| Abstract: | Objective] To research on the changes of total polysaccharides content and plant morphology in the 1- to 5-year-old leaves of Panax quinquefolius L.,which were harvested from May to September in Canada.Methods]Plant morphological characteristics( length,diameter,dry weight and fresh weight) of the leaves of P. quinquefolius with different growth years in different harvest periods were detected; and the drying rate was calculated. Total polysaccharides content in the leaves of P. quinquefolius was detected by UV spectrophotometry. Results]The dry rates of P. quinquefolius stems with different growth years had no significant differences( P = 0. 278 8 0. 05) with two-year-old leaves( 0. 394) one-year-old leaves( 0. 372) five-year-old leaves( 0. 30) three-year-old leaves( 0. 27) four-year-old leaves( 0. 26).Drying rates of P. quinquefolius leaves in different harvest periods showed significant differences( P = 0. 028 9 0. 05). According to the mean values,it could be concluded that July( 0. 452) May( 0. 348) June( 0. 274) September( 0. 26) August( 0. 248). The total polysaccharides content of P. quinquefolius leaves had extremely significant changes in different growth years( P = 0. 000 0 0. 01) with two-yearold leaves( 16. 678 mg / g) three-year-old leaves( 15. 154 mg / g) four-year-old leaves( 14. 559 mg / g) one-year-old leaves( 13. 497 mg / g) five-year-old leaves( 11. 929 mg / g). Total polysaccharides contents of P. quinquefolius stems also had extremely significant changes in different harvest periods( P = 0. 000 0 0. 01) with June July August May September.Conclusions]In the leaves of P. quinquefolius,content of total polysaccharides had little correlation with the drying rate. Therefore,the content of total polysaccharides could not be judged by the drying rate of the leaves of P. quinquefolius. Total polysaccharides contents in one-to five-year-old P. quinquefolius leaves firstly enhanced and then decreased from May to September,and were the relatively high in June. Two-year-old P. quinquefolius leaves had the maximum content of average total polysaccharides. According to the previous researches,the average contents of total polysaccharides in P. quinquefolius roots,stems and leaves were 8. 4%,2. 6% and 1. 5%,respectively. The sum of total polysaccharides contents in P. quinquefolius stems and leaves was 4. 1%,which was only 1 /2 of the total polysaccharides content in roots. Stems of P. quinquefolius were usually abandoned during the harvest of RADIX PANACIS QUINQUEFOLII in Ontario of Canada. Therefore,it was suggested that the stems( aboveground parts) of P. quinquefolius could be used as the raw materials for the extraction of total polysaccharides. |
