A kind of novel cellulose ether-trihydroxybutyl cellulose (THBC) was synthesized. The process includes the steam explosion treatment of cotton cellulose, alkalization, etherification and purification. Sweep electron m...A kind of novel cellulose ether-trihydroxybutyl cellulose (THBC) was synthesized. The process includes the steam explosion treatment of cotton cellulose, alkalization, etherification and purification. Sweep electron microscope (SEM), Fourier transform infrared (FTIR) and X-ray diffraction were used to characterize the cellulose pretreated and the product. The effects of reaction conditions (temperature, time) on the molecular substitution (S_m) were discussed. To obtain a higher degree of molecular substitution, the reaction temperature is 80 ℃, and the reaction time is 4 h.展开更多
Two new compounds, oleanolic acid 28-O--D-glucopyranosyl-3-O--L-arabinopyrano- syl-(13)-(6-butyl ester)--D-glucuropyranoside 1, oleanolic acid 28-O--D-glucopyranosyl- (16)--D-glucopyranoside 2 have been isolated from ...Two new compounds, oleanolic acid 28-O--D-glucopyranosyl-3-O--L-arabinopyrano- syl-(13)-(6-butyl ester)--D-glucuropyranoside 1, oleanolic acid 28-O--D-glucopyranosyl- (16)--D-glucopyranoside 2 have been isolated from the roots of Hemsleya penxianensis var. gulinensis. Their structures were determined on the bases of the spectral and chemical evidences.展开更多
文摘A kind of novel cellulose ether-trihydroxybutyl cellulose (THBC) was synthesized. The process includes the steam explosion treatment of cotton cellulose, alkalization, etherification and purification. Sweep electron microscope (SEM), Fourier transform infrared (FTIR) and X-ray diffraction were used to characterize the cellulose pretreated and the product. The effects of reaction conditions (temperature, time) on the molecular substitution (S_m) were discussed. To obtain a higher degree of molecular substitution, the reaction temperature is 80 ℃, and the reaction time is 4 h.
基金supported by Natural Science Foundation of Yunnan and National Natural Science Foundation of China (Grant No.98C089M and No.39970086). The authors were grateful to the Departmental of Instrument Analysis Kunming Institute of Botany Chinese Academy o
文摘Two new compounds, oleanolic acid 28-O--D-glucopyranosyl-3-O--L-arabinopyrano- syl-(13)-(6-butyl ester)--D-glucuropyranoside 1, oleanolic acid 28-O--D-glucopyranosyl- (16)--D-glucopyranoside 2 have been isolated from the roots of Hemsleya penxianensis var. gulinensis. Their structures were determined on the bases of the spectral and chemical evidences.
