A multifunctional selective "turn-on" fluorescent chemosensor for detection of Group IIIA ions Al3+, Ga3+ and In3.

A versatile chemosensor 1 (E)-2-(((8-hydroxy-2,3,6,7-tetrahydro-1H,5H-pyrido[3,2,1-ij]quinolin-9-yl)methylene)amino)-1H-benzo[de]isoquinoline-1,3(2H)-dione, based on naphthalimide and julolidine moieties, was developed for highly distinguishable and selective recognition of Group IIIA metal ions (Al3+, Ga3+ and In3+). Sensor 1 exhibited significant 'off-on' fluorescence responses at 488 nm in the presence of Al3+ and at 570 nm in the presence of Ga3+ and In3+. The same emission of Ga3+ and In3+ could be distinguished through different color changes (from colorless to yellow for Ga3+ and no color change for In3+). Binding constants of 1 for Ga3+ and In3+ are the highest reported to date for an organic chemosensor. A 2 : 1 binding mode between 1 with Al3+, Ga3+ and In3+ is proposed based on electrospray ionization mass spectrometry, Job plot analysis, and theoretical calculations.

A Multi-Responsive Naphthalimide-Based "Turn-on" Fluorescent Chemosensor for Sensitive Detection of Trivalent Cations Ga3+, Al3+ and Cr3.

A new multifunctional chemosensor 1, (E)-2-(((2-hydroxynaphthalen-1-yl)methylene)amino)-1H-benzo[de]isoquinoline-1,3(2H)-dione, based on naphtalimide and naphthaldehyde was developed, which showed the fluorescence responses to trivalent metal ions (Ga3+, Al3+ and Cr3+). Sensor 1 detected and differentiated selectively trivalent metal ions Ga3+, Al3+ and Cr3+ by fluorescence enhancement at different emissions. The association constant of Ga3+-2∙1 complex is the highest one among those of the organic chemosensors reported, to date. The sensing mechanisms for Ga3+, Al3+ and Cr3+ were explained by UV-vis titrations, Job plots, ESI-mass analyses and theoretical calculations.

Sequential detection of Fe3+/2+ and pyrophosphate by a colorimetric chemosensor in a near-perfect aqueous solution.

A novel colorimetric chemosensor 1 was designed and synthesized for Fe3+/2+ and pyrophosphate. Sensor 1 showed a selective color change toward both Fe3+ and Fe2+ from yellow to brown in a near-perfect aqueous solution. The detection limits (0.36 µM and 0.37 µM) for Fe3+ and Fe2+ were much lower than the guideline (5.37 µM) set by the Environmental Protection Agency (EPA) for iron in drinking water. Sensor 1 could be used to quantify Fe3+ in real water samples. Moreover, the resulting Fe3+-2·1 complex can detect pyrophosphate selectively over various anions especially including phosphate-based anions through a metal-complex displacement method. Based on UV-vis titrations, Job plot and ESI-mass spectrometry analyses, the sensing mechanisms of Fe3+, Fe2+ and PPi were proposed.

Short-term periodic restricted feeding elicits metabolome-microbiome signatures with sex dimorphic persistence in primate intervention.

Dietary restriction has shown benefits in physiological, metabolic, and molecular signatures associated with aging but is a difficult lifestyle to maintain for most individuals. In mice, a less restrictive diet that allows for cyclical periods of reduced calories mitigates aging phenotypes, yet the effects of such an intervention in a genetically heterogenous, higher-order mammal has not been examined. Here, using middle-aged rhesus macaques matched for age and sex, we show that a regimen of 4 days of low-calorie intake followed by 10 days of ad libitum feeding (4:10 diet) performed in repeating cycles over 12 weeks led to significant loss of weight and fat percentage, despite the free access to food for most of the study duration. We show the 4-day restriction period is sufficient to drive alterations to the serum metabolome characterized by substantial differences in lipid classes. These phenotypes were paralleled by changes in the gut microbiome of restricted monkeys that highlight the involvement of a microbiome-metabolome axis. This regimen shows promising phenotypes, with some sex-dimorphic responses, including residual memory of the diet. As many calorie restriction interventions are difficult to sustain, we propose that this short-term diet may be easier to adhere to and have benefits directly relevant to human aging.

Purification and characterization of neoagarotetraose from hydrolyzed agar.

Whitening effect, tyrosinase inhibitions, and cytotoxicity of neoagarotetraose were measured after purification from hydrolyzed agar by gel filtration chromatography. In melanoma B16F10 cells, melanin content of neoagarotetraose-treated cells was as same as that treated by kojic acid or arbutin. In addition, tyrosinase of melanoma cells was strongly inhibited by neoagarotetraose at a concentration of 1 micron/ml and similarly inhibited at 10 and 100 microg/ml compared to those by arbutin or kojic acid. The activity of mushroom tyrosinase showed a 38% inhibition by neoagarotetraose at 1 microg/ml, and this inhibitory effect was more efficient than that by kojic acid. Neoagarotetraose revealed similar IC(50) (50% inhibition concentration) value for mushroom tyrosinase as that by kojic acid. These data suggest that neoagarotetraose generated from agar by recombinant beta-agarase might be a good candidate as a cosmetic additive for whitening effect.