Thermodynamics and 2H NMR study on the insertion of small quinones into a discotic nematic lyotropic liquid crystal.

A detailed description of the distribution, interaction, and dynamics of molecules with biological activity dissolved in a hydrophobic bilayer, a simple model of a biological membrane, provides valuable information for a better understanding of drug functioning, which can be very useful in drug design. Here we present an (2)H NMR and molecular dynamics study on the insertion, distribution, interactions, and thermodynamics of two biologically active molecules, 9,10-dihydroxy-4,4-dimethyl-1,4,5,8-tetrahydroanthracen-1-one (HQ), with anticancer activity, and 4,4-dimethyl-1,4,5,8,9,10-hexahydroanthracen-1,9,10-trione (Q) a fungicide, dissolved in a nematic discotic lyotropic liquid crystal (ndllc) composed of sodium dodecylsulphate (SDS), decanol (DecOH) and Na2 SO4 in water. (2)H NMR quadrupole splittings (ΔνQ ) and longitudinal relaxation times (T1) from HQ-d6, Q-d4, DecOH-α-d2, partially deuterated water, and SDS-d25 were measured and several molecular dynamics trajectories were also calculated.

Counterion and composition effects on discotic nematic lyotropic liquid crystals II. Ion exchange and molecular dynamics.

The static fluorescence quenching of pyrene by bromide, at the interface of mixed TTAC/TTAB discotic nematic lyotropic liquid crystals, allowed an estimation of the equilibrium constant for the exchange of chloride by bromide. The affinity of the interface for bromide is much higher than for chloride (K(Br-/Cl-) = 13.2).