Determination of Total Anthraquinone and Free Anthraquinone in Different Processed Products of Rhubarb

[Objectives]The content of total anthraquinone and 5 free anthraquinones in different processed products of rhubarb were determined.[Methods]Using emodin as the reference,the concentration of 1%magnesium acetate methanol solution was used for color development,and the absorbance was measured at 516 nm wavelength;the mobile phase was methanol-0.1%phosphoric acid(76∶24)aqueous solution,the detection wavelength was set at 256 nm,the flow rate was 1.0 mL/min,the column temperature was 30℃,and the sample size was 10μL.[Results]The content of total anthraquinones in rhubarb was determined by UV spectrophotometry.The linear range was 0.98-23.52μg/mL,R2=0.9993,the average recoveries were 100.12%,99.66%and 99.15%,with RSDs of 1.58%,0.94%and 1.41%,respectively.The linear ranges of emodin,emodin,emodin,chrysophanol and emodin methyl ether were 0.0207-0.414(R2=0.9999),0.1721-3.442(R2=0.9996),0.0203-0.406(R2=0.9999),0.148-2.96(R2=0.9998)and 0.164-3.28(R2=0.9993),respectively.[Conclusions]The contents of total anthraquinones and free anthraquinones in different processed products of rhubarb were determined by UV spectrophotometry and HPLC.The method can be used for quality control of rhubarb and its different processed products.

Box-Behnken response surface method combined with fingerprint to optimize the extraction process of total anthraquinone from Cassia seeds

Objective:The Box-Behnken response surface method combined with fingerprints was used to optimize the extraction process of total anthraquinone from Cassia seeds.Methods:A three-factor,three-level response surface test was conducted based on the single-factor test with comprehensive evaluation as the measurement index.The comprehensive evaluation indexes included the extraction rate of total anthraquinone of Cassia seeds or the equivalent amount of herbs per gram of total anthraquinone of Cassia seeds,the normalized value of peak areas of 5 index components such as aurantio obtusin in the fingerprint of each sample to 16 shared peaks and the similarity of fingerprints(the reference fingerprint was established by the extraction solvent for the determination of Cassia seeds content in the Chinese Pharmacopoeia 2020 edition)with the weights of 0.2,0.5 and 0.3,respectively.Results:The best extraction process was obtained:the liquid-to-material ratio was 20:1(mL·g-1),the extraction solvent was mixture of 60%ethanol-ethyl acetate(2:1),and the extraction time was 15.12 min.The results of five sets of validation experiments showed that the overall evaluation of total anthraquinone of cassia seeds by the best process was 0.528(RSD=0.45%),and the prediction result of response surface method model was 0.531,and the relative error with the prediction result was 0.531.The relative error of the predicted results was 0.56%,and the best extraction process was consistent with the model prediction,and the obtained best process could be used for the extraction of total anthraquinone from Cassia seeds.Conclusion:The Box-Behnken response surface method combined with the fingerprint technique can be used to find the best reaction conditions and examine the interactions among the factors in a comprehensive and accurate manner,which can provide reference for the optimization and evaluation of the extraction process of Chinese medicine.

Establishment of the Determination Methods of Total Anthraquinone Content in Different Processed Products of Rhubarb

[Objectives]Ultraviolet spectrophotometry was established for the determination of total content of anthraquinone in different processed products of rhubarb.[Methods]Emodin was used as the control substance,and its color was developed by magnesium acetate methanol solution with the concentration of 1%,the absorbance was determined at the wavelength of 516 nm,the content of total anthraquinone in different processed products of rhubarb was determined to compare the content differences.[Results]The regression equation was y=0.0452 x+0.0015,R 2=0.9991.Emodin had a good linear range in the concentration of 0.98-23.52μg/mL,with high accuracy,good repeatability and stable detection results.This method revealed the content changes of total anthraquinone in rhubarb before and after processing.[Conclusions]This method could be used as the quality control method of different processed products of rhubarb,and provided reference for the comprehensive development and utilization of rhubarb resources in the future.

Chronic toxicity of both raw and processed Polygoni Multiflori Radix on rats

Recently, adverse effects of Polygoni Multiflori Radix（PMR） and Polygoni Multiflori Radix Praeparata（PMRP） have attracted intensive attention worldwide. These adverse effects most occurred in cases with high dose of prolonged medication course. Liver is usually the target organ of these adverse effects. In the present research, we performed in vivo chronic toxicity study and aimed to evaluate relationships between major constituents of water extractions and total anthraquinone of PMR and PMRP and chronic toxicity. SD rats of both sexes were given water extractions as well as total anthraquinone of PMR and PMRP for 12 weeks. We evaluated basic biochemical indexes, conducted microscopic observations of main organs and assessed early indicators of liver and renal fibrosis. Simvastatin, with hypertriglyceridemia and hypercholesterolemia as its main therapeutic areas, was investigated in our study. Component-toxicity relationships were also discussed. Five male rats died in our study, while all female rats survived, suggesting that some gender differences might be involved. Body weight was significantly changed, and basic biochemical indexes were sporadically occurred during the research. Pathological examinations on liver and kidney showed slight alternations after 12 weeks without dose-dependent relationship. Increase in serum laminin（LN） was observed in almost all male rats, indicating that the risks of liver or kidney fibrosis still existed, especially for males, although no fibrosis was found in the pathological examination of liver and kidney. No major and severe adverse effects were observed after 12 weeks of administration of PMR and PMRP. Regular safety monitoring is still necessary during medication in order to prevent possible risks.