Preliminary Research On The Quality Of Polygonatum Sibiricum By Electrochemical Method And Infrared Spectroscopy

ObjectivePolygonatum cyrtonema Hua from ten different areas and five species of Polygonatum Mill.were studied in order to establish identification and preliminary quality evaluation of Polygonatum sibiricum.MethodsElectrochemical fingerprint technology,fourier transform infrared spectroscopy and fourier transform infrared microspectroscopy were used to identify and evaluate the quality of Polygonatum cyrtonema Hua from different origins and Polygonatum Mill..ResultsThe electrochemical fingerprints of Polygonatum sibiricum were analyzed and compared,the optimum detection conditions were obtained:the dosage of medicinal material was 0.1000 g,the temperature of super thermostatic bath was 310 K,and the speed of magnetic stirrer was 500 r/min.Under these conditions,the main parameters of Polygonatum cyrtonema Hua from different areas and Polygonatum Mill.were compared and disscused.The fourier transform infrared spectroscopy of Polygonatum cyrtonema Hua from different origins and Polygonatum Mill.were studied separately.It was found that the peaks of each spectrum were similar.The result showed that the main absorption peaks of Polygonatum cyrtonema Hua were mainly distributed around 3369、2929、2159、2031、1974、1620、1407、1018、930、866 cm^-1,the main absorption peaks of Polygonatum Mill.were in the vicinity at 3301、2978、2159、1627、1407、1018、928 cm^-1,but the intensity,position and shape of the main absorption peaks were obviously different,indicating that content of chemical components were different.In addition,the second derivative infrared spectroscopy was also compared,the second derivative infrared spectroscopy can well separate the overlapping peaks,broad peaks and weak peaks in the original spectrum.It can eliminate the interference band overlap,background absorption and improve the anti-interference ability of infrared spectroscopy.The comparison of the second derivative spectroscopy of Polygonatum cyrtonema Hua from different areas and Polygonatum Mill.also further intuitively verified the above results.The fourier transform infrared microspectroscopy of the Polygonatum cyrtonema Hua from different areas and Polygonatum Mill.were studied,the optimum detection conditions were obtained:the slice thickness was 30μm,the detection mode was transmission and the window piece was Ba F₂.Since 1018 cm^-1was the characteristic absorption peak of polysaccharide,microscopic infrared image was observed at 1018cm^-1.There were significant differences between the images of the samples,indicating that the content of polysaccharide components were different.The contents of polysaccharides in Polygonatum cyrtonema Hua from different areas ranged from high to low as follows:tongren,qimen,chibi,tianmushan,ruichang,huaihua,chongyang,hefei,liupanshui,jiuhuashan.In Polygonatum Mill.,the polysaccharides contents of Polygonatum sibiricum Red.and Polygonatum filipes Merr.were relatively high,Polygonatum verticillatum（L.）Al and Polygonatum kingianum Coll.et Hemsl were in the middle,Polygonatum cyrtonema Hua was the lowest.ConclusionDifferent fingerprint characteristics and information parameters of the electrochemical fingerprint of Polygonatum cyrtonema Hua from different origins and Polygonatum Mill.showed that Polygonatum sibiricum can be classified,which provided a fast,convenient and economical identification method.Fourier transform infrared spectroscopy combined with second derivative spectroscopy provided the main information of chemical components in Polygonatum sibiricum.Differences in absorption peak strength,location and shape can identify and distinguish Polygonatum cyrtonema Hua from different areas and Polygonatum Mill..The second derivative infrared spectroscopy showed the slope change characteristics of the masked spectrum so that the difference between the sample spectrum was more obvious,which can be used to quickly identify and distinguish the Polygonatum sibiricum.Fourier transform infrared microspectroscopy can observe the distribution of main chemical components in different scanning microregions of Polygonatum sibiricum.The microscopic infrared image can not only image the local shape and appearance of the cross section of Polygonatum sibiricum,but also display the relevant infrared spectral information of different positions in space.The method has advantages such as visibility and high sensitive.