The changes in crystalline properties of starch from Rhizoma Dioscorea by acid hydrolysis was characterized by X-Ray diffractometry （XRD）. The results revealed that the crystalline type of Rhizoma Dioscorea starch c...The changes in crystalline properties of starch from Rhizoma Dioscorea by acid hydrolysis was characterized by X-Ray diffractometry （XRD）. The results revealed that the crystalline type of Rhizoma Dioscorea starch changed from C-type to A-type after 16 days of the acid hydrolysis. This phenomenon was different from that of other starches subjected to the acid hydrolysis. The results revealed that the B-polymorphs of C-type starch constituted the amorphous regions while the crystalline areas were mainly composed of A-polymorphs. The degree of crystallinity of the acid-thinned starch increased gradually with the time of acid hydrolysis.展开更多
Two new phenethanol glycosides,named ligurobustoside P（1）,ligurobustoside Q（2） have been isolated from the leaves of Ligustrum robustum,together with the known compound angoroside A（3） which was firstly isolated...Two new phenethanol glycosides,named ligurobustoside P（1）,ligurobustoside Q（2） have been isolated from the leaves of Ligustrum robustum,together with the known compound angoroside A（3） which was firstly isolated from this species.The structures of the two new phenethanol glycosides（1-2） were elucidated by a combination of high-resolution electron ionization mass spectrometry（HR-ESI-MS）,~1H NMR,^（13）C NMR,HMQC,and HMBC spectra for the first time.展开更多
文摘The changes in crystalline properties of starch from Rhizoma Dioscorea by acid hydrolysis was characterized by X-Ray diffractometry （XRD）. The results revealed that the crystalline type of Rhizoma Dioscorea starch changed from C-type to A-type after 16 days of the acid hydrolysis. This phenomenon was different from that of other starches subjected to the acid hydrolysis. The results revealed that the B-polymorphs of C-type starch constituted the amorphous regions while the crystalline areas were mainly composed of A-polymorphs. The degree of crystallinity of the acid-thinned starch increased gradually with the time of acid hydrolysis.
基金financially supported by a grant(No200800230040)from Doctoral Station Foundation of the national colleges and universitiesA grant(No2009ZX09301-003)from National Important Sciences Special Purpose Foundation of China
文摘Two new phenethanol glycosides,named ligurobustoside P（1）,ligurobustoside Q（2） have been isolated from the leaves of Ligustrum robustum,together with the known compound angoroside A（3） which was firstly isolated from this species.The structures of the two new phenethanol glycosides（1-2） were elucidated by a combination of high-resolution electron ionization mass spectrometry（HR-ESI-MS）,~1H NMR,^（13）C NMR,HMQC,and HMBC spectra for the first time.
