Determination of ³¹P Chemical Shift Tensor from Microcrystalline Powder by Using a Magnetically Oriented Microcrystal Array

The ³¹P chemical shift tensor for phenylphosphonic acid (PPA) was determined by using a magnetically oriented microcrystal array (MOMA)a single-crystal-like composite in which microcrystals are aligned three-dimensionally in a polymer matrixprepared from a microcrystalline powder of PPA. High-resolution ³¹P NMR spectra were obtained for a PPA-MOMA without magic angle spinning (MAS), from which the chemical shift anisotropy (CSA) was determined. The single-crystal rotation method was applied to the MOMA to determine the principal axes of the ³¹P chemical shift tensor with respect to the crystallographic axes. The present results demonstrate that the MOMA method can provide a powerful means of determining all of the information on ³¹P CSA from a microcrystalline powder without MAS

Metabolic Fate of Luteolin in Rats: Its Relationship to Anti-inflammatory Effect

Luteolin is a naturally occurring flavone that reportedly has anti-inflammatory effects. Because most luteolin is conjugated following intestinal absorption, free luteolin is likely present at low levels in the body. Therefore, luteolin metabolites are presumably responsible for luteolin bioactivity. Here we confirmed that luteolin glucuronides, especially luteolin-3′-<i>O</i>-glucuronide, are the major metabolites found in plasma after oral administration of luteolin (aglycone) or luteolin glucoside (luteolin-7-<i>O</i>-glucoside) to rats. Luteolin-4′-<i>O</i>-glucuronide and luteolin-7-<i>O</i>-glucuronide were also detectable together with luteolin-3′-<i>O</i>-glucuronide in the liver, kidney, and small intestine. Next, we prepared these luteolin glucuronides and compared the anti-inflammatory effects of luteolin and luteolin glucuronides on gene expression in lipopolysaccharide-treated RAW264.7 cells. Luteolin glucuronides, especially luteolin-7-<i>O</i>-glucuronide, reduced expression of inflammatory genes in the cells, although their effects were weaker than those of luteolin. These results indicate that the active compound responsible for the anti-inflammatory effect of luteolin in vivo would be luteolin glucuronide and/or residual luteolin