Ferrocenylmethylation of estrone and estradiol: Structure,electrochemistry, and antiproliferative activity of new ferrocene–steroid conjugates

Conjugates of ferrocene with steroidal estrogens as selective antiproliferative agents against hormone-dependent breast cancer cells are believed to be limited by the inherent estrogenicity of the conjugates. Motivated by a significant cytotoxicity of the ester of ferrocenecarboxylic acid and the phenolic group of estradiol toward such a cell line, we decided to explore other a -ring-tethered ferrocene–estra-1,3,5(10)-triene conjugates; in this study, ferrocenylmethylation of estradiol and estrone with (ferrocenylmethyl)trimethylammonium iodide in the presence of potassium carbonate yielded five new compounds ( 1 – 5 ). In dimethylformamide, only O-alkylated products formed ( 1 and 3 ), while a mixture of O- and C-alkylated products was obtained when methanol was used ( 2 , 4 , and 5 in addition to 1 and 3 ). All compounds were characterized using 1D and 2D NMR, IR, UV–Vis, and high-resolution mass spectrometry. Two of the conjugates, a 3-O- and a 4-C-alkylated derivative of estrone ( 3 and 4 , respectively), were also analyzed using single-crystal X-ray diffraction. A cyclic voltammetric investigation of the electrochemical properties of 1 – 5 was performed. While some of the compounds were shown to have a slight-to-moderate antiproliferative activity against at least one of the six tested human tumor cell lines and were nontoxic to (the noncancerous) fetal human fibroblasts, compound 2 (4-(ferrocenylmethyl)estra-1,3,5(10)-triene-3,17β-diol) with an IC₅₀ value of 0.34 μM was found to be more active against the hormone-dependent breast cancer cell line MCF-7 than doxorubicin. These results suggest that a -ring substitution of steroidal estrogens is a plausible strategy for preparing other ferrocene–steroid conjugates acting against tumor cells.     

Radiometric mapping and radiation dose assessments in sediments from Şavşat Black Lake,Turkey

Journal of Radioanalytical and Nuclear Chemistry - In this study, natural and artificial radioactivity concentrations in sediment samples taken from ?av?at Black Lake located on the...     

B‐spline collocation algorithms for numerical solution of the RLW equation

Both sextic and septic B‐spline collocation algorithms are presented for the numerical solutions of the RLW equation. Numerical results resolve the fine structure of the single solitary wave propagation, two and three solitary waves interaction, and evolution of solitary waves. Comparison of the numerical results is done by the results of some earlier schemes mentioned in the article. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 27: 581–607, 2011     

Levels of cesium radionuclides in lichens and mosses from the province of Ordu in the Eastern Black Sea area of Turkey

Chemobyl nuclear power plant accident in Ukraine in April 26, 1986 has affected Scandinavia and European countries, the Balkans and the northside of Turkey. Radioactive clouds depending on meteorological conditions had contaminated soil surface and flora in the region of Thrace and the seaside of the Black sea. This study has been done on mosses and lichens in which radioactive isotopes can live for a long time. These specimens have been collected in various regions of Ordu located in the Eastern Black Sea region of Turkey. On the basis of the results of this study the geographic distribution of pollution on the flora has been done.     

Optimization of Multilevel Investments Using Dynamic Programming Based on Fuzzy Cash Flows

Dynamic programming is applicable to any situation where items from several groups must be combined to form an entity, such as a composite investment or a transportation route connecting several districts. The most desirable entity is constructed in stages by forming sub-entities of progressively larger size. At each stage of the development, the sub-entities that are candidates for inclusion in the most desirable entity are retained, and all other sub-entities are discarded. In deterministic dynamic programming, a specification of the current state and current decision is enough to tell us with certainty the new state and costs during the current stage. In many practical problems, these factors may not be known with certainty, even if the current state and decision are known. In this paper, the dynamic programming is applied to the situation where each investment in the set has the following characteristics: the amount to be invested has several possible values, and the rate of return varies with the amount invested. Each sum that may be invested represents a distinct level of investment, and the investment therefore has multiple levels. A fuzzy present worth based dynamic programming approach is used. A numeric example for a multilevel investment with fuzzy geometric cash flows is given. A computer software named FUZDYN is developed for various problems such as alternatives having different lives, different uniform cash flows, and different ranking methods.     

Loading effect on ACPD of a crack in ferromagnetic material

The loading effect on alternating current potential drop (ACPD) for a ferromagnetic material containing a two-dimensional surface crack was investigated under opening mode loading without shear (mode I). The change in potential drop due to load was obtained with and without a magnetic field around the specimen. To remove the magnetic field from the circumference of the specimen, a new measuring system using the characteristic of coaxial transmission line was made. When the magnetic field does not exist around the specimen, the change in potential drop with load is governed by the change in electromagnetic properties near the crack tip. The results obtained by using the new measuring system are the basis for an application of the ACPD technique to the experimental determination of the stress intensity factor, since they are independent of the arrangement of the measuring probe lines and the current supply lines. The relationship between the change in potential drop and the change in load is linearized by demagnetization. The change in potential drop per unit change in the stress intensity factor is independent of the crack length.     

Secondary‐Ion Mass Spectrometry of Genetically Encoded Targets

Secondary ion mass spectrometry (SIMS) is generally used in imaging the isotopic composition of various materials. It is becoming increasingly popular in biology, especially for investigations of cellular metabolism. However, individual proteins are difficult to identify in SIMS, which limits the ability of this technology to study individual compartments or protein complexes. We present a method for specific protein isotopic and fluorescence labeling (SPILL), based on a novel click reaction with isotopic probes. Using this method, we added ¹⁹F‐enriched labels to different proteins, and visualized them by NanoSIMS and fluorescence microscopy. The ¹⁹F signal allowed the precise visualization of the protein of interest, with minimal background, and enabled correlative studies of protein distribution and cellular metabolism or composition. SPILL can be applied to biological systems suitable for click chemistry, which include most cell‐culture systems, as well as small model organisms.     

An intramolecular one-pot synthesis of steroidal triazoles via 1,3-dipolar cycloadditions of in situ generated diazo compounds

A novel synthetic route is reported for the preparation of steroidal triazoles via intramolecular 1,3-dipolar cycloaddition of a steroidal 16,17-seco-17-diazo-16-nitrile system. The structures of the products are established by X-ray and NMR studies. The in vitro antiproliferative activity of the steroidal triazoles against three tumor cell lines was evaluated.     

Measurement of stress-intensity factor by means of a-c potential drop technique

A loading effect on a-c potential difference measured for two-dimensional stationary surface crack is examined under opening load without shear. An increment of potential difference caused by a load change is revealed to have a proportional relationship with an increment of the stress-intensity factor,K _I. Also, the constant of proportionality of the relationship is found to be independent of the crack length. Based on this relationship, a procedure is developed for measurement ofK _Iby means of the a-c potential drop technique.