Tag: M.W=300-350

Trapani, Patricia published the artcileUse of Phenacyl Thiosalicylates for the Preparation of 3-Hydroxybenzo[b]thiophene Derivatives, Application In Synthesis of 119-80-2, the publication is Synlett (2018), 29(6), 810-814, database is CAplus.

In this work, an attempted to synthesize thioflavonols using rearrangement of phenacyl thiosalicylates prepared by two different approaches and subjected to cyclization under acidic conditions. However, the isolated products were identified as (3-hydroxybenzo[b]thiophen-2-yl)(phenyl)methanones, e.g., I. The detailed reaction mechanism was elucidated by characterization of all reaction intermediates with HPLC and NMR spectroscopy. The applicability of the reaction using different phenacyl esters was tested.

Synlett published new progress about 119-80-2. 119-80-2 belongs to catalysis-chemistry, auxiliary class sulfides,Carboxylic acid,Benzene, name is 2,2′-Dithiodibenzoic acid, and the molecular formula is C5H13Cl2N, Application In Synthesis of 119-80-2.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Li, Jian published the artcileOn-Resin Synthesis of Linear Aryl Thioether Containing Peptides and in-Solution Cyclization via Cysteine S_NAr Reaction, Product Details of C20H19NO4, the publication is Organic Letters (2022), 24(8), 1673-1677, database is CAplus and MEDLINE.

Cyclic peptides represent one of the most promising therapeutic agents in drug discovery due to their good affinity and selectivity. Herein, an on-resin synthesis of aryl thioether containing peptides and a concise cyclization strategy via chemoselective cysteine S_NAr reaction was developed. The arylation group could be incorporated into a series of amino acids and used for standard SPPS and peptides cyclization. Constructed cyclic peptides showed increased cellular uptakes compared to their linear peptides.

Organic Letters published new progress about 71989-31-6. 71989-31-6 belongs to catalysis-chemistry, auxiliary class Amino acide derivatives,pyrrolidine, name is Fmoc-Pro-OH, and the molecular formula is C20H19NO4, Product Details of C20H19NO4.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Ni, Feng published the artcileRemarkably Stereospecific Utilization of ATP ¦Á,¦Â-Halomethylene Analogues by Protein Kinases, COA of Formula: C17H37NO3, the publication is Journal of the American Chemical Society (2017), 139(23), 7701-7704, database is CAplus and MEDLINE.

ATP analogs containing a CXY group in place of the ¦Á,¦Â-bridging oxygen atom are powerful chem. probes for studying ATP-dependent enzymes. A limitation of such probes has been that conventional synthetic methods generate a mixture of diastereomers when the bridging carbon substitution is nonequivalent (X ¡Ù Y). We report here a novel method based on derivatization of a bisphosphonate precursor with a D-phenylglycine chiral auxiliary that enables preparation of the individual diastereomers of ¦Á,¦Â-CHF-ATP and ¦Á,¦Â-CHCl-ATP, which differ only in the configuration at the CHX carbon. When tested on a dozen divergent protein kinases, these individual diastereomers exhibit remarkable diastereospecificity (up to over 1000-fold) in utilization by the enzymes. This high selectivity can be exploited in an enzymic approach to obtain the otherwise inaccessible diastereomers of ¦Á,¦Â-CHBr-ATP. The crystal structure of a tyrosine kinase Src bound to ¦Á,¦Â-CHX-ADP establishes the absolute configuration of the CHX carbon and helps clarify the origin of the remarkable diastereospecificity observed We further synthesized the individual diastereomers of ¦Á,¦Â-CHF-¦Ã-thiol-ATP and demonstrated their utility in labeling a wide spectrum of kinase substrates. The novel ATP substrate analogs afforded by these two complementary strategies should have broad application in the study of the structure and function of ATP-dependent enzymes.

Journal of the American Chemical Society published new progress about 17351-62-1. 17351-62-1 belongs to catalysis-chemistry, auxiliary class Salt,Amine, name is Tetrabutylammonium hydrogencarbonate, and the molecular formula is C17H37NO3, COA of Formula: C17H37NO3.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Volpina, Olga M. published the artcileProteolytic degradation patterns of the receptor for advanced glycation end products peptide fragments correlate with their neuroprotective activity in Alzheimer’s disease models, HPLC of Formula: 71989-31-6, the publication is Drug Development Research (2021), 82(8), 1217-1226, database is CAplus and MEDLINE.

The receptor for advanced glycation end products (RAGE) plays an essential role in Alzheimer’s disease (AD). We previously demonstrated that a fragment (60-76) of RAGE improved the memory of olfactory bulbectomized (OBX) and Tg 5 x FAD mice – animal models of AD. The peptide analog (60-76) with protected N- and C-terminal groups was more active than the free peptide in Tg 5 x FAD mice. This study investigated proteolytic cleavage of the RAGE fragment (60-76) and its C- and N-terminally modified analog by blood serum using HPLC and mass spectrometry. The modified peptide was proteolyzed slower than the free peptide. Degrading the protected analog resulted in shortened fragments with memory-enhancing effects, whereas the free peptide yielded inactive fragments. After administering the different peptides to OBX mice, their performance in a spatial memory task revealed that the ED of the modified peptide was five times lower than that of the free peptide. HPLC and mass spectrometry anal. of the proteolytic products allowed us to clarify the differences in the neuroprotective activity conferred by administering these two peptides to AD animal models. The current study suggests that the modified RAGE fragment is more promising for the development of anti-AD therapy than its free analog.

Drug Development Research published new progress about 71989-31-6. 71989-31-6 belongs to catalysis-chemistry, auxiliary class Amino acide derivatives,pyrrolidine, name is Fmoc-Pro-OH, and the molecular formula is C20H28B2O4S2, HPLC of Formula: 71989-31-6.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Hara, Toshihiko published the artcileDevelopment of ¹⁸F-fluoroethylcholine for cancer imaging with PET: synthesis, biochemistry, and prostate cancer imaging, Related Products of catalysis-chemistry, the publication is Journal of Nuclear Medicine (2002), 43(2), 187-199, database is CAplus and MEDLINE.

The effectiveness of ¹¹C-choline PET in detecting various cancers, including prostate cancer, is well established. This study was aimed at developing an ¹⁸F-substituted choline analog, ¹⁸F-fluoroethylcholine (FECh), as a tracer of cancer detection. Methods: No-carrier-added ¹⁸F-FECh was synthesized by 2-step reactions: First, tetrabutylammonium (TBA) ¹⁸F-fluoride was reacted with 1,2-bis(tosyloxy)ethane to yield 2-¹⁸F-fluoroethyl tosylate; and second, 2-¹⁸F-fluoroethyl tosylate was reacted with N,N-dimethylethanolamine to yield ¹⁸F-FECh, which was then purified by chromatog. An automated apparatus was constructed for preparation of the ¹⁸F-FECh injection solution In vitro experiments were performed to examine the uptake of ¹⁸F-FECh in Ehrlich ascites tumor cells, and the metabolites were analyzed by solvent extraction followed by various kinds of chromatog. Clin. studies of ¹⁸F-FECh PET were performed on patients with untreated primary prostate cancer as follows: A dynamic ¹⁸F-FECh PET study was performed on 1 patient and static PET studies were performed on 16 patients, and the data were compared with those of ¹¹C-choline PET on the same patients. Results: ¹⁸F-FECh was prepared in high yield and purity. The performance of the automated apparatus was excellent. The in vitro experiment revealed that ¹⁸F-FECh was incorporated into tumor cells by active transport, then phosphorylated (yielding phosphoryl-¹⁸F-FECh) in the cells, and finally integrated into phospholipids. The clin. PET studies showed marked uptake of ¹⁸F-FECh in prostate cancer. A dynamic PET study on 1 patient revealed that the blood level of ¹⁸F-FECh decreased rapidly (in 1 min), the prostate cancer level became almost maximal in a short period (1.5 min) and it remained constant for a long time (60 min), and the urinary radioactivity became prominent after a short time lag (5 min). Static PET studies conducted under bladder irrigation showed no difference between ¹⁸F-FECh uptake and ¹¹C-choline uptake in prostate cancer. However, ¹⁸F-FECh gave a slightly higher spatial resolution of the image, which was attributed to the shorter positron range of ¹⁸F. Conclusion: The synthesis of ¹⁸F-FECh was easy and reliable. ¹⁸F-FECh PET was very effective in detecting prostate cancer in patients. The chem. trap, consisting of active transport of ¹⁸F-FECh and formation of phosphoryl-¹⁸F-FECh, seemed to be involved in the uptake mechanism of ¹⁸F-FECh in tumors.

Journal of Nuclear Medicine published new progress about 17351-62-1. 17351-62-1 belongs to catalysis-chemistry, auxiliary class Salt,Amine, name is Tetrabutylammonium hydrogencarbonate, and the molecular formula is C17H37NO3, Related Products of catalysis-chemistry.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Oka, Marina published the artcileGreen Aerobic Oxidation of Thiols to Disulfides by Flavin-Iodine Coupled Organocatalysis, Application of 2,2′-Dithiodibenzoic acid, the publication is Synlett (2021), 32(12), 1227-1230, database is CAplus.

Coupled catalysis using a riboflavin-derived organocatalyst and mol. iodine successfully promoted the aerobic oxidation of thiols to disulfides under metal-free mild conditions. The activation of mol. oxygen occurred smoothly at room temperature through the transfer of electrons from the iodine catalyst to the biomimetic flavin catalyst, forming the basis for a green oxidative synthesis of disulfides from thiols.

Synlett published new progress about 119-80-2. 119-80-2 belongs to catalysis-chemistry, auxiliary class sulfides,Carboxylic acid,Benzene, name is 2,2′-Dithiodibenzoic acid, and the molecular formula is C14H10O4S2, Application of 2,2′-Dithiodibenzoic acid.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Borbala Horvath, Lilla published the artcileHost cell targeting of novel antimycobacterial 4-aminosalicylic acid derivatives with tuftsin carrier peptides, Name: Fmoc-Pro-OH, the publication is European Journal of Pharmaceutics and Biopharmaceutics (2022), 111-130, database is CAplus and MEDLINE.

Mycobacterium tuberculosis is an intracellular pathogen and the uptake of the antimycobacterial compounds by host cells is limited. Novel antimycobacterials effective against intracellular bacteria are needed. New N-substituted derivatives of 4-aminosalicylic acid have been designed and evaluated. To achieve intracellular efficacy and selectivity, these compounds were conjugated to tuftsin peptides via oxime or amide bonds. These delivery peptides can target tuftsin- and neuropilin receptor-bearing cells, such as macrophages and various other cells of lung origin. We have demonstrated that the in vitro antimycobacterial activity of the 4-aminosalicylic derivatives against M. tuberculosis H₃₇Rv was preserved in the peptide conjugates. The free drugs were ineffective on infected cells, but the conjugates were active against the intracellular bacteria and have the selectivity on various types of host cells. The intracellular distribution of the carrier peptides was assessed, and the peptides internalize and display mainly in the cytosol in a concentration-dependent manner. The penetration ability of the most promising carrier peptide OT5 was evaluated using Transwell-inserts and spheroids. The pentapeptide exhibited time- and concentration-dependent penetration across the non-contact monolayers. Also, the pentapeptide has a fair penetration rate towards the center of spheroids formed of EBC-1 cells.

European Journal of Pharmaceutics and Biopharmaceutics published new progress about 71989-31-6. 71989-31-6 belongs to catalysis-chemistry, auxiliary class Amino acide derivatives,pyrrolidine, name is Fmoc-Pro-OH, and the molecular formula is C20H19NO4, Name: Fmoc-Pro-OH.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Bjorgaard, Josiah A. published the artcileAmplified quenching of conjugated polymer nanoparticle photoluminescence for robust measurement of exciton diffusion length, Safety of 5,9-Diaminobenzo[a]phenoxazin-7-ium acetate, the publication is Journal of Applied Physics (Melville, NY, United States) (2013), 113(20), 203707/1-203707/6, database is CAplus.

A new method for measuring exciton diffusion length in nanoparticles (NPs) of conjugated materials is presented. Cationic acceptor dyes are used to quench the photoluminescence in NPs of the prototypical conjugated polymer poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV). Amplified quenching of MEH-PPV emission is observed with an initial Stern-Volmer constant >10⁵ M^-1. Stern-Volmer plots are nonlinear with 2 distinct quenching regimes, hinting saturation of NP surfaces with acceptor mols. at some point during titration experiments Using an assumption that highly efficient quenching of excitons occurs after saturation with acceptors at the NP surfaces, the amount of maximum emission quenching can be compared with a model of exciton diffusion to determine exciton diffusion length. By assuming quenching efficiency >80%, the measured 3 dimensional exciton diffusion length is 12 ¡À 1 nm. This result is in the lower region of reported values ranging from 10 to 25 nm in MEH-PPV thin films. Both the derived model and the exptl. methodol. allow robust measurement of exciton diffusion length for any luminescent conjugated material from which NPs can be prepared (c) 2013 American Institute of Physics.

Journal of Applied Physics (Melville, NY, United States) published new progress about 10510-54-0. 10510-54-0 belongs to catalysis-chemistry, auxiliary class Other Aromatic Heterocyclic,Salt,Amine,Inhibitor,Inhibitor, name is 5,9-Diaminobenzo[a]phenoxazin-7-ium acetate, and the molecular formula is C18H15N3O3, Safety of 5,9-Diaminobenzo[a]phenoxazin-7-ium acetate.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Modrzycka, Sylwia published the artcileParallel imaging of coagulation pathway proteases activated protein C, thrombin, and factor Xa in human plasma, Synthetic Route of 71989-31-6, the publication is Chemical Science (2022), 13(23), 6813-6829, database is CAplus and MEDLINE.

Activated protein C (APC), thrombin, and factor (f) Xa are vitamin K-dependent serine proteases that are key factors in blood coagulation. Moreover, they play important roles in inflammation, apoptosis, fibrosis, angiogenesis, and viral infections. Abnormal activity of these coagulation factors has been related to multiple conditions, such as bleeding and thrombosis, Alzheimer¡äs disease, sepsis, multiple sclerosis, and COVID-19. The individual activities of APC, thrombin, and fXa in coagulation and in various diseases are difficult to establish since these proteases are related and have similar substrate preferences. Therefore, the development of selective chem. tools that enable imaging and discrimination between coagulation factors in biol. samples may provide better insight into their roles in various conditions and potentially aid in the establishment of novel diagnostic tests. In our study, we used a large collection of unnatural amino acids, and this enabled us to extensively explore the binding pockets of the enzymes¡ä active sites. Based on the specificity profiles obtained, we designed highly selective substrates, inhibitors, and fluorescent activity-based probes (ABPs) that were used for fast, direct, and simultaneous detection of APC, thrombin, and fXa in human plasma.

Chemical Science published new progress about 71989-31-6. 71989-31-6 belongs to catalysis-chemistry, auxiliary class Amino acide derivatives,pyrrolidine, name is Fmoc-Pro-OH, and the molecular formula is C20H19NO4, Synthetic Route of 71989-31-6.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Lastovickova, Lenka published the artcileDried blood spot as an alternative sample for screening of fatty acid, amino acid, and keto acid metabolism in humans, HPLC of Formula: 6217-54-5, the publication is Biomedical Chromatography (2022), 36(9), e5431, database is CAplus and MEDLINE.

Dried blood spot (DBS) is a simple and noninvasive sample collection technique allowing self-collection at home. It can be used as an alternative sample for the screening of metabolism in humans because changes in the levels of some fatty acids (FAs), amino acids (AAs), and keto acids (KAs) can be associated with metabolic disorders (e.g., diabetes mellitus). In this study, we optimized three different methods that are sensitive enough for the determination of the aforementioned analytes from a small volume of biol. material in DBS. A total of 20 AAs, 5 KAs, and 24 FAs were determined This sampling technique was applied to prepare samples from 60 individuals by a finger prick. The samples were analyzed using chromatog. methods, and acquired data were statistically evaluated. Even though most analytes were higher in men, only five AAs, three KAs, and eight FAs showed significant gender dependency (¦Á = 0.05). Asparagine, serine, and ¦Á- and ¦Ã-linolenic acids showed significant age dependency (¦Á = 0.05). Most statistically significant correlations were pos. and were found within one category. This work shows that because of many benefits, the DBS sample could be a good alternative to whole blood sample collection for the screening of metabolism in humans, in general, or in individualized medicine. The chromatog. methods can be used in future research, for example, to set the reference range or plasma-correction factors (various aspects such as age or gender should be considered).

Biomedical Chromatography published new progress about 6217-54-5. 6217-54-5 belongs to catalysis-chemistry, auxiliary class Alkenyl,Carboxylic acid,Aliphatic hydrocarbon chain,Metabolic Enzyme,RAR/RXR,Natural product, name is Docosahexaenoic Acid, and the molecular formula is C22H32O2, HPLC of Formula: 6217-54-5.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia