Other Syntheses of Boc-Protected Amino Groups
Fmoc-N-(propargyl)-glycine - Chem-Impex International
Fmoc- N -(propargyl)-glycine ..
We review nucleotide modifications, such as those to phosphate and sugar moieties that increase nuclease resistance or the range of activities possible, as well as whole nucleobase replacement that results in selective pairing and the creation of unnatural base pairs. Both in vitro and in vivo examples are discussed, including efforts to create semi-synthetic organisms with altered or expanded genetic alphabets.
We have synthesized DNA-encoded libraries based on two representatives of these scaffolds, a benzodiazepine and a pyrazolopyrimidine, and additionally a third library based on propargyl glycine.
norvaline, nor-leucine, ornithine, propargyl-glycine ..
Jeong demonstrated the use of galactose-conjugated SPIONs as a hepatocyte-targeted dual contrast agent (nuclear imaging/ MRI) in a mouse model . Generally, SPIONs are nonspecifically phagocytosed or endocytosed by RES in the liver, spleen, lymph, and bone marrow after i.v. injection. Therefore, hepatocyte-selective imaging was needed for the evaluation of hepatocytic function under certain clinical conditions, such as partial liver transplant or hepatitis, as well as for monitoring the disease progress. This research group synthesized lactobionic acid- (LBA) with a high affinity for ASGP-R, and immobilized the LBA onto SPIONs via amide linkages between the dopamine-modified SPIONs bearing a primary amine group and the lactobionic acid using 1-ethyl-3-(3-(dimethylamino)-propyl) carbodiimide/ -hydroxysuccinimide (EDC/NHS) chemistry. To radiolabel nanoparticles with 99mTC, diethylene triamine pentaacetic acid (DTPA) was then conjugated to the remaining amine groups of dopamine-SPIONs. After tail vein injection, micro-single photon emission computed tomography (SPECT)/CT images and T2-weighted MR images indicated that the 99mTC-LBA-SPION mainly accumulated in the liver within a few minutes. A competition study involving blocking of the ASGP-R with free galactose showed a large decrease in the liver uptake, suggesting ASGP-R-mediated uptake of 99mTC-LBA-SPIONs. TEM analysis confirmed that the LBA-SPIONs were located in the mitochondrial matrix as well as in the cytoplasm, indicating ASGP-R-mediated internalization of the nanoparticles into hepatocytes.
Riboflavin is an essential vitamin for cellular metabolism, and the riboflavin carrier protein (RCP) is highly upregulated in metabolically active cells [,]. Thus, flavin mononucleotide (FMN), an endogenous RCP ligand, was used as a small molecule targeting ligand for metabolically active cancer or endothelial cells. Kiessling and co-workers synthesized FMN-coated ultrasmall superparamagnetic iron oxide nanoparticles (FLUSPIO) as MRI/optical dual probes for cancer detection . USPIO was coated with FMN through the phosphate groups of FMN, and guanosine monophosphate was added to stabilize the colloid. The hydrodynamic radius of FLUSPIO was 97 ± 3 nm, and an intense fluorescence emission band was observed at 530 nm due to FMN. cellular uptake of FLUSPIO was investigated by MRI (3T), TEM, and fluorescence microscopy of PC3 cells and HUVEC cells. Both PC3 cells and HUVEC cells showed a significantly higher R2 relaxation rate after 1 h incubation with FLUSPIO than with nontargeted USPIO. Such an uptake was considerably reduced by competitive blocking of RCP with free FMN. A strong green fluorescence in the cells was observed after FLUSPIO incubation. The perinuclear fluorescence signal suggested endosomal localization of the nanoparticles, consistent with TEM results, suggesting that FMN could serve as a versatile building block for generating tumor-targeted imaging and therapeutic modalities.
Larock indole synthesis - Wikipedia
HBO was synthesized and incorporated into DNA oligonucleotides and each oligonucleotide was hybridized to a complementary oligonucleotide containing an abasic site at the position opposite HBO. Analysis of steady state emission spectra of the oligonucleotides indicates that the DNA environment selectively stabilizes the proton-transfer product tautomer of HBO, suggesting that flanking bases may be strongly coupled electronically.
To generate residue-specific information on the equilibrium folding of cyt c, we have semisynthesized the protein with specifically deuterated residues. Plotted as a function of added guanidine hydrochloride denaturant, the absorption intensities of the protein C-D bonds reveal that cyt c undergoes a conformational change at the protein-based heme ligand, Met80, which is then followed by a more global unfolding at 2.3 M GdnHCL.
Pyrrole synthesis - Organic chemistry
Thiazole synthesis - Organic chemistry
Thieme E-Books & E-Journals - Synthesis / Issue
Categories: Synthesis of N-Heterocycles, Synthesis of S-Heterocycles > Synthesis of thiazoles
The Journal of Organic Chemistry (ACS Publications)
Protecting group - Wikipedia
The chemistry of isatins: a review from 1975 to 1999 - SciELO
Medarova . synthesized a breast tumor-targeted nanodrug designed to specifically shuttle siRNA to human breast cancer while simultaneously allowing for the noninvasive monitoring of the siRNA delivery process . The nanodrug consisted of SPIONs for MRI monitoring, Cy5.5 fluorescence dye for near-infrared (IR) optical imaging, and siRNA to target the tumor-specific antiapoptotic gene . Magnetic iron oxide nanoparticles are extensively used as multimodal imaging probes in combination with optical fluorescence dyes to obtain the benefits of optical imaging, such as rapid screening and high sensitivity. Because tumor-associated underglycosylated mucin-1 (uMUC-1) antigen is overexpressed in >90% of breast cancers and in >50% of all cancers in humans , researchers have decorated nanodrugs with uMUC-1-targeting EPPT synthetic peptides for selective tumor targeting. As shown in Figure A, amine-functionalized superparamagnetic iron oxide nanoparticles with a cross-linked dextran coating (MN) have been prepared, and a Cy5.5 dye was conjugated to the surface of nanoparticles to produce MN-Cy5.5. Subsequently, thiol-modified, FITC-labeled EPPT peptides and siRNA were coupled to MN-Cy5.5 via a heterofunctional cross-linker, -succinimidyl 3-(2-pyridyldithio) propionate (SPDP). The resulting therapeutic and diagnostic nanodrug (MN-EPPT-siBIRC5) exhibited superparamagnetic and fluorescence properties. After intravenous injection of the nanodrugs into mice with BT-20 breast tumors, the tumors were clearly imaged, as verified simultaneously by T2 MRI and near-IR optical imaging (Figure B). Systemic administration of the nanodrug once a week over 2 weeks induced considerable levels of necrosis and apoptosis in the tumors as a result of the siBIRC5-mediated inhibition of the antiapoptotic survivin protooncogene, translating into a significant decrease in tumor growth rate (Figure C). This tumor-targeted, imaging-capable nanodrug highlights the potential of MRI-guided tumor treatment, which can be used to quantify changes in the tumor volume over the treatment schedule as well as to guide selection of an optimal treatment time course.
An irreversible inhibitor of H 2 S synthesis
Mechanism of action: Trimetrexate is a competitive inhibitor of dihydrofolate reductase (DHFR) from bacterial, protozoan, and mammalian sources. DHFR catalyzes the reduction of intracellular dihydrofolate to the active coenzyme tetrahydrofolate. Inhibition of DHFR results in the depletion of this coenzyme, leading directly to interference with thymidylate biosynthesis, as well as inhibition of folate-dependent formyltransferases .The end result is disruption of DNA, RNA, and protein synthesis, with consequent cell death 13.
FR2747676A1 - New propargyl glycine derivatives - …
We report the synthesis and analysis of the ribo- and deoxyribo-variants, (d)5SICS and (d)MMO2, modified with free or protected propargylamine linkers that allow for the site-specific modification of DNA or RNA during or after enzymatic synthesis. We also synthesized and evaluated the α-phosphorothioate variant of d5SICSTP, which provides a route to backbone thiolation and an additional strategy for the post-amplification site-specific labeling of DNA.
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