The effects of CO2 pressure and pH on the Suzuki coupling of basic nitrogen containing substrates.

The Suzuki coupling reaction of basic nitrogen containing substrates (2-bromo- and 2-chloro-4-aminopyridine, and 2-bromo and 2-chloropyridine) with phenylboronic acid using Pd(TPP)2Cl2/K3PO4 in acetonitrile-water biphasic solvent systems under a CO2 or a N2 atmosphere is discussed. It was observed that 2-halo-4-aminopyridine produced quantitative yields of coupled products under a CO2 atmosphere while the yields for the 2-halopyridines were poor. In contrast, the yields of coupled products for the 2-halopyridines substrates were quantitative under a N2 atmosphere while only poor yields were realized for the 2-halo-4-aminopyridines under the same conditions. Evidence is presented which suggests that the presence of CO2 alters the pH of the aqueous phase of the reaction system and the accompanying efficiency of the coupling process. Using a series of buffers to adjust the pH of the aqueous phase, the pH dependence associated with the efficiency of the coupling process is illustrated.

Piperylene sulfone: a labile and recyclable DMSO substitute.

The properties and uses of piperylene sulfone as a new, recyclable dipolar, aprotic solvent for conducting organic reactions are presented.

Synthesis and evaluation of cryptolepine analogues for their potential as new antimalarial agents.

The indoloquinoline alkaloid cryptolepine 1 has potent in vitro antiplasmodial activity, but it is also a DNA intercalator with cytotoxic properties. We have shown that the antiplasmodial mechanism of 1 is likely to be due, at least in part, to a chloroquine-like action that does not depend on intercalation into DNA. A number of substituted analogues of 1 have been prepared that have potent activities against both chloroquine-sensitive and chloroquine-resistant strains of Plasmodium falciparum and also have in common with chloroquine the inhibition of beta-hematin formation in a cell-free system. Several compounds also displayed activity against Plasmodium berghei in mice, the most potent being 2,7-dibromocryptolepine 8, which suppressed parasitemia by 89% as compared to untreated infected controls at a dose of 12.5 mg kg(-1) day(-1) ip. No correlation was observed between in vitro cytotoxicity and the effect of compounds on the melting point of DNA (DeltaT(m) value) or toxicity in the mouse-malaria model.

Diet-induced mood changes in normal populations.

Using an 11-item questionnaire and a double-blind experimental design, changes in mood, hunger and food preference after taking caffeine (100 mg), tryptophan (500 mg), tyrosine (500 mg) or placebo, were investigated in 60 volunteers. At the end of the study, volunteers also ranked the four treatments on a sedation/stimulation scale. Caffeine significantly increased scores for wakefulness, vigor, clarity of mind, energy, feeling full of ideas, feeling full of go and feeling efficient. Caffeine was also ranked as the most stimulating treatment (p less than 0.001). Tyrosine produced no changes, while tryptophan shifted mean scores towards somnolent and lethargic, and was ranked most sedating (p less than 0.05). None of the treatments changed hunger ratings or carbohydrate/protein preference.

Production performance, carcass composition, and adipose tissue traits of heavy pigs: influence of breed and production system.

Both breed and production systems are responsible for production efficiency and quality traits of pork. Effects of breed and production system within breed on growth, body fatness, and adipose tissues traits were assessed in the pure Basque (B, nonselected, local French) and conventional Large White (LW) breeds, reared either in a conventional (C, slatted floor), alternative (A, indoor straw bedding and outdoor area), or extensive (E, free range) system. A total of 100 castrated males were produced in 2 replicates, each involving 50 pigs distributed in 5 treatments based on breed and production system (i.e., BC, BA, BE, LWC, and LWA [10 pigs/group and per replicate]). From 35 kg BW to slaughter at around 145 kg BW, the BC, BA, LWC, and LWA pigs received the same growing and finishing diets, whereas the BE pigs had free access to the natural resources of the E pen and received a standard growing-finishing diet at restricted allowance according to the farming practices of the B pork chain. The B pigs had lower (P < 0.001) ADG and G:F than the LW pigs and were much older (P < 0.001) at slaughter. The LWA pigs had similar ADG but lower (P = 0.03) G:F than the LWC. Within the B breed, the BA had higher (P = 0.04) and the BE lower (P < 0.001) ADG compared with BC pigs. The B pigs had a higher (P < 0.001) carcass dressing an exhibited around 2-fold higher (P < 0.001) back fat proportion, perirenal fat weight and LM lipid content than the LW pigs. Compared with C, the A system decreased (P = 0.04) carcass dressing within LW but did not influence carcass traits within B pigs. The E system decreased (P ≤ 0.05) carcass dressing, back fat proportion, and LM lipid content in BE compared with BC pigs. The B pigs exhibited larger (P < 0.001) adipocytes in both subcutaneous adipose tissue (SCAT) and LM than the LW pigs. Malic enzyme activity was higher in SCAT of B than LW pigs despite their greater fatness, and was higher (P ≤ 0.01) in BA but lower (P < 0.001) in BE than in BC pigs. The B pigs had higher (P < 0.001) MUFA but lower (P ≤ 0.006) SFA and PUFA fatty acid percentages in SCAT than the LW pigs. Compared with C, the A system had scarce influence on FA composition within each breed, whereas the E system led to lower (P = 0.015) SFA and greater (P < 0.001) PUFA in SCAT of the B pigs. Altogether, the E production system can counteract the genetic potential of B pigs for growth rate but also body fatness.

Effects of slow release carbohydrates in the form of bean flakes on the evolution of hunger and satiety in man.

This study was undertaken to test the effects of plausible meals containing slow release starches in the form of bean flakes on plasma glucose and hunger in man. In a first study, volunteers consumed a hachis paramentier (shepherd's pie) containing either bean purée or potato purée. After the meal containing potato, plasma glucose levels rose sharply, peaked at 30-45 min and fell below initial levels 2 to 3 h later. With bean purée there was a low, sustained increase in blood glucose. In a second study, volunteers consumed six hachis parmentier (three with bean purée, three with potato purée, topped with spinach, ratatouille or tomatoes). Relative to potato, the bean purée delayed the return of hunger and decreased ratings for propensity to eat a tasty snack.

Variation in 8-methoxypsoralen profiles during long-term psoralen plus ultraviolet A therapy and correlations between serum 8-methoxypsoralen levels and chromametric parameters.

Three serum 8-methoxypsoralen (8-MOP) kinetics tests were performed on 15 patients undergoing PUVA therapy. The first test was carried out before beginning PUVA treatment, the 2nd one at the 10th session and the 3rd test at the 20th PUVA session. Blood samples were taken every 30 min after the drug was taken and a standard meal ingestion during 3 h to determine the serum 8-MOP peak level and corresponding time. For 14 patients, UVA-induced erythema was measured with a Minolta CR 200 chromameter, 3 (before beginning PUVA treatment, just before 10th session and 48 h later) or 5 times (before beginning PUVA treatment, just before 10th session and 48 h later, just before 20th session and 48 h later). There was a wider distribution of serum 8-MOP peak levels in the 3rd test than in 2nd one and in the 2nd one than in the first one. These facts suggest a heterogeneity in 8-MOP metabolism in the 15 patients: 11 patients showed an earlier serum 8-MOP peak and an earlier appearance of the drug in blood in the 3rd and 2nd test than in the first one. For 9 of these 11 patients, serum 8-MOP peak levels were higher and higher from the first profile to the 3rd one, suggesting an inhibition of 8-MOP metabolism in time. In the remaining 4 patients, the 8-MOP peak time and the appearance of the drug in blood were delayed in the 3rd test compared with the first profile.(ABSTRACT TRUNCATED AT 250 WORDS)