Multi-index determination and optimization of liquirtin separated from polyamide resin The Chemical Constituents of Glycyrrhiza aspera Root Studies on effects of Achyranthes bidentata on Tongsaimai pellets main active ingredients chlorogenic acid, isoliquiritin, harpagoside and glycyrrhizin in vivo pharmacokinetics Analysis on changing rules of four active components alignment in Glycyrrhizae Radix et Rhizoma Praeparata cum Melle and its compatibility carrier Effects of flavonoids from Glycyrrhizae Radix on function and expression of P-glycoprotein in Caco-2 cells