ABSTRACT
OBJECTIVE:To establish a method for the separation and detection of related substances in baicalein,identify its structure and preliminarily explore the degradation mechanism. METHODS:HPLC was adopted to detect the baicalein,related impurities and forced destruction of degradation products in synthesis process:the column was ES Industries? FluoroSep-RP Phenyl with mobile phase of 0.3%formic acid-methanol-acetonitrile(gradient elution)at a flow rate of 1.0 mL/min,the detection wavelength was 275 nm,the column temperature was 10℃,and the injection volume was 10μL. LC-MS/MS was conducted to identify the related substances and conjecture degradation mechanism:the column was ES Industries? FluoroSep-RP Phenyl with mobile phase of 0.3%formic acid- methanol (gradient elution)at a flow rate of 1.0 mL/min,the detection wavelength was 275 nm,column temperature was 10℃,and the injection volume was 10μL;ion source was electrospray ion source,positive and negative ions,nebulizer pressure was 55 psi and the drying gas flow was 11 L/min,drying gas temperature was 350℃,capillary voltage was 4.0 kV,detection modes were full-scan first-order MS and selective ion full-scan second-order MS,scan ranges were m/z 100-1000 (first-order MS) and 50-500(second-order MS),ionization voltage was 80-135 eV,and the collision energy was 10-30 eV. RESULTS:The linear range of baicalein was 2.4-480μg/mL(r=0.9999);RSDs of precision,stability and reproducibility tests were lower than 2.0%;the limit of quantitation was 7.2 ng,the limit of detection was 2.4 ng. Baicalein was well separated with related substance and 3 major degradation products,the related substance was chemical synthesis precursor wood butterfly;the degradation products were 6,7-quinone derivatives and 7,8-quinone derivatives,which were isomers;oxidative degradation products were benzoic acid phenyl ester derivatives. CONCLUSIONS:The main mechanisms of alkali degradation and oxidative degradation of baicalein include pyran, reciprocal rearrangement and oxidation reaction;the established method is specific and sensitive,and can be used for the detection of related substances in baicalein.
ABSTRACT
Objective To investigate the common chromosome abnormalities in the patients with multiple myeloma and the relationships of cytogenetic abnormalities and clinical features. Methods The interphase fluorescence in situ hybridization (I-FISH) analysis method was designed to detect RB1-/13q14-and 14q32 rearrangements in 49 MM patients. The statistic value of its effect on clinical features were determined. Results FISH disclosed 14q32 translocations in 26 of the 40 (53.1%) patients. 25 out of the 49 (51.02 %) cases were found with deletion of chromosome 13q14 included del(RB1) in 9 (18.4 %) and del(13q14.3) in 18 (36.7 %). 13q14 deletion and 14q32 translocation were simultaneously observed in 18 (36.7 %) cases. Spearman correlation analysis were found associated of 14q32 rearrangement with the percentage of plasma cells in bone marrow (r=0.316, P=0.27). Conclusion The frequency of 13q14 deletion and 14q32 gene translocation in multiple myeloma are high. There is a significant correlation between the presence of 14q32 translocations and chromosome 13 abnormalities in MM patients. The percentage of 14q32 translocation in plasma cells was increased significantly. The 14q32 translocation is an independent prognostic factor.