Application Of Multivariate Curve Resolution In The Analysis Of Flavonoids

The flavonoids are series of compounds with the structure of2-phenyl-chromone,widely existing in nature.Recently,in the field of scientific research,great attentions have been paid to many flavonoids for their medicinal value.For example,they can not only prevent and cure senile hypertension,strokes,coronary heart disease,angina pectoris,et al,but also take on the activity of arresting cough,dissolving phlegm,allaying asthma,fighting off bacteria,expelling poison,protecting liver.In this thesis,there were four parts,which were detailed as follows:In Chapter1,the development of multivariate curve resolution was summarized,and it detailed some multivariate curve resolution methods concerned in this thesis.The structure and classification of flavonoids were summed up.Some analytical methods usually used to study flavonoids were discribed in detail.In addition,the significance of the research was revealed.In Chapter2,three mixed solutions containing Cu2+and quercetin with the molar ratio0.2,1.0and5.0were tracked and scaned in230-520nm by UV-visible spectrophotometry.To get along with multivariate curve resolution-alternating least squares,the reaction process of Cu2+and quercetin was qualitatively researched.Results showed that the reaction process had nothing to do with molar ratio,and finally only one product(absorbance peak295nm)was got,absorbance peak438nm as a transition state emerging during the reaction process.In Chapter3,the absorbance spectra of the research systems where the complexes were developed from the chemical reaction between luteolin and Al3+in ethanol and methanol were derived by UV-visible spectrophotometry.It discussed concentration and spectral changes of each component,coordination ratio and molecular structure of the complexes,coordinated order of the binding sites of luteolin molecular,in the reactions of luteolin and Al3+with different concentration retion,by multivariate curve resolution-alternating least squares and infrared spectroscopy.Results showed that the structure of the complex was luteolin binding Al3+to form a tetracoordinated organetic compound with a six-membered ring in ethanol,coordination ratio for1:1,the binding site for5-hydroxy-4-ketone.In methanol,the reaction was divided into two steps.For one step,the structure of the complex was Al3+in the center binding two luteolin molecules to form a tetracoordinated organetic compound with a six-membered ring,coordination ratio for1:2,the binding site for5-hydroxy-4-ketone.For another step,the structure of the complex was two Al3+respectively binding one luteolin molecule to form a tetracoordinated organetic compound with a five-membered and a six-membered rings,coordination ratio for2:1,the binding site respectively for5-hydroxy-4-ketone and3’,4’-two hydroxyl groups.In Chapter4,data matrix consisted of the absorbance spectra of quercetin and rutin pure standards,synthetic mixtures and the medicine samples in a column-wise augmented way.This matrix was analyzed by multivariate curve resolution-alternating least squares.The results showed that the relative standard errors were lower than1%for rutin in compound rutin tablets and the recoveries were between94%and108%both for quercetin and rutin in ginkgo leaf tablets and Gan Su Ke Li.