Fluorinated probes activity

Rice JW, Weyand EH, Burrill C, et al. 1990. Fluorine probes for investigating the mechanism of activation of indeno(1,2,3-cd)pyrene to a tumorigenic agent. Carcinogenesis 11(11) 1971-1974. 

The C-l Hydroxyl. We examined the role of the C-l hydroxyl in binding the receptor based on the activity of a fluorinated probe. Fluorination of biologically active compounds is useful for studying the... 

The significance of such rudimentary probes of mechanistic pathways rests with their dispelling the myth of fluorine s unpredictability In fact, fluorine, though highly reactive and with few activation barriers is highly predictable if the energy density (exothermicity per unit volume) of its reactions can be controlled so as not to disturb the integrity of the substrates with which it reacts Precise control of... 

To probe the effects of HCFC structure on toxicity the metabolism of three penta-haloethanes, HCFC-123, HCFC-124, and HCFC-125 were studied. The three compounds differ one from the other by the number of fluorine atoms present in the /3-carbon (Fig. 4.64). It was found that the enthalpies of activation, AHact, for hydrogen atom abstraction paralleled the rate of trifluoroacetic acid excretion suggesting that the more difficult it was... 

A. Ohno, M. Shimizu, S. Yamada, Fluorinated vitamin D analogs to probe the conformation of vitamin D in its receptor complex F-NMR studies and biological activity, Chem. Pharm. Bull. 50 (2002) 475-483. 

In this chapter, we describe an account of our research on the chemistry and biology of paclitaxel and taxoid anticancer agents (taxoid = taxol-like compound). The topics covered in this chapter include (i) the development of a practical and efficient method for the semisynthesis of paclitaxel and docetaxel using chiral 3-hydroxy-P-lactams as synthetic intermediates, (ii) structure-activity relationship (SAR) studies of various taxoids that led to the discovery of the extremely potent second-generation taxoids, and (iii) biological and conformational studies with the use of fluorine-containing taxoids as probes. ... 

Direct evidence for a combination of catalytic fluorination and chlorination [4] was obtained from radiotracer studies in which fluorinated chromia catalysts were labelled with the short-lived (t /2 = 110 min) / + emitting isotope fluorine-18 [11]. Using this isotope it was possible to probe the interactions between HF and various fluorinated chromia catalysts more directly than had been possible hitherto. Three types of surface F-containing species were differentiated, weakly adsorbed HF which was easily removed by an inert gas flow, non-labile F, believed to be bound directly to surface Crin, and catalytically active F which could be incorporated into the organic products [12]. The controversy between dismutation (concerted F-for-Cl and Cl-for-F transfers) and non-concerted halogen exchange processes has been resolved more recently and the evidence is described later in the chapter. What is clear from this early work however, is the importance of aluminium and chromium(III) oxides as catalyst precursors. Fluorination of the surfaces of these oxides is slow (cf [12]) and although there are many references to alu-... 

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