Isolation of six isoprenylated biflavonoids from the leaves of Garcinia subelliptica.

The acetone-soluble parts of Garcinia subelliptica leaves were analyzed and six new biflavonoids were isolated, i.e., garciniaflavones A-F (1-6), as well as the five known biflavonoids amentoflavone (7), podocarpusflavone A (8), (+)-morelloflavone (9), (+)-morelloflavone-7"-O-β-glucopyranoside (10), and (+)-4'''-O-methylmorelloflavone (11) and the three triterpenoids oleanan-3-one, β-amyrin, and cycloartenol.

Quantification of polyphenols and pharmacological analysis of water and ethanol-based extracts of cultivated agarwood leaves.

Mangiferin (3) and genkwanin 5-O-β-primeveroside (5) are the two major bioactive polyphenols with laxative property present in the extracts of agarwood (Aquilaria sinensis) leaves (AL). Here we developed an HPLC method to determine these bioactive components and four other major polyphenols in AL extracts and evaluated the pharmacological equivalence of organic and water extracts. Using mobile phase gradient conditions combined with UV detection at 330 nm, all six compounds were separated and we determined the relative extraction ratios of the six compounds present in A.