ABSTRACT
OBJECTIVE:To synthesize 4-hydroxyphenylacetic acid(PHPAA)molecular imprinted polymers(MIPs),and to provide reference for separation and enrichment of PHPAA in urine of cancer patients. METHODS:With PHPAA as template molecule and azobisisobutyronitrile as evocating agent,MIPs was synthesized by precipitation polymerization using 4-vinyl pyridine(4-V),acrylamide(AM),1-vinyl imidazole(1-V)and o-diaminobenzene as functional monomers,ethylene glycol dimethacrylate(EGDMA)and trimethylolpropane trimethacrylate(TRIM)as crosslinking agent. Using scanning electron microscope,infrared spectrum,static adsorption test and molecular recognition performance test used adopted to characterize the structure and performance of MIPs. RESULTS:MIPs1(4-V,EGDMA)microspheres adhered seriously,and MIPs2(AM, EGDMA)microspheres are aggregated. MIPs3(1-V,TRIM),MIPs4(o-diaminobenzene,TRIM)microspheresare were dispersed and had good sphericity. Characteristic absorption peak of PHPAA was not found in infrared spectrum of MIPs. The adsorption capacity of each MIPs was higher than that of blank imprinted polymer without the template molecule,and increased as the increase of template molecular concentration. The adsorption capacity of MIPs3 was significantly higher than that of other MIPs,and its static distribution coefficient(0.14)of PHPAA was higher than that of other structural analogues [PHPA(0.06),TA(0.01)],selective separation factors of PHPAA to PHPA,PHPAA to TA were 2.3,11.5,respectively. CONCLUSIONS:MIPs synthesized with 1-V as functional monomer and TRIM as crosslinking agent has the ability of specific adsorption and selective recognition. It can used as solid phase extractant to separate and enrich low content of PHPAA in the urine of tumor patients.
ABSTRACT
Objective: To investigate the chemical constituents from the water extract of Rhodiola wallichiana. Methods: The chemical constituents were isolated by repeated dynamic axial compression chromatography, Sephadex LH-20 column chromatography, and prep-HPLC, and their structures were identified by the basis of spectral data analysis. Results: Eleven compounds were isolated from the water extract and identified to be gallic acid (1), syringic acid (2), tyrosol (3), salidroside (4), 3,4- dihydroxybenzoic acid (5), 4-hydroxybenzoic acid (6), 4-hydroxyphenylacetic acid (7), p-coumaric acid (8), p-coumaric acid-4-O-β-D- glucopyranoside (9), benzyl-O-β-D-glucopyranodide (10), piceoside (11), dihydroconiferin (12), bergeninum (13), rhodiocyanoside A (14), and 5-hydroxymethylfurfural (15). Conclusion: Compounds 7 and 15 are isolated from the plants of Rhodiola L. for the first time, and compounds 5-6, 8-12, and 14 are obtained from R. wallichiana for the first time.