7 research outputs found

    Analysis of Carotenoids Using LC-MS-MS with Ion Mobility Spectrometry and Photoionization

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    Carotenoids are naturally occurring fat-soluble pigments found principally in bacteria and plants including edible plants. Because of their extensively conjugated carbon-carbon double bond system, carotenoids are potent antioxidants. The most abundant carotenoid and best singlet oxygen quencher found in red tomatoes is lycopene. Using lycopene as a potential dietary chemopreventive agent, a four-arm randomized, placebo-controlled, and double-blind phase II clinical intervention trial was carried out at the University of Illinois at Chicago. In the investigation, it was found that lycopene supplements at either 30 mg/d or 60 mg/d lycopene for 21 d were well tolerated by healthy men enrolled to the two lycopene intervention arms. Similar increases in serum levels of lycopene were observed in both treatment groups during this intervention study. However, stronger effects were observed for the two antioxidant biomarkers (urinary 8-oxo-deoxyguanosine and 8-iso-prostaglandin-F2) with the high dose intervention arm compared with its placebo control. Even though significant progress has been made in analyzing carotenoids, there is a continuing demand for more efficient and more sensitive analytical methods. Technologies that have seldom been applied to carotenoid analysis including ion mobility spectrometry and photoionization mass spectrometry were explored for their potential utility in this area. The use of LC-IM-tandem mass spectrometry helped confirm that in-source isomerization of lycopene, β-carotene, lutein, and zeaxanthin occurred during positive ion electrospray. This in-source isomerization was found to be temperature dependent. After separation using IM, the cis and all-trans isomers of lycopene, β-carotene, lutein, and zeaxanthin were shown by MS-MS with CID to produce unique fragmentation patterns that could be used to distinguish them. Atmospheric pressure photoionization is a mass spectrometric ionization technique that is new in carotenoid analysis. In the study, we first reported that carotenoids can be ionized during negative ion APPI. It was also suggested that dopants were essential for the formation of positive carotenoid ions as well as negative ions during APPI. Among the dopants evaluated, methyl-tert-butyl ether was found to be particularly effective towards the photoionization of carotenoids during negative ion APPI. As for positive ion APPI, the dopants anisole and chlorobenzene were the most effective

    A Two-Step Immunocapture LC/MS/MS Assay for Plasma Stability and Payload Migration Assessment of Cysteine–Maleimide-Based Antibody Drug Conjugates

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    Plasma stability assessment under physiological temperature is an essential step for developing and optimizing antibody drug conjugate (ADC) molecules, especially those with cleavable linkers. The assessment of plasma stability often requires monitoring multiple analytes using a combination of bioanalytical assays for free payloads, conjugated payloads (or conjugated antibodies), total antibodies, and payloads that have migrated from antibodies to plasma constituent proteins. Bioanalytical assays are needed in early drug discovery to quickly screen diverse ADC candidates of different antibody constructs, linker variants, and antibody anchor sites. To improve the sensitivity and selectivity of LC/MS/MS-based assays for the assessment, immunocapture has been widely used for extracting ADCs and unconjugated antibodies from plasma samples. In this study, a novel two-step immunocapture LC/MS/MS assay was described to allow the quantification of conjugated payloads, total antibodies, and migrated payloads forming adducts with albumin in the plasma samples for stability assessment. A target antigen immobilized on magnetic beads was used to exhaustively extract the ADC and antibody-associated species. The remaining supernatant was then extracted further with anti-albumin beads for recovering the albumin-associated adducts for quantification. The method was optimized for higher efficiency and cost-effectiveness using microwave enhanced papain-based enzymatic cleavage for measuring conjugated payloads of ADCs and lysyl endopeptidase cleavage in the total antibody assay. A maleimide linker-based ADC with a proprietary payload, TAK-001, was used to demonstrate the streamlined workflow of the ADC stability assessment. The method could provide valuable evaluation of the stability of the ADC as well as the quantitative assessment of the albumin adducts formed from the linker-payload migration in mouse and human plasma. Furthermore, the method should be readily adaptable for other ADCs using thiol–maleimide conjugation chemistry

    Table_1_An evaluation method for product design solutions for healthy aging companionship.pdf

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    BackgroundWith the development trend of healthy aging and intelligent integration, escort products have become a new means of healthy aging. Healthy old-age care pays attention to the convenience and informatization of life. To meet the needs, designers often design multiple accompanying product solutions, and it is very important to use reasonable evaluation methods to decide on the optimal solution.PurposesA new comprehensive evaluation method is proposed to reduce the subjectivity and one-sidedness of the selection process of intelligent escort product design solutions, and to make the decision more objective and reasonable. Such decisions can enhance the experience and naturalness of the elderly using intelligent products.MethodsFirst, a large number of user interviews were analyzed using the grounded theory, gradually refine through theoretical coding, and abstracted with the design scheme evaluation index. Second, the idea of game-theoretic weighting is used to optimize a linear combination of subjective and objective weights to determine the final weights of each evaluation indicator. Finally, the evaluation and selection are completed based on the solution ranking determined by the approximate ideal solution ranking method (TOPSIS). It is applied for the selection of the elderly escort robot design, and the usability test is conducted using the PSSUQ to verify the selection results.ResultsA new comprehensive evaluation method can better complete the preferential selection of product design solutions for healthy aging escorts, and reduce the subjectivity and one-sidedness of the evaluation.ConclusionThis method compensates for the reliance on personal experience in the selection of options, and improve the subjectivity of the evaluation index determination process and the deviation of index weighting. Improving the objectivity and scientificity of decision-making reduces the blindness of design and production. It also provides a theoretical reference for the research scholars of healthy aging companion products.</p

    Data_Sheet_1_Sampling locations and processing methods shape fungi microbiome on the surface of edible and medicinal Arecae semen.doc

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    IntroductionArecae semen, which is derived from the dried ripe seed of Areca catechu L., has been commonly used as one of the major traditional Chinese medicines (TCMs). Three types of crude herbal preparations, namely, raw Arecae semen (AS), Arecae semen tostum (SAS), and Arecae semen carbonisata (FAS), are available for different clinical applications in TCMs. Although aflatoxin contamination in Arecae semen has been reported preliminarily, only a few studies have been conducted on fungal contamination.MethodsIn this study, the presence of fungi on the surface of three Arecae semen (AS, SAS, and FAS) that collected from four provinces were investigated using high-throughput sequencing and internal transcribed spacer 2.ResultsResults showed that the phyla Ascomycota (75.45%) and Basidiomycota (14.29%) and the genera Wallemia (7.56%), Botryosphaeria (6.91%), Davidiella (5.14%), and Symbiotaphrina (4.87%) were the dominant fungi, and they presented significant differences in four areas and three processed products (p ConclusionsIn conclusion, the diversity and composition of microbiome on the surface of Arecae semen were shaped by sampling location and processing methods. This work provides details on the surface microbiome of Arecae semen samples and highlights the importance of roles of origin and processing methods in microbiomes, ensuring drug efficacy and food safety.</p
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