Research And Application Of Anthocyanidin Extraction From Flower Of Rhododendron Ripense M.

Rhododendron is one of chinese traditional famous flowers, which has highlyornamental and cultural values. China is the birthplace of world rhododendrons. In ourcountry, a lot of mountains and hills are covered with large tracts of rhododendrons. Therhododendron resources are extremely rich; however, we rarely exploit and utilize them.In recent years many artificial pigments have been shown to have security issues, suchas carcinogenic potential. Countries are scrambling to develop natural pigments,especially red natural pigments, to meet the growing new idea of green consumption.There are abundant species and varieties in the genus of Rhododendron to obtain a largenumber of natural pigments. But at present, domestic and foreign scholars focuse on thestudy of chemicals which are rich in the genus of Rhododendron plants, especially thosewith high medicinal value. The composition and structure of anthocyanidins ofrhododendrons are rarely reported. The composition analysis of anthocyanins helps usto clarify the mechanism of color formation and it is also conducive to the geneticengineering breeding of anthocyanins’ color as well as the exploitation and utilization ofnatural pigments that is rich in anthocyanins.The purple rhododendron （Rhododendron ripense M.）was chosen as the testmaterial in this study. Hydrolysates (aglycones and sugars) were identified by themethods of paper chromatography (PC), column chromatography (CC), and thin layerchromatography (TLC) and high performance liquid chromatography (HPLC)combined with acid hydrolysis. We determined some pigments contained in the petals ofrhododendrons and studied on the fluorescent pigment which is presented in theseparation and purification process. The results obtained are as follows:(1) By colorimetric determination of the color of solutions, we considered that theanthocyanidin from Rhododendron ripense was perfectly extracted by10%formic acid,so we selected it as the extraction solvent. (2) In the purification process,six pigment components were isolated by columnchromatography through glucan LH-20and two-dimensional paper chromatography fortwo times.(3) According to different retention time, we selectively collected the anthocyaninswhose relative content was much more in six pigment fractions and totally obtained10sample solutions of high-purity anthocyanin.(4) Aglycones of three single peak pigment materials (Rt:13.80,13.30and12.58min) were identified and found out that: the material of peak at13.80min was mavlvidin;the materials of peak at13.30min were mavlvidin, cyanidin and peonidin; the materialsof peak at12.58min were mavlvidin and peonidin.(5) Sugars combined with anthocyanins of three single peak pigment materials (Rt:13.80,13.30and12.58min) were identified and found out that: the sugars of peak at13.80min were glucose and arabinose; the sugar of peak at13.30min was glucose; thesugar of peak at12.58min was glucose.(6) Organic acids combined with anthocyanins of three single peak pigmentmaterials (Rt:13.80,13.30and12.58min) were identified and found out that there areno organic acids combined with anthocyanins.(7) Pigment materials with strong yellow-green fluorescent effect in the process ofseparation and purification of anthocyanidin extraction may be isoflavones, flavanonesor dihydro-flavonols. These results showed that it could very well inhibit the growth ofsome bacteria species. we should further explore the application prospect of fluorochro-me from plant organs used in food preservation and developing a new type of anti-counterfeit printing materials.