39684-80-5Relevant articles and documents
In vitro and in vivo evaluation of 99mTc-DO3A-EA-Folate for receptor-mediated targeting of folate positive tumors
Mishra, Gauri,Hazari, Puja Panwar,Kumar, Nitin,Mishra, Anil K.
, p. 761 - 769 (2011)
Background: The cell membrane folate receptor is a potential molecular target for tumor selective drug delivery via receptor-mediated endocytosis, including delivery of radiolabeled folate-chelate conjugates for diagnostic imaging. Method: A new radiopharmaceutical, 99mTc-1,4,7-tris (carboxymethyl)-10-(4-aminoethyl)-1,4,7,10-tetraazacyclododecane (DO3A-EA)-Folate has been synthesized introducing DO3A-EA to the γ-carboxyl group of folic acid and was characterized by different spectroscopic techniques. Cytotoxicity was determined by macrocolony and MTT assay on three different cell lines. Cell uptake studies and receptor binding assay were performed using 99mTc-DO3A-EA-Folate. Tumor imaging was performed in KB cell line implanted tumor bearing nude mice, and uptake of the radiotracer was estimated. Results: The synthesized conjugate binds with 99mTc at high efficiency at ambient temperature. The resulting conjugate is stable under physiological conditions for 24h after radiocomplexation. Using an in vitro receptor binding assay, the conjugate showed Kd in μM range on human tumor cell lines (KB, U-87MG and OAW). The pharmacokinetic data revealed rapid wash out of the more than 75% activity within 5min from the circulation with hepato-biliary clearance. Data from γ scintigraphic and biodistribution studies performed in KB tumor bearing nude mice revealed major accumulation of radiotracer at tumor site. High tumor uptake was shown in the tumor bearing mice; tumor to blood ratios reached 2.27±0.32 and 6.05±1.02 at 1 and 4h after post injection, respectively. Conclusion: These results suggest that 99mTc-DO3A-EA- Folate may be clinically useful as a noninvasive radiodiagnostic imaging agent for the detection of FR-positive human cancers.
Silver-guided excimer emission in an adenine-pyrene conjugate: fluorescence lifetime and crystal studies
Pandey, Mrituanjay D.,Mishra, Ashutosh Kumar,Chandrasekhar, Vadapalli,Verma, Sandeep
, p. 2020 - 2022 (2010)
This Communication describes a novel adenine-pyrene conjugate (1) and its solid-state structure with silver and copper ions. Singlecrystal studies of metal complexes of 1 offer insight into molecular interactions and provide a basis to rationalize possible interactions in the solution state, leading to excimer formation. The robust nature of this interaction was further confirmed by deposition of the silver complex on a graphite surface, which exhibited a remarkable resemblance to its solid-state structure. The structural basis of selective excimer formation in the presence of Ag+ ions presents a viable approach for ratiometric detection of these ions.
Enhanced Out-of-Plane Conductivity and Photovoltaic Performance in n = 1 Layered Perovskites through Organic Cation Design
Passarelli, James V.,Fairfield, Daniel J.,Sather, Nicholas A.,Hendricks, Mark P.,Sai, Hiroaki,Stern, Charlotte L.,Stupp, Samuel I.
, p. 7313 - 7323 (2018)
Layered perovskites with the formula (R-NH3)2PbI4 have excellent environmental stability but poor photovoltaic function due to the preferential orientation of the semiconducting layer parallel to the substrate and the typically insulating nature of the R-NH3+ cation. Here, we report a series of these n = 1 layered perovskites with the form (aromatic-O-linker-NH3)2PbI4 where the aromatic moiety is naphthalene, pyrene, or perylene and the linker is ethyl, propyl, or butyl. These materials achieve enhanced conductivity perpendicular to the inorganic layers due to better energy level matching between the inorganic layers and organic galleries. The enhanced conductivity and visible absorption of these materials led to a champion power conversion efficiency of 1.38%, which is the highest value reported for any n = 1 layered perovskite, and it is an order of magnitude higher efficiency than any other n = 1 layered perovskite oriented with layers parallel to the substrate. These findings demonstrate the importance of leveraging the electronic character of the organic cation to improve optoelectronic properties and thus the photovoltaic performance of these chemically stable low n layered perovskites.
Exploring hydrogen bonding and weak aromatic interactions induced assembly of adenine and thymine functionalised naphthalenediimides
Narayanaswamy, Nagarjun,Avinash,Govindaraju
, p. 1302 - 1306 (2013)
Adenine and thymine functionalised naphthalenediimide (NDI) conjugates and complementary peptide nucleic acid (PNA) dimers are designed to exploit complementary hydrogen bonding and aromatic interactions for controllable molecular organization. These nucleobase appended NDIs organized into well-defined fibers, nanoribbons, porous spheres, belts and petal-like 2D sheets.
Purine-Based Fluorescent Sensors for Imaging Zinc Ions in HeLa Cells
Pratibha,Singh, Swati,Sivakumar, Sri,Verma, Sandeep
, p. 4202 - 4209 (2017)
We synthesized three chelate-tethered purine ligands, having a Schiff base linkage at the N9 position, which resulted in the dipolar imine-methoxyphenol adenine Schiff base HL1, the 2-aminopurine Schiff base HL2, and the 2,6-diaminopurine Schiff base HL3. These ligands selectively showed enhancement of the fluorescence of the zinc ions. The imine-based compound HL1 chelated with zinc ions to give the discrete dimeric structure 1, a green fluorescent complex, which was again stabilized by purine–purine interactions to give a 1D polymeric structure. The ligands having a 6-amino group, HL1 and HL3, have high quantum yield, which gives higher fluorescence enhancement of the free zinc ions in the HeLa cells. HL1 was localized in the cytoplasm and the nucleoli of the HeLa cells, which was confirmed by an RNase digestion test.
Synthesis, Computational Studies and Assessment of in Vitro Activity of Squalene Derivatives as Carbonic Anhydrase Inhibitors
Clima, Lilia,Craciun, Bogdan Florin,Angeli, Andrea,Petreni, Andrea,Bonardi, Alessandro,Nocentini, Alessio,Carta, Fabrizio,Gratteri, Paola,Pinteala, Mariana,Supuran, Claudiu T.
, p. 2052 - 2057 (2020)
We report novel molecules incorporating the nontoxic squalene scaffold and different carbonic anhydrase inhibitors (CAIs). Potent inhibitory action, in the low-nanomolar range, was detected against isoforms hCA II for sulfonamide derivatives, which proved
Pd(II)-Mediated C?H Activation for Cysteine Bioconjugation
Tilden, James A. R.,Lubben, Anneke T.,Reeksting, Shaun B.,Kociok-K?hn, Gabriele,Frost, Christopher G.
supporting information, (2022/01/19)
Selective bioconjugation remains a significant challenge for the synthetic chemist due to the stringent reaction conditions required by biomolecules coupled with their high degree of functionality. The current trailblazer of transition-metal mediated bioconjugation chemistry involves the use of Pd(II) complexes prepared via an oxidative addition process. Herein, the preparation of Pd(II) complexes for cysteine bioconjugation via a facile C?H activation process is reported. These complexes show bioconjugation efficiency competitive with what is seen in the current literature, with a user-friendly synthesis, common Pd(II) sources, and a more cost-effective ligand. Furthermore, these complexes need not be isolated, and still achieve high conversion efficiency and selectivity of a model peptide. These complexes also demonstrate the ability to selectively arylate a single surface cysteine residue on a model protein substrate, further demonstrating their utility.
Ni-Catalyzed Formal Cross-Electrophile Coupling of Alcohols with Aryl Halides
Lin, Quan,Ma, Guobin,Gong, Hegui
, p. 14102 - 14109 (2021/11/20)
Direct coupling of unactivated alcohols remains a challenge in current synthetic chemistry. We herein demonstrate a strategy building upon in situ halogenation/reductive coupling of alcohols with aryl halides to forge Csp2-Csp3 bonds. The combination of 2-chloro-3-ethylbenzo[d]oxazol-3-ium salt (CEBO) and TBAB as the mild bromination reagents enables rapid transformation of a wide range of alcohols to their bromide counterparts within one to 5 min in CH3CN and DMF, which is compatible with the Ni-catalyzed cross-electrophile coupling conditions in the presence of a chemical reductant. The present method is suitable for arylation of a myriad of structurally complex alcohols with no need for prepreparation of alkyl halides. More importantly, the mild and kinetically rapid bromination process has shown good selectivity in the bromination/arylation of symmetric diols and less sterically hindered hydroxyl groups in polyols, thus offering promise for selective functionalization of diols and polyols without laborious protecting/deprotecting operations. The practicality of this work is also evident in the arylation of a number of carbohydrates, drug compounds, and naturally occurring alcohols.
