Associations between whole peripheral blood fatty acids and DNA methylation in humans

Fatty acids (FA) modify DNA methylation in vitro, but limited information is available on whether corresponding associations exist in vivo and reflect any short-term effect of the diet. Associations between global DNA methylation and FAs were sought in blood from lactating infants (LI; n = 49) and adult males (AMM; n = 12) equally distributed across the three conventional BMI classes. AMM provided multiple samples at 2-hour intervals during 8 hours after either a single Western diet-representative meal (post-prandial samples) or no meal (fasting samples). Lipid/glucose profile, HDAC4 promoter and PDK4 5'UTR methylation were determined in AMM. Multiple regression analysis revealed that global (in LI) and both global and PDK4-specific DNA methylation (in AMM) were positively associated with eicosapentaenoic and arachidonic acid. HDAC4 methylation was inversely associated with arachidonic acid post-prandially in AMM. Global DNA methylation did not show any defined within-day pattern that would suggest a short-term response to the diet. Nonetheless, global DNA methylation was higher in normal weight subjects both post-prandially and in fasting and coincided with higher polyunsaturated relative to monounsaturated and saturated FAs. We show for the first time strong associations of DNA methylation with specific FAs in two human cohorts of distinct age, diet and postnatal development stage

Dual-State Emission in Molecular Rotors with Reorientable Benzotriazole Acceptors

Dual-State Emission (DSE) of organic molecules in both solution and solid-state is an elusive property that has recently drawn significant interest. In this work, we report two molecular rotors 1 and 2 with exceptional photoluminescence (PL) in solution (ФPL = 0.53 and ФPL = 0.43) and in the solid state (ФPL = 0.92 and ФPL = 0.84). To the best of our knowledge, this is the first report containing Donor-pi-Acceptor-pi-Donor (D-pi-A-pi-D) compounds with high quantum yields in both states that features a rotary acceptor. Furthermore, we describe the marked variations in PL in solution upon polarity and viscosity changes. TD-DFT computations indicate that these changes are facilitated by the fast molecular rotation in these molecules. The symmetry (or lack of it) in 1 and 2 plays a crucial role in producing noticeable differences in the X-ray crystal arrays with variations in the solid-state PL. We attribute this DSE behavior to the favorable combination of the D--A--D architecture and the twisted conformations adopted in the solid state

Tailoring the cavities of hydrogen-bonded amphidynamic crystals using weak contacts: towards faster molecular machines.

This work describes the use of C-H⋯F-C contacts in the solid-state from the stator towards the rotator to fine-tune their internal motion, by constructing a set of interactions that generate close-fitting cavities in three supramolecular rotors 1-3I. The crystal structures of these rotors, determined by synchrotron radiation experiments at different temperatures, show the presence of such C-H⋯F-C contacts between extended carbazole stators featuring fluorinated phenyl rings and the 1,4-diazabicyclo[2.2.2]octane (DABCO) rotator. According to the 2H NMR results, using deuterated samples, and periodic density functional theory computations, the rotators experience fast angular displacements (preferentially 120° jumps) due to their low rotational activation energies (E a = 0.8-2.0 kcal mol-1). The higher rotational barrier for 1 (2.0 kcal mol-1) is associated with a larger number of weak C-H⋯F-C contacts generated by the stators. This strategy offers the possibility to explore the correlation among weak intermolecular forces, cavity shape, and internal dynamics, which has strong implications in the design of future fine-tuned amphidynamic crystals

Associations between whole peripheral blood fatty acids and DNA methylation in humans

Fatty acids (FA) modify DNA methylation in vitro, but limited information is available on whether corresponding associations exist in vivo and reflect any short-term effect of the diet. Associations between global DNA methylation and FAs were sought in blood from lactating infants (LI; n = 49) and adult males (AMM; n = 12) equally distributed across the three conventional BMI classes. AMM provided multiple samples at 2-hour intervals during 8 hours after either a single Western diet-representative meal (post-prandial samples) or no meal (fasting samples). Lipid/glucose profile, HDAC4 promoter and PDK4 5'UTR methylation were determined in AMM. Multiple regression analysis revealed that global (in LI) and both global and PDK4-specific DNA methylation (in AMM) were positively associated with eicosapentaenoic and arachidonic acid. HDAC4 methylation was inversely associated with arachidonic acid post-prandially in AMM. Global DNA methylation did not show any defined within-day pattern that would suggest a short-term response to the diet. Nonetheless, global DNA methylation was higher in normal weight subjects both post-prandially and in fasting and coincided with higher polyunsaturated relative to monounsaturated and saturated FAs. We show for the first time strong associations of DNA methylation with specific FAs in two human cohorts of distinct age, diet and postnatal development stage