ObjectiveTo establish a method for simultaneous analysis of catalpol, leonurus glycoside, rehmannin A, rehmannin D, pilose glycoside, isostaminoside and 5-HMF in Rehmanniae Radix Praeparata, and determine the contents of seven chemical constituents in three different processed products of steamed rehmannia glutinosa; rehmannia rehmannia stewed in wine; nine steam nine sun cooked rehmannia, and explore the effects of different processing methods on the chemical constituents of Rehmanniae Rodix Praeparata.

MethodsThree different processed products of Rehmanniae Rodix Praeparata were extracted by ultrasonic extraction, and Thermo C₁₈ column (250 mm×4.6 mm, 5 μm) was used.The mobile phase was 0.1% phosphoric acid(A)-acetonitrile(B), the gradient elution procedure was 0-8min, 1%B; 8-9min, 1%-4%B; 9-25min, 4%B; 25-35min, 4%-20%B; 35-50min, 20%B; 50-50.01min, 20%-1%B and 50.01-55min, 1%B.The column temperature was 30℃, the detection wavelength was 203nm and 332nm, and the contents of seven chemical constituents in three samples were determined.

ResultsThe 5-HMF was not detected in radix rehmanniae.In steamed Rehmanniae Rodix Praeparata and stewed Rehmanniae Rodix Praeparata in wine, the cycliterpene monoglycoside catalpol and leonurus glycoside were almost complete degraded, the contents of iridoid diterpenoid glycoside rehmannin A, rehmannin D, phenylpropanoid glycoside piloside and isobruchin glycoside were low compared with Rehmanniae Radix, and 5-HMF could be detected.The cyclioterpene monoglycoside catalpol, leonurus glycoside, cyclioterpene diglycoside rehmanin A, rehmanin D, phenylpropyl glycoside mullein glycoside and isomullein glycoside were almost degraded, and 5-HMF could be detected in nine steam nine sun cooked rehmannia.

ConclusionDifferent processing methods have great influence on the components of decoctian piecesof.This method can be used for the quality control of Rehmanniae Radix Praeparata.