews the analytical chemistry of impurities in amino acids and highlights major variations in the purity of commercial products. Furthermore, it examines the international standards and global regulatory risk assessment of amino acids utilized in dietary supplements and foods, recommending (1) further research on analytical methods that can comprehensively separate impurities in amino acids, and (2) re-focusing on the regulatory risk management of amino acids to the analytical chemistry of impurities.

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“…However, it can be concluded from the graph that the improvement could not be maintained over 24 hours of fermentation as the level started decreasing at 48 hours of fermentation. We proposed that this phenomenon occurred due to the thermolabile and pHsensitive characteristics of the amino acids (Banki et al, 2021;Kato et al, 2017). Furthermore, it is also suspected that the amino acids were utilized as growth-promoting materials for our fermenting agent (Ferreira & Guido, 2018).…”

Section: Metabolites Characterizationmentioning

confidence: 99%

Metabolites Alteration and Antioxidant Activity of Gracilaria verrucosa After Fermentation Using Aureobasidium melanogenum MTGK.31

Sibero

Savitri

Frederick³

et al. 2023

Squalen Bull. Marine Fisheries Postharvest Biotech.

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Gracilaria verrucosa is a red seaweed that has been widely utilized in the food andpharmaceutical industries due to its biological properties. The utilization of biologicalagents in obtaining certain bioactive compounds would confront unavoidable issues,particularly its bioactive sustainability. Hence, microbial fermentation has been reported as a practical approach to maintaining bioactive production and boosting its properties. Our study aimed to evaluate the potential of marine yeast Aureobasidium melanogenum MTGK.31 as a fermenting agent for G. verrucosa and characterize the seaweed metabolite profile and antioxidant activity after fermentation. The seaweed was fermented using A. melanogenum MTGK.31 in a medium consisting of yeast extract, peptone, and glucose. The fermentation was done for 24, 48, and 72 hours. Total plate count and pH were measured after each fermentation period. The primary and secondary metabolites of G. verrucosa in each fermentation were observed. Antioxidant assay using the 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) method was conducted, followed by total phenolic content using the Folin-Ciocalteu method. It was highlighted that yeast colony increased during the fermentation, while the pH level was decreasing. We found that the fermentation not only boosted some elements in primary metabolites, but also increased G. verrucosa bioactive groups. After 72 hours of fermentation, the G. verrucosa percent radical scavenging activity (%RSA) increased more than two times compared to the fresh G. verrucosa with a %RSA value of 16.09±6.57. Nevertheless, the highest total phenolic content of 5.62±0.00028 mg GAE/g extract was shown by G. verrucosa after 48 hours of fermentation.

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Effects of the pH and Concentration on the Stability of Standard Solutions of Proteinogenic Amino Acid Mixtures

Cited by 7 publications

References 19 publications

Lipidomic Profiling on Oxidized Phospholipids in Type 2 Diabetes Mellitus Model Zebrafish

Lipidomic Profiling on Oxidized Phospholipids in Type 2 Diabetes Mellitus Model Zebrafish

Analytical Chemistry of Impurities in Amino Acids Used as Nutrients: Recommendations for Regulatory Risk Management

Metabolites Alteration and Antioxidant Activity of Gracilaria verrucosa After Fermentation Using Aureobasidium melanogenum MTGK.31

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