Mitochondria play an important role in controlling the life and death of a cell. Consequently, mitochondrial dysfunction leads to a range of human diseases such as ischemia-reperfusion injury, sepsis, and diabetes. Although the molecular mechanisms responsible for mitochondria-mediated disease processes are not fully elucidated yet, the oxidative stress appears to be critical. Accordingly, strategies are being developed for the targeted delivery of antioxidants to mitochondria. In this review, we shall briefly discuss cellular reactive oxygen species metabolism and its role in pathophysiology; the currently existing antioxidants and possible reasons why they are not effective in ameliorating oxidative stress-mediated diseases; and recent developments in mitochondrially targeted antioxidants and their future promise for disease treatment.

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Alkylated perfluorooctanesulfonamides are compounds of environmental concern. To make these compounds available for environmental and toxicological studies, a series of N-alkylated perfluorooctanesulfonamides and structurally related compounds were synthesized by reaction of the corresponding perfluoroalkanesulfonyl fluoride with a suitable primary or secondary amine. Perfluoroalkanesulfonamidoethanols were obtained from the N-alkyl perfluoroalkanesulfonamides either by direct alkylation with bromoethanol or alkylation with acetic acid 2-bromo-ethyl ester followed by hydrolysis of the acetate. N-Alkyl perfluorooctanesulfonamidoacetates were synthesized in an analogous way by alkylation of N-alkyl perfluoroalkanesulfonamides with a bromo acetic acid ester, followed by basic ester hydrolysis. Alternatively, N-alkyl perfluoroalkanesulfonamides can be alkylated with an appropriate alcohol using the Mitsunobu reaction. Perfluorooctanesulfonamide was synthesized from the perfluorooctanesulfonyl fluoride via the azide by reduction with Zn/HCl. All perfluorooctanesulfonamides contained linear as well as branched C 8 F 17 isomers, typically in a 20:1 to 30:1 ratio. The crystal structures of N-ethyl and N,N-diethyl perfluorooctanesulfonamide show that the S-N bond has considerable double bond character. This double bond character results in a significant rotational barrier around the S-N bond (ΔG ≠ = 62-71 kJ mol −1 ) and a preferred solid state and solution conformation in which the N-alkyl groups are oriented opposite to the perfluorooctyl group to minimize steric crowding around the S-N bond.

The interaction of four long-chain nicotinates, compounds that are of interest as potential chemopreventive agents, with dipalmitoylphosphatidylcholine (DPPC) was investigated in monolayers at the air-water interface and in fully hydrated bilayers. For the monolayer studies, the compression isotherms of mixtures of the respective nicotinate with DPPC were recorded at various compositions on a hydrochloric acid subphase (pH 1.9-2.1, 37 ؎ 2 ؇ C). The headgroup of the nicotinates (24-29 Å 2 /molecule) is larger than that of the hydrophobic tail (20 Å 2 /molecule). The pure nicotinates exhibit a temperature-and chain lengthdependent transition from an expanded to a condensed phase. Analysis of the concentration dependence of the average molecular area at constant film pressure and the concentration dependence of the breakpoint of the phase transition from the expanded to the condensed state suggests that all four DPPC-nicotinate mixtures are partially miscible at the air-water interface. Although a complex phase behavior with several phase transitions was observed, differential scanning calorimetry studies of the four mixtures are also indicative of the partial miscibility of DPPC and the respective nicotinate.Overall, the complex phase behavior most likely results from the head-tail mismatch of the nicotinates and the geometric packing constraints in the twocomponent lipid bilayer. Nicotinic acid and its alkyl esters are of considerable biological and pharmacological importance. Besides being the precursor of cofactors to many vital enzymes, nicotinic acid is a drug possessing vasodilating and fibrinolytic properties. Nicotinic acid itself has been proven beneficial against bleomycin-and cyclophosphamide-induced lung injury in animal models (1-5). Dietary supplements of nicotinic acid and dermatologic formulations of its longchain esters are under investigation for the prevention and treatment of skin carcinogenesis (6). Therefore, nicotinic acid esters may be useful as a chemopreventive agent for the prevention of lung cancer.Currently, there is significant interest in the pulmonary administration of several chemopreventive agents, such as steroids and retinoids, directly to the lung because of reduced systemic toxicity (7-11). This route of administration may also be advantageous for the administration of nicotinic acid esters, by using either an aerosol or a perfluorocarbon vehicle (12, 13). Although the interaction of various chemopreventive agents, especially retinoids, with phospholipids has been investigated (14, 15), there is no current knowledge about the factors that determine the interaction (i.e., phase behavior) of nicotinates with biological lipids such as the phospholipids present in pulmonary surfactant. A better understanding of these interactions, however, is a prerequisite for the rational design of nicotinates for pulmonary administration, especially using a perfluorocarbon-based drug delivery system (12, 13). The aim of this study is to understand which molecular characteristics influe...

Background: Subchronic administration of the potent pharmaceutical estrogen diethylstilbestrol (DES) to female Fischer 344 (F344) rats induces growth of large, hemorrhagic pituitaries that progress to tumors. Phytoestrogens (dietary plant estrogens) are hypothesized to be potential tumor inhibitors in tissues prone to estrogen-induced cancers, and have been suggested as "safer" estrogen replacements. However, it is unknown if they might themselves establish or exacerbate the growth of estrogen-responsive cancers, such as in pituitary. Methods:We implanted rats with silastic capsules containing 5 mg of four different phytoestrogens -either coumestrol, daidzein, genistein, or trans-resveratrol, in the presence or absence of DES. We examined pituitary and other organ weights, blood levels of prolactin (PRL) and growth hormone (GH), body weights, and pituitary tissue histology.Results: Blood level measurements of the administered phytoestrogens confirmed successful exposure of the animals to high levels of these compounds. By themselves, no phytoestrogen increased pituitary weights or serum PRL levels after 10 weeks of treatment. DES, genistein, and resveratrol increased GH levels during this time. Phytoestrogens neither changed any wet organ weight (uterus, ovary, cervix, liver, and kidney) after 10 weeks of treatment, nor reversed the adverse effects of DES on pituitaries, GH and PRL levels, or body weight gain after 8 weeks of co-treatment. However, they did reverse the DES-induced weight increase on the ovary and cervix. Morphometric examination of pituitaries revealed that treatment with DES, either alone or in combination with phytoestrogens, caused gross structural changes that included decreases in tissue cell density, increases in vascularity, and multiple hemorrhagic areas. DES, especially in combination with phytoestrogens, caused the development of larger and more heterogeneous nuclear sizes in pituitary.Conclusions: High levels of phytoestrogens by themselves did not cause pituitary precancerous growth or change weights of other estrogen-sensitive organs, though when combined with DES, they counteracted the growth effects of DES on reproductive organs. In the pituitary, phytoestrogens did not reverse the effects of DES, but they did increase the sizes and size heterogeneity of nuclei. Therefore, phytoestrogens may oppose some but not all estrogenresponsive tissue abnormalities caused by DES overstimulation, and appear to exacerbate DES-induced nuclear changes. BackgroundSteroid hormones such as the dominant physiologic estrogen, estradiol (E 2 ) have many effects on pituitary function, including regulation of most pituitary hormones and proliferation of several pituitary cell types