New porphyrin platinum conjugates for the cytostatic and photodynamic tumor therapy

Brunner, Henri; Schellerer, Karl-Martin

doi:10.1016/s0020-1693(02)01490-1

Cited by 38 publications

(27 citation statements)

References 24 publications

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“…Benzaldehydes 2a and 2b were not commercially available, and therefore, they were synthesised from 4-hydroxybenzaldehyde (1) and the corresponding alkyl chloride. [27] Afterwards, 6-[4-(2-methoxyethoxy)phenyl]fulvene (3a) and 4-[2-(dimethylamino)ethoxy]benzaldehyde (3b) were obtained in the described condensation reaction as orange solids in yields of 78 % and 51 %, respectively (Scheme 1). Scheme 1.…”

Section: Resultsmentioning

confidence: 99%

Glycol Methyl Ether and Glycol Amine Substituted Titanocenes as Antitumor Agents

et al. 2006

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Abstract6‐[4‐(2‐Methoxyethoxy)phenyl]fulvene (3a) and 6‐{4‐[2‐(dimethylamino)ethoxy]phenyl}fulvene (3b) were prepared as the starting materials for the synthesis of three different classes of titanocenes, which are ansa‐titanocenes, diarylmethyl‐substituted titanocenes and benzyl‐substituted titanocenes. Because the synthetic possibilities seem to be limited, only ansa‐titanocene {1,2‐bis(cyclopentadienyl)‐1,2‐bis[4‐(2‐methoxyethoxy)phenyl]ethanediyl}titanium dichloride (4a) and benzyl‐substituted titanocene bis‐{[4‐(2‐methoxyethoxy)benzyl]cyclopentadienyl}titanium(IV) dichloride (6a) were obtained and characterised. The change in the substitution pattern of the phenyl moiety from an oxygen atom to a nitrogen atom had such a big influence on the reaction that not one compound of the three titanocene classes could be synthesised, and it was also not possible to obtain diarylmethyl‐substituted titanocenes with the use of either of the fulvenes. When benzyl‐substituted titanocene 6a was tested against pig kidney cells (LLC‐PK), an antiproliferative effect that results in an IC50 value of 43 μM, was observed. This IC50 value is in the lower range of the cytotoxicities evaluated for titanocenes up to now. ansa‐Titanocene 4a surprisingly showed, when tested on the same cell line, a proliferative effect together with a fast rate of hydrolysis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

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Section: Resultsmentioning

confidence: 99%

Glycol Methyl Ether and Glycol Amine Substituted Titanocenes as Antitumor Agents

et al. 2006

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“…Fortunati and co-workers found that pre-incubation of MCF-7 (ER + ) cells with SHBG before estradiol treatment counteracted the anti-apoptotic effect of the latter. [18a] To prove that compound 4 b is still recognised by the nuclear estrogen receptor, its binding affinity was measured by competitive displacement of specifically bound [2,4,6, H]17b-estradiol from calf uterine cytosol as the source of ER a . The binding constant K i as calculated according to the Cheng-Prusoff equation was found to be 27.5 AE 5.5 nm.…”

Section: Cytotoxicities and Receptor Affinitiesmentioning

confidence: 99%

“…The affinity to the estrogen receptor was measured in a competitive radioligand assay [23] using calf uterus cytosol as receptor source and 1 nm [2,4,6, H]17b-estradiol (specific activity: 3.48 TBq mmol À1 ; Amersham Biosciences Europe GmbH, Freiburg, Germany) as tracer. Freshly excised calf uteri were freed from fat, perimetrium, and parametrium, washed with a solution of 0.9 % NaCl, and cut into small pieces.…”

Section: Estrogen Receptor Ligand Binding Assaymentioning

confidence: 99%

“…For the quantitation of estrogen receptor binding, K i values were calculated according to the Cheng-Prusoff equation (K d for [2,4,6, H]17b-estradiol = 0.60 nm). [27] IC 50 values were determined with SigmaPlot 9.0 by logit-log plots of the data from three independent experiments.…”

Section: Estrogen Receptor Ligand Binding Assaymentioning

confidence: 99%

“…[1][2][3][4][5] Promising candidates are conjugates of Pt II complexes with bioactive shuttle components such as porphyrins and hormones. [4][5][6][7][8][9][10] Sex hormones play a crucial role in the etiology and growth of the majority of breast and prostate cancers. Following the rationale that for the binding of 17b-estradiol derivatives to the nuclear estrogen receptor ER a a free 3-OH is more important than a free 17-OH group, most Pt II complex conjugates contain the steroid tethered at positions remote from the A-ring such as C16 or C17.…”

Section: Introductionmentioning

confidence: 99%

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Steroid Conjugates of Dichloro(6‐aminomethylnicotinate)platinum(II): Effects on DNA, Sex Hormone Binding Globulin, the Estrogen Receptor, and Various Breast Cancer Cell Lines

et al. 2007

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Esters of 6-aminomethylnicotinic acid with various steroidal alcohols were treated with K(2)PtCl(4) to give the N,N-chelated dichloroplatinum(II) complex conjugates 4. Their interaction with plasmid DNA was monitored by electrophoretic mobility measurements. Their affinities towards sex hormone binding globulin (SHBG) and towards the nuclear estrogen receptor ER(alpha) were assessed by competitive displacement radioassays. The inhibitory effect of 4 on breast tumour cells MCF-7 ER(+)/ER(-) and MDA-MB-231 was investigated in vitro. Conjugates with 3-O-linked estrogens 4 a,b or 17-O-linked androgens 4 g bound strongly to SHBG. The conjugate complex 4 b, featuring a 3-O-linked estradiol, also bound strongly and agonistically to the estrogen receptor. It also elicited distinct growth retardation of MCF-7 (ER(+)) cells, presumably by a mechanism different from that of cisplatin.

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Azide: A Unique Dipole for Metal‐Free Bioorthogonal Ligations

et al. 2010

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Covalently bound azide on a (small) organic molecule or a (large) biomolecular structure has proven an important handle for bioconjugation. Azides are readily introduced, small, and stable, yet undergo smooth ligation with a range of reactive probes under mild conditions. In particular, the potential of azides to undergo metal‐free reactions with strained unsaturated systems has inspired the development of an increasing number of reactive probes, which are comprehensively summarized here. For each individual probe, the synthetic preparation is described, together with reaction kinetics and the full range of applications, from materials science to glycoprofiling. Finally, a qualitative and quantitative comparison of azido‐reactive probes is provided.

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New porphyrin platinum conjugates for the cytostatic and photodynamic tumor therapy

Cited by 38 publications

References 24 publications

Glycol Methyl Ether and Glycol Amine Substituted Titanocenes as Antitumor Agents

Glycol Methyl Ether and Glycol Amine Substituted Titanocenes as Antitumor Agents

Steroid Conjugates of Dichloro(6‐aminomethylnicotinate)platinum(II): Effects on DNA, Sex Hormone Binding Globulin, the Estrogen Receptor, and Various Breast Cancer Cell Lines

Azide: A Unique Dipole for Metal‐Free Bioorthogonal Ligations

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