The Flavonoid Composition In Victoria

Victoria,a perennial or annual large floating-leaves herbage,belongs to Nymphaeaceae of Nymphaeales family,Victoria genus,which consists two species,Victoria cruziana and Victoria amazonica.Victoria’Longwood Hybrid’,hybridized by these two species,are widely cultivated among the various varieties.The single flower of Victoria has a short flowering season,generally only 30 hours in Beijing area,and its color and flower gradually deepen with the change of flowering time.Either the inner or outer petals of Victoria cruziana、Victoria’Longwood Hybrid’ and hybrids and different tissues of the plants(pedicel,calyx,stamen,internal stamen,ovary,internal ovary,leaf curl,vein)were collected for the flavonoid components analysis.We conducted qualitative and quantitative analysis to explore the temporal and spatial variation of flavonoid with the help of HPLC-DAD and UPLC-MS2 technology.The chemical mechanism of color formation and change during the Victoria flowering were studied,and flavonoid metabolism pathway of Victoria were also discussed.The lightness L*and hue a*and b*were measured by Spectrophotometer under the C/2° light,describing the color of petals.There were significant differences between seven flowering stages of every variety,while the differences were not significant among the varieties.In the three-dimensional space based on L*a*b*coordinates,all the scattered points were distributed on a three-dimensional curve,illustrating the color of petals varied with time.The regular pattern of color change was single.In the two-dimensional space based on a*b*coordinates,the color of every flowering stages petals fell on a curve which acrossed the first,second and fourth quadrants.The curve was white in the second quadrant,and then pink in the first quadrant,finally red in the fourth quadrant.The trend of color change was deeper and deeper.We established and optimizated the microscale and effective HPLC-DAD analysis methods which was suitable for Victoria flavonoid component analysis.This method was established by adjusting the parameters(mobile phase system,temperature,elution gradient and flow velocity)after comparing the assembly of different mobile phases and different lengths of chromatographic columns.Compared samples with standards,15 types of flavonoids were detected and identified in petals of different flowering stages,comtaining 4 anthocyanins:delphinidin3-O-galactoside(Dp3Gal);delphinidin3-O-(2"-O-galloyl-galactoside)(Dp3galloylGal);cyanidin derivative(Cy derivative);cyanidin 3-O-(2"-O-galloyl-galactoside)(Cy3galloylGal)。11 flavonol glycosides:kaempferol 3-O-hexose-7-O-hexose(Ka3Hex7Hex);quercetin 7-O-galactoside(Qu7Gal);quercetin 7-O-glucoside(Qu7Glc);quercetin 3-O-galactoside(Qu3 Gal);myricetin 3-O-glucoside(My3Glc);kaempferol 3-O-galactoside(Ka3Gal);kaempferol 4’-O-galactoside(Ka4’Gal);quercetin 4’-O-galactoside(Qu4’Gal);kaempferol 4’-O-glucoside(Ka4,Glc);quercetin 4’-O-glucoside(Qu4’Glc);kaempferol 3-O-(2"-O-galloyl-galactoside)(Ka3galloylGlc).The Dp3Gal and Cy derivative in each stage had high content as the main anthocyanin;the flavonols content in each stage were different,mainly in Qu7Gal、Qu3Gal、Ka3Gal、Ka4,Gal、Qu4’Gal、Qu4’Glc.The main flavonoids components which effected the petals’ color were detected by stepwise multiple regression analysis.They were Dp3Gal、Dp3galloylGal、Qu7Glc、My3Glc、Ka3Gal,etc.Dp3Gal and Qu7Glc were negatively correlated with lightness L*,while Dp3 galloylGal、My3Glc and Ka3Gal had positive correlation with L*.Dp3galloylGal and Ka3Gal were negatively correlated with hue a*,while Dp3Gal had positive correlation with a*.Dp3Gal was negatively correlated with hue b*,while Dp3galloylGal had positive correlation with b*.We can found that increasing Dp3Gal would increase the petals red tone and make color more bright,increasing Dp3galloylGal and Ka3Gal would increase the petals yellow tone,increasing Dp3galloylGal、My3Glc and Ka3GaI would reduce petals brightness.According to the UV-Vis absorption spectra of anthocyanin,20 kinds of flavonoids were detected in the samples of different components of Victoria,containing 5 anthocyanins and 15 flavone and flavonol glycosides.4 anthocyanins and 6 flavonol glycosides had been identified in petals.The distribution of each component in different parts were different.The distribution is as follows:Calyx:Dp3Gal、Dp3galloylGal、Cy derivative、Cy3galloylGal、My3galloylGal、Qu7Gal、Qu7Glc、Qu3Gal、My7Glc、Qu4’Gal、Qu4’Glc;Pedicel:Dp3galloylGal、Qu7Glc;Stamen:Dp3Gal、Dp3galloylGal、Cy derivative、Cy3galloylGal、Qu7Glc、Ap derivative、Ap derivative;Internal stamen:Dp3Gal、Dp3galloylGal、Cy derivative、Cy3galloylGal、Qu7Glc;Ovary:Dp3Gal、Dp3galloylGal、Cyderivativel、Qu7Glc;Internal ovary:Dp3Gal、Dp3galloylGal、Cy3galloylGal、Qu7Glc;Leaf curl:Dp3Gal、Dp3galloylGal、Cy3galloylGal,Dp3galloyl-acetylGal、Ap3Hex、Di derivative、My3 derivative、My3Gal、Ka3Hex、My3galloylGal、My3Rha、Qu7Glc、Qu3Gal、My7Glc、Qu4’Glc;Vein:Dp3Gal、Dp3galloylGal、Cy3galloylGal、Ap3Hex、Di derivative、My3Rha、Qu7Glc、Qu3Gal、My7Glc、Qu4’Glc。We presumed flavonoid metabolic pathways of Victoria according to the flavonoids detected by Victoria.Similar to the general flavonoid metabolism pathway,the pathway began with the synthesis of 4,2’,4’,6’-tetrahydroxychalcone from 4-coumaroyl CoA and malonyl CoA.Then naringenin was generated with the catalysis of CHI,which was a reaction center.naringenin generated 4 branches under the action of various enzymes(F3H、F3’H、FNS、F3’5’H、DFR、FLS、etc.),leading that 7 different types of flavonoids were finally synthesized.