A micellar electrokinetic capillary chromatography (MEKC) method, using UV detection, was developed for the determination of polyphenols in Toona sinensis (Meliaceae); the procedure involved precipitation of polyphenols from the leaves of T. sinensis using methanol. The structures can be established with fifteen compounds including methyl gallate, gallic acid, kaempferol, quercitin, quercitrin, rutin, kaempferol-glucoside, catechin, epicatechin, stearic acid, palmitic acid, b-sitosterol, stigmasterol, bsitosteryl-glucoside, and stigmasteryl-glucoside by spectroscopic analysis. However, there has been no investigation to quantitate the polyphenols that form T. sinensis. Thus, seven polyphenols of T. sinensis with UV absorbance, catechin (C), epicatechin (EC), methyl gallate (MG), rutin (R), gallic acid (G), quercitrin (Q), and kaempferol (K) were separated within 10 min with a 40 cm uncoated fused-silica column, with the RSD < 3% (migration times), voltage at 15 kV using this method. On-column detection was carried out at 254 nm. The detection limit of this method for all analytes ranged from 19.5 to 0.02 mM (RSD < 3.1%). The method provided a rapid and sensitive identification of polyphenols of interest in T. sinensis and is suitable for biological activity studies.

547.972Cinnamomum insulari-montanum Hayata (Lauraceae) is an endemic tree that grows in Taiwancs natural hardwood forest at elevations between 400 and 1500 m [1]. In the course of screening for biologically and chemically novel agents from Formosan Lauraceous plants [2][3][4][5][6][7][8][9][10][11][12][13][14][15], C. insulari-montanum Hayata was chosen for further phytochemical investigation. In this paper, we reinvestigated the constituents in the stems of C. insulari-montanum Hayata [16][17][18][19][20][21]. The MeOH extract of its stems was subjected to solvent partitioning and chromatographic separation to afford eight pure substances. The chemical constituents in the stems of C. insulari-montanum Hayata were separated with column chromatography. Seven compounds, including a mixture of E-sitosterol (1) and stigmasterol (2) [22], coumarin (3) [14], cinnamyl alcohol (4) [14], cinnamic acid (5) [14], p-hydroxybenzoic acid (6) [14], kaempferol (7) [15], and kaempferitrin (8) [15], were isolated from the stems of C. insulari-montanum Hayata. All of these compounds were found for the first time in this plant.