A5067353582- Chemical Synthesis and Analysis
- Carbohydrate Chemistry and Synthesis
- Photodynamic Therapy Research Studies
- Click Chemistry and Applications
- Crystallization and Solubility Studies
- Nanoplatforms for cancer theranostics
- Fluorine in Organic Chemistry
- Porphyrin and Phthalocyanine Chemistry
- Neuropeptides and Animal Physiology
- X-ray Diffraction in Crystallography
- Chemical Synthesis and Reactions
- Synthesis and Catalytic Reactions
- Biochemical and Structural Characterization
- Genetics, Aging, and Longevity in Model Organisms
- Cyclopropane Reaction Mechanisms
- Asymmetric Synthesis and Catalysis
- CRISPR and Genetic Engineering
- Pharmacological Receptor Mechanisms and Effects
- Monoclonal and Polyclonal Antibodies Research
- DNA Repair Mechanisms
- Receptor Mechanisms and Signaling
- Peptidase Inhibition and Analysis
- Asymmetric Hydrogenation and Catalysis
- Synthesis and Biological Evaluation
- Neurobiology and Insect Physiology Research
University of Zurich
2019-2022
Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases
2014-2017
University of Cologne
2014-2017
Bangalore University
1999-2011
College of Staten Island
2002-2010
City University of New York
2004-2010
Central College
2005
University of Tennessee at Knoxville
2002
Chesterfield Royal Hospital
2001
DNA damage causally contributes to aging and age-related diseases. Mutations in nucleotide excision repair (NER) genes cause highly complex congenital syndromes characterized by growth retardation, cancer susceptibility, accelerated humans. Orthologous mutations Caenorhabditis elegans lead delay, genome instability, functional decline, thus allowing investigation of the consequences persistent during development a simple metazoan model. Here, we conducted proteome, lipidome, phosphoproteome...
Photodynamic therapy (PDT) is used to treat various cancerous diseases. Recently, we have demonstrated that platinated pyridyl-substituted porphyrins are potent agents for PDT with very high phototoxicity (IC50 down 17 nM) and excellent phototoxic indices of higher than 5800 (p.i. = IC50(dark)/IC50(light)) [Rubbiani, R. et al., Chem. Commun. 2020, 56, 14373]. However, the absorption not ideal treatment larger tumors because they essentially do absorb light between 650 850 nm. Herein, report...
We report the synthesis of first transplatin-BODIPY conjugates for application in photodynamic therapy (PDT). The distyryl BODIPYs containing two iodine atoms were designed to absorb red region, easily undergo intersystem crossing efficient singlet oxygen generation, and additionally offer possibility coordination with mono-activated transplatin. able demonstrate that a transplatin increases phototoxic index photosensitizers significantly, giving rise highly BODIPY derivatives, which one was...
Transplatin-modification of photosensitizers improves their phototoxic index without increasing dark toxicity.
Saccharomyces cerevisiae haploid cells communicate with their opposite mating type through peptide pheromones (α-factor and a-factor) that activate G protein-coupled receptors (GPCRs). S. was used as a model system for the study of peptide-responsive GPCRs. Here, we detail synthesis characterization number α-factor (Trp-His-Trp-Leu-Gln-Leu-Lys-Pro-Gly-Gln-Pro-Met-Tyr) pheromone analogues containing photo-cross-linkable group 4-benzoyl-l-phenylalanine (Bpa). Following characterization, one...
Phthalocyanines (Pcs) are promising candidates for photodynamic therapy (PDT) due to their absorption in the phototherapeutic window. However, highly aromatic Pc core leads undesired aggregation and decreased reactive oxygen species (ROS) production. Therefore, short PEG chain functionalized A3B type asymmetric photosensitizers (PSs) were designed order decrease increase aqueous solubility. Here we report synthesis, characterization, optical properties, cellular localization, cytotoxicity of...
We report the first exocyclically metallated tetrapyridinoporphyrazine, [tetrakis-(trans-Pt(NH3)2Cl)-tetra(3,4-pyrido)porphyrazine-zinc(ii)](NO3)4 (4), synthesized in a multistep synthesis starting from 3,4-pyridinedicarbonitrile (1). The synthetic procedure involved platination reaction of intermediate tetra(3,4-pyrido)porphyrazine-zinc(ii) (2), whereby zinc(ii) enhanced solubility enabling reaction. A similar approach to synthesize...
In this study, we addressed an important drawback of our previously reported tetraplatinated (metallo)porphyrin-based photosensitizers (PSs) for photodynamic therapy (PDT), namely, the poor solubility in aqueous media. We aimed to create porphyrin-based PSs that are soluble media modified with polysorbate (Tween) and do not need be pre-dissolved organic solvents. A structural optimization resulted synthesis extremely potent novel PS. The PS displays effective phototoxicity upon light...
Coupling of Fmoc‐amino acid chlorides can be mediated by the potassium salt 1‐hydroxybenzotriazole (KOBt), reaction being carried out in an organic medium. The use a base like NaHC03/Na2C03 or DIEA/NMM/pyridine is not necessary. fast and racemization free; work‐up, isolation product scale‐up are easy. pentapeptide sequence Fmoc‐[Leu]enkephalin was thus synthesized solution phase on 5 mmol scale without any intermediate. Acylation C ‐protected N ‐methylamino esters Fmoc‐ this procedure also...
The yeast Saccharomyces cerevisiae undergoes cell fusion during sexual conjugation to form diploid cells. haploids participating in this process signal each other through secreted peptide-mating factors (alpha-factor and a-factor) that are recognized by G-protein-coupled receptors. receptor (Ste2p) recognizing the tridecapeptide alpha-factor is used as a model system our laboratory understand various aspects of peptide-receptor interactions structure. Using chemical procedures we have...
Abstract: The deprotonation of hydrochloride salts ethyl and methyl esters amino acids peptides is accomplished using activated zinc dust. reaction neat quantitative. Thus, the free acid peptide have been isolated in good yield purity.
Abstract: A new and efficient method for the synthesis ofN α ‐Fmoc‐/Boc‐/Z‐β‐amino acids using two‐step Arndt‐Eistert approach is described. Fmoc‐/Boc‐/Z‐α‐Amino acid fluorides were used acylation of diazomethane synthesizing Fmoc‐/Boc‐/Z‐α‐aminodiazoketones as crystalline solids with good yield purity. They then converted to corresponding β‐amino PhCOOAg/dioxane/H 2 O.
The homologation of α‐amino acids to β‐amino by the two‐step Arndt–Eister method is achieved using Fmoc‐α‐amino acid pentafluorophenyl esters for acylation diazomethane, synthesizing key intermediates Fmoc‐aminoacyldiazomethanes as crystalline solids in good yields and purity.
Abstract A new and efficient method for the homologation of urethane protected α-amino acids to its β-homomers by Arndt-Eistert using TBTU as a coupling agent is described. Several Fmoc-/Boc-/Z-protected diazoketone derivatives have been obtained crystalline solids in good yield. The found be rapid stereospecific. Keywords: L-amino acidHomologationDiazoketonesWolff rearrangementArndt-Eistert approach Acknowledgments We thank Professors K. M. Sivanandaiah B. S. Sheshadri Bangalore University...
Abstract: A simple, efficient and stereospecific approach for the homologation of urethane‐protected α ‐amino acids to β‐amino by Arndt–Eistert method employing Fmoc‐/Boc‐ acid 2‐(1H‐benzotriazole‐1‐yl)‐1,1,3,3‐tetramethyl‐uronium hexafluorophosphate mixture acylation diazomethane synthesizing key intermediates ‐aminodiazomethanes as crystalline solids is described.
Abstract Fmoc-peptide acid chlorides are prepared and used as rapid efficient coupling agents in fragment coupling. Thus the synthesis of model tetrapeptide Leu-Ala-Gly-Val P-casomorhin (Tyr-Pro-Phe-Pro-Gly) accomplished by (2+2) (3+2) divergent approach respectively.
Avascular necrosis of bone can be almost silent until it comes under unusual strain. We report a case in point and lessons learned.