Study On The Chemical Constituents From Camellia Reticulata And Dracaena Cambodiana

The flowers of Camellia reticulata have been found application for folk medicine as a diuretic, a haemostatic and an astringent in China and Japan. Detailed chemical investigation of the fresh flowers extract has resulted in the isolation of four new acetylated kaempferol glycosides, namely, Kaempferol 3-O-P-D-glucopyranosyl-(6→1)-2''' ,3''''-O-acetyl-α-L-rhamnopyranosyl-(4→1 )-2''',3''',4'''-O-acetyl-a-L-rh amnopyranoside. Kaempferol 3-O-β-D-glucopyranosyl-(6→1)-2''',3'''-O-acetyl-α-L-rhamnopyranosyl-(4→1)-2''',3'''-0-acetyl-α-L-rhamnopyranoside.Kaempferol 3-O-β-D-glucopyranosyl-(6→1 )-2''',3'''-O-acetyl-α-L-rhamnopyranosyl-(4→1 )-2'''-O-acetyl-α-L-rhamnopyranoside.Kaempferol3 -O-β-D-glucopyranosyl-(6→1 )-2''',3'''-O-acetyl-a-L-rhamnopyranosyl-(4→l)-α-L-rhamnopyranoside, together with four known compounds. This paper describes the structure elucidation of the new compounds on the basis of spectroscopic methods and the antioxidant activity of these isolated compounds on DPPH radical scavenging assay. Hydrolysable tannins showed much more effective antioxidant activity in DPPH assay while acetylated kaempferol glycosides displayed very low activity.Dracaena cambodiana is a small herb of genus Dracaena, abundance of steroidal saponins in its stem arouse our interest in investigation on its chemical constituents. As a result of study in chemical constituent, two steroidal saponins and two phenolic glucoside were encountered, namely, 26-O-β-D-glucopyranosylfurosta-5,20(22), 25(27)-triene-1 P,3 β,26-triol-1-O-[O-α-L-rhamnopyranosyl-( 1→2)-α-L-arabinopyranosi de]. 26-O-β-D-glucopyranosyl-22-O-methoxylfurosta-5, 25(27)-diene-1β, 3β, 22ξ, 26-tetrol 1-O-{O-α-L-rhamnopyranosyl-(l→2) -a-L-arabinopyranoside}. 1-hydroxy- 3,4,5-trimethoxyphenyl-1-O-β-D-apiofuranosyl- (1→6) -O-β-D-glucopyranoside. 4-O-β-D-glucopyranosyl-phenethyl alcohol. The details of their structural elucidation on the basis of spectroscopic methods, especially by means of 2D NMR(e.g.~1H-~1H COSY,HMQC or HSQC,HMBC and DEPT), are presented in this paper .