Study On The Extraction Kinetic Model Of Flavonoids From Five Rhizome Medicinal Materials

Extraction is the most important part of pharmaceutics;Chinese patent mediation quantity depends largely on the extraction process,especially for drugs with favorable cellular structures.The extraction of traditional Chinese medicine goes through the following 5 steps:solvent infiltration,solvent permeating into intra-cellular,desorption of target,dissolve of target and out diffusion.The mechanism is complicated,accompanied by many variables,so that many problems existed like:poor reproducibility of the process,low extraction efficiency.In addition,the current research methods of traditional Chinese medicine extraction process are mostly orthogonal design,uniform design,and star design,which is difficult to expect the rapid changes if the extraction factors differed.These design results only reflect the optimal level within a certain range.Referring to the above two points,exploring new methods to study the traditional Chinese medicine extraction process is meaningful.Relevant research literature shows that:at present,most of extracts study aimed at the thermodynamic or kinetic parameters of the extraction process,such as the apparent activation energy,diffusion coefficient,relative raffinate rate.However,not a research get into the filed to uncover the mathematical relationship between the target components and extraction factor or level;other researches deduced the equation based on Fick’s law,but with variety derived parameters,form is complex,difficult to solve.So they were just used to qualitative analysis cannot achieve a good prediction function.Therefore,the actual situation of these studies was difficult to fit TCM production.Referring to the current research status,preliminary idea of my research in this area was formed.Based on Fick’s law,equation of mathematical model was formed through rigorous mathematical derivation,then the non-essential parameters was simplified in order to reflect the outstanding factors of extraction process.At last,the mathematical relationship of extract concentration or contents and levels of factors was finally determined;after establishment of the models,prediction that fitted the industrial production was achieved.Meanwhile the idea of data mining method was introduced to study the extraction process to compensate the insufficiency of mathematical model.Using data mining techniques to find inner mathematical relationship of extraction process,and establishing networks to achieve prediction is a new study method in extraction filed of Traditional Chinese Mediation.Mathematical models and computer algorithms assist each other,complement each other.Part of My Dissertation mainly includes the following 3 sections:Section 1:explanation the relevant parameters of the extraction kinetics model and its application to describe the kinetic decocting process of total flavonoids in Radix Puerariae and Glycyrrhiza.Based on the general kinetic model for extraction,we established appropriate experimental methods to study the kinetic extraction process of decocting method of Radix Puerariae and Glycyrrhiza,choosing the concentration of total pueraria flavonoid as the index,in order to investigate how this method can fit the Kinetic model for extraction.The results showed that the relation of natural logarithm of the concentration of total pueraria flavonoid to extraction time and solvent volume was approximate linearity.Through calculating and fitting the parameters in the equation,we successfully established the kinetic model for extraction of Radix Puerariae and Glycyrrhiza.Then we verified its accuracy.The kinetic model for extraction of Radix Puerariae and Glycyrrhiza can meet the industrial deviation.But the influence of temperature factor on this kinetic model and correction factor of equation deserves further study,Section 2:Model simplification and the establishment of total flavonoids extracted models of Drynaria,Shegan,and Baikal Skullcap Root.Due to the irregularity of Chinese crude drug,we simplified the general extraction kinetic model deduced before.The grade size was mixed in parameter"a",so that we did not need to measure it.And this not only improved the accuracy of the kinetic model but also got closer to the practical manufacture.After the simplified model was established,we conducted our experiment to test its accuracy and suitability in the total flavonoids extraction process of the three herbs.Total flavonoid in the three herbs was determinate as the index and its natural logarithm was in linear correlation with the natural logarithm of extraction time and solvent quantity.After calculating and fitting,the kinetic model of the total flavonoids extraction process of the three herbs in decocting method.Its accuracy was testified at last and the error can be easily controlled in production claimed range.So,the simplified model can be used to describe the extraction process of water decocting.Section 3:Prediction of total flavonoids concentration based on locally weighted regression(LWR)algorithm of the five Chinese crude drugs.Due to the limitation of Mathematical Model,we turned to the data mining technology---locally weighted regression algorithm to achieve the prediction of extraction results.Using the experimental data determined already,we selected the optimum parameters in order to get the best correlation coefficient.After comparison of the prediction results of both methods,we found that locally weighted regression models got the better accuracy than the Mathematical Model in Radix Puerariae Glycyrrhiza,Drynaria and Shegan.So,LWR can be used as a new method to predict the extraction process efficiency.