Attempted deprotonation of 1,2-di(fluorenylidene)cyclobutane, 8, using n-butyl or tert-butyl-lithium led instead to 1,4-addition across the 1,3-butadiene unit to yield the 1-(9H-fluorenyl-2-(9-butyl-9H-fluorenyl)cyclobutene 10 or 11, respectively; analogously, n-butyl-lithium and trans-3,4-bis(t...

Disodium and ditetraphenylphosphonium salts of 2,4-bis(cyanamido)cyclobutane-1,3-dione, Na2(2,4-NCNsq) · 2H2O (1) and (Ph4P)2(2,4-NCNsq) · 4H2O (2) have been synthesized and used to prepare three nickel(II) complexes: [Ni(Him)4(2,4-NCNsq) · 2H2O]n (3), [Ni(Him)3(H2O)(2,4-NCNsq) · H2O]n (4) a...

From the 2,4-bis(cyanamido)cyclobutane-1,3-dione dianion (2,4-NCNsq2−), two copper complexes [Cu2(PPh3)4(PhCN)2(μ-2,4-NCNsq)] · PhCN (1) and [Cu(dien)(μ-2,4-NCNsq) · H2O]n (2) have been synthesized and characterized by IR and electronic absorption spectroscopies. Their structures have been d...

The reaction of copper(II) ions with the 2,4-bis(dicyanomethylene)cyclobutane-1,3-dione dianion (2,4-dcmsq2−), a pseudo-oxocarbon derived from squaric acid in which two carbonyl oxygen atoms have been substituted by dicyanomethylene groups C(CN)2, leads to many complexes according to the prepara...

In order to develop potential radiolabelled probes for imaging estrogen receptor (ER) positive tumours, we have synthesized and characterized a series of novel 7α-alkoxy-17α-(4′-iodophenylethynyl)estra-1,3,5(10)-triene-3,17β-diols and 7α-alkoxy-17α-(4′-fluorophenylethynyl)estra-1,3,5(10)-...

IntroductionSeveral lines of evidence suggest that 7α-substituted estradiol derivatives bind to the estrogen receptor (ER). In line with this hypothesis, we designed and synthesized 18F-labeled 7α-fluoroalkylestradiol (Cn-7α-[18F]FES) derivatives as molecular probes for visualizing ERs. Previ...

The majority of breast cancer cases are estrogen receptor positive (ER+). Although, third-generation aromatase inhibitors (AIs) are used as first-line treatment in post-menopausal women, they cause endocrine resistance and bone loss, which limits their success. Therefore, there is a demand to di...

From incubations of testosterone with rat testicular homogenates in the presence of a NADPH-generating system, the following 7α-hydroxylated metabolites could be isolated and identified: 7α,17β-dihydroxy-4-androsten-3-one (7α-hydroxy-testosterone), 7α-17β-dihydroxy-5α-androstan-3-one (7α...

Different stereoselective synthetic routes for the preparation of 7α/β-substituted estradiol derivatives, that is, 7α-alkynylestra-1,3,5(10)-triene-3,17β-estradiol (13) and its 17β-acetate derivative (14), are explored. These steroids are key starting materials for Pd-catalyzed Sonogashira ...

High-affinity biotinylated derivatives of 17β-estradiol (E2) are of value for isolation of various estrogen-binding proteins (including estrogen receptors) and also for studying protein–protein interactions involving these proteins. In this study, we developed a simplified route for the chemic...

The description of dehydroepiandrosterone (DHEA) as a neuroactive neurosteroid has raised the important question of whether the steroid itself and/or its metabolite(s) are active in the brain. Classical transformations of DHEA in brain and peripheral tissues include its conversion to testosteron...

Prostate cancer is a major public health problem worldwide and, more specifically, new treatments for hormone-refractory cancers are highly sought by several research groups. Although platinum(II)-based chemotherapy and other strategies grow in interest to treat castration-resistant prostate can...

Several studies have shown that the native 7α-hydroxy-dehydroepiandrosterone (7α-hydroxy-DHEA) is a substrate for the human 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) which converts the 7α- into the 7β-epimer through an oxido-reduction process. Research on the 11β-HSD1 has investi...

Androst-5-ene-triols are metabolites of dehydroepiandrosterone, the most abundant steroid hormone in human circulation. Many observations in rodents have demonstrated the anti-inflammatory and immune modulating activity of 7β-hydroxy-androst-5-enes, and on the basis of these experiments androst...

During absorption ricinoleic acid is activated to its acyl-thiolester, and subsequently appears in neutral lipid but never in phospholipid. Consideration of these and related facts suggests that the synthesis of triricinolein in vivo proceeds exclusively via the acylation of monoglyceride, and n...

The preparation of 2,3-diricinolein by lipase-catalyzed hydrolysis of triricinolein has been developed. Lipase-catalyzed hydrolysis of triricinolein provided (2R)-2,3-diricinolein in high diastereoselectivity.

A polymer inclusion membrane (PIM) is reported consisting of 45% (m/m) di(2-ethylhexyl)phosphoric acid (D2EHPA) immobilized in poly(vinyl chloride) (PVC) for use as a solid phase absorbent for selectively extracting Zn(II) from aqueous solutions in the presence of Cd(II), Co(II), Cu(II), Ni(II) ...

The effects of di-(2-ethylhexyl) phthalate (DEHP) at five different doses from 10 to 1000 mg kg−1 soil on biological properties were investigated over a period of 56 days. Meanwhile, the dissipation of DEHP was also monitored. The results indicated that the microbial biomass C (Cmic) fluctuated ...

Two amide synthetic derivatives of 3,4-di(OH)-hydrocinnamate (HC), 3,4-dihydroxyphenylpropionic (l-serine methyl ester) amide (E030) and 3,4-dihydroxyphenylpropionic (l-aspartic acid) amide (E076), were investigated to compare their lipid-lowering efficacy with HC. Male rats were fed a 1 g/100 g...

The tagging methods utilizing FL detection reagents for physiologically important carboxylic acids including fatty acids in HPLC are reviewed in terms of the tagging conditions, handling, flexibility, sensitivity, selectivity and stabilities of the reagents and the corresponding derivatives. Emp...