Study On The Content Determination, Side Effect And Bioavailability Of Parts Of Flavonoids

Flavanoids is widely distributed in plants. Over 4000 different flavonoids have been described. Flavonoids have a variety of biological effects, and is widely applied in clinic. With the further study and broad application of flavonoids in clinic, we find that the content of parts of flavonoids can not be accurately determined, that certain flavonoids often cause side effects when applied, especially applied as injection, and that some flavonoids have very low bioavailability. These adverse characters limit application of flavonoids.Researchs on flavonoids reveal that the content of parts of flavonoids could not be accurately determined. In this study, baicalin and rutin are taken as the object of my research. 2-phenyl-chrome, the basic structure of baicalin and rutin, is a cross conjugation system. In order to make conjugation system steadier, the electron rearrangement and electron transfer occur in parts of bacailin molecules, and therefore conjugation chain is extended. In consequence, A-ring and B-ring become electropositive. Electron transition of flavones molecules could happen by the irradiation of excitation light, and this process is the same as electron transition during the forming process of protonated ether, so that a part of flavones molecules which is present in the form of protonated ether can not absorb energy of light and release energy. The flavones molecules are excluded and can not be detected by UV. As a result, Content of flavones determined by HPLC is relatively low. The content of baicalin samples with different contents and different crystal water were determined by HPLC. The aim of our study is to search for the reason that baicalin content can not be determined accurately and the methods to resolve it.Although flavonoids have various biological effects, flavonoids cause almost same side effects such as allergic response, pyrogen reaction, shock, even death and so on. Researchs on side effects of flavonoids reveal that side effects are caused by complex compound formed by flavonoids and lipoprotein. By electron rearrangement and electron transfer of cross conjugation system, protonated ether and carbocation form in flavonoids molecule, so that protein can bind to flavonoids molecules by interaction of electric charge. The interaction of flavonoids molecules and protein is very firm, so that the impurities could not be removed completely and therefore cause side effects. The aim of our research is to make the impurities and their physico-chemical property clear, adopt certain method to remove impurities thoroughly to supply safe flavonoids medicine for clinic. All those will bring remarkable economic and social benefits.Parts of flavonoids are cross conjugation system, so the spatial structure of molecules are plane. Because of this planar structure, molecules combine tightly and the union among molecules is firmly bound. Consequently, the interspace between adjacent molecules is extremely limited. These make the solvent molecules difficult to enter molecules and break the attractive force of molecules. So parts of flavonoids can not dissolve in most of the solvents, and can not be absorbed when taken orally. Take rutin as example. Rutin is a well known flavonoid found in Artemesia scoparia and some other plants. It exhibits multiple actions such as spasmolytic and inhibition of arachidonic acid metabolism. It antagonize the increase of capillary fragility associated with haemorrhagic disease, reduces high blood pressure ,dcreases the permeability of the blood vessels and has an anti-oedema effect, reduces the risk of arteriosclerosis and has antioxidant activity. But rutin is not nearly soluble, and it can not be absorbed by taking orally, so its effects by taking orally is uncertain. So its application is limited. At present, many reserchers attempt to improve water-solubility of rutin by design of preparation. But because of the high cost, it is impossible for these preparations to be applied widely.Experiment results indicate that water-solubility of rutin increases remarkably by preventing hydrogen bond interaction of oxygen in one position with water molecule, and thus bioavailability of rutin is improved. The cost of this method is low, and so it is promising to succeed in making rutin becoming excellent preparation by taking orally.