benzofurans and phosphoric-acid

Chiral phosphoric acid and Hoveyda-Grubbs II were found to catalyze an olefin cross-metathesis-intramolecular oxo-Michael cascade reaction of the ortho-allylphenols and enones to provide a variety of benzofuran and benzoxazine derivatives in moderate to good yields and enantioselectivity.

Topics: Alkenes; Benzofurans; Benzoxazines; Catalysis; Oxidation-Reduction; Phosphoric Acids; Stereoisomerism

A precise and reproducible HPLC method has been established and validated for determination of salvianolic acid B (SalB) in rat plasma after oral administration of Radix Salviae Miltiorrhizae extract. Liquid-liquid extraction was adopted for the sample preparation. Separation was accomplished on a C(18) column with a linear gradient elution consisting of acetonitrile and aqueous phosphoric acid. Ultraviolet detection was at 280 nm. The method was validated over the concentration range 10.8-259.4 microg/mL using 1 mL of plasma. The assay was linear over this concentration range with a coefficient of variation less than 7%. The extraction recovery of SalB was within the range 71-83% with RSD 11%. The mean recovery of the internal standard was 84% (n = 6) with RSD of 5.6%. This method is suitable to determine SalB in plasma and to investigate the pharmacokinetics of SalB.

Topics: Acetonitriles; Administration, Oral; Animals; Benzofurans; Chromatography, High Pressure Liquid; Drugs, Chinese Herbal; Male; Phosphoric Acids; Plant Extracts; Rats; Rats, Sprague-Dawley; Reproducibility of Results; Salvia miltiorrhiza; Sensitivity and Specificity