Insights into the mechanism for ring-opening polymerization of lactide catalyzed by Zn(C6F5)2/organic superbase Lewis pairs

2016 ◽  
Vol 6 (21) ◽  
pp. 7763-7772 ◽  
Author(s):  
Xiao-Qing Li ◽  
Bin Wang ◽  
He-Yuan Ji ◽  
Yue-Sheng Li
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Experimental Results ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Good Consistency ◽  
Plausible Mechanism ◽  
Tof Ms ◽  
Lewis Pairs

A plausible mechanism for ring-opening polymerization of lactide catalyzed by Zn(C6F5)2-based Lewis pairs was proposed based on in situ NMR and MALDI-TOF MS analyses. Several experimental results show very good consistency with the proposed mechanism.

Lithium, sodium, potassium and calcium amine-bis(phenolate) complexes in the ring-opening polymerization of rac-lactide

2020 ◽  
Vol 49 (5) ◽  
pp. 1531-1544 ◽  
Author(s):  
Katalin Devaine-Pressing ◽  
Fabio J. Oldenburg ◽  
Jan P. Menzel ◽  
Maximilian Springer ◽  
Louise N. Dawe ◽  
...  
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Sodium Potassium ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms ◽  
Lactide Polymerization

Li, Na, K and Ca complexes capable of rac-lactide polymerization in both the melt and in solution were synthesized. MALDI-TOF MS showed mainly cyclic PLA was obtained even in the presence of an alcohol co-initiator.

scholarly journals Controlled density glycodendron microarrays for studying carbohydrate–lectin interactions

2021 ◽  
Author(s):  
Antonio Di Maio ◽  
Anna Cioce ◽  
Silvia Achilli ◽  
Michel Thépaut ◽  
Corinne Vivès ◽  
...  
Keyword(s):  
Maldi Tof Ms ◽  
Maldi Tof ◽  
On Chip ◽  
Tof Ms

Density depended binding and selectivity is studied on glycodendron microarray with defined valency, which were prepared by on-chip synthesis and analysed by in situ MALDI-TOF MS.

In Vitro and In Situ Tracking of Choline-Phospholipid Biogenesis by MALDI TOF-MS

2006 ◽  
Vol 78 (4) ◽  
pp. 1174-1180 ◽  
Author(s):  
Rosendo Estrada ◽  
Douglas Borchman ◽  
John Reddan ◽  
Anne Hitt ◽  
M. Cecilia Yappert
Keyword(s):  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Choline Phospholipid ◽  
Tof Ms

scholarly journals Novel In Situ Pretreatment Method for Significantly Enhancing the Signal In MALDI-TOF MS of Formalin-Fixed Paraffin-Embedded Tissue Sections

PLoS ONE ◽  
2012 ◽  
Vol 7 (8) ◽  
pp. e41607 ◽  
Author(s):  
Yu Kakimoto ◽  
Tatsuaki Tsuruyama ◽  
Takushi Yamamoto ◽  
Masaru Furuta ◽  
Hirokazu Kotani ◽  
...  
Keyword(s):  
Pretreatment Method ◽  
Maldi Tof Ms ◽  
Tissue Sections ◽  
Maldi Tof ◽  
Formalin Fixed Paraffin ◽  
Formalin Fixed Paraffin Embedded ◽  
Formalin Fixed ◽  
Tof Ms

In situ generation of milk protein-derived peptides in drying-off cows

2010 ◽  
Vol 77 (4) ◽  
pp. 487-497 ◽  
Author(s):  
Chin H Ho ◽  
Chai J Chang ◽  
Wen B Liu ◽  
Huo C Peh ◽  
Shuen E Chen ◽  
...  
Keyword(s):  
Milk Protein ◽  
Peptide Sequence ◽  
Functional Screening ◽  
Post Translational Modification ◽  
Peptide Profile ◽  
Maldi Tof Ms ◽  
Esi Ms ◽  
Maldi Tof ◽  
Tof Ms

Our previous studies demonstrated prompt elevation of proteinase activity in mammary secretion of drying-off cows and goats. The current study examined the progressive changes in composition of cow mammary secretion following drying-off and, in parallel, characterized the mode of peptide neogenesis using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and liquid chromatography-electrospray-ionization (LC-ESI) MS/MS. The results show that the percentage of casein of total milk protein at time of drying-off was 76%, which dropped to 41%, 24%, and 16%, respectively, 1, 2, and 3 weeks after drying-off. Levels of β-lactoglobulin and α-lactoalbumin in mammary secretions of drying-off cows decreased prominently while levels of lactoferrin, BSA, and casein derived-proteins increased concomitantly compared with regular milk. A fractionation procedure was applied to remove molecules larger than 10 kDa before MALDI-TOF MS and LC-ESI MS/MS and the results show that the MALDI-TOF MS peptide profile of mammary secretion ranging from m/z 600 to 4000 was apparently modified after drying-off for 1 week, whereas species 1590 m/z and 2460 m/z were most obviously enriched compared with regular milk. LC-ESI MS/MS results were used to map peptide sequence with Mascot search server and under no post translational modification to reduce database size and 202 novel β-casein-derived peptides were successfully identified in mammary secretion after drying-off for 1 week in contrast to regular milk. Accordingly at least 48 additional cleavage positions were assigned on β-casein for mammary secretion. Among the 202 novel peptides, 5 are homologous with confirmed opioid agonists, angiotensin 1-converting enzyme inhibitors, or immuno-modulators. In conclusion, peptides are released in situ from milk proteins within short intervals following drying-off in cows. They might play roles in the transition of mammary glands from lactating to non-lactating. With specified post-translational modifications and focused functional screening, novel peptides are yet to be discovered in dry cow mammary secretion.

In situ derivatization of Au nanoclusters via aurophilic interactions of a triphenylphosphine gold(i) salt with neurotransmitters and their rapid MALDI-TOF-MS detection in mice brain tissue extracts

2020 ◽  
Vol 8 (1) ◽  
pp. 38-44 ◽  
Author(s):  
Sivakumar Palanisamy ◽  
Shuai Huang ◽  
Huiyuan Zhao ◽  
Di Zhu ◽  
Xiaozhe Zhang
Keyword(s):  
Brain Tissue ◽  
Au Nanoclusters ◽  
Maldi Tof Ms ◽  
Ms Detection ◽  
Maldi Tof ◽  
Tissue Extracts ◽  
Mice Brain ◽  
Aurophilic Interactions ◽  
Tof Ms

Rapid MALDI-TOF-MS detection of neurotransmitters in mice brain tissue extracts using triphenylphosphine gold(i) salt as an efficient matrix.

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