The Glycosidation Synthesis Of Shell Pigment From Strongylocentrotus Nudus

Sea urchin belongs to Echinodermata,Echinoidea.With more than 100 species in our country,most of them can't be eaten.The common species of ten edible ones are strongylocentrotus nudus,Anthocidaris crassispina,hemicentrotus pulcherrimus.With processing of sea urchin,the by-products-sea urchin spines and shell has some value for utilization,the pigments from sea urchin spines and shells are polyhydroxylated,and it has been proved that these pigments has many biological activities like antioxidant,anti-rejection,lower blood pressure,but it is so hard to dissolve in the water that the application of it in food and medicine has be limited.In this study,the pigments of dalian purple sea urchin shell was used to react with galactose.Firstly,the experiment of suitable phase transfer catalyst for glycosidation reaction was designed,then the thin layer chromatography condition of products had been determined.Secondly,the reaction conditon for glycosidation reaction were optimized by optimization experiment.The result showed that among three selected phase transfer catalysts(tetrabutylammonium bromide,hexadecyl trimethyl ammonium bromide,hexadecyl trimethyl ammonium chloride),the hexadecyl trimethyl ammonium bromide was proper for galactose.The result of optimization experiment demonstrated that the suitable reaction conditon for galactose was as follows:temperature of 60 ?,reflux reaction of 3h,the amount of phase transfer catalyst was 1%.Meanwhile,the mixture could be seperated better by thin layer chromatography with the solvent:N-butanol:water:anhydrous ethanol(3:2:5).The products was analysed by ultraviolet full wavelength scanning,IR,Silica gel column chromatography,reverse phase-high performance liquid chromatograpy,thin layer chromatography and nuclear magnetic resonance.The result of ultraviolet full wavelength scanning indicated that products had characteristical absorption at 214nm,268nm,310nm,475nm,and it accorded with typical spectrum absorption of naphthoquinone compounds.The IR result was as follows:the special functional groups such as the absorp of hydroxy turns to be narrow,the ether bond was generated,carbonyl stretch vibration of naphthoquinone and Br had been removed.After isolation by silica gel column,the products was detected by high performance liquid chromatograpy,the retention time of glucose products eluted after petroleum ether,petroleum ether:ethyl acetate(2:1),ethyl acetate and some other solvent showed difference with that of pigments,tetraacetyl bromo sugar,and the catalyst.Each eluted system had no characteristical absorption at 470nm.It can be concluded that the products was in N-butanol:water:anhydrous ethanol(3:2:5).The products was detected by 1H-NMR,and with the help of mass spectrum,its foumula was C22H26O11,themolecular weight was 448.