scholarly journals A Simple and Advantageous Synthesis of the Privileged 1,4-Benzodiazepine Nucleus

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Neetu Jain ◽  
Dharma Kishore
Keyword(s):  
High Yield ◽  
Easy Access ◽  
Consecutive Series ◽  
Butyl Lithium ◽  
Incipient Species ◽  
Intramolecular Reactions ◽  
Hydrolysis Of ◽  
Yield And Purity

A novel domino approach has been described for an easy access of the privileged nucleus of 5-carbomethoxy substituted 1,4-benzodiazepin-2-ones 4(a–i) from an in situ methanolic hydrolysis of an incipient species formed from the interaction of 1-chloroacetylisatin 2(a–i), hexamethyldisilazane, and n-butyl lithium. The reaction is believed to take place through a consecutive series of intramolecular reactions in a cascade to first generate a highly reactive carbene intermediate 3(a–i) from 1-chloroacetylisatin and n-butyl lithium which is simultaneously trapped by hexamethyldisilazane before undergoing its in situ hydrolysis with methanol to initiate its concomitant cyclocondensation to produce 4(a–i) in high yield and purity.

scholarly journals A novel high-yield synthesis of aminoacyl p-nitroanilines and aminoacyl 7-amino-4-methylcoumarins: Important synthons for the synthesis of chromogenic/fluorogenic protease substrates

2011 ◽  
Vol 7 ◽  
pp. 1030-1035 ◽  
Author(s):  
Xinghua Wu ◽  
Yu Chen ◽  
Herve Aloysius ◽  
Longqin Hu
Keyword(s):  
Amino Acids ◽  
High Yield ◽  
Easy Access ◽  
General Applicability ◽  
Peptide Substrates ◽  
Peptide Chemistry ◽  
Amino Acid Peptide ◽  
Hydroxysuccinimide Esters ◽  
Fluorogenic Peptide

Aminoacyl p-nitroaniline (aminoacyl-pNA) and aminoacyl 7-amino-4-methylcoumarin (aminoacyl-AMC) are important synthons for the synthesis of chromogenic/fluorogenic protease substrates. A new efficient method was developed to synthesize aminoacyl-pNA and aminoacyl-AMC derivatives in excellent yields starting from either amino acids or their corresponding commercially available N-hydroxysuccinimide esters. The method involved the in situ formation of selenocarboxylate intermediate of protected amino acids and the subsequent non-nucleophilic amidation with an azide. Common protecting groups used in amino acid/peptide chemistry were all well-tolerated. The method was also successfully applied to the synthesis of a dipeptide conjugate, indicating that the methodology is applicable to the synthesis of chromogenic substrates containing short peptides. The method has general applicability to the synthesis of chromogenic and fluorogenic peptide substrates and represents a convenient and high-yield synthesis of N α-protected-aminoacyl-pNAs/AMCs, providing easy access to these important synthons for the construction of chromogenic/fluorogenic protease substrates through fragment condensation or stepwise elongation.

INDIREKTE PAPIERCHROMATOGRAPHISCHE METHODE ZUR BESTIMMUNG DER HARNOESTROGENE

1961 ◽  
Vol 38 (4) ◽  
pp. 545-562 ◽  
Author(s):  
L. Kecskés ◽  
F. Mutschler ◽  
I. Glós ◽  
E. Thán ◽  
I. Farkas ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Granulosa Cell ◽  
Iron Content ◽  
List Type ◽  
Granulosa Cell Tumour ◽  
Hydrolysis Of ◽  
Phenol Fraction ◽  
Qualitative Determination

ABSTRACT 1. An indirect paperchromatographic method is described for separating urinary oestrogens; this consists of the following steps: acidic hydrolysis, extraction with ether, dissociation of phenol-fractions with partition between the solvents. Previous purification of phenol fraction with the aid of paperchromatography. The elution of oestrogen containing fractions is followed by acetylation. Oestrogen acetate is isolated by re-chromatography. The chromatogram was developed after hydrolysis of the oestrogens 'in situ' on the paper. The quantity of oestrogens was determined indirectly, by means of an iron-reaction, after the elution of the iron content of the oestrogen spot, which was developed by the Jellinek-reaction. 2. The method described above is satisfactory for determining urinary oestrogen, 17β-oestradiol and oestriol, but could include 16-epioestriol and other oestrogenic metabolites. 3. The sensitivity of the method is 1.3–1.6 μg/24 hours. 4. The quantitative and qualitative determination of urinary oestrogens with the above mentioned method was performed in 50 pregnant and 9 non pregnant women, and also in 2 patients with granulosa cell tumour.

In Situ Microscopy for In-line Monitoring of the Enzymatic Hydrolysis of Cellulose

2013 ◽  
Vol 85 (17) ◽  
pp. 8121-8126 ◽  
Author(s):  
Britta Opitz ◽  
Andreas Prediger ◽  
Christian Lüder ◽  
Marrit Eckstein ◽  
Lutz Hilterhaus ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Enzymatic Hydrolysis Of Cellulose ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of

scholarly journals Generation of Monoclonal Antibodies for Sensitive Detection of Pro-Inflammatory Protein S100A9

2021 ◽  
Vol 11 (10) ◽  
pp. 4659
Author(s):  
Eun-Jung Kim ◽  
Gyu-Min Im ◽  
Chang-Soo Lee ◽  
Yun-Gon Kim ◽  
Byoung Joon Ko ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Calcium Binding ◽  
Nucleotide Sequences ◽  
Antibody Fragments ◽  
High Yield ◽  
Antigen Binding ◽  
Hybridoma Cell Culture ◽  
Inflammatory Protein ◽  
Inflammatory Processes ◽  
Yield And Purity

The calcium-binding protein S100A9 regulates inflammatory processes and the immune response. It is overexpressed in a variety of inflammatory and oncologic conditions. In this study, we produced a recombinant human S100A9 (hS100A9) antigen with high yield and purity and used it to generate a hybridoma cell culture-based monoclonal anti-hS100A9 antibody. We selected five anti-hS100A9 antibodies from cell supernatants that showed high antigen binding efficiency and identified the nucleotide sequences of three antibodies: two with high effective concentration values and one with the lowest value. The antigen and antibody development procedures described herein are useful for producing large amounts of monoclonal antibodies against hS100A9 and other antigens of interest. The nucleotide sequences of the anti-hS100A9 monoclonal antibody revealed herein will be helpful in the generation of recombinant antibodies or antibody fragments against hS100A9.

scholarly journals Defined MSC exosome with high yield and purity to improve regenerative activity

2021 ◽  
Vol 12 ◽  
pp. 204173142110086
Author(s):  
Jun Yong Kim ◽  
Won-Kyu Rhim ◽  
Yong-In Yoo ◽  
Da-Seul Kim ◽  
Kyoung-Won Ko ◽  
...  
Keyword(s):  
Cell Culture ◽  
Culture Medium ◽  
Density Lipoprotein ◽  
High Yield ◽  
Human Umbilical Cord ◽  
Cell Culture Medium ◽  
Human Coronary Artery ◽  
Isolation Methods ◽  
Regenerative Activity ◽  
Yield And Purity

Exosomes derived from mesenchymal stem cells (MSCs) have been studied as vital components of regenerative medicine. Typically, various isolation methods of exosomes from cell culture medium have been developed to increase the isolation yield of exosomes. Moreover, the exosome-depletion process of serum has been considered to result in clinically active and highly purified exosomes from the cell culture medium. Our aim was to compare isolation methods, ultracentrifuge (UC)-based conventional method, and tangential flow filtration (TFF) system-based method for separation with high yield, and the bioactivity of the exosome according to the purity of MSC-derived exosome was determined by the ratio of Fetal bovine serum (FBS)-derived exosome to MSC-derived exosome depending on exosome depletion processes of FBS. The TFF-based isolation yield of exosome derived from human umbilical cord MSC (UCMSC) increased two orders (92.5 times) compared to UC-based isolation method. Moreover, by optimizing the process of depleting FBS-derived exosome, the purity of UCMSC-derived exosome, evaluated using the expression level of MSC exosome surface marker (CD73), was about 15.6 times enhanced and the concentration of low-density lipoprotein-cholesterol (LDL-c), known as impurities resulting from FBS, proved to be negligibly detected. The wound healing and angiogenic effects of highly purified UCMSC-derived exosomes were improved about 23.1% and 71.4%, respectively, with human coronary artery endothelial cells (HCAEC). It suggests that the defined MSC exosome with high yield and purity could increase regenerative activity.

scholarly journals Permeability of muscle capillaries to small heme-peptides. Evidence for the existence of patent transendothelial channels.

1975 ◽  
Vol 64 (3) ◽  
pp. 586-607 ◽  
Author(s):  
N Simionescu ◽  
M Siminoescu ◽  
G E Palade
Keyword(s):  
Plasma Proteins ◽  
Intercellular Junctions ◽  
Rat Diaphragm ◽  
Enzymic Hydrolysis ◽  
Graphic Analysis ◽  
Heme Peptides ◽  
Future Work ◽  
Hydrolysis Of ◽  
Muscle Capillaries

Two heme-peptides (HP) of about 20-A diameter (heme-undecapeptide [H11P], mol wt approximately 1900 and heme-octapeptide [H8P], mol wt approximately 1550), obtained by enzymic hydrolysis of cytochrome c, were sued as probe molecules in muscle capillaries (rat diaphragm). They were localized in situ by a perixidase reaction, enhanced by the addition of imidazole to the incubation medium. Chromatography of plasma samples showed that HPs circulate predominantly as monomers for the duration of the experiments and are bound by aldehyde fixatives to plasma proteins to the extent of approximately 50% (H8P) to approximately 95% (H11P). Both tracers cross the endothelium primarily via plasmalemmal vesicles which become progressively labeled (by reaction product) from the blood front to the tissue front of the endothelium, in three successive resolvable phases. By the end of each phase the extent of labeling reaches greater than 90% of the corresponding vesicle population. Labeled vesicles appear as either isolated units or chains which form patent channels across the endothelium. The patency of these channels was checked by specimen tilting and graphic analysis of their images. No evidence was found for early or preferential marking of the intercellular junctions and spaces by reaction product. It is concluded that the channels are the most likely candidate for structural equivalents of the small pores of the capillary wall since they are continuous, water-filled passages, and are provided with one or more strictures of less than 100 A. Their frequency remains to be established by future work.

scholarly journals HIGH-YIELD PREPARATION OF ISOLATED RAT LIVER PARENCHYMAL CELLS

1969 ◽  
Vol 43 (3) ◽  
pp. 506-520 ◽  
Author(s):  
M. N. Berry ◽  
D. S. Friend
Keyword(s):  
Gap Junctions ◽  
Rat Liver ◽  
Structural Integrity ◽  
Cell Injury ◽  
High Yield ◽  
Isolated Cells ◽  
Nylon Mesh ◽  
Parenchymal Cells

A new technique employing continuous recirculating perfusion of the rat liver in situ, shaking of the liver in buffer in vitro, and filtration of the tissue through nylon mesh, results in the conversion of about 50% of the liver into intact, isolated parenchymal cells. The perfusion media consist of: (a) calcium-free Hanks' solution containing 0.05% collagenase and 0.10% hyaluronidase, and (b) magnesium and calcium-free Hanks' solution containing 2 mM ethylenediaminetetraacetate. Biochemical and morphologic studies indicate that the isolated cells are viable. They respire in a medium containing calcium ions, synthesize glucose from lactate, are impermeable to inulin, do not stain with trypan blue, and retain their structural integrity. Electron microscopy of biopsies taken during and after perfusion reveals that desmosomes are quickly cleaved. Hemidesmosome-containing areas of the cell membrane invaginate and appear to pinch off and migrate centrally. Tight and gap junctions, however, persist on the intact, isolated cells, retaining small segments of cytoplasm from formerly apposing parenchymal cells. Cells which do not retain tight and gap junctions display swelling of Golgi vacuoles and vacuoles in the peripheral cytoplasm. Cytoplasmic vacuolization in a small percentage of cells and potassium loss are the only indications of cell injury detected. By other parameters measured, the isolated cells are comparable to normal hepatic parenchymal cells in situ in appearance and function.

1-Carba-arachno-pentaborane(10) Derivatives

1997 ◽  
Vol 62 (8) ◽  
pp. 1254-1262 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Hans-Jörg Schanz
Keyword(s):  
High Yield ◽  
Exchange Reactions ◽  
Nmr Data ◽  
Substituted 1 ◽  
C Nmr

The formation of organo substituted 1-carba-arachno-pentaborane(10) derivatives is shown to proceed in high yield via in situ generated 1,1,1-tris(diethylboryl)propane (2) from diethyl(propyn-1-yl)borane (1) by hydroboration with an excess of diethylborane (hydride bath). In the hydride bath, exchange reactions between 2 and other geminal bis(diethylboryl)alkanes take place until the carbaborane skeleton is formed. If tris(diethylboryl)methane is used under the same conditions, the corresponding 1-carba-arachno-pentaborane(10) derivatives 11 and 12 are formed in mixture with other unknown boranes or carboranes. 11B and 13C NMR data are presented to allow for straightforward identification of the 1-carba-arachno-pentaboranes(10).

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