ABSTRACT
Objective To investigate the polysaccharides constituents from the transgenic crown gall cultures of Panax quinquefolium. Methods The crude polysaccharides PPQ50 and PPQ70 were extracted by water-ethanol method from the crown gall of P. quinquefolium. Four polysaccharides, named PPQ50-1, PPQ50-2, PPQ70-1, and PQ70-2, were isolated and purified by DEAE Sepharose and Sephacry S-100 column chromatography. Results The homogeneity of four polysaccharides was examined by gel chromatography and polarimetry. Their molecular weights were determined by gel filtration chromatography. They were 4.7?104, 2.9?105, 7.5?104, and 1.3?105, respectively. The sugar composition was analyzed by HPLC. The polysaccharides are mainly composed of neutral sugar particularly of D-glucose. The structure elucidation of PPQ50-2 was also supported by 1H-NMR and 13C-NMR spectroscopy. Conclusion All of the four polysaccharides are first isolated and purified from the transgenic crown gall cultures of P. quinquefolium.The result shows the PPQ50-2 and PPQ70-2 are both glucans.
ABSTRACT
Objective To investigate the biosynthesis of arbutin by suspension culture of crown gall of transgenic Panax quinquefolium. Methods Hydroquinone in methanol(60 mg/mL) was added to the medium of the crown gall of P.quinquefolium after precultured for 20 d,then they were co-cultured for another 60 h.The product was isolated and purified by column chromatography and its structure was identified by physicochemical properties and spectroscopic data.The dynamic curve of biotransformation was investigated by quantative analysis of arbutin with HPLC.Results The product could be obtained from both of the culture and medium,which was isolated and elucidated as 4-hydroxyphenyl-?-D-glucopyranoside(arbutin).After co-cultured for 60 h,the mole conversion ratio of hydroquinone is 88.4%,the product contents in culture and medium are 63.69 mg/flask and 1.86 mg/flask,respectively,and the excretion ratio of arbutin reaches the highest(2.92%).Conclusion It's the first time around the world that the crown gall of transgenic P.quinquefolium is used as a biotransformation system and arbutin which shows varied pharmacological activites have been got successfully.