Changes of transport sugar content in different organs of Rehmannia glutinosa / 中国中药杂志

Raffinose series oligosaccharides are the transport and storage sugars of many plants, Rehmannia glutinosa is one of the commonly used Chinese herbal medicines, medicinal parts ist he roots. Root and tuber of R. glutinosa contains stachyose, raffinose and other oligosaccharides, but the study about the process of growth and development of other organs in the non-structural changes in sugar content is rare.In this study, leaves, stems and roots of R. glutinosa were used as materials to analyze the diurnal variation and the changes of sugar content of sucrose, raffinose and stachyose in different organs of R. glutinosa. The results showed that the content of sucrose in R. glutinosa leaves gradually increased from seedling stage.However, the content of stachyose did not change much at the early stage of growth, and the stachyose rapidly increased at the later stage of growth. The raffinose content gradually decreased throughout the growing season, young leaves of R. glutinosa have higher ability to sucrose synthesis than mature leaves, while mature leaf has higher raffinose and stachyose synthesis ability than young leaves. Sucrose and stachyose content in stem gradually increased, while there was little change in raffinose content. The content of raffinose and stachyose in root increased rapidly from the beginning of fast growing period, while the content of sucrose did not change much. The content of sucrose in leaves of R. glutinosa did not change much at day and night, while the daily changes of raffinose and stachyose contents were very obvious. The contents of raffinose and stachyose in daytime were higher than those at night. The content of raffinose in root and stem was not changed much, but the change of stachyose in root, stem and leaf was very obvious, especially in stem and leaf. In summary, the leaf is the main synthetic organ of raffinose, leaves, stems and roots are stachyose synthesis organ. Sucrose, raffinose and stachyose are the major transport forms of carbohydrates in R. glutinosa.

Study on distribution and dynamic accumulation of catalpol and total iridoid in fresh Rehmannia glutinosa / 中国中药杂志

Iridoid glycosides were the main active ingredient of Rehmannia glutinosa, of which catalpol has the highest content. This work will provide theoretical basis for metabolic study and cultivation of iridoids on the basis of the dynamic accumulation of catalpol and total iridoids in the growth of R. glutinosa. The samples of rehmannia 85-5 were gathered in the same filed from July to October. The contents of catalpol and total iridoid glycosides were measured by HPLC and specteophotometric, respectively. The results showed that youngest leaves had the higher content of catalpol and total iridoid glyosides than that of the other two leaf ages in the same growth stage from July to September, while their content of catalpol and total iridoid glycosides were all decreased as the growth of leaves of R. glutinosa. The content of catalpol didn't differ significantly from July to September, whereas it has significantly increased in October in the three leaf stage. In the same stage, the wider the root diameter is, the higher content of the effective components are. In August and September, the total iridoid glycosides have the fastest accumulation. The content of catalpol was increased as the accumulation of total iridoid glycosides.