Analysis On The Volatile Oils And The Quercetin Content Of Houttuynia Cordata Thunb. From Different Valleys And Altitudes Of Mt.Emei

HERBA HOUTTUYNIAE., the whole plant of Houttuynia cordata Thunb., is a kind traditional Chinese medicine(TCM) and also a kind of delicious vegetable. It is called Yuxingcao because of fishy smell after its stem and leaf being teared up. It has the function of antibacterial, anti-virus and diuresis, and could enhance body immunity. Sichuan Province is one of the main producing areas of H.cordata Thunb.Volatile oils and quercetin compounds are the main chemical components and effective components of H.cordata. The chemical constituents of volatile oils were separated and identified by GC-MS. Quercetin content were detected by RP-HPLC. The underground parts of each wild populations were transplanted to the orchard of Sichuan Agricultural University in the meantime. After one year's cultivations the volatile oils of the aerial parts of the cultivated ones were obtained and detected by the same methods. Volatile oil components in cultivated conditions were compared with volatile oil components in wild conditions. The relationships between volatile oil components, quercetin contents and altitude, soil nutrient contents were discussed. The main results were described as follows:1. Totally, thirty-five chemical components were identified from the volatile oils of 17 wild populations. The average contents of ten chemical components were higher, includingβ-Myrcene, trans-β-Ocimene, 2-Undecanone,β-Phellandrene, Ethyl decanoate, Dodecanal, Bornyl acetate, Decanal, 4-Terpineol andα-Pinene. The components and contents of volatile oils in different H.cordata populations were various. The populations from valley C and D located in west slope of Mt.Emei had the same main components(average content>10%), includedβ-Myrcene, trans-β-Ocimene and 2-Undecanone. The populations from valley A and v B located in east slope of Mt.Emei have different main components. The main components of the population from valley A wereβ-Phellandrene,/3-Myrcene, trans-β-Ocimene and Bornyl acetate, while in population from valley B wereβ-Myrcene, Decanal and 2-Undecanone. Totally, six main componentswere identified from the populations of 4 valleys, and myrcene was the only main component detected in all populations.2. The underground parts of each wild populations were transplanted to the orchard of Sichuan Agricultural University(cultivated groups) in the meantime, the EOs of the aerial parts of the cultivated ones were obtained and detected by the same methods after one year's cultivation. Totally, thirty-one components were identified from the volatile oils of 17 cultivated groups. The average contents of ten chemical components were higher, includingβ-Myrcene, 2-Undecanone,β-Phellandrene, Dodecanal, 1,13-Tetradecadien-3-one, trans-β-Ocimene, Decanal, 4-Terpineol,α-Pinene andβ-Pinene. The components and contents of volatile oils in different H.cordata populations were various. The populations from valley C and D located at the west slope of Mt.Emei had the same main components, includedβ-Phellandrene,β-Myrcene and 2-Undecanone. The population from valley A and B located at the east slope of Mt.Emei have different main components. The main components of the populations from valley A wereβ-Phellandrene,β-Myrcene, 2-Undecanone and 1,13-Tetradecadien-3-one, while that from valley B wereβ-Myrcene and 2-Undecanone. Totally, four main chemical components were identified from all the populations of 4 valleys, myrcene was also the only main component detected in all populations.3. Totally, 41 components were identified in all the populations of two different growth conditions. Twenty-five chemical components could be detected in both wild populations and cultivated groups, accounting for 91.03% and 91.81% of the whole volatile oils, respectively. Ten chemical components could only be detected in the wild populations, and six could only be detected in the cultivated groups. Eleven main chemical components which could be detected among almost all the wild populations and its cultivated populations were selected to detect the EO variations between the wild and cultivated populations through t-test. The results indicated the content ofα-pinene and D-limonene in the cultivated populations is significantly higher than that in the wild ones, and the reverse was found in the content of trans-β-ocimene. The content of camphene and 2-undecanone in cultivated populations is also higher than that in the wild populations. There are no significant differences of the other main components between the wild and cultivated populations.4. Totally, 41 volatile oil components were detected in all populations of two growth conditions. All the 41 components could be divided into 9 chemical compositions, namely, monoterpene hydrocarbon, monoterpenyl alcohols, monoterpenyl esters, sesquiterpene hydrocarbons, diterpenyl hydrocarbons, diterpenyl alcohols, diterpenyl aldehydes, diterpenyl ketones and diterpenyl esters. Seven chemical compositions could be detected both in the wild and cultivated populations except for diterpenyl hydrocarbons and diterpenyl esters. Among CVs of 7 chemical compositions, CVs of 5 chemical compositions in wild populations were higher than these in cultivated populations, and the reverse was found in the contents of diterpenyl alcohols and diterpenyl aldehydes. The content of these two chemical compositions were 10.79%and 8.5 % in wild and cultivated populations, respectively. Other 5 chemical compositions were 84.05%and 90.12%, respectively. The previous results indicated that the volatile oils polymorphism decrease distinctively as all the wild populations of H. cordata were transplanted to the uniform environmental conditions.5. The pH value of most soil samples were acid and slight acid, and the content of soil organic matter of the localities of H. cordata populations at Mt. Emei was relatively higher. Of all the macroelements, the content of Tot. N, Alk-hydro. N, avai. K. were at the higher level, while the content of avai. P were at the moderate level. All the content of microelements elements were in the surplus state except for avai. B were less than the critical value. So most of the soil samples have high fertility, which was adapted to the growth of H.cordata populations.6. The results of variance analysis and multiple comparisons further showed that the altitude and valley had significant influence on the compositions and contents of volatile oils of H.cordata populations. In wild populaions, the content of bornyl acetate had positive correlation with the altitude, and the content of trans-β-ocimene had significant positive correlation with the altitude. The cluster analysis result showed that all the populations could be divided into 7 clusters at the genetic distance of 6.50. Most of the populations from the altitude over 1000m could be divided into one group. It was found that microelements have more important influence on volatile oil components than macroelements through partial correlation analysis. Available B is the most important influence factor in all microelements. Available K is the most important influence factor in all macroelements. Soil nutrients which have significant influence on 10 mutual volatile oil components were deduced by stepwise regression analysis, respectively. These soil nutrients for each mutual volatile oil components were various.7. The results of RP-HPLC indicated that mere were significant differences among the quercetin content of 9 populations from the different altitudes. The average content is 1.17mg/g, ranging from 0.24 to 3.26 mg/g. The correlationship between quercetin contents and altitudes or soil nutrient was insignificant.