Related Experiment Video
Updated: May 6, 2026
Synthesis and Bioconjugation of Thiol-Reactive Reagents for the Creation of Site-Selectively Modified Immunoconjugates
Published on: March 6, 2019
Synthesis and structure-activity relationship study of organometallic bioconjugates of the cyclic octapeptide
Annika Gross1, Daniel Habig, Nils Metzler-Nolte
1Lehrstuhl für Anorganische Chemie I-Bioanorganische Chemie, Fakultät für Chemie und Biochemie, Ruhr-Universität Bochum, Universitätsstrasse 150, 44801 Bochum (Germany).
Abstract:
The chemically stabilized somatostatin-derived cyclic octapeptide octreotate has a number of interesting applications in medicinal chemistry. Here, a number of different organometallic derivatives of octreotate were prepared, and their properties were investigated. Specifically, we report the synthesis and characterization of ruthenocene, ferrocene, and cobaltocenium octreotate derivatives and their fluorophore-labeled conjugates as well as a dicobalt hexacarbonyl alkyne functionalized octreotate. To provide further insights into their characteristics, the log P values and electrochemical properties of the novel metal conjugates were compared. For biological activity, we determined their toxicity in three different cell lines. Cellular uptake and colocalization of selected compounds were studied by fluorescence microscopy with particular focus on efficiency and specificity of their uptake through the somatostatin receptor SSTR to elucidate the value of the metallocene head group for its potential use as a nontoxic and universal peptide label.
Related Concept Videos
01:23Properties of Organometallic Compounds
02:34Structural Isomerism
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly,...
01:22Direct-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship
The direct-acting...
01:29Indirect-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship
Reversible inhibitors display short to medium durations of action. Short-acting agents include simple alcohols with...
01:16Adrenergic Agonists: Chemistry and Structure-Activity Relationship
Aromatic ring substitutions: Substituting the aromatic ring with –OH groups at positions 3 and 4 yields catecholamines (e.g., epinephrine), which have a high affinity for adrenoceptors. Hydrogen bonding between –OH groups and receptors enhances adrenergic activity.
Separation of...
02:52Stereoisomerism
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...