Synthesis of Novel Dendrimeric Systems Containing NLO Ligands

Brouwer, Arwin J.; Liskamp, Rob M. J.

doi:10.1002/ejoc.200400609

Cited by 21 publications

(13 citation statements)

References 21 publications

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“…This is due to formation of a five-member chelating ring instead of a four-member ring or monodendate binding, which occurs in the case of carboxylic acid ligands (see Scheme 1). 55,56 This may permit to transfer iron oxide nanoparticles from non-polar solvents into polar solvents, such as water, by using appropriate ligands. 1,17,21 Especially, hydroxamic acids are advantageous because they can be prepared with a large number of bifunctional ligands 57 in contrast to phosphonic acid molecules.…”

Section: Introductionmentioning

confidence: 99%

Highly monodisperse water-dispersable iron oxide nanoparticles for biomedical applications

et al. 2010

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Section: Introductionmentioning

confidence: 99%

Highly monodisperse water-dispersable iron oxide nanoparticles for biomedical applications

et al. 2010

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“…The synthetic pathway for the preparation of branching monomer with variable arm length of AB 2 or AB 1 B 2 structure from 3,5-dihydroxybenzoic acid is shown in Scheme 1. The monomer of AB 2 type was synthesized via modification of a procedure published by Liskamp et al, yielding di-substituted compound 2 with equal arm length, and mono-substituted product 3 that was later used for synthesis of monomer 5 with non-equal arm length [22].…”

Section: Methodsmentioning

confidence: 99%

Molecular Antioxidant Properties and In Vitro Cell Toxicity of the p-Aminobenzoic Acid (PABA) Functionalized Peptide Dendrimers §

et al. 2019

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Background: Exposure to ozone level and ultraviolet (UV) radiation is one of the major concerns in the context of public health. Numerous studies confirmed that abundant free radicals initiate undesired processes, e.g. carcinogenesis, cells degeneration, etc. Therefore, the design of redox-active molecules with novel structures, containing radical quenchers molecules with novel structures, and understanding their chemistry and biology, might be one of the prospective solutions. Methods: We designed a group of peptide dendrimers carrying multiple copies of p-aminobenzoic acid (PABA) and evaluated their molecular antioxidant properties in 1,1’-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) tests. Cytotoxicity against human melanoma and fibroblast cells as well as against primary cerebral granule cells (CGC) alone and challenged by neurotoxic sodium glutamate and production of reactive oxygen species (ROS) in presence of dendrimers were measured. Results: PABA-terminated dendrimers express enhanced radical and radical cation scavenging properties in relation to PABA alone. In cellular tests, the dendrimers at 100 M fully suppress and between 20–100 M reduce proliferation of the human melanoma cell line. In concentration 20 M dendrimers generate small amount of the reactive oxygen species (<25%) but even in their presence human fibroblast and mouse cerebellar granule cells remain intact Moreover, dendrimers at 0.2–20 µM concentration (except one) increased the percentage of viable fibroblasts and CGC cells treated with 100 M glutamate. Conclusions: Designed PABA-functionalized peptide dendrimers might be a potential source of new antioxidants with cationic and neutral radicals scavenging potency and/or new compounds with marked selectivity against human melanoma cell or glutamate-stressed CGC neurons. The scavenging level of dendrimers depends strongly on the chemical structure of dendrimer and the presence of other groups that may be prompted into radical form. The present studies found different biological properties for dendrimers constructed from the same chemical fragments but the differing structure of the dendrimer tree provides once again evidence that the structure of dendrimer can have a significant impact on drug–target interactions.

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“…3,5-Dihydroxybenzoic acid (16) was esterified 22 and alkylation with 18 23 yielded monomer 19 (73%), 6,24,25 from which the methyl ester group was cleaved using sodium hydroxide in methanol to give acid 20 (94%). The hydroxamic acid protecting benzyl group was introduced with Obenzylhydroxylamine hydrochloride by using N- [3-(dimethylamino)propyl]-N¢-ethylcarbodiimide hydrochloride (EDCI) and 1-hydroxybenzotriazole (HOBt) as carboxylic acid activating agents.…”

Section: Scheme 1 Synthesis Of the Key Intermediate Compounds 6 8 Amentioning

confidence: 99%

Synthesis of Bifunctional Hydroxamic Acids as Novel Ligands for the Hydrophilic Stabilization of Iron Oxide Nanoparticles

Hofmann¹,

Gräf²,

Kung³

et al. 2010

Synthesis

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A general method for synthesizing bifunctional hydroxamic acids containing carboxylic acid or amino functionalities is reported. Various products from simple alkyl to complex dendrimerlike structures are described. Such molecules have recently been used in ligand-exchange reactions for the hydrophilic stabilization of originally oleic acid protected iron oxide nanoparticles.Hydroxamic acid derivatives possess a wide spectrum of biological activity 1 and are well known as chelating ligands for metal ions. 2 Extensive studies have shown that the bond strength between Fe(II)/Fe(III) ions and hydroxamic acids greatly exceeds that between carboxylic acids and iron ions because of the possibility of forming a fivemembered chelating ring, instead of the four-membered rings or monodendate species formed in case of the carboxylic acid ligands. 3,4 This enhanced bond strength could also be observed with other isolated metal ions, such as Co(II), Ni(II), Cu(II), and Zn(II) as well as on metal surfaces and self-assembled monolayers. 2,3,5 As a consequence, hydroxamic acid derivatives are particularly suitable for functionalizing metal-containing complexes as well as metal-containing nanoparticles. 6 Moreover, the use of hydroxamic acid ligands with additional functional groups allows the introduction of new functional groups into the ligand sphere of nanoparticles and permits alteration of the solubility of nanoparticles in a controlled way. This is especially interesting for the transfer of iron oxide nanoparticles from nonpolar solvents into polar solvents. 7

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Synthesis of Novel Dendrimeric Systems Containing NLO Ligands

Cited by 21 publications

References 21 publications

Highly monodisperse water-dispersable iron oxide nanoparticles for biomedical applications

Highly monodisperse water-dispersable iron oxide nanoparticles for biomedical applications

Molecular Antioxidant Properties and In Vitro Cell Toxicity of the p-Aminobenzoic Acid (PABA) Functionalized Peptide Dendrimers §

Synthesis of Bifunctional Hydroxamic Acids as Novel Ligands for the Hydrophilic Stabilization of Iron Oxide Nanoparticles

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