Studies On The Chemical Compositions And Biological Activites From Nymphaea Hybrid

Nymphaea hybrid is one of large tropical lotus of Nelumbl Nuciferea Gacrtn.There is no correlative report on it's chemical composition and biological activity all over the world so far.Besides carbohydrate,fat and protein,Nymphaea hybrid also contains polysaccharide,flavonoid and alkaloid that may have obvious biological activity and physiological functions.In this thesis,the extraction,isolation,purifica- tion as well as structure determination of hydro-soluble and alcoh-soluble constituents from Nymphaea hybrid were studied,and its effects on the lipids level in blood and on the process of melanin production were also researched preliminarily in vivo or in vitro respectively.Firstly,the crude polysaccharide named XLDT was extracted with hot water and precipitated with ethanol,then the acidic polysaccharide(ADT) and neutral polysaccharide (NDT)in XLDT were divided each other by CTAB complexation,and ADT took the percentage of about 89%.After passing through the column of Sephadex G-150 ATD was further separated into ADT-â… and ADT-â…¡,and ADT-â…¡is the main part.The molecular weight of ADT-â…¡was determined to be about 2.7^*10⁵ Dalton by high performance liquid chromatography(HPLC) technology.After complete hydrolysis in acid,the hydrolysate of ADT-â…¡was analyzed by nuclear magnetic resonance(NMR) spectrum and gas chromatographic(GC).The result showed that ADT-â…¡was mainly made up of galacturonic acid,and with galactose and mannose as the minor parts.Secondly,the raw material of Nymphaea hybrid was extracted by 80%ethanol.Five compounds were isolated from the ethanol extract through the silica gel and Sephadex LH-20 column chromatography.Two compounds were identified as stearic acid andβ-sitosterin by the spectroscopic methods(¹H NMR,¹³C NMR and MS).The identification of other compounds is in progress.Thirdly,two defferent color flowers(red,violet) from Nymphaea hybrid were used as materials,the essential oil was extracted respectively by distillation and its chemical constituents were analyzed by GC-MS.37 compounds were separated and identified.The main constituents of essential oil from the two colour samples were very similar as follows,Benzyl Alcohol,6,9-Heptadecadiene,8-Heptadecene,2-Heptadecanone, pentadcane,etc.At last,the biological activites of the flower of Nymphaea hybrid such as decreasing the level of blood lipids and inhibition the process of melanin production were studied. Quails fed with high lipid food to form hyperlipidemic models were taken as the experiment animals.The result indicated that the flower powder of Nymphaea hybrid could decrease the level of blood lipids and protect the liver against fatty accumulation.In the inhibiting melanin experiment,the tyrosinase inhibition activity of the stamen and receptacle ethanol extracts were tested in vitro comparing with the common used skin whitening agentβ-Arbutin(+CK),using the crude enzyme liquid of tyrosine(Tyr) which was extracted from potato.The results showed that,both of the ethanol extracts of stamen and receptacle could inhibit the activity of tyrosinase,The extract of stamen showed a higher inhibitory rate followed by the extract of receptacle,and then theβ-Arbutin.In view of the good inhibition activity on tyrosinase,the ethanol extracts of the flower of Nymphaea hybrid could be used in the area of cosmetic industry as a new whitening agent.